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The Truth About Solar Energy

Rosana Francescato's picture
Principal, Rising Sun Communications

Rosana is a seasoned clean energy communications consultant. For over four years she served as Director of Communications at the Clean Coalition, a nonprofit with the mission to accelerate the...

  • Member since 2018
  • 145 items added with 87,559 views
  • Mar 26, 2013

There’s a lot of debate these days about the future of solar power. Certain news media outlets who must not be named have brought renewed attention to the issue, likely confusing the public further. I’m here to tell you that solar IS our future. Why? In addition to being an important part of fighting climate change, solar makes financial sense, creates jobs, is abundant, and enjoys widespread popular support.

Solar makes financial sense

“Wait,” I hear you say, “Isn’t solar just too expensive?” There are so many ways to answer with that, but they all lead to “No, get with the times.” The perception that solar is too expensive is outdated. The current reality:

  • The price of solar has been plummeting, to the tune of 30% in the past two years.

  • New financing options have brought solar within reach of the average person, allowing more lower- and middle-income people to go solar.

  • Schools, corporations, and government agencies wouldn’t be installing solar in droves if it didn’t make financial sense.

  • Costs may go down even further if the DOE’s SunShot Initiative succeeds in lowering soft costs, such as permitting and financing. Lower soft costs have helped Germany top the U.S. in installations despite having much less sun.

  • Many areas have already achieved grid parity, where unsubsidized solar power is on par with or cheaper than retail electricity prices. That’s expected to spread to many more regions in the coming decade:


Former Energy Secretary Steven Chu agrees — in fact, he believes solar is close to being as cheap as any other power source: “This is not something that’s going to happen 20-30 years from today. This is going to happen 10 years from today. Maybe sooner.” 

Solar benefits all utility customers

Utilities still aren’t convinced, and a major conflict is brewing with them. They’re saying that solar customers tied to the grid are driving up costs for everyone, because they buy much less power from the utilities than other customers and therefore pay less for the utility’s fixed costs. In effect, they claim that non-solar customers are subsidizing solar.

However, it’s likely that the utilities are reacting out of fear of losing profits. Their math just doesn’t add up. In fact, two recent studies have shown that net metering not only benefits all electric customers but can also help a state’s economy. We haven’t heard the last of this hot topic — the California Public Utilities Commission is due to weigh in with their own study in October 2013.


Some utilities are getting behind solar, though, as they see the benefits not only to customers but also to themselves. Most of the power grids in the U.S. are old, under stress, and in need of upgrades. In some cases, utilities are finding they can incorporate customers’ solar generation into the planning for these stressed networks and defer upgrades — not to mention avoiding the costs of new distribution lines — which results in savings to their customers. It’s a win-win-win!

Solar has lower externalities and indirect costs than fossil fuels

So let’s assume you’re convinced so far: solar is in fact cost-effective compared to fossil fuels. What happens if you add the costs of fossil fuels beyond what it costs to generate them? These include externalities, or hidden costs, such as pollution and resulting illnesses. Fossil fuel-related health costs in the U.S. alone are estimated at $120 billion a year. 

Some of the costs are unexpected. A recent study by the World Future Council provides a new take on the costs of fossil fuels — the costs of using them instead of renewables. All the fossil fuels we burn for energy, the study notes, are fuels we are taking out of circulation for other purposes. Given the petrochemical industry’s reliance on these substances, the study estimates that using conservative measures, the future use loss amounts to $3.2 – $3.4 trillion dollars a year.

Suppose, though, that in the future we figure out ways to make our stuff without fossil fuels. We’re still left with other externalities and indirect costs, such as the costs of extreme weather events.

Superstorm Sandy is estimated to have cost as much as $71 billion in damages — and we’re seeing many more major storms resulting from climate change. A recent study estimated that U.S. storms between 2011 and 2012 have cost us $188 billion.

We’ll continue to see the costs of extreme weather not only in damages but also in damage prevention, something cities like New York will have to invest in further. A major coal company has already invested significant shareholder dollars to protect their coal export infrastructure from these increasing superstorms. 

