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A Look at Wind and Solar, Part 2: Is There An Upper Limit To Variable Renewables?

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Jesse is a researcher, consultant, and writer with ten years of experience in the energy sector and expertise in electric power systems, electricity regulation, energy and climate change policy...

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Full Spectrum: Energy Analysis and Commentary with Jesse Jenkins

This is a two-part series on the future prospects of renewables. Read Part 1 here.

In our last post, we offered a survey of the progress made so far in wind and solar deployment at the grid-wide scale throughout the world. An accurate and honest accounting of variable renewable energy (VRE) is essential to our goal of building zero-carbon power systems on a high-energy planet. In this follow-up post, we’ll consider what we can glean from VRE performance and modeling about scaling wind and solar further this century.

As our journey through the world’s variable renewable energy leaders illustrates, while wind and solar have come a long way, they have only recently reached double-digit penetration at the grid-wide level in a couple of places (namely Texas, Iberia, and Ireland).

But is it only a matter of time before wind and solar dominate power systems worldwide?

We think there are clear reasons to expect the share of VRE in system-wide electricity mixes to be constrained. Indeed, we offer a rough rule of thumb that is supported by a growing body of power systems research: it is increasingly difficult for the market share of variable renewable energy sources at the system-wide level to exceed the capacity factor of the energy source.

Capacity factor is the ratio of the average output of a wind or solar plant to its maximum rated capacity. For wind power, this typically ranges between 20 and 40 percent, while for solar it runs between 10 and 25 percent, depending on the quality of the renewable resource.

Why is the share of wind and solar in the grid likely constrained to a share equal to their capacity factors?

While much ink has been spilled about the challenges of “integrating” variable renewables into the grid — ie, the increased system flexibility needed to handle the wider variations in power system output necessitated by fluctuating wind and solar output — we actually have a couple more fundamental dynamics in mind. These integration costs are real, but power systems can be remarkably flexible. Natural gas combined-cycle and combustion turbines ramp rapidly, and even coal and nuclear power plants can contribute to system flexibility needs. While accurately accounting for system integration costs is important, we don’t believe these costs will be a showstopper.

Instead, the fundamental economics of supply and demand is likely to put the brakes on VRE penetration.

First, as a growing body of scholarship concludes, the marginal value of variable renewable energy to the grid declines as the penetration rises.

Indeed, where renewable energy earns its keep in the energy market — and is not supported outside the market by feed-in tariffs — the revenues wind or solar earn in electricity markets decline steadily as their market share grows. Here’s why.

Why wind and solar eat their own lunch

Wind and solar produce electricity at roughly zero marginal cost. In effect, whenever they are generating, they shift the supply curve of power plants to the right, or the so-called “net demand” curve (demand minus wind/solar output) to the left. Like any market, more supply and equal demand means lower prices. In the electricity market, this is known as the “merit-order effect.”

Price suppression or merit order effect of wind and solar energy

As wind or solar energy production increases, the “net demand” (demand minus wind/solar) declines, reducing the electricity market clearing price (eg, from P1 to P2).

In other words, wind and solar depress the market price at exactly the times of day these VREs are generating the most power. The revenues earned by wind and solar for each unit of generation thus falls as the share of renewables rises.

This isn’t a hypothetical. The following graphic illustrates the decline in midday wholesale electricity prices already caused by the rise of solar in Germany from 2006 to 2012.

Price suppression or merit order effect of solar in Germany

Source: Lion Hirth, “The market value of variable renewables: The effect of solar wind power variability on their relative price,” Energy Economics (2013)reprinted in the MIT Future of Solar study (2015).

While market prices and thus revenues fall for all generators, the impact is particularly acute for VRE generators, whose output is concentrated in the hours of greatest wind or solar resources, which also tend to be correlated across fairly large areas. The following graphic from MIT’s Future of Solar study illustrates the decline in revenues for a solar farm owner relative to the decline in average wholesale market prices, as solar penetration rises in a Texas-like power system.

Declining value of solar energy

Source: MIT Future of Solar study, Chapter 8.

A 2013 Energy Economics paper by Lion Hirth illustrates, the same dynamic as the market share of wind power rises as well. The figure below depicts the decline in the “value factor” or the ratio between the market prices earned by wind generation and the average market price (effectively the ratio between the blue and red lines in the MIT figure above) as wind penetration grows (the rightmost graphic also includes solar).

Declining value of wind and solar

Source: Lion Hirth, “The market value of variable renewables: The effect of solar wind power variability on their relative price,” Energy Economics (2013).

In short, wind and solar eat their own lunch!

If renewable energy is ever to become truly subsidy independent and earn its keep in electricity markets, that means there is a natural stopping point at which a marginal increment of wind or solar will become unprofitable. The market revenues earned by these VREs will eventually fall far enough that it’s no longer worth deploying more.

This is also why the idea of reaching “grid parity,” or a levelized cost equal to the prevailing market price, is pretty meaningless. As soon as wind or solar penetration grows, the goal posts move further away due to this merit-order or market price effect. Wind and solar costs will have to keep falling to secure greater penetration levels and remain profitable at the ever lower and lower market prices caused by increasing VRE penetration.

Alternatively, if wind and solar are to remain subsidized, the amount of public subsidy per unit of energy supplied will have to keep growing in order to push VRE shares higher and higher. The total subsidy cost could rise sharply, as the price per MWh required increases alongside the quantity of electricity generated from these sources. 

Economic and security-related curtailment

While the ‘merit-order’ or market price suppression effect could limit the maximum wind and solar penetration all on its own, there’s a second, even more challenging effect which kicks in right around the point where wind or solar reach a market share equal to their capacity factor.

In effect, once the market share of wind or solar equals its capacity factor, output from this resource will regularly vary between 0 and 100 percent of total electricity demand.

At that point, wind or solar output will have to be regularly curtailed or spilled as VRE supply will begin to routinely exceed demand.

We can illustrate this dynamic by considering the case of Germany. In 2013, 4.5 percent of Germany’s total electricity generation came from solar PV. But on certain sunny days in the summer, solar power supplied half of midday electricity demand.

Simple math suggests what will happen when German solar approaches just 10 percent of total annual generation: at certain times, solar panels will be generating more than 100 percent of demand.

In the short-term, Germany can solve this problem by exporting excess solar output to its neighbors, just as Denmark sends excess wind production to its Nordic friends. Yet if variable renewables are to contribute this kind of share to the whole power system, and not just isolated pieces of the grid, export is not an option.

Indeed, it will be both economical and necessary to curtail wind or solar output long before they reach 100 percent of system-wide electricity demand at any given hour.

To keep the power system stable, a certain amount of flexible and controllable generation (“dispatchable generation” in industry parlance) must remain online and “spinning” to provide the “operating reserves” needed to meet unexpected fluctuations in either demand or VRE output or the failure of a thermal power plant or transmission line. These generators have minimum technical output levels, so in order to keep enough flexible capacity running, wind and solar will not be able to supply 100 percent of demand in any given hour. System security requirements will require curtailment of VRE before this point.

Indeed, according to a major new study of the challenges of integrating wind and solar in the Western Interconnection of North America, the maximum production of variable renewables at any instant can’t exceed about 55-60 percent of total demand without risking system stability.

In Ireland, which, as we saw in part 1 is the world leader in variable renewable penetration, system operators currently limit variable renewable production to 50 percent of demand at any given time, although operators are working to increase this limit.

