The Fundamental Limitations of Renewable Energy

You write that the most optimistic estimates see installed cost of solar leveling off at $1.44 per Watt.  That’s surprising, as the installed cost at utility scale is already in the neighborhood of $2 per Watt, having dropped from $4 / Watt since 2011.  That trajectory makes a floor of $1.44 look quite unlikely.

See this post, also at The Energy Collective: http://theenergycollective.com/zachshahan/236606/49-new-us-electricity-capacity-solar-q1-record-report

The last century of experience tells us that the cost of standardized mass manufactured goods, including deployment, falls towards zero.  There’s very little reason to believe that solar panels, invertors, wind turbines, batteries, or any other piece of renewable technology will be any different. Indeed, as I think we all know, we’ve seen the cost of solar PV (the modules themselves) drop by a factor of 20 over the last 30 years, and Li-ion batteries drop by a similar factor over the last 20 years.  

It’s legitimate to question what the future slope of that curve will be, and to question whether the ‘soft cost’ and balance of system costs can drop at nearly the same rate (now that they dominate the overall cost) but it’s clear that they will to decline.  Rate and timing are the issues (and they are very real issues), not fundamantal limits to the bottom cost.

Thanks Schalk for the civil presentation. It is worth a civil response. Basically, we need different renewable energy concepts.

First, there is a reason NASA looks for water on Mars to search for life. It is water, specifically the proton, that is ultimately excited by solar energy to store energy in chemicals. Any physicist knows the electon excited state is fleeting. The difficulty storing electron volts derived from silicon crystal conduction bands or magnetic induction has proven many physicists right. In short, we are working with the wrong charged particle.

Second, we don’t know how much biology can do. We do know that watering and fertilizing our garden and lawn makes them grow better. We also know there are many plant forms. And we know much of the Earth is currently too dry and infertile to grow anything. And we know plant growth is a CCS method that has been around longer than us, creating air and coal for us.

Lastly, agriculture was the first notable step of humans out of cave dwelling hunter gatherers. I don’t object to fossil fuel hunter gatherers. But when some boneheads think we grow corn for the waste ethanol, or grow wheat for the straw, it is hard to discuss much.

I like the graphic above which shows the comparative size of the Earth’s energy resources and current human demand.  It makes a great response to claims that the energy-rich lifestyles enjoyed by those of us in developed countries are somehow unsustainable. Although I would complain that where an enormous nuclear bubble ought to be  (including thorium and uranium for use with breeder reactors), a small “economically recoverable Uranium-235” bubble is placed; like the solar and OTEC resources, these nuclear resources require technology which is pre-commercial but prototyped; see D.MacKay. 

I would dispute what appears to be an underlying assumption in this post: that for an energy source to  “compete with fossil fuels in an open market” requires a lower cost than fossil fuels.  I can think of two groups of real-world exceptions to this assumption.

In developed nations, we already pay more than the minimum prices for our energy, in order to improve the emissions of pollutants and improve safety.  We mine coal in a way that reduces the incidence of black lung desease among miners.  Rather than buying coal from the lowest bidder, we pay extra and transport it larger distances in order to get lower sulfur and mercury content.  We buy and install expensive filters to reduce particulate emissions in coal exhaust.  We also pay extra for diesel fuel with low sulfur content and burn gasoline in a way that trades away some fuel efficiency for reduced NOx emissions.

In a small segment of our automobile fleet, we pay extra to get freedom from fuel efficiency regulations.  In the US, manufacturers of gas-guzzeling luxury cars must sell more economy cars (or buy credits from those who do, or add extra-cost flex-fuel compatibility) in order to meet the Corporate Average Fuel Economy regulations.

So clearly, we’ll pay extra for cleaner energy, furthermore I’ve seen estimates of the external cost of fossil fuel use that suggest that we would save money by switching to a cleaner electricity source like nuclear.

Regarding the renewable energy resource giants, sun and wind, I agree that they are unlikely to be viable in conjunction with batteries any time soon.  However, when they are used with demand-response fuel synthesis making transportation fuel, the intermittency problem is largely solved (here I refer to desert CSP with thermal storage and heartland plains wind, not “cloudy-town rooftop PV” or local wind).  When the energy going to fuel synthesis is of comparable size to the electric demand, the dispatchable load is large enough that very little syn-fuel must be converted back to electricity.