There’s another aspect to calculating costs: we must consider costs of the entire life cycle of generating any form of electricity. Just about everything we make on this planet comes with some waste, and even solar is not immune. But the waste caused by producing solar systems is much less than that from fossil fuels, and solar’s actual power generation is very clean.

Solar is looking more appealing all the time, isn’t it?

Solar makes sense even without subsidies

Whether solar can thrive without subsidies depends on a number of factors, including location.  Solar is coming closer to holding its own thanks to falling costs, but what about subsidies being cut in many places? Will that make solar unsustainable economically?

Let’s start by asking the same question about fossil fuels. What would happen if we cut all the subsidies for coal, oil, and gas?

For one thing, we’d have a lot more money to spend on other things. During the time they’ve been getting subsidies in the U.S., according to a DBL Investors study, oil and gas have received $4.86 billion a year. That’s over 13 times more than the $0.37 billion a year in subsidies for renewables.


Coal also gets more subsidies than renewables. It can be hard to calculate the actual amounts coal and other fossil fuels benefit from when you consider all the tax credits, tax breaks, and indirect subsidies — not to mention externalities. When you add those, a 2011 Harvard study estimated the real cost of U.S. coal subsidies at $345 billion up to that time.

The U.S. trend is mirrored globally: in 2008, according to the U.S. Energy Information Administration, fossil fuels received $557 billion in global subsidies, compared to $43 billion for renewable energy. 

And if solar got the same treatment? Keeping in mind that One Block Off the Grid created this graphic in 2010 and by now more of the U.S. can support solar without subsidies, this is still a nice illustration of what we’d be looking at:


So why are we even asking if solar can thrive without subsidies? The fossil-fuel industry has been around for a long time and is still benefiting from that help. The newer renewables industries should be getting more of a boost, shouldn’t they? Whatever your opinion on that, they’re not. In fact, during the first 15 years of subsidies for the respective industries, oil and gas subsidies represented half a percent of the federal budget, about $1.8 billion a year, and all renewables only about a tenth of a percent, or $0.5 billion.

It’s especially odd that there would be such a fuss about this when a majority of Americans support subsidies and incentives for solar. But when you have such entrenched financial interests as the fossil fuel industry has, it’s hard to let go.

The good news for solar is that it’s becoming more cost-effective even without subsidies. The grid parity it’s reaching in more areas is in relation to existing fossil fuel generation. When it comes to new power plants, many places around the world are finding that solar and other renewables are cheaper than coal and gas even without subsidies. Global investment banking analysts at UBS recently predicted a boom in unsubsidized solar in Europe. And a new analysis by Deutsche Bank predicts that by the end of 2014, the global solar market will be sustainable without subsidies.

We can still benefit from subsidizing clean power. Some countries are still putting feed-in tariffs and other programs in place to accelerate solar adoption. To see what can be done with smart subsidy policies, just check out Wildpoldsried, Germany, a town generating so much clean power that they’re making money selling the excess. And to put the icing on the cake, you need look no further than Gainesville, Florida, whose feed-in tariff has helped it become a world leader in solar.

Solar creates jobs 

One benefit of subsidizing solar is the jobs it creates. In fact, that comes to many more jobs per dollar invested than is true of fossil fuels, according to a University of Massachusetts study:


And the actual job numbers for 2012 were good. According to the Solar Foundation’s National Solar Jobs Census 2012:

  • As of mid-November 2012, over 119,000 Americans were employed in the solar industry.

  • The employment growth rate in solar over the previous 12 months was 13.2%, compared to 2.3% for the overall economy.

  • Out of every 230 U.S. jobs created in the past year, 1 was in the solar industry.

As Danny Kennedy, co-founder of Sungevity, points out, this doesn’t even account for all solar jobs. The census focuses on jobs related to installing, but the industry also employs thousands in solar-related financing, as well as software and information technology services.

Solar is abundant and popular

Some are quick to point out that even in places with increased solar adoption, it’s still a small part of all power generation. But this is not an argument for not doing more. It doesn’t need to be this way. The sun is our most abundant resource, shining enough rays on the United States every day to more than power us for 10 years. Coal, oil, and gas combined can’t come close to matching that. 