In short, the capacity factor threshold may actually be generous: if the instantaneous penetration of wind and solar can’t exceed half or two-thirds of power system demand in any given moment, system security concerns will begin to bind before the penetration of variable renewables reaches their capacity factor. 

In addition, it is often economic to curtail wind or solar even if it is not strictly necessary for system security. Big coal, gas, or nuclear-fueled power stations can’t switch on or off on a minute’s notice and have to remain offline for several hours before they can restart. If wind or solar generation is expected to peak for only an hour or two, as is common, it doesn’t make economic sense to turn these lower-cost baseload power plants off to make room for a short-term surge of wind or solar. That would require relying on costlier combustion turbines or other quick-acting power stations when the wind or solar output inevitably died back until the baseload plants can be turned back on again. It is thus cheaper for consumers to ramp the baseload power plants down to their technical minimum output, but then curtail any wind or solar beyond that point. And if those baseload plants are emissions-free nuclear stations, this strategy is both less costly and just as good for the climate.

The following figure, again from the MIT Future of Solar study, illustrates how both economic and system security related curtailment rises rapidly as solar penetration reaches its capacity factor in a Texas-like power system.

Economic and security-related curtailment of wind and solar 

Source: MIT Future of Solar study, Chapter 8.

As the figure illustrates, security related curtailment picks up precisely as solar’s share equals its capacity factor—about 18 percent in Texas—while economic curtailment begins well before that point. The same dynamic holds for wind power as well, although it tends to have a higher capacity factor and less “peaky” production profile (which may reduce the amount of economic curtailment compared to solar).

This all matters because even a small percentage of curtailment can quickly ruin the economics of a solar or wind project.

Can’t energy storage help avoid curtailment and keep VRE shares growing? Yes, but only somewhat.

Storage isn’t free after all, and storage owners will make their money on the spread between the price they buy power at and the price they sell at later in the day. They can’t afford to pay a premium for excess VRE output, nor will they have to: with wind or solar output flooding the market at zero variable cost, these VRE generators will be willing to sell at close to nothing to avoid losing all revenues to curtailment.

So storage can help, particularly at reducing the prevalence of economic curtailment, but it’s no a panacea

The capacity factor threshold: new rule of thumb

If we look at both the market price suppression effect and the growing levels of curtailment as VRE penetration rises, its clear that the “capacity factor threshold” introduced above could be considered a (fairly generous) rule of thumb for power system planning.

We believe this concept — that it is increasingly difficult for the market share of variable renewable energy sources at the system-wide level to exceed the capacity factor of the energy source — should become a much more significant part of power systems discussions now that wind and solar power have left their infancy and are becoming integral parts of power systems worldwide.

This capacity factor threshold is a rough rule of thumb, one that is useful in guiding our thinking about the eventual role of mature wind and solar sectors in various electricity grids.

So far, the insights behind this capacity factor threshold are primarily drawn from modeling the impact of VRE on the grid, but as wind and solar shares grow in a variety of real-world power systems, these dynamics will soon become realities.

Where does this leave us? Wind and solar’s role in decarbonized power systems

The capacity factor threshold implies that wind may eventually be able to provide on the order of 25-35 percent of a power systems’ electricity, while solar may top out at 10-20 percent in most regions.

Achieving those penetration levels would be a remarkable accomplishment for any energy source.

A wind sector at that scale would supply more electricity than nuclear power currently does in the United States or Europe and would rival natural gas for market share. Solar would generate two to three times more electricity than hydropower in the United States today and could even match nuclear’s share in very sunny regions.

Indeed, no single energy source today supplies more than 40 percent of US electricity, so wind and solar could become major contributors to electricity supplies before running afoul of the capacity factor threshold.

No surprise then that the US wind energy industry and the Department of Energy’sambitious “vision” calls for wind to provide 20 percent of America’s electricity by 2030 and 35 percent by 2050. That would make wind one of the most important energy sources in the country.

Yet even at that scale, it’s clear that wind and solar alone will come far short of decarbonizing the electricity system, let alone the full energy sector.

That’s where the capacity factor threshold is most important: in considering the contribution of wind and solar to a fully decarbonized power system, which is an essential component of any credible plan to confront climate change.

At the upper end, this threshold indicates that wind and solar may be able to supply anywhere from a third to a half of all electricity needs. Whether you’re a glass-half-empty or half-full kind of person, that still leaves the job at most half done.

This is precisely why we both laud the growth of wind and solar, but are very concerned when conversations about decarbonizing the power system become overly focused on a “renewables-only” path forward. Wind and solar will be important contributors to a high-energy, low-carbon planet. But they can’t do the job alone — far from it.

Other nonvariable renewable power technologies like biomass and geothermal face different, but potentially even greater obstacles in the form of resource availability in the case of geothermal and land footprint in the case and bioenergy. Nonrenewable zero-carbon technologies like nuclear power and carbon capture, likewise, have their own challenges. An honest conversation about decarbonization necessitates we ask tough questions about how these technologies fit together (and of course it requires making clean energy cheap!). 

We are quite doubtful that a renewables-only path is the most technically or economically feasible or desirable path to a high-energy, low-carbon planet. It’s well past time for a much more nuanced discussion about the role wind and solar will play in global power systems.

A systems-level perspective is critical for that conversation, as we hope this article has illustrated.

Wind and solar power are becoming mature, important contributors to power grids worldwide. It’s time for an equally mature conversation about the role of variable renewable energy sources in the decarbonized power systems of the future.

The series:

Part 1: A Look at How Far Wind and Solar Have Come

Part 2: Is There An Upper Limit to Variable Renewables?

Jesse Jenkins is a PhD student and researcher at MIT and a freelance writer and consultant. He pens the Full Spectrum column at He previously directed the Energy and Climate Program at the Breakthrough Institute from 2008 to 2012.

Alex Trembath is a senior energy analyst at the Breakthrough Institute, where he authors the Energetics column.

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Joris van Dorp's picture
Joris van Dorp on Jun 2, 2015

Darius AKA Bas Gresnigt does not make comments in good faith.

Over the last few years, his worst behaviour was to continually repeat blatant fear mongering propaganda about radiation health effects, even after being shown by readers of TEC time and time again that his sources were unscientific. He just continued posting the same nonsense again a few days later!

People who deliberately cause radiophobia by spreading baseless scare stories about radiation, especially during and after the Fukushima accident are rated by me to be almost subhuman in quality. They are the worst kind of people, causing serious injury to the public who are influenced by their lies. I regard them as psychological terrorists waging war on humanity at large. So I was very glad when Bas Gresnigt was finally banned from TEC, and I am not very happy about his return under a different nickname.

He is still spreading unfounded, scary nonsense about radiation health effects on TEC.

Bruce McFarling's picture
Bruce McFarling on Jun 2, 2015

“Changing the market design (from marginal-price bid-clearing, to one of the other suggestions, variations on regulated) can help prevent price collapse which would occur well before variable renewables reach the capacity factor limit, but they don’t solve the other underlying problem: that the output from new generators would be correlated with that of the existing generators (adding more energy when there is too much, and adding little when more is needed).”

Pricing systems on their own cannot solve that kind of problem … it is a system design problem, and while pricing systems can reward different features of different designs, they cannot design a complex system on their own. I guess the baseline feed-in tariff could be argued to offer rewards for certain kinds of solutions to those problems.