As far as cost goes (i.e. an independent check of Jim Bairds calculations above), note that one gallon of gasoline has 34.4 kWh of energy (same for 1kg of H2).  Using the US DOE’s EIA data for the cost of wind energy, $0.086/kWh, and assuming 60% conversion efficiency, and guessing a 50% cost increase due to added capital cost, we get $7.40/gge (gallon_of_gas_equivalent).  This is competitive with gasoline today, assuming an H2 or ammonia fuel cell vehicle with 2x the energy efficiency of a gasoline ICE (affordable implementations of which are admittedly futuristic), and is in the ball-park for ammonia-fueled ICE cars (affordable today, with 20% better energy efficiency than gasoline ICE). 

This is not to say that the renewable solution would be cheaper than fossil fuels or nuclear but only that abandoning our energy-rich lifestyle is unnecessary.

“But the only way to argue that the renewable transition is not going to happen is to to have blind folds on and pretend the world and technology will stay as they were yesterday.”

How certain are you that renewables are the only sector that will advance technologically and that they are in fact the next evolutionary step from thermal generation?

Is this simply an article of faith?

“The last century of experience tells us that the cost of standardized mass manufactured goods, including deployment, falls towards zero.  There’s very little reason to believe that solar panels, invertors, wind turbines, batteries, or any other piece of renewable technology will be any different.”

But not advanced nuclear, thorium. CCGT or coal with CCS?

That is odd, isn’t it? Only the renewable sector will advance?

I am confused.

Schalk,

I’d be delighted to discuss in more detail.  My email address is easy to find on my website.

I agree with you on the wind turbine learning curve, though somewhat more optimistic (with admitted uncertainties) on the other issues.

Best,

Ramez

It is in a sense odd that the cost of nuclear power plants has been rising rather than falling.  One explanation for this (which I favor) is that nuclear power plants, at least within the United States, are not standardized mass manufactured goods.  Were they built in a more standardized assembly-line manner, we should see economies of scale drive their cost down.  I have some hope for small modular reactors in this regard, though their costs have yet to be demonstrated.

Similarly, all reasonable cost assessments of CCS use a model that shows a high cost per ton for CCS initially, which then drops over time as CCS matures – in line with our experience over time.

With coal and CCS, a counteracting wrinkle is an upward price pressure caused by exhaustion of the best coal seams and CCS locations, which can work counter to the downward price pressure of mass production.

Best,

Ramez

Schalk,

I see several major holes in your analysis. It’s based on some ideas that need to be examined. First that any transition away from fossil fuels MUST be free market competetive and that we, as a species, have the option to continue altering the atmosphere in the reckless manner that we have been to date. You have omitted some major exigent factors that cannot be ignored. Coal (and other carbon based fuels) have inpacts on health, climate and the environment that we pay for in taxes. insurance premiums and possibly in the near future our very lives. Were those costs reflected in our electric bills or at the pump your numbers would simply not “crunch”.

Bottom line: Fossil fuels will run out soon (in geologic terms) and their continued use will lead to a Permian type extinction event. Consequently we MUST develop a carbon neutral energy production paradigm regardless of perceived “variability” or profit/market concerns. Retooling energy, while we still have the necessary resources, will be the only way to avoid the economic catastrophe of declining coal and oil and the spectre of human extinction. Before you poo poo that do a bit more research.

Regards,

Edward Kerr

Schalk,

Perhaps, based on your reply, we are not so far apart on the many issues that coincide with fossil fuels and climate. (I’ll read the article you referred me too when I have a bit more time) We are truly in a dilemma and I’m beginning to fear that all of the competing factions will prevent a solution.

When you say nuclear I trust that you are referring to Thorium reactors.

Thanks for the trply and clairification.

Ed

Schalk,

Lack of political will is, as you note, the core of not only our climate/energy problem, but most of our concurrent problems as well. It’s particularly disturbing to me as I have grandchildren and the situation is more dire than most can conceive.

I’m still in the camp that calls for renewables vs CCS and nuclear. Yes, there are inconveniences to renewables but with a revamped grid technologies like CSP/molten salt, wind, other solar, tidal, hydro (though it is already a mature technology) and algal oil, I believe that we could have a carbon neutral energy paradigm. One can also hope for some zero point energy but I’m not holding my breath there. Sadly, as you point out, the divisions amoung us will likely prevent any meaningful change in time to avert the obvious consequences.