Support for solar, while not as abundant as sunshine itself, is widespread. A September poll of likely U.S. voters showed that 92% of Americans support developing more solar, and a majority want the government to support solar with tax credits and other financial incentives. And despite claims that Germans are fed up with solar, a recent poll found that most favor renewable energy and many even think its progress in Germany is too slow.

Why are so many people in favor of solar? When you look at the benefits of solar — plus the costs of fossil fuels, both direct and indirect — it just makes sense. Isn’t an ounce of prevention worth a pound of cure? We have to ask ourselves if we care more about our planet, and all the life on it, or about the financial interests of a few people who already have more money than they need. Isn’t the answer obvious? Isn’t the answer solar?

This post was originally published at PV Solar Report.

Ivor O'Connor's picture
Ivor O'Connor on Mar 26, 2013

I was hoping for a piece that would say how much it now costs for ground mounted panels. Maybe showing the price per kWh across the country. With no subsidies and how much with the current subsidies. Something to make unbelievers stop and say "That's cost effective, how do I proceed". 

Rosana Francescato's picture
Rosana Francescato on Mar 26, 2013

That's a good idea, maybe I'll have to write something on that. Any reason you're wondering about ground-mounted panels in particular?

Rick Engebretson's picture
Rick Engebretson on Mar 26, 2013

Hang in there, Rosana. We all know solar energy of some sort works. I'm not a big fan of solar panels in Minnesota. But many areas aren't covered in a glacier 4 months of the year.

I have some good friends who are right wing farmers that tease me about my environmental concerns. One thing that works is to ask if they have EVER grown something people can eat. Corn and beans as far as the eye can see but nothing to eat!

So ask your critics if they know what is in the water they drink? Or where that air they breathe might have been? You want to know and control your energy sources, and they don't? So who's the dumb one?

Paul O's picture
Paul O on Mar 26, 2013

The real  truth about Solar Power is this:


1) You can't put it in your car (like the petrochemicals you alluded to).

2) You won't have any at night or on cloudy days.


I rather think your piece is incomplete since it doesn't address these key questions. The problem with solar power by itself is that it doesn't meet our needs, to do that it needs storage and a way to convert solar power to a form that cars can use, which might ultimately mean better batteries.

Lets talk again sometime in the future when solar has got the prices/costs of realistic storage built in.

Bob Meinetz's picture
Bob Meinetz on Mar 27, 2013

Rosana, it's important to make a distinction between residential/local application of solar and utility solar. The first shows promise, especially in developing countries without a solid infrastructure.

Utility solar is a different matter. To call a variable energy source abundant with the footprint, transmission infrastructure, and meager capacity factor of solar is just wishful thinking. I honestly wish the sun provided as much energy as you believe it does; it doesn't. The average daily solar irradiance for the United States is somewhere in the neighborhood of 5 kWh/m^2, multiply that by .15 capacity factor and again by .14 for efficiency and you have a supplemental power source which is completely dependent on fossil fuels and subsidies to be practical. With ultra-efficient, cheap energy storage it might be practical in the southwestern U.S.; there is currently no technology which fills the bill and nothing on the horizon.

I think you realize that 100% of the country going solar is impossible, unless people suddenly find turning off their refrigerators for a few days when a storm blows in an acceptable compromise. This kind of self-deception takes us backwards, not forwards. It keeps us dependent on natural gas, on fracking, on sucking more and more carbon out of the ground in the hopes that one day the magic storage solution will appear and fossil fuel people will all retire - their "transitional" energy source outmoded. Fossil fuel magnates like T. Boone Pickens are all too happy to indulge that delusion, for obvious reasons.

The pursuit of renewables is taking on the mythic proportions of a religion, and that's dangerous. If we were to claim that the amount of water going over Niagara Falls would end thirst in Africa, we probably wouldn't be far off the mark. Of course that fact won't save one African's life - just as the amount of sunshine falling on the entire U.S. is irrelevant to how much of it we can practically capture, and use. Because statistics gleaned from advocacy websites of any kind are typically misleading, we should be looking at the wealth of reputable information that's available to make these important decisions. That data tells us that the levelized cost of PV solar is one-third higher than nuclear, and that thermal solar costs twice as much as nuclear and four times as much as natural gas. Worse yet, both extend our dependence on natural gas indefinitely.