A baseline feed-in tariff would reward the integration of higher capacity factor wind in a way that a total feed-in tariff does not (and after all, we have wind resources in parts of the Great Plains that are 40%-50% CF with wind turbines optimized for cost per kWh … they could well be 50%-60% with wind turbines that trade off cost per kWh for higher CF). It would also place windfarm operators in a position of being able to enter into PPA’s for complementary qualifying resources that allow them to put an aggregate of qualifying resources with a higher ratio of average to maximum yield, raising the share of total output qualifying for the feed-in tariff.

“So while the market design argument delays the effects that are cited by analysis by Hirth, the curtailment effects predicted by Kreifels (see this study) would still occur.”

I have never seen any cost-optimized all-renewable portfolio which consists of nothing but wind and solar, so we already know that a wind+solar-only portfolio is not the cheapest way to get to any high-penetration renewables portfolio of energy sources. The next time it is studied, it will continue to not be the cheapest way to get to a high-penetration renewables portfolio. But on the other hand, we are nowhere near that frontier at present … we have a decade to sort out the details of how heavy a reliance we ultimately place on renewables. During that decade, we will continue to see my colleagues doing studies that assume that “a market price” is always an unbiased benchmark, and so in my view, the more widely it is understood that a pure marginal-pricing system discriminates against most of our lowest cost low carbon energy sources, the more likely we are to be able to put functional policy in place when the time comes.

Joris van Dorp's picture
Joris van Dorp on Jun 3, 2015

The external cost of coal power is said to be at most 10 ct/kWh, for natural gas it’s supposed to be at most 5 ct/kWh. (There are different research groups who have different estimates, each having some merit.) In terms of fuel consumed, that would come to around 4 ct/kWh for coal and 2.5 ct/kWh for natural gas. But solar and wind also have external costs, namely in the form of greater consumption of transmission and storage equipment, caused by their diffuse and intermittent nature. These external costs are tremendous at high penetration of wind and solar (which is what will be needed to end climate destruction using wind and solar), probably somewhere in the range of 15 to 30 ct/kWh, if not more, at 100% RE.

So no, wind and solar will not compete with coal and natural gas, even if the currently estimated externalised costs of fossil fuels are fully internalised.

What this means is that switching to a 100% renewable energy system will be even more costly for humanity than simply continuing business as usual with fossil fuels. The amount of resources saved by sticking to fossil fuels instead of ‘going solar/wind’ is greater than the amount of resources needed to neutralise climate impacts resulting from the combustion of fossil fuels. Basically, this is the argument of influential ‘climate policy skeptics’ like Bjorn Lomborg (who I’m sure you’ve heard of).

Of course, we can set the external cost of fossil fuels at an arbitrarily high level, (after all, isn’t a livable climate ‘priceless’) and eventually we will be able to ‘show’ that wind/solar becomes ‘economic’, but who are we fooling? The majority of humanity couldn’t care less about climate change, and even if they did, they don’t have the resources needed to pay for ultra-expensive 100% RE energy.

The responsible and pragmatic approach is to leave environmental external costs for what they are for the moment, and make sure we enable technology which can already compete with the internal cost of fossil fuels, since this means that we don’t have to convince 6 billion humans to give up a substantial part of their resources in order to ‘save the climate’. That technology would be nuclear, and nothing else (unfortunately).

Jenny Sommer's picture
Jenny Sommer on Jun 3, 2015

0,5ct/kWh (2005) doesn’t strike me as that expensive for a 100% RE European grid.

That’s a 70% wind based supply. With further advances in storage and wind development since 2005 the total system cost could be even lower than the 4.6ct/kWh Gregor Czisch came up with 10years ago.

(Nuclear was part of the modeling and ruled out because of cost.)

I am sure you are familiar with his work so I am not sure why you are claiming “ultra expensive 100% RE” in the first place? 

Maybe somebody should invite Gregor Czisch to end those myth for good.

Clayton Handleman's picture
Clayton Handleman on Jun 3, 2015

“The external cost of coal power is said to be at most 10 ct/kWh”

Please provide some references.  Your externalities numbers appear to be wishful thinking, see the metastudy referenced in this post.

I think your numbers on transmission are very high.  And if it is going to be counted as an externality for renewables then it must also be counted as an externality for FF and other sources.  Would be great if you could find some credible info on transmission costs as well.  The numbers I have seen are far lower than yours.

Joris van Dorp's picture
Joris van Dorp on Jun 3, 2015

Here’s a recent study having some credibility (although it is critically flawed in some areas) which can be assumed to contain high estimates for external costs of fossil fuels.


On p.37, it puts the climate-only external cost of coal power generation at about 5 ct/kwh (so I was being generous in my above comment). For natural gas power generation, it puts the climate cost at less than 3 ct/kWh.

I did not seperately give a figure for the (additional) transmission cost of (intermittent) renewables. The transmission costs are a function of penetration, so any single figure is meaningless. At low penetrations, the additional transmission costs tend to be small, but at high penetrations, costs rise due to the greater distance travelled by large, short-lived volumes of intermittent energy trying to find a consumer. Offshore windfarms and windfarms in remote locations carry high transmissions costs, as does transmission costs through habited areas. By my reckoning (based on reading many studies, and on my own work experience in engineering), additional transmission costs for intermittent renewables should remain less than 5 ct/kWh at high penetrations.

My 15-30 ct/kWh external cost estimate for 100% renewables is dominated by storage costs, and includes:

– Transmission costs (<5 ct/kWh)

– Power quality equipment costs (~1 ct/kWh)

– Storage costs 10-25 ct/kWh

The storage costs are high, because pumped hydro is insufficient to provide enough storage at the global scale. This leaves only highly costly alternatives, of which compressed air storage is probably the cheapest. I have little faith in breakthroughs in battery technology which are supposed to lead to bery low cost (seasonal) storage. Storing electrons is always going to be hard. It would be a genuine miracle if battery technology ever becomes cheap enough for seasonal storage.

To be sure, I don’t subscribe to the popular theory that climate can be protected by using fossil fuels as backup for large amounts of solar and wind. It is quite easy to show that fossil fuel burning will have to be all but eliminated in order to truly protect the climate in the long term. Without eliminating fossil fuel burning, all we are doing is buying time. We aren’t solving the problem.

Clayton Handleman's picture
Clayton Handleman on Jun 3, 2015

 Thanks for the reference, have added it to the blog post.


– Transmission costs (<5 ct/kWh)

Got it, that is more in line with what I have seen.

RE the storage, I am hoping to have some time this summer to do some analysis in my own that considers high EV penetration of EVs.  In the Great Plains the current average CF is 37% but there has been little deployment in the higher CF areas such as SW KS.  Assuming use of those night peaking sites combined with night time charging of EVs to address the night time intermittency I am curious to see how much improvement there could be.  People argue about it on the board but I have not seen studies on it, only crude BOE calcs with lots of hand waiving to support various positions.  There is good data from ERCOT that offers a reasonable proxy for great plains as a starting point.


Joris van Dorp's picture
Joris van Dorp on Jun 3, 2015

I’m familiar with the Czisch report(s). They are found to be simplistic and ignore significant cost centers, as do all studies claiming minimal costs of high renewables penetrations.

A more recent, rigourous bottom-up analysis of the effects of high renewables penetration, using detailed computer modelling of actual grid and plant behaviour, is this one, which shows electricity costs will double long before 100% RE is reached.

Another report on this subject, commissioned by none other than Greenpeace, comes to similar conclusions, which must have shocked Greenpeace, since it (predictably) laid waste to their fancifull [re]evolution energy scenario’s at the time.