Regards,

Ed

Why compete in an open market ?

In fact, markets are the big obstacles renewables face.  Markets were designed for predictable energy, coal, nuclear, gas.  But they don’t know what to do with renewables which have seasonal, daily and even hourly variations (in the case of wind and solar).

Go look at the case of any country without an electricity market.  Say Costa Rica, with 92% penetration of renewables.

Jorge.

My point is just that, if government got out of the energy business and instead only imposed the carbon tax necessary to get the free market to reduce the carbon intensity of our economies in the most cost-effective way, this would happen chiefly through CCS and nuclear instead of through expensive and impractical renewables. 

Why CCS and nuclear? Whichever one is cheaper would win the day in a free market. If it happens to be CCS then we would have to wait for rising coal prices to determine the successor technology. I sure hope that all the CO2 stays where we put it.

However, the hope that an economic system governed by ‘free markets’ (i.e. private credit markets and the unbounded competitive accumulation of consumption rights) will be able to effectively limit CO2 emissions and keep private credit markets from collapsing seems relatively remote. The system of private credit markets is already groaning under its debt load. A carbon tax large enough to make a significant impact on CO2 emissions would probably cause a financial collapse. If we really want to address ecological limits then we need to address limits to economic growth. We need to agree upon a standard of consumption by a social/political discussion that is completely independent of the desire of rich people to preserve and increase the value of their financial holdings and is strongly dependent on intelligent analysis of the earth’s resource base, both mineral and biological. Once a standard of consumption is agreed upon we can use competitive methods to produce the goods and services required to meet that standard as efficiently as possible. But so-called ‘free markets’ and unbridled consumerism as they now exist are not going to get us where we need to go.

Yes, I agree that carbon-free syn-fuel made from sun or wind would be much more expensive than a product made in the US from fossil fuel with CCS (nuclear would be in the middle for initial levelized cost, but as is usual for nuclear, would deliver low average cost over the plant life).  I have no aversion to ammonia made from fossil fuel; the important thing for me is the clear path to sustainability.  

It seems likely that in China and other developing countries with low labor costs and large oil imports, things could be different (note that China makes nuclear plants for $2/W, and likely has cheap wind too).

An affordable hydrogen fuel cell car is the holy grail we strive toward many decades in the future (the DOE’s equivalent of a Mars program).  Ammonia fuel cars work today (see Korean NH3 proto), and are about the same complextity/cost as gasoline powered cars.  We could easily be building them by the tens of millions/year, 10 years from now, if we choose to do so.

Note also that ammonia fuel is a great way to smooth seasonal supply/demand mismatch in energy supply.  With refrigeration, ammonia can be stored at normal atmospheric pressure.  This means that warehouse-sized insulated tanks are feasible.

Here’s a good intro to ammonia fuel:  NH3 – The Other Hydrogen

Here is a presentation on ammonia safety.  

The IEA does not have data for Costa Rica.  

What are they using?  Hydro? Biomass?  Those are dispatchable, and small energy resources.  They tell us nothing about the variable, larger resources of wind and solar.

We know how to handle these variable renewables in a non-fossil energy portofolio, but we ignore the obvious solution because we know it makes solar and wind very expensive.  The only solution today to the variability (other than continuing to burn fossil fuel to supply the majority of load) is fuel synthesis.

Obviously, a breakthrough in energy storage could occur any time, but that’s where we are today.

We have four technologies for reducing CO2 emissions: efficiency, renewables, nuclear, and CC&S.

Deep reduction in CO2 will be extremely difficult, so it is absolutely crazy how many so-called environment groups want to limit our options to only two.

Nuclear and CC&S are the cheapest ways to limit emissions, withholding them hurt the poor (who still need energy), and greatly increase our odds of failure (note that nuclear+hydro is the only solution which is scalable and proven via past experience).

” Firstly, energy does not like to be concentrated, hence the fact that the average commercially available solar panel is only about 13% efficient. And secondly, because the energy source is so diffuse, vast areas need to be covered in order to harvest this diffuse energy. As a result of this challenge, it was previously calculated that the solar panel price needs to fall to about $0.31/W installed in order to compete with coal at $100/ton. “

This bureaucrat is again proving that he does not know what is going on in the real world. My PV panels on my home roof (installed in 2010) achieve 15% energy conversion efficiency (Bisol), and recent cheap SunPower PV panels commercially mass produced in 100% automated production lines  (made in the  USA) are above 18% efficiency.