Utility solar is a false solution and a waste of precious time.

Ivor O'Connor's picture
Ivor O'Connor on Mar 27, 2013

Ground mounted I figure is the least common denominator. (I think this is true but please correct me if I'm wrong.)



Nathan Wilson's picture
Nathan Wilson on Mar 28, 2013

"Utilities ... They’re saying that solar customers tied to the grid are driving up costs for everyone, because they buy much less power from the utilities than other customers and therefore pay less for the utility's fixed costs."

Rosana, utilities are generally regulated monopolies that have to justify all of their costs to regulators. Fixed cost is a real thing that is taught in every industrial accounting class.  Fixed costs are things like transmissions system and power plant capital cost, plus salary for all employees who don't get furloughed when electrical demand is low.  Variable cost, on the other hand, is mostly fuel (they tend to be 2-4 cents per kWh).  The simpler "levelized cost" combines fixed and variable, but does not tell the whole story when dispatchable and non-dispatchable energy sources are compared.  Solar PV and wind plants reduce variable cost of the rest of the grid, but not fixed cost. 

As another datapoint, consider that utilities are buying desert solar plants with storage, even though it makes the plants cost more!  Solana has 6 hours, Andasol 1 has 7.5 hours, Gemasolar has 15 hours.  One of the motivating factors is that for desert solar plants, adding >5 hours of storage actually contributes to the grid's fixed cost by eliminating a corresponding capacity fossil fuel peaking plant (without storage or a desert location, the peaking plant is still needed, and it's cost is still completely born by ratepayers, but it doesn't run as many hours per year).

The truth about netmetering and grid parity is that grid parity is the point at which all utilities will be forced for petition regulators for an end to netmetering (because otherwise the rapidly growing solar industry be transfering far too much cost from solar haves to the have-nots). The article in Cleantechnica that you linked states that already the California netmetering program is capped at 5% of non-peak system load, and said that the program is schedule'd to end in 2015.

Probably you are too young to remember ratcheted meters.  Before netmetering programs (which were designed to encourage solar rollout, not fairly spread the costs of power), utilities used to install two meters on homes and businesses with on-site power generation.  That let them charge retail prices for electricity taken from the grid, and buy power at much lower wholesale prices when power goes into the grid.  Of course with smart meters, this feature can be activated the day after the regulators approve it.

Even without netmetering, there will be some owners of solar systems that substantially reduce their grid electrical demand, and therefore under-pay for their share of the fixed grid cost.  Ratepayer without solar will need to be protected from them too, so you can expect more utilities to divide customers bills into fixed and variable cost portions (i.e. most of you bill will be a fixed charge, with an extra 6 cent/kWh or so for electricity use).  This will greatly reduce the economic incentive to implement efficiency improvements, and eventually could offset all of the fossil fuel reductions provided by solar

So the truth about solar is that as costs fall, utility solar power with storage could be an important and economical source of electricity in locations with nearby deserts like California, Nevada, and Arizona.  For other locations, the solar choices are: 1) pay a high cost for long distance transmission of desert solar power (e.g. Desertec) or 2) use local solar and lock-in large amounts of fossil fuel backup at a time when climate scientists want us to end CO2 emissions.  Regardless of location, customer-owned rooftop PV solar without storage will cause fairness problems that must be addressed by regulators.

I K's picture
I K on Mar 29, 2013

Good post, so few people understand this fact which applies to about all variable power sources including solar and also wind.
The output is not worth the retail electricity price, nor the wholesale price, but the marginal fuel saving from the marginal coal or gas plant that needs to back off.

However this does not mean solar or wind is useless, it just means they need to produce at a cost equal to or lower than this marginal fuel cost.

In the USA if you use $4.50 / mmbtu for natural gas through a 50% efficient CCGT it means wind/solar need to produce at $30/MWh. In europe with gas at $9.00 / mmbtu they need to produce at $60/MWh or lower.