For what it’s worth, I developed my own simulation of electricity production and dispatch, cost- and co2-optimised for a combination of natural gas backup, wind energy, and sodium sulphur bulk battery storage (which I still think is one of the best battery technologies available). This was ten years ago. I used the most optimistic (but credible) estimates of the future cost of these technologies I could find in the literature, and I found that the optimum mix of these technologies yielded a trebling of electricity cost and a best-case co2 intensity of about 100 grams of co2 per kWh. That does not solve climate change. In the ten years since then, I have found nothing new in the literature which shows I was too pessimistic at the time. Hence, I submit that we must enable advanced nuclear technology, globally, ASAP!

Joris van Dorp's picture
Joris van Dorp on Jun 3, 2015


Budishak did a fairly good (but still flawed, and widely misinterpreted) ~100% RE study on the effect on costs of including EV batteries for RE storage (AKA V2G). It might be a good starting point, if you’re able to spot the flaws and deal with them satisfactorily.

Clayton Handleman's picture
Clayton Handleman on Jun 4, 2015

Will check it out.

I think the viability of V2G is quite a ways off.  However a lot of benefit can be had by partial charging for the following day and arbitraging the remainder on the intermittent peaks thereby creating a customer for the power and avoiding curtailment.

I.e. smart grid load shift.

Clayton Handleman's picture
Clayton Handleman on Jun 4, 2015


Clayton Handleman's picture
Clayton Handleman on Jun 4, 2015

Putting together my summer reading list:

Because both they and the NREL tell us that the energy available in the wind scales with the square of rotor radius, while the cost of the turbune scales with its mass, which scales with the cube of rotor radius — which means that building larger turbines costs more per Watt-hour delivered.

Can you provide any reference that suggests the optimal turbine size.  They seem to just keep building them bigger and the economics appear to favor the larger turbines.  What I am reading is that the size limits are more a function of transportation than physical limits.

Eventually the cube vs square will win but currently it seems to be used as a hand waiving argument and I haven’t seen anything convincing that says when we will cross over.  I recall when people thought Kenetech had come close to the limit at 250kW!

Consider that height gets us to higher wind velocities and power goes as the cube of wind velocity.  Since rotor diameter accesses more wind at higher velocity that likely is one factor that drives the economics of increased size.  Another is the relentless march of technology.  From direct drive permanent magnet units to superconducting generators there is more power being pulled out of less mass.  And GE is developing a lattice tower that allows for taller towers while addressing transportation problems.  They put a “skin” on the outside to address aesthetics and wildlife issues that plagued the Altimont Pass lattice towers.

So far my investigations suggest units as large as 20 MW are being considered in the forseable future.  And Enercon has a 126 m unit at 7.5GW in production.  If you can provide some credible references that set a limit then I would appreciate your sending them my way and I will add them to my blog post on turbine size.  


Willem Post's picture
Willem Post on Jun 4, 2015


The capacity factor threshold implies that wind may eventually be able to provide on the order of 25-35 percent of a power systems’ electricity, while solar may top out at 10-20 percent in most regions.”

But not at the same time, such as on a sunny and windy day, given the existing balancing and storage mode.

However, there is no upper limit with weather-dependent, variable renewable energy, if there is enough energy storage capacity.

Here is a scenario for the future:

NOTE: This presupposes there would be no fossil fuel and nuclear energy in the future. Currently, they, in addition to hydro, are used to:

– Balance the variable energy and

– Serve as energy reservoirs.

A large number of distributed renewable systems (wind, solar, tidal, etc.), located in suitable places, would more or less continuously pump energy into distributed energy storage reservoirs (hydro, battery, etc.) and society would drain energy, as needed, from these reservoirs.

For example: One hydro reservoir would be 1,000 ft or more below grade and wind energy would drive pumps to transport water from the lower reservoir to the upper reservoir located at grade level. The water from the upper reservoir would drive the turbine-generators located near the lower reservoir. Visible at grade level would be the upper reservoir and power lines. The lower reservoir would consist of a number of parallel, concrete-lined tunnels, about 50 ft in diameter, each about several miles long. They would be made with boring machines similar to those used to make tunnels through mountains, etc.

NOTE: World energy storage capacity with batteries would be limited due to a lack of suitable materials. This would not be the case with water-filled, upper and lower reservoirs.

NOTE: It would be good to start implementing such storage while there still is an abundance of low-cost fossil fuels at wholesale prices of about 5 c/kWh. To do it with renewables at 10 – 15 c/kWh would be so much more expensive.

NOTE: The tunnels would be similar to those under the Alps, which are many decades old. The chamber with T/Gs and pump rooms would have half cylindrical roofs. The Alps of Switzerland, France and Italy would be a natural, as some of the lakes could serve as upper reservoirs.

Other renewable energy systems, mostly solar, would be integral with buildings/building complexes to make these buildings/building complexes near-zero energy or energy surplus.

These buildings/building complexes would not have energy storage systems.

They would be connected to the grid so they could draw whatever little energy they need from the reservoirs.

Most of transportation would need to be electric. High-speed rail would almost entirely replace air transportation; any remaining air transport would be kept to a minimum by means of high taxes/passenger-mile.

Nathan Wilson's picture
Nathan Wilson on Jun 4, 2015

Yes, I like the sodium-sulfur battery as well.  Perhaps when NGK‘s patents expire in a few years the costs will fall, provided demand for the product increases.  They only have 450 MW*7 hours in the field now.

It should be much easier to recycle than Lithium-ion cells (at least the sodium and sulfur), and have longer life.  However, the lithium-ion cells are likely better for 1 hour storage (to limit ramping-rates of PV output).

I doubt that any grid battery technology will ever beat the cost of thermal energy storage at high temp nuclear plants though, at least in the 12-24 hour range (complimenting wind?).  And I don’t think any grid storage will be able to compete with dispatchable fuel synthesis for long term storage.

Bruce McFarling's picture
Bruce McFarling on Jun 4, 2015

“However, the lithium-ion cells are likely better for 1 hour storage (to limit ramping-rates of PV output).”

“I doubt that any grid battery technology will ever beat the cost of thermal energy storage at high temp nuclear plants though, at least in the 12-24 hour range (complimenting wind?).”

12-24hr thermal storage with adequate generator capacity would allow full load-following operation, which would complement on-shore wind, off-shore wind, solar, run-of-river hydro, as well as the traditional baseload renewable electricity generators of geothermal generation and landfill biogas.

In a pricing system with a capacity market, the capacity market can help with the financials of a high temperature nuclear power with 12-24hr thermal storage, since the peak generating capacity on the generator side will represent more than the steady-state thermal output of the nuclear fuel cycle. Where a pure-baseload plant may earn 1 MW of capacity payment for 1 MW worth of steady-state thermal output, a plant with 12-24hr thermal storage might have generator capacity that is twice steady-state output, and so might earn 2 MW of capacity payment for 1 MW worth of steady state thermal output.

“And I don’t think any grid storage will be able to compete with dispatchable fuel synthesis for long term storage.”

Quite … dispatchable fuel synthesis decouples cost of total storage capacity, cost of “charging” and cost of “discharging”, and the storage cost per kWh stored can be quite low.

The cost of “charging” is a capital cost that is scaled at the maximum capacity per hour, and a variable cost that is driven by how the cost of variable renewables are priced. A flexible production rate would give a higher average cost from a lower capacity utilization, but could reduce the average cost of power consume, and would allow it to earn services income from operating as a flexible dispatchable load.