The vast area’s are already being covered. Many big flat plant and office building roofs are being carpeted with solar PV panels, to send the electricity production down to the users on the floor, were it is immediately consumed, instead of piped in from far away, requiring an expensive grid extension.

i do not care about the price of coal. My fossil fuel and nuke power plant electricity bill before installing solar PV panels was above euro 20 cents per consumed kWh, in Belgium. Taxes, high grid maintenance and expansion costs, import duties on fossil fuels (Belgium imports 100% of it’s fossil fuels), make it an expensive proposition. Today, my electricity bill = zero, since my PV panels are put on my home’s roof.

I recently was contacted by Tractebel, a Belgian engineering corporation. They needed a dude to help install a onshore 30MW windturbine park in desertic sun rich Mauritania, near the sea 20 km form the capital Nouakchott. Cheaper than importing coal or building a nuke plant, given that the sea wind regime was very predictable and constant, and electricity consumption in that country is too small to allow a big centralised PP to be built.

Fossil fuels power plants are getting more expensive by the day, and renewables PP are getting cheaper by the day. I built a 250 000 ton per year biodiesel manufacturing plant in 2008, who uses as feedstock waste animal fat and waste cooking oil that cannot be dumped in landfills anymore, and the biuodiesel is then used to power car engines (6% biodiesel mixed in 94% petrol diesel) or is used to be burned in caterpillar piston genset coupled to an alternator connected to the centralised grid.

Next to this biodiesel plant, someone else built a mammoth biogas production plant, who converted boatloads of agro and home food/vegetable waste into methane and compost, methane being burned in turbine/piston genset rows and the compost being sold to flower and gardening wholesale customers, while getting rid of a massive amount of vegetable city waste that cannot anymore be dumped in a landfill.  

fossil fuels rose in the 20th century, matured and now the same is happening with renewables in the 21st century. I hope we will continue on this road, and I hope we will continue to search for even more cheaper ways of recycling wastes into energy and even more cheaper ways to produce clean energy. The will is there, you only have to look how horribly poisoned China is with it’s 70% of electricity coming from coal PP, and only have to remind yourself of the smog clogged London city movies of Dickensian origin to remind yourself of the benefits of coal home heating…..

No need to reply. I have unchecked the notify box, since I am not interested in debating you, I already have made my personal choices, using my own savings money in the process….

The thesis that a carbon-tax is “needed” rests on a soft foundation that is becoming ever more rotten – i.e. man-caused-global-warming-catastrophe. The models have been unable to replicate the +15 year “pause” in global temperatures, which means there is something going on not properly accounted for by the climate models. The panic to “do something” is misplaced and unnecessary.

Rather than place forlorn hopes on the government White Knight of “taxing carbon” saving the day, reduce costs. If renewable energy cannot compete, then it belongs on the scrap-heap of economically dumb ideas.

Also, the cost of power generation is not static. Economic forces are at play and that means productions cost are pushed ever downwward by more cost efective and efficient machines as well as advances in producing fuels (e.g. “fracking” and shale gas).

” Also, the cost of power generation is not static. Economic forces are at play and that means productions cost are pushed ever downwward by more cost efective and efficient machines as well as advances in producing fuels (e.g. “fracking” and shale gas). “

That is if you happen to sit on large deposits of fossil fuel resources that are easily extractable….  Where I live, in tiny Bellgium, the only fuel resource we still have are sea wind sun wood and city and agro wastes, unless we import fossil fuels ….

Looks like Schalk hit a nerve.

Mr. Cloete, who works with carbon capture processes, would have us believe that carbon capture and sequestration, which outside of limited value in enhanced oil recovery has no direct economic value,  is more viable than renewables. Amusing.

As others have pointed out, he’s using old data and ignoring negative externalities in his perspectives on the value of renewable energy. It’s so easily debunked, it’s not worth getting into more.

His second point is fascinatingly incorrect however. Energy storage’s heyday was in the 1950’s in California, when huge amounts of it was built. Why? Nuclear plant proliferation. All of those nuke plants couldn’t be turned down at night, so it was cheaper to build hydro storage and pump water into them at night to balance peaks during the daytime. Sensible, realistic, and ignored by Mr. Cloete.