Even just two years ago I would have laughed at the notion that $60/MWh could be hit with wind or solar. Today im not so sure, I think they possibly can produce at or below $30-60/MWh one day in the not so distant future

That means solar at $657/KWp (20% capacity factor location) or Wind at $1,314/KW (40% capacity factor location) for the USA. Or double those prices for europe (since gas is twice the price here)

Well it seems you guys are already installing wind at a price which is lower than the marginal fuel cost in europe. Wind costs a lot more to install here, not sure why. But solar costs less here and is close to the marginal cost of fuel in europe in sunny locations like spain or south Italy

I K's picture
I K on Mar 29, 2013

Oh also bear in mind that there are situations when the reverse is true, for instance if you live in a state or country where peak loads corresponds to peak sunshine.

Eg heavy air conditioning loads when its hot outside, then solar PV is worth not the marginal fuel cost but the wholesale peak prices because installing say 3GW of solar will allow you to close 2.5GW of your least efficent coal or gas plants

In those cases instead of solar output worth $30/MWhe they would be worth peak wholesale prices which might be double or triple the $30 marginal cost.

Nathan Wilson's picture
Nathan Wilson on Mar 30, 2013

yes, but generally this is only true with a few hours of added storage.  Sunshine peaks at solar noon, demand peaks after work and stays high past sunset.  Without storage, the peaker plant is still needed in the evening so still must amortize all of its fixed cost over the power it sells, but it produces less power.

pyrroho empricus's picture
pyrroho empricus on Mar 29, 2013

It would be nice if even one fact in the piece was even close.

Avg. US retail price of electricity is $.12 per kWh.  without subsidies solar rooftop is around $.25-50 and utility scale is about $.18-.25.  the lower end represents areas with 7 KW daily insolation (roughly 30% of the US with <20% of the population) and the upper where it is around 4.5 KW a day . In Germany it is 4 and the price of solar runs well above $.30 (70% of US with 20% of the population). 

Fossils are subsidized at a rate of around $.002 per kWh.  Solar is subsidized depending on location at mare than $.20 per kWh depending on location.  Anywhere solar is not subsidized there is no solar so the whole idea that solar “makes sense” without subsidies is pure unadulterated fantasy (except Hawaii).

Avg. rooftop install cost 2012 for US was $5 a watt (LBNL).  Avg. utility was $2.5 a watt (LBNL).  Capacity factor for a very good solar resource such as Portugal is around 15% (Smil).  German solar farms run around 8% (Smil).  

Above figures do not include the “truth about solar” because in most cases solar has net metering or some type of FIT so it does not have to include storage.  Solar without storage costs the grid another $.02-.04 per kWh.

Add to all this these are not delivered cost in the case of utility solar.  Rolling in everything utility ex-urban solar would need in storage and transmission to make a dent in fossil would put its price well above $.60 per kWh.

Outside of utility, rooftop solar can contribute according to the San Francisco Net-Zero planning board roughly 100MW technical resource of generation to SF which means it can offset 3% of the current fossil demand.  NYC is less than 1%.  LA is around 3%.

So the max dent solar could ever make is around 20% and the likely dent in fossil is less than 5%.  

Solar is fool’s gold and the opinion in the above article is uninformed and seriously inaccurate.  The author must either be a true believer and prone to ignoring reality or work for a VC that went heavy into solar.  Solar is a waste of time and money that could be better spent elsewhere creating a technology that actually has a shot of working.



Nathaniel Pearre's picture
Nathaniel Pearre on Apr 19, 2013

I suspect those low low number of job creation for coal don’t count all the awesome jobs in the health-care industry for cancer care, lung and heart diseases, etc.

Geoff Russell's picture
Geoff Russell on Mar 29, 2013

Rosana, how do you compare the price of solar with that of any grid based system?  Here’s how I’d do it.

Build two houses, connect one to the grid, note the price.

Install solar on the other until you have an equivalent energy supply both in quantity and reliability, note the price.

We have a term in Australia for people who freeload on services provided by others without making a contribution, it’s called “bludging”. What you call “grid parity”, I call grid bludging. 