The cost of “discharging” is the capital cost of the generation plant. Give the relatively low fixed costs of turbine generators per MW capacity, and the energy efficiency benefits of a thermal cycle after a turbine cycle, one can imagine an integrated complex with a nuclear power plant with 12-24 hr thermal storage with electrofuel turbines as well, since during peak net-load, when the electrofuel would be used, the thermal generation could be supplemented from a second cycle from the turbine powered by the electrofuel.


Joris van Dorp's picture
Joris van Dorp on Jun 4, 2015

This study is written-up by the German antinuclear movement. It deliberately intends to cause fear and mislead the reader.

Here is a part of what they say about the Chernobyl accident:

The consequences of a major accident are huge. The accident in Chernobyl led to high levels of contamination across large areas in Belarus, Ukraine and Russia. A large part of the radioactive materials released by the accident also contaminated other European countries. A variety of health effects are discernible in exposed populations, not only thyroid cancer and leukemia but also a wide range of other cancers, heart diseases, cataracts, diseases of the endocrine system and the digestive system, genetic and teratogenic effects, etc. All in all several million people were, and still are, affected by the catastrophe. They have been evacuated and relocated, lost their homes, communities and 4 Renewable Energies versus Nuclear Power – Comparing Financial Support 5 places of work, become sick and have had to live on contaminated soil. The 2011 accident in Fukushima had similar consequences for hundreds of thousands of people. 

Compare this scary story to the following, authoritative version of the consequences of Chernobyl, from the United Nations Scientific Committee on the Effect of Atomic Radiation (UNSCEAR):

Apart from the dramatic increase in thyroid cancer incidence among those exposed at a young age [6000 cases were found, of which all but 15 were cured], and some indication of an increased leukaemia and cataract incidence among the workers, there is no clearly demonstrated increase in the incidence of solid cancers or leukaemia due to radiation in the exposed populations. Neither is there any proof of other non-malignant disorders that are related to ionizing radiation. However, there were widespread psychological reactions to the accident, which were due to fear of the radiation, not to the actual radiation doses.

The rest of the study is littered with standard antinuclear/prorenewables misinformation, fear mongering and outright lies. Don’t be fooled.

Jenny Sommer's picture
Jenny Sommer on Jun 4, 2015

This is based on our Green-X toolbox and it is not even a German line of research.


Your nuclear propaganda and anti-RE attitude is getting tiresome.

Joris van Dorp's picture
Joris van Dorp on Jun 4, 2015

You’re right, it’s not German but Austrian. The rabid anti-nuclearism is the same.

I’m not criticising the Green-X tool, I’m criticising the content of the study.

In my opinion, baseless anti-nuclear fearmongering as displayed in this study is a crime against humanity, especially while the need for expansion of nuclear power to combat climate change is beyond urgent.

I’m also not anti-renewables. What I am against is pretending that renewables will save people money. They won’t, and pretending that they will simply means that the money needed to build RE won’t be there. If we want to go 100% renewable, that is fine by me, but only if the costs are honestly reported and democratically accepted. In that case, I will gladly pay my share to gain a global 100% RE energy system. But if the costs are hidden from the public in order to lure them into commiting themselves to unfunded RE stimulus policies, thinking that this will put money in their pocket instead of taking money out, then we will not only cause social strife and reduced prosperity sooner or later, we will also fail to solve climate change.

In Germany, all these worrying dynamics are already apparent, if not yet widely recognised. Nothing good will come of it.

And not to be smug, but I suppose Google also has an anti-RE attitude?

Grace Adams's picture
Grace Adams on Jun 4, 2015

I followed your link about needing to eliminate burning of fossil fuel almost entirely.  I doubt that excise taxes to capture externalized costs alone will be enough.  I suspect what would work better might be to start with a 10% tax on all energy products including exports, and the energy footprints of imports, and energy both made and consumed by the same party (mostly rooftop solar and farmer made and used bio-diesel from oil seeds.) If US Labor Bureau of Statistics claim that the demand coefficient of energy is -0.37 still holds, then between 40 and 50% of the revenue from such a tax would have to go to energy producers especially fossil fuel firms to compensate them for loss of sales to the tax alone, which this is for sales lost to tax should buy fossil fuel as mineral rights at a price somewhat higher than market price for fuel extracted and ready to burn. I would like to see what is left of the tax revenue after that go for buying from our too big to fail military industrial complex firms equipment for harnessing renewable energy (mostly wind and solar), spare parts to improve our electric grid to make it more resistant to electro-magnetic pulse, energy storage equipment, smart grid parts to make good use of energy storage. I hope by using MIC firms to manufacture, it will be possible to divert some funds from weapons to renewable energy. I hope government also gets its act together about issuing licences, permits, and leases for geothermal to gas and oil firms. I also note, though I believe it was on a link higher in these comments leading to a computer simulation of electric supply and demand for the PMJ area (mostly Maryland and bordering states) to find least cost combination of equipment to meet, 30%, 90%, or 99.9% of demand for electricity without burning any fossil fuel. I was surprised, hydrogen fuel cells were the only energy storage to do the whole job of storing energy when generating excess renewable energy and using stored energy to avoid need for fossil fuel–Hydrogen fuel cells missed only 9 hours in a month.  I suspect we will want to capture old CO2 emissions from ambient air to clean up after fossil fuel.  Using Global Thermostat for that is likely to be very expensive–$31 to $32/metric ton of CO2 captured plus another $18 or $19/metric ton to compress it enough to use as hydraulic and heat-transfer fluid in enhanced geothermal systems. If you want to feed CO2 to something photosynthetic, capture alone is enough. 



Spec Lawyer's picture
Spec Lawyer on Jun 5, 2015

Yeah, this is nonsense.  We can do whatever we want to do.  If we want 100% renewables, we can do it.  Just implement steep carbon taxes, build more transmission lines so it is easier to move electricity around, build lots of storage, implement demand-response programs, use diversity of renewable sources (onshore wind, solar PV, CSP, offshore wind, geothermal, tidal, etc.), use dispatchable renewable sources (hydropower, biomass, geothermal, etc.) . . . 

Some people are such quitters . . . such “Can’t do” whiners.  

Willem Post's picture
Willem Post on Jun 5, 2015

Spec Lawyer,

The measures you list are the usual ones frequently seen in RE publications.

That list aims to show lay people how to fit RE into the existing power system.

In practice it is much more difficult, as Germany has found out. Fortunately, it is rich enough to afford its programs, whereas most other countries are not.

The 2-reservoir concept was proposed by a leading, Dutch doctor-engineer. It is planned to be implemented as a pilot program for $1.8 billion near Maastricht, the Netherlands.

You can be sure it is not nonsense.

In the future, energy storage would be essential to enable using weather-dependent, 100% wind and solar energy, after fossil energy becomes minimal.

NOTE: It is not likely nuclear energy will become minimal, as Russia obtained worldwide orders for about 50 nuclear reactors, each 1000 MW and up, during the past 12 months. They will produce 50,000 x 8760 x 0.90 = 394 TWh/yr of world energy production of about 22,000 TWh/yr. China and India are rapidly expanding their nuclear capacity, MW.

The world already has a lot of experience with digging large, reinforced-concrete-lined tunnels.