What’s happening now? Well, 45 jurisdictions around the world are now getting 60% plus from renewables. Some are hitting 70%. A lot of that is hydro, but a remarkable amount is from wind and solar. Texas regularly exceeds 25% of demand from it’s wind energy alone.  

If Mr. Cloete’s argument were in any way correct, then all of these jurisdictions must have enormous amounts of storage implemented, correct? So, do they? No, they don’t. These jurisdictions use passive storage in the form of unused hydro, grid interconnection and unburnt fossil fuels to achieve these remarkably high levels of renewables.  

Mr. Cloete is correct that getting to 100% everywhere will require storage. But it will be balanced against just building more easily curtailed renewables capacity, more grid-interconnectedness and smarter demand management as an economic choice, and it won’t be necessary in nearly the degree that anti-renewables folks seem to believe. Odd how they refuse to look at what’s happening in the real world.

http://barnardonwind.com/2013/02/24/how-much-backup-does-a-wind-farm-req...

For the record, I encourage continued work and investement in CCS. It’s part of the toolkit for solving the mess we’ve gotten ourselves in. But claiming it’s a silver bullet is just silly, and attacking renewables to promote it is sillier.

“… looking around at what drives the low-carbon energy market today…”

Alas, it seems that most renewable enthusiasts today would rather gamble on a future breakthrough in biofuel or batteries than accept a stinky bird-in-the-hand like NH3. But who can see tomorrow?

My apologies, but your point 1 is a bald and false assertion without support. I appreciate that you have an opinion and are entitled to it, but ignoring the presented argument in favour of a bald and unsupported assertion is not a useful debating approach.

You really do not seem to get it. CO2 is the tip of the iceberg. You are so focused on your narrow specialty that you do not seem to be aware that the chemistry of combustion is about to destroy the planet’s capacity to provide us with a hospitable living environment. This can only happen because the phony economics of fossil fuels lets people like you act as if they are actually cheap, when, in fact they are unbelievably expensive and not just in the present but ten thousand years into the future. Its not just CO2, it’s the wholesale chemical pollution of the atmosphere, land and water.

As a thought experiment why don’t you try to calculate the costs of remediation for every oil spill, pollution-related death, warfare to protect fossil fuels, and then add to that the climate effects like wild-fires, heat-waves, floods, mega-tornados, enormous hurricanes and massive wearther volatility. But we are not finished yet, because we have not included the acidification of the oceans and the destruction of the planetary ecology, which are probably pinpricks compared to the losses that will result frrom from rising sea levels.

The only way to save the planet from these inevitable  costs is to stop burning stuff and to do that as quickly as possible. That means solar energy with storage and it means energy efficiency and zero waste strategies. The only way that this can happen is if we force the fossil-fuel profiteers to actually pay the true costs of their enterprise and not shove it under the rug in the name of phony profits. There needs to be a huge carbon tax, starting modestly and increasing year by year untiil the economic proposition for phony fossil fuel profits is strangled. Without that, we are entering into a period of rapid extinctions which will inevitably include much of the human race. And I am not talking about 100 years from now. This has already started and it will get worse.

Boy, are you behind the times. Lithium Titanate cells already in mass-production from a major Japanese manufacturer have a wholesale cost of less than $0.12/kWh today. And the price is expected to fall. The batteries operate from -30 C. to +55 C., retain 85% of their capacity after 6000 cycles and a properly sized battery coupled with PV according to local capacity factor, can provide deep cycle storage for 20 + years in low to medium power applications – such as household electricity or building integrated applications. By integrateding all components at the PV module level, including power electronics, battery cells and IT modules, these units can be paralleled to any size up to MW arrays. If one module stops working, it informs the operator and all the rest continue working. This bundling of all components at the module level, reduces material costs and allows for UL and other certifications reducing permitting requirements while allowing for very rapid, low-cost  and versatile installation  procedures. This is the future of electrical energy. Why? because it can be done and it requires no huge investments in centralized technologies with no track record.

I have been living on PV with battery storage for thirty years. I have never had a power outage. My amortized costs of batteries has been $10-$15 per month. But I had to add water to my batteries, a bit of a pain in the neck. The new batteries require zero-maintenance. They have 4x the specific energy of the FLA batteries that at ~ $0.13/kWh  have been the only affordable solution until now.