But apart from not comparing costs properly, you entirely ignored the environmental costs. Solar on rooftops simply can’t solve our climate problems and solar elsewhere is just the biofuel debacle all over again. Here’s an analysis in the Australian context … but with some mention of one US Solar installation:

Richard Rodriguez's picture
Richard Rodriguez on Mar 29, 2013

Watch for over optimism. When governement intervention is involved eventaully costs rise and so do regulations. Government is dangerous when to much control lies in their hands. Let the matket dictate what price will be and for that matter whether coal is retired and carbon based fuels. Who ever said government’s job was to provide. You people don’t get it..Don’t believe for one minute solar or wind will be cheaper then biomass. Giant King Grass will soon gain serious attention with creating jobs and the cheapest choice to reduce carbon usage.

Rosana Francescato's picture
Rosana Francescato on Mar 29, 2013

Ground-mounted or otherwise, it would be an interesting comparison to make. Of course, prices and policies are changing all the time, so it would be a snapshot in time.

Rosana Francescato's picture
Rosana Francescato on Mar 30, 2013

The government has already intervened for many years by providing generous subsidies for fossil fuels. For the market to dictate the price and whether coal is retired, we’d have to stop all those subsidies. And I agree that biomass is one option we should use in the mix of renewables — along with wind, solar, and others.

Rosana Francescato's picture
Rosana Francescato on Mar 30, 2013

Thanks, Rick! I don’t believe promotion of renewables should be a partisan issue. I like your approach to discussing this with your neighbors. People need to think about how this all affects them, what’s in it for them. In California we saw George Shultz lead the campaign against Prop 23 (which would have suspended AB 32, which sets greenhouse gas emission reduction goals) — for national security reasons. We all breathe the air and drink the water, and we should all be concerned about what’s happening to our planet. 

By the way, I just saw this article: Although I don’t think we should rule out solar in Minnesota, wind may be a better option there. Having grown up in Illinois, I know how it blows in the Midwest!

Appreciate your comment.

Rosana Francescato's picture
Rosana Francescato on Mar 30, 2013

True, you can’t put solar in your car. Unless you drive an electric car and power it with solar. 

Storage is for sure an issue. For now, most people are using the grid for storage, and it will be a while till that becomes an issue. In the meantime, I’m reading every day about advances in storage technologies. And a recent study found that using a mixture of distributed renewables and storage, by 2030 we could power a large electric grid with renewables 99% of the time: 

Solar was the subject of my post, but that doesn’t mean I think we can rely on it alone. I believe we can go far, though, with a mix of disributed renewables.

pyrroho empricus's picture
pyrroho empricus on Mar 31, 2013

great breakdown, Nathan.  Only thing you missed is the added transmission cost for ex-urban utility solar.  With that it is hard to see how utilities would do any of this without the heavy subsidization solar gets.

pyrroho empricus's picture
pyrroho empricus on Mar 31, 2013


The fossil subsidization is larger on an absolute basis, not on a per kWh produced basis which is the metric that matters.  When the subsidies are examined on the per kWh basis fossil is a small fraction of the retail price whereas solar’s is more than the retail price.  Solar is purchased in areas such as CA, MA, NJ, etc. that have both federal and state subsidies and net metering and REC trading.  When you roll up net metering, ITC, PTC, state subsidies,  and SREC trading (which until recently had floors in places like MA of $.28 per kWh, ~2 times the regional avg. retail price) the subsidy for solar is 2-3 times the retail cost from fossils.  In MA when they killed the floor 6 months ago and let solar REC’s trade like wind or geothermal (which is ~$.025) solar installations dropped by 50%.  

To say that removing the miniscule fossil subsidy (less than a 1/10th of a cent) is somehow going to change the market forces in favor of solar just reflects a dangerous lack of knowledge of the actual landscape.  

If GHG reduction relies solely on market forces with all subsidies removed there is not a KW of renewables that would be installed except on islands like Hawaii where they use oil for generation.

The problem is subsidization slows R&D and innovation on new technologies because it supports technologies that are already in the marketplace and removes the investor incentive to create new branches of technologies.  If solar had a real chance of making a difference without causing serious problems for the global economy (try looking at Edenhoffer’s ADAM modeling studies.  provenance should be fine as he was the co-author or SRREN) then I would say “go for it”.  Solar cannot make a serious dent, so spending billions each year on subsidies that could have been spent on researching something that actually would make a dent does not make sense.