The tunnels would be similar to those under the Alps, which are many decades old.
A facility could have in parallel any number of such water storage tunnels.
The chamber with T/Gs and pump rooms would have reinforced, half-cylindrical roofs.
The Alps of Switzerland, France and Italy would be a natural, as some of the lakes could serve as upper reservoirs.
It would be best to start while low-cost fossil energy at 5c/kWh is still available, instead of doing it with RE at 10 – 15 c/kWh.

Clayton Handleman's picture
Clayton Handleman on Jun 5, 2015


Thank you for more clearly articulating the point I was trying to make.  And I had not thought about the smaller vehicle caveat that you threw in.

I would add, Tesla already allows you to set the charge and, in fact, recommends an 85% charge for maximum battery life rather than topping off.  You can partially automate the charging by telling it what time to begin charging.  It would appear that, in their vehicles, all of the hardware is in place to switch over to fully automated charging algorythms.  I.e. external price signal.

Clayton Handleman's picture
Clayton Handleman on Jun 5, 2015


Thank you for more clearly articulating the point I was trying to make.  And I had not thought about the smaller vehicle caveat that you threw in.

I would add, Tesla already allows you to set the charge and, in fact, recommends an 85% charge for maximum battery life rather than topping off.  You can partially automate the charging by telling it what time to begin charging.  It would appear that, in their vehicles, all of the hardware is in place to switch over to fully automated charging algorythms.  I.e. external price signal.

Nathan Wilson's picture
Nathan Wilson on Jun 5, 2015

If you consider climate change to be urgent, you have to support a fast transition…”

This peer-reviewed journal article, 

Potential for Worldwide Displacement of Fossil-Fuel Electricity by Nuclear Energy in Three Decades Based on Extrapolation of Regional Deployment Data

by Qvist and Brook argues that historic nuclear deployment rates are more than adequate to support a rapid transition away from fossil fuels.  

The best part about nuclear is that we know that it works and is affordable in a very low fossil fuel grid (e.g. France, Sweden, Switzerland).  With variable renewables, there is a very good chance that society will not be willing to pay the high cost of using them at penetrations above the capacity factor limit.

Note Bas, that I have previously explained that all of your examples of 100% renewable fall in to two categories: “100% renewable offsets” where one town offsets its predominantly fossil fuel use with renewable exports, and island grids with extremely expensive electricity.  Neither of these approaches is viable at large scale.

Nathan Wilson's picture
Nathan Wilson on Jun 5, 2015

Let’s look at 2050 in Germany.”

‘If there is one thing which is hard to predict, it’s the future’ (Yogi Bera).  Actual, the Germany renewable vision for 2050 is perfect propaganda, with no accountability.  If the rosy projections don’t come true, you can always blame the politicians for inadequate support, or blame the neighbors for not doing their part with a continental grid, or blame the Americans for not helping develope the technology enough, or blame the Chinese for unfair trade practices, etc.

Nathan Wilson's picture
Nathan Wilson on Jun 5, 2015

6-12 hours energy storage schemes only have good potential in solar-dominated portfolios (due to the strong diurnal pattern).  With lots of wind or nuclear, the balance will likely tilt towards dispatchable fuel synthesis (unless demand for liquid fuel somehow goes away), as the higher capacity factor improves the economics of the fuel plant.  Also wind produces a lot of times when the electricity supply is in-between high and low (storage only operates during times of higher or low supply).  Stored-fuel is also better suited to the extremely seasonal and peaky nature of electricity demand. 

Joris van Dorp's picture
Joris van Dorp on Jun 5, 2015

As an aside to these articles, for those who embrace the prospect of using wind energy to supply clean electricity, I submit the following set of current images from Germany for your contemplation.

Looking at these images caused a knot in my stomach and made my blood boil. I knew things were bad, but this shocked even me. Shameful! Obscene!

Is this what we really want?

And this is only the start. Germany has not succeeded in reducing hardly any co2 emissions at all yet, since it embarked on it’s massive wind energy expansion, of which only a small part has been completed to date.

I submit we have to demand safe, clean, unobtrusive, inexhaustible and affordable nuclear power, to prevent the disgracefull destruction of our living environment caused by the callous and counterproductive ‘green’ policies which have caused the situation which is visible in the above presentation.

Now, I’d like to be told by wind energy proponents why I am wrong and why wind energy is so much better than nuclear energy.

Clayton Handleman's picture
Clayton Handleman on Jun 5, 2015

I have watched his posts over time.  TEC community is a pretty sophisticated bunch.  He generally gets upvoted comparably to others on the threads, that alone should be sufficient permission for him to voice his views.  However I routinely fact check other posters who appear to me to be crossing the line and knowingly posting false, very biased or just plain wrong information to back up their positions.  I don’t think he is any worse than some other frequent posters, he just has a perspective that is unpopular with some of the more aggressive posters.  As with the other controversial posters, he brings energy to the comment space by provoking commentary where otherwise folks might not participate.

Clayton Handleman's picture
Clayton Handleman on Jun 5, 2015

Nice propganda piece.  Germany is not the USA.  There should, of course, be common sense applied to siting.  However, I don’t think that rural KS, TX, ND, SD or off shore in the Atlantic are scenery issues.  I agree with Willem, keep them off of VT ridgetops for a variety of reasons, but no need to keep them out of TX ranchland where nobody travels.  The CF is much higher than in Germany as is the statistical decorrelation.  I think it is interesting that folks want to ban Darius yet are silent on this kind of sillyness. 

In the US we are permanently destroying prime habitat for short term gain with coal. and screwing up prime watershed with pathetically little press.  Much can be substituted with wind.  The amount of wind and solar is a function of a number of factors which will be debated for years to come on this board.  But if we choose to build the HVDC power lines from prime locations we can use 50% CF wind, decorreleate with additional high CF off shore, and include load shifted EV charging to manage much of the intermittency. 

Germany is small has a moderate wind resource and nowhere near the geograpical extent to decorrelate sources.

Also, correct me if I am wrong, but Germany’s choice on Nuclear was in response to Fukushima, not part of their original push to do renewables.  So again the continued use of the German example to fan the flames of discord between the nuclear and and renewables camps rises to the same level of disingenuous dialog as anything I have seen Bas or Darius accused of.

Joris van Dorp's picture
Joris van Dorp on Jun 5, 2015

Nice propganda piece.  Germany is not the USA.  There should, of course, be common sense applied to siting.”

Of course common sense should be applied. But it isn’t, as the pictures prove. That’s the point. And the same kind of thing is happening in the USA. Be warned.

So again the continued use of the German example to fan the flames of discord between the nuclear and and renewables camps rises to the same level of disingenuous dialog as anything I have seen on the board from Bas or Darius.”

Not hardly.

Bas is deliberately causing radiophobia by posting lies about radiation health effects. Radiophobia is a potentially deadly mental illness, which can and does lead to depression and even suicide. Deliberately causing radiophobia is a crime, in my opinion. Do you disagree?

The pictures I showed above are actual fact. They really do show what wind turbines are doing to the countryside in Germany, today. As such, they provide reliable and accurate information.

The relevance of all this is that wind energy economics relies on ignoring external costs. If wind energy is only located in suitable sites, then wind energy becomes even more costly than it already is. Offshore wind is a financial no-go in any case.

The poor siting of wind turbines is not an accident. It is a result of callous attempts to prop-up their financial viability by completely disregarding their wrenching external cost. (i.e. the wholesale industrialisation of idylic countryside)

On the other hand, nuclear economics in the West have been badly affected by a long history of fabrication of external costs by the anti-nuclear movement, and subsequent forced internalisation of these fabricated costs through crippling regulatory turbulence and ratcheting.