Shalk,

I fully agree with the elements in your assessment and your conclusions, and have done so for about a decade. The high cost of intermittent renewable energies make them unsuitable for a global roll-out in a free market context. If they were only a little bit more expensive than fossil options, there would be no problem. But they are far more expensive, as you have explained, and they will likely remain so.

So I am very happy with your article, the professional and transparent way in which you formulate your arguments and the civilitity with which you engage the nay-sayers and doubters. You are an example to all of us who are in some way engaged in the business of solving grand (wicked) problems such as anthropogenic global warming.

I do have one question about CCS which I would like your opinion about, since I gather you are an expert on it as well.

Having also studied the feasiblity of CCS within the context of eliminating the anthropogenic global warming problem I ended up concluding that while the cost of CC at the power plant was going to be affordable sooner or later – given some incentive – the cost of then taking the carbon and securing it in suitable geological strata was going to be far harder than the proponents of CCS would have it. While there are many suitable geologies, not all coal power plants are located near such geologies. So ultimately, there will need to be a CO2 transport infrastructure that perhaps approaches the footprint (and costs) of the existing infrastructure for natural gas. That infrastructure will need to carry the co2 to places with suitable geological conditions. Futhermore, since such infrastructure will be financed completely on the condition of permanent subsidies (i.e. a carbon tax), owners of such infrastructure are constantly at risk from politicians suddenly phasing out such subsidies and thereby leaving the owners of the infrastructure stranded, which adds significat risk premiums to such projects that hardly exist for the natural gas infrastucture and further increase the overall costs of CCS.

So my question is: is your ultimate cost estimate for CCS of 0,03 $/kWh (for coal PP’s, I assume) including the off-site costs for CO2 transport and storage aspect?

Thank you,

Joris

They say a picture is worth a thousand words.  Here’s Aug 8, 2013 dispatch.

http://db.tt/oh3Iln4H

(I couldn’t paste the graph here, but there’s a link to it)

You can see, Geothermal (yellow) at the base, wind (white), hydro PPA’s (blue, mostly run-of-the-river plants), ICE run of the river plants (lighter blue), Arenal Complex (light blue, multi year reservoir), fuels generation (red, diesel, bunker or gas), and exchange with neighbor systems (black).

On a yearly basis Costa Rica’s generation goes something like this (data for 2012):

Hydropower           77%

Geothermal           14%

Fuels Generation    8,2%

Wind                   5,2%

Biomass                1%

Solar  …           0,03%

That sums up to 91,8% renewable energy, with a very very low carbon footprint of about 80 tonCO2eq/GWh.

Fuel synthesis ???

Ah, forgot the most important piece.  Costa Rica does not have an electricity market.

I cannot link you to any data. I have signed an NDA which includes pricing.

However, most of the info is public. 2.3 VDC cell , 20 AH, 6000 cycle, to 85% of capacity.

http://www.toshiba.com/ind/data/tag_files/SCiB_Brochure_5383.pdf

As to your figures for grid-tied battery back-up systems, that is a complete misinterpretation of reality. Nearly all battery backup systems are tremendously expensive because they duplicate the main power system. Only when grid power is down, do they come online and then only for critical loads. They usually use the most expensive AGM batteries (which also wear out the quickest) and since they are only in use a small percentage of the time their actual cost per kWh is astronomical. Only when PV with battery storage is the MAIN system and the grid is the backup does battery storage make good sense. For example, I put three such systems in the field powering 2 person households. 2000 Wp PV, 9.6 kWh battery (nominal) derated 50% to maximize battery life. All costs were:

• Electronic parts including  PV – $8791.68
• Electrical parts – $2047.23
• Batteries – $2083.62
• Rack and component housing – $1119.97
• Design, Construction and installation – $5786.12

So you see that the batteries equal roughly 1/5 of the cost of the system in order to provide uninterruptible solar generated electricity 24/7/365. In the rare event that the sky is so dark for a prolonged period that the solar PV is insufficient, the grid automatically comes on and powers the whole system for a short time while also charging the batteries – no shift to critical loads only. In practice this means that the Solar PV provides 98-99% of the electrical energy used annually. No power is fed to the grid, the grid only acts as backup.