This is all assuming you care about GHG ppm rises over the next 20 years.  Right now after a decade of subsidizing the crap out of solar we are on target for 550ppm by 2030 which is very very bad news. If we keep throwing money at subsidizing solar and other first gen renewables we are going to roll into 2030 with a guaranteed temp rise of >2C with all the attendant severe weather effects and a 10-25 meter sea level rise by 2100.  EIther that or we are going to have to scrub the atmosphere. 

Biomass and CCS are the two primary techs in every non-solar funded study on GHG restraint.  Biomass has some serious land-use issues which leaves us with CCS which is getting a very small fraction of the dollars solar is.  

If your worry is climate change you should be against the current subsidization and focus on solar as there is not a single piece of real data out there that shows it is going to make the slightest difference.

If you are invested in solar companies then the above article makes perfect sense. 

Also Chu is a chemist.  He does not seem to ever have bothered to really dig into the physics of power and instead seems to have bought the VC lobbyist’s line on solar rather than do what is best for the country and the world which would have been to pioneer research into viable areas.  Solar’s power density is so low that anyone viewing it dispassionately and logically would eliminate it from the mix. 

Nathaniel Pearre's picture
Nathaniel Pearre on Mar 31, 2013

That’s a bit of a silly cost comparision.

Would you evaluate the cost of nuclear by pricing out a house with its own miniscule nuclear generator?  Solar, like nuclear, big coal, wind, what-have-you, only makes any sense when it’s part of a diverse system that has demand and supply variability diffusion.

Nathaniel Pearre's picture
Nathaniel Pearre on Mar 31, 2013

How can Germany get 4 kWh/m2/day, or 17% insolation.  But only 8% capactiy factor?  You can’t tell me panels in Germany are inoperable more than half the time.

pyrroho empricus's picture
pyrroho empricus on Apr 19, 2013

there is no such metric as n% insolation.  what are you referencing the 17% to?  At atmospheric entry?  insolation varies by latitude so % of what exactly?

anyway the 8% reference the panels’ rated capacity factor.  insolation is the total energy hitting the square meter of land.  Rating is the portion of that the panel can convert at maximum efficiency.  capacity factor is the percentage of energy the panel actually produces on a yearly basis relative to the annual production at the panel rating. 


pyrroho empricus's picture
pyrroho empricus on Apr 19, 2013

this is a coincidence but 4kWh is the 24 hour insolation during which the solar panel does not produce for the 12-14 hours of low or no light.  generally crystalline panels will convert 12-17% during the daylight hours so if you wanted to calculate a daily production based on conversion efficiency instead of capacity factor then you would take ~1/2 of the daily figure and multiply by the conversion factor.



pyrroho empricus's picture
pyrroho empricus on Apr 19, 2013

rooftop is not any better.   actually it is worse.

Nathaniel Pearre's picture
Nathaniel Pearre on Apr 19, 2013

% of the day.  At solar peak on a perfectly clear day about 1 kW of light energy hits the Earth’s surface at noon, per m2 panel oriented perpendicular to the light (a little more at the equator, a little less once you get up to Germany or Canada, but close enough to 1kW).  Thus getting 4 kWh/m2/day in a fixed panel means you’re getting ‘full production’ for 4 hours out of 24, or 17% of the day. 

Nathaniel Pearre's picture
Nathaniel Pearre on Apr 19, 2013

4kWh is the 24 hour insolation”  Right.  Following you.

generally crystalline panels will convert 12-17% during the daylight hours”  Good.  Still with you.

you would take ~1/2 of the daily figure and multiply by the conversion factor.”  What?  Where is the extra 50% loss coming from?  

If 4 kWh/day hits the panel, and it converts it at 12 – 17% efficiency, that m2 panel (rated at ~120-170W) would produce 480 – 680 Wh of electricity, right?  In other words, it produces at its rated capacity for 4 hours of the day, thus it has a 4/24 capacity factor, or 17%.