Aedan Kernan's picture
Aedan Kernan on Jun 5, 2015

Jesse cites energy storage but seems to ignore the cheapest and easiest solution here – demand management.

The e-harbours survey of energy use at some of Europe’s largest industrial ports found massive potential for flexible energy consumption.

Chemicals plants, cold stores and many others could flex their production schedules to take advantage of lower power costs with little downside. The thousands of refrigerated containers were designed for the heat of tropical fruit ports, yet had no mechanism to reduce power consumption for a winter’s night in Hamburg.

As for Jesse’s assertion that nuclear is a cheap baseload solution. The UK government has contracted to pay more than $140 MWh for 35 years  plus covering all insurance, decommissioning and waste management costs (billions) to get agreement on one nuclear plant. It may not happen. The contractors are worried about potential cost overruns.

It’s time we had an honest conversation about the fact that nuclear is a platinum bullet wrapped in pipe dreams.

Willem Post's picture
Willem Post on Jun 5, 2015


My above storage comment does not rule out up to 50% worldwide nuclear for at least the next 200 years, especially if thorium plants are being built, as will be the case in China.

The thinking of most people is trapped by fitting RE into the existing power system, but the increasing needs of 10 billion people and decreasing fossil production, at least 70% of ALL worldwide energy consumption, makes it necessary to increase various renewables, energy storage and nuclear.

There will likely not be enough materials to use batteries for all that storage, whereas there is plenty of water and space for building below-ground facilities.

Joris van Dorp's picture
Joris van Dorp on Jun 5, 2015

There’s a difference between making unpopular, controversial claims, and making demonstrably false, fear-mongering claims.

And there’s a difference between doing this once, by accident, and doing this time and time again, year after year, ignoring all evidence offered by those who respond to one’s ‘mistakes’.

I have a family member who is/was radiophobiac – since she lived through the worst of the cold-war propaganda in the last century. Her condition was inflamed by the Fukushima incident and the resulting sensationalist headlines in the media. She drove herself half crazy reading scare stories on the internet. It took me quite some time and effort to convince her that it was all nothing but lies.

I can only imagine the suffering of people who have nobody they trust to turn to, while their mind is being turned to mush due to reading the fear-mongering drivel from people like Darius.

But I don’t have to imagine the fact that significant number of people have irrational fear of radiation. Also people with power in politics and civil service. This irrational fear is doing serious damage to our societies, because it causes the formulation of counterproductive, ineffective energy policy, from which everybody will suffer the consequences.


Willem Post's picture
Willem Post on Jun 5, 2015


Thank you for this info.

He is a poorly-informed, opinionated person regarding energy issues. It is best to ignore him until he goes away. Hopefully, the TEC site curator will ban him soon.

Joris van Dorp's picture
Joris van Dorp on Jun 5, 2015

nuclear is a platinum bullet wrapped in pipe dreams.”

The Chinese disagree about that.

China National Nuclear Power Co Ltd (CNNPC) (601985.SS), a unit of one of the country’s two state nuclear reactor builders, on Thursday said it locked up 1.69 trillion yuan ($272.69 billion) of funds in its IPO this week.


Willem Post's picture
Willem Post on Jun 5, 2015


Total capacity, MW, and power produced, MWh/yr, of those PUMPED storage facilities?

Willem Post's picture
Willem Post on Jun 5, 2015


It is not likely nuclear energy will become minimal, as Russia obtained worldwide orders for about 50 nuclear reactors, each 1000 MW and up, during the past 12 months. They will produce 50,000 x 8760 x 0.90 = 394 TWh/yr of world energy production of about 22,000 TWh/yr.

China and India are rapidly expanding their nuclear capacity, MW.

Bob Meinetz's picture
Bob Meinetz on Jun 5, 2015

Joris, I grew up during the tail end of cold war propaganda in the 1960s. Under an eight-inch concrete slab in the house my father built in 1964 was a bomb shelter, with radiation-proof doorway (located in America’s Midwest, it saw use as a tornado shelter).

We lived 40 miles from Argonne National Laboratory, the nexus of reactor research at the time, and accomplishments there infiltrated local culture – nuclear energy was every bit as exciting as nuclear war was frightening. We can either accept responsibility for the enormous potential nuclear energy offers, or surrender to our inability to protect ourselves and our environment. I’d like to think we’re up to the challenge. Enrico Fermi:

History of science and technology has consistently taught us that scientific advances in basic understanding have sooner or later led to technical and industrial applications that have revolutionized our way of life. It seems to me improbable that this effort to get at the structure of matter should be an exception to this rule. What is less certain, and what we all fervently hope, is that man will soon grow sufficiently adult to make good use of the powers that he acquires over nature.

Under the spectre of climate change, making good use of those powers has never been more imperative.

Andy Maybury's picture
Andy Maybury on Jun 5, 2015

Some interesting points and a good rule of thumb.

It is also instructive to look at independent systems that have achived a hight level of renewable energy generation in the mix. The Isle of Eigg micro-grid is a good example.

They have 120kW of hydro, 24kW of wind generators and 30kW of PV along with a battery bank and an emergency diesel generator. This gives proportions of 69%, 14% & 17% for the three technologies. Given the latitude and weather, a 10% capacity factor for PV would be reasonable if not optomistic whereas the penetration of PV is significantly higher than that. 70% CF for the hydro is probably unreachable either given that some of the water courses dry up in the summer.

The bottom line is that where there is a will there is a way and the way in which we will consume electricity in the future will be different to how we ‘demand’ it now.

Clayton Handleman's picture
Clayton Handleman on Jun 6, 2015

Thank you for the clarification.

Nathan Wilson's picture
Nathan Wilson on Jun 6, 2015

“…easiest solution here – demand management

But where are the success stories that demonstrate integration of high penetration variable renewables using primarily demand management?  I’ve seen none, just promises and projections (usually by people who ignore cost of the necessary customer incentive and provide only enough demand management to help with a few high-priority incidents per year, which last under an hour each, rather than the consistent lack of evening solar, and wind lulls every few days).

“…honest conversation about the fact that nuclear is a platinum bullet …”

Yet another claim that nuclear is too expensive, supported only by a first-of-a-kind project (for the UK), in a country where much of the cost is risk premium, based on the risk of hostile government policies as enacted by neighboring countries.  And yet that high priced nuclear power is still cheaper than much of the other low-emission generation being installed (e.g. off-shore wind and solar), and much less dependent on fossil fuel for balancing.

In the US, the situation is similar, with the EIA reporting that nuclear costs about the same as other sustainable energy sources, except that there is no need for energy storage, vast long distance transmission networks, or the near 100% fossil fuel backup required by solar and wind.


I think that usually, when an environmentalist says nuclear is too expensive, it really means “I wish nuclear was too expensive, because then I would not have to face the reality that my real reason for hating nuclear is completely irrational, and my anti-nuclearism contributes to our fossil fuel dependence and the resulting environmental damage“.

Nathan Wilson's picture
Nathan Wilson on Jun 6, 2015

Bas, once again you are improperly using the concept of inflation adjustment; the Hinkeley power does not become less affordable over time as you’ve implied, the affordability stays exactly the same (that’s the point of an inflation adjustment).  Furthermore, you’ve compared costs in 2050 dollars for nuclear and 2014 dollars for solar.

You’ve ignored the expensive storage and long distance transmission that are required to use solar and wind without the fossil fuel crutch that makes them viable.