Now granted that these systems are small, with the owner investing in the most efifcient appliances that can be purchased at a reasonable price. All modern amenities including refrigerator, dishwasher, microwave, washer/dryer,  power tools, big screen TVs, stereos, computers etc.are powered by this system.

So the idea that batteries are so expensive is really a myth. In such a system as described above, the batteries only store about 1/4 or less of the energy generated. Its mostly needed for night-time use. The next day the batteries get charged again by the PV array which also provides ~95% of the energy used during the day.. In my system, the biggest problem is what to do with surpluses. However there are more and more electrical tools and appliances available and ultimately I will also have an EV.

The reason for the mythical super-high battery cost is that it totally depends on the system design. Most system designers are insufficiently experienced with batteries and therefore generally use too many batteries, because they are using faulty formulae for determing what battery size to use.

So you do the math. 12 VDC, 800 AH battery = 9.6 kWh (nominal it is actually more since the battery’s voltage operates between 12.1 and 12.6 (rest state).Then derate that by 50% to prolong battery life and you get ~4.8 kWh. Operated in the correct charging regime (40% -90% SOC) yields a 90% efficent battery according to Sandia Labs. So 4.8 kWh x .9 = 4.32 kWh per cycle. Operated in the efficient charge regime also maximizes cycle life, .The mid-range L-16 solar batteries (which are used in the above-described system) operated this way using shallow cycling can expect  ~3000 cycles over ten years. that comes out to ~$016/ kWh. The more expansive 20 yearFLA  batteries sized properly for the system and operated this way can yield $0.13/kWh stored.

The new lithium titanate batteries from Toshiba do not need to be derated and require zero maintenance. I trust Toshiba’s specifications because the Japanese are rigorous in product development and they have too much to lose to lie about their products. These batteries are in mass production since the beginning of this year.

Hi Schalk, I think your intent on trying to answer the main questions that we’re all trying to find answers to falls short on a couple of important points:

1. The fact that fossil fuel prices go up, and renewables prices go down; these lines are not linear

2. Technological breakthroughs are already happening (batteries & other energy storage systems, concentrated solar CSP, among others)

3. The fossil fuels are actually much more expensive if you weigh in factors like increased severe weather events like flooding and hurricains, and of course deep pollution which is very if not impossible to reverse

I’d strongly suggest you to update yourself on technologies and facts and rewrite this article. You will see that if you do your home work well you will find that renewables actually outpace other energy technologies, and there must be a reason for it.

The one reason is we need to stop as soon as possible burning fossil fuels and replace them with renewables, where possible non-intermittent and for the rest using intermittent backed up by energy storage systems.

We really need to leave the fossil fuels where they are, in the ground. What we need are advocates that believe we can do it, not visions that stick with the old beliefs.

Renewable energies do not have the resource limitations and extraction problems that fossil fuels do have. Renewables are the way to go if we want a sustainable future, and well who doesn’t want a future like that?

You have got to be joking!! Since when did the Chinese people have the opportunity to price anything into their voting decisions. What voting decisions? Chinese are imprisoned for criticizing the government.

Why don’t you take a  look at this article that just came out today.  http://www.sciencedaily.com/releases/2013/08/130808091930.htm

To summarize: Aug. 8, 2013 — Particulate air pollution from incomplete combustion is affecting climate over East Asia more than carbon dioxide and cause premature deaths of over half a million annually in China alone, yet its sources have been poorly understood.

I wonder how those half a million dead people would vote, if they could.

As I said, CO2 is just the tip of the iceberg. So far it is not killing many people directly. But burning carbon fuels regardless of their source is already killing millions of people world-wide. CCS while perhaps being a part of the solution if it can be cost-effectively implemented should not be used as a cover for the much larger problems of poisoning our life-support system for profits. Continuing on this path is total insanity. We need to move to benign energy technologies. We need to change our economic model from one that gives an advantage to churning massive amounts of virgin materials to give a flash-in-the-pan economic advantage to a few rich people, to one that gives economic advantage to extremely durable goods that recognize the vast store of energy in processed materials and reward enterprises that make profits by creating real value. Our speculative, short-term hustling after money at any cost, will be the death of us and our descendents. It is not necessary to organize society and economies this way.

Some ideas for how we need to change can be read at:

http://lightontheearth.blogspot.com/p/eco-industrial-revolution.html