Nathaniel Pearre's picture
Nathaniel Pearre on Apr 19, 2013

I don’t see how panels can be rated for capacity factor, since the manufacturers don’t know where they will be installed.  Some inexpensive thin-film panels have about an 8% conversion efficiency (rather than 12-17%).  Is that what you mean?

Marcus Pun's picture
Marcus Pun on Sep 6, 2013

Your objections to solar have little merit and BTW, Steven Chu is a physicist. Formerly a professor of physics at Stanford.  Following that a professor of physics and molecular and cellular biology at UC Berkeley  (that’s 2 of the top 3 universities in the world) and dirctor of Lawrence Berkeley Lab, where they do a LOT of energy research and much of the consultation for California’s very successful energy conservation program came from. Oh, and 1997 Nobel prize winner in…….. you guessed it. Physics.

To your other points. Of course solar gets more per KWH because it is relatively new in the commercial sector. In total dollars spent though over the last 50 years,  nuclear is number one, fossil 2nd and renewables last.

While these numbers are not up to date they do represent thistorical flow of money into energy technology. From 2002-2008, fossil fuels received $72.5 billion in federal subsidies while renewable energy received $29 billion. Of this $29 billion, $16.8 billion were given to corn ethanol fuels and only $12.2 billion were given to traditional renewable energies. So non-corn renewables got 1/12th the funding duriing the Bush Administration. BTW, 72 billion is not miniscule.

As for solar standing on it’s own, in California there are rebates but their effect is one time only at purchase and affects ROI by only a couple of years. In California most solar energy falls unter NEM, Net Energy metering where cost avoidance is key.  If you use 6KWH/day and your sytem produces 5KWH/day on average you pay the difference in energy used. There is no special pricing . they even pay for other fees related to grid and other infrastructure. Pricing is based on TOU. Your  argument blows REC out of proportion and conveniently misses this part which is representative of most of California. Typical of larger installations is this example. The Firebaugh-Las Deltas United School District is expected to save more than $900,000 in their systems’ first five years, and that is mostly under NEM except on weekends where I expect some of the surplus is sold. For how much? Peak power from a residential solar system in the program gets 20.7 cents for peak hour production in summer. A dime/kwh part peak and 5.6 cents off peak. Winter you get 6 to 7 cents/kwh. FYI, avg charge for a residential customer is 13.5 cents/kwh . So where you get your numbers from I do not know. Mine are from PG&E’s E-6 tariff schedule. BTW, PGE also dings the producer with all sorts of little fees. 

As far as solar not making  a serious dent? in 2012, with 1GW of solar entering the grid, solar accounted for a mere 0.9% or 2,609GWH of solar energy. Total renewables excluding large hydro accounted for 15% of California’s on the grid energy needs. Not included are many systems that are net metered and supply all their output on site. 8 months into 2013, solar production is 2.5 times that of last year, or 2500MW. Likely the total will come to about 2-3% of state usage for a total of 6000GWH for 2013. It is more than doubling. Meaning in 3 years we could be up to over 10% of the state’s usage and a few years later be well over 25%.

This is PV and CS. Coincidently, MWH scale power storage technologies are coming on line and are now commercially available. Instead of being highly centralized they can be dispersed all over the state to store up local renewable generation or store base load at off peak periods for later use.

Marcus Pun's picture
Marcus Pun on Sep 7, 2013

Solar costs about $2000/KW to install these days. A DIY can do it cheaper as long as the planning dept does not get in the way For a 1KW.let us say that the collector gets roughly 3-5KWH /day.  So let’s say 4KWH. 300 days per year. other days not so much sun. That’s 1200KWH or at California pricing if you count the fees on top  of my energy bill including the nuke decommisioning part, 14 cents/kwh. $168/year saved. 20 year lifetime warranty on the system. 2000/168 = 12 years payback time. For 20 years of operation, I save $3,360 in electicity costs.  So I save over thos e 20 years, minus the cost and assuming no rate increases (HAH!!) $1,160 dollars. So solar ends up not costing me a dime. In fact I get a nickel per KWH over the 20 year lifetime of my system

So what cost are you talking about?

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Thank Rosana for the Post!
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