Also, you’re comparing a UK first-of-a-kind price for nuclear to new solar 35 years from now; the learning effect garantees that nuclear costs will come down with experience (in Hinkeley’s case, even the contracted price for the first plant will drop if the planned follow-on plant is built).

We’ve had this discussion before, so this is no honest oversight on your part.

Bas, you might also want to read this TEC article, in which the US government EIA gives their forecast for electricity cost by source out to 2040.  They don’t share Agora’s optimism about solar and wind cost declines; they look pretty flat (with geothermal even going up).  The EIA also predicts that costs for wind and solar will be higher than the value of the electricity they produce (hence the requirement for contined government incentives in 2040).

Nathan Wilson's picture
Nathan Wilson on Jun 6, 2015

I’ll agree with the other commenters that the before-and-after photo pairs were clearly Photoshopped.  But I think the point they were trying to make is valid: if I don’t want the wind farms in my backyard (and I don’t), then maybe it’s not right for me to impose them on other people.

I live in the windy US heartland, and actually, I don’t much mind the wind farms we have now (to produce 10-15% of our electricity), which are in another part of the state.  But I shudder at the thought that we might get an order of magnitude more to go all wind, then if Clayton gets his way, another order of magnitude after that to supply power to people far away.

Andy Maybury's picture
Andy Maybury on Jun 6, 2015


The major problem with nuclear power as far as electricity networks is concerned is that it so SLOW in terms of ramping up and ramping down. This is why we developed ‘off-peak’ electricity, to soak up the surplus generation from nuclear power plants during the night when no one wanted it. This actually answers your first question as it is a classic success story of demand-side response that incentivised significant proportions of the population to switch their energy use to when there was surplus. It has been done half a century ago, it is being done in new ways now (see for example what is happening at Knoydart) and will become common-place in the forthcoming decades.

Nathan Wilson's picture
Nathan Wilson on Jun 7, 2015

Bas, the French report you linked is not from the French government, but a group called WISE-Paris, that decided to jump on the renewable bandwagon, and make an unsupported prediction of low cost renewable energy.  No solutions offered, they simply ignored the capacity factor threshold.  Similar with other studies.

The IMF study you linked (actually an article by TEC contributor Elias Hinckley) does not show conclusions inline with Agora.  It doesn’t discuss future renewable cost at all, just fossil fuel subsidies (unpriced externalities).

I don’t dispute that we should replace fossil fuels.  But I don’t believe renewables alone will be an adequate path to achieve that.  And I don’t believe that nuclear power has the harmful down-sides that you seem to believe, in defiance of the science establishment.

By the way, I’ve not seen any studies done in future dollars.  This Agora report uses 2014 Euros (it also ignores the capacity factor limit).

Clayton Handleman's picture
Clayton Handleman on Jun 7, 2015


I agree with much of what you have said.  Resource diversity has always been considered an important part of maintaining the robust electricity system required for an advanced industrialized society.  That said, it is unfortunate that you have positioned the various challenges for renewable energy as a “rule of thumb”.  Some commentors are already throwing it around as if it is a theoretical hard limit when, of course, it is not. I think it would be much more helpful to leave it at – ‘For economic and reliability reasons, it is important to have a diverse portfolio of sources to power the grid, particularly if we electrify transportation. Here are reasons that over-reliance on renewables is a mistake and we should continue to develop sources beyond wind and solar’.

Lets look at one of your evidence pieces:

“At that point, wind or solar output will have to be regularly curtailed or spilled as VRE supply will begin to routinely exceed demand.

But shouldn’t any discussion of decarbonization assume decarbonized transportation either hydrogen or battery powered?  That will put somewhere between 1/2 and a full day’s storage onto the grid.  With that much storage available it occurs to me as an economic impossibility that some of it won’t be utilized for grid stability.  

In a scenario that I have commented on before, and which addresses your above comment, real time pricing would allow for EV charging to reduce curtailment significantly.  The night time charging with real time pricing would have the following effects:

 – More renewables could be depoloyed thus increasing the amount available during the day for baseload.

– Night time varability would be soaked up by simple charging algorythms in EVs thus dramatically reducing need for curtailment.

And looking at renewables in general in a high penetration scenario:

– Large percentages of renewables would be pulled from high CF regions so even using your approach we would see much higher viable renewables penetration.

– As solar costs come down and real time pricing is implimented there will be added incentive for west facing PV arrays, further shaving peaks reducing overall costs and reducing need for curtailment.

   This dramatically alters your hypothetical dispatch curve, extending renewables both up and to the right with low emissions gas being the primary peaking source (and substantially reduced), and oil all but dissappearing off of the chart.

– Since you hang much of your argument’s hat on the poor economics of curtailment then it is important to recognize that using decorrelated sources along with load shifting would dramatically reduce the peaks making curtailment rarer and thus far less economically damaging.  If the cost of the renewables is low then some curtailement is not a show stopper.

But, if we are to use rules of thumb lets be fair:

1) There is more than enough Great Plains wind available at >50% CF to power the country.  And that could be further supported with offshore, decorrelated wind.

2) Solar in the Southwest, with trackers, has 25% CF.  Alternatively, with real time pricing driving the economics, people will have incentive to put in West facing systems to capture higher rates at peak, i.e. economically benefitting by accessing value from the neck of the Duck in CA.

3) In a high penetration scenario, EVs using only load shifting (No V2G so the storage is free) offer, conservatively, another 10% as ‘sinks’ for excess generation.  But if we build the real time pricing and load shifting infrastructure then load shifting benefits will accrue from other loads as well.

4) Ongoing efficiency improvements, probably most importantly LED lighting since it also reduces heat and therefore HVAC loading, offer pessimistically 5% reduction at peak times.  Probably much more.

5) Existing hydro will likely not be reduced and likely will increase in Canada. 

The above gets us pretty close to decarbonized without additional source diversity.  It also allows for higher penetrations without destabilization.

Of course there are intermittency considerations that may not be fully covered but the nonlinear technology development is such that we should be focused on building a real market where the diverse and unpredictable possibilities are given the opportunity to emerge.  Lets put away the artificial caps such as rule-of-thumb about renewables.  And if you must keep it then use the criteria of a CF cap at 75% since solar and wind are highly decorrelated in the most productive areas.

Clayton Handleman's picture
Clayton Handleman on Jun 8, 2015

The areas I favor have very low population densities and the farmers and ranchers typically like the additional revenues they can earn by putting turbines on their land.  The last thing I want to do is deprive the people who grow our food the opportunity to have a more stable revenue stream.  Most of the sites I favor are off the beaten track so vacationers and cross country travellers would not likely see them unless they chose to. 

I do not favor massive build-outs in low CF areas.  



Joris van Dorp's picture
Joris van Dorp on Jun 8, 2015

“1. Because at least most of the ‘dirty’ pictures are filled with non-existing wind turbines (using photoshop or another program).”

Nope. No windturbines were photoshopped *into* the images. They were photoshopped *out* of the pictures in order to visualise what the situation was *before* the turbines were put up.

I also note that you once again post fear-mongering lies about radiation health effects, which have already been dealt with earlier on TEC. You need to be banned for that.

Joris van Dorp's picture
Joris van Dorp on Jun 8, 2015

Jenny, check out the following video comparing the land-use impact of wind versus nuclear.

Video: Wind turbines or nuclear power?

Now, how do you suppose shutting down nuclear plants in favour of wind turbines is going to work as a way of reducing the number of eyesores scattered around the country?


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