Friday, June 10, 2011

Global Solar Capacity Grew 73% in 2010

BP are now including a page on solar power in their big energy spreadsheet, which is a wonderful development.  The above graph shows the overall capacity installed worldwide (in gigawatts of peak capacity at year end).  It's pretty clear who's making all the effort here!

It should be born in mind that the graph shows total capacity, and this needs to get multiplied by what's called the capacity factor to be turned into actual electricity generation.  This is what makes allowance for the fact that solar plants are not generating much electricity when it's cloudy, or the sun is at low angles, and they aren't generating any at night.  I don't have global data for capacity factor, but it's probably in the ballpark of 30%.  Given that there are 8760 hours in the year, this gives about 100 TWhr of solar power generated.  BP also have data for total electricity consumption globally and it's 21325 TWhr in 2010.  So solar is something like 0.5% of total electricity generation.

This is miniscule, of course, but still, it's a lot less miniscule than it was five years ago!  Indeed the rapid growth rates of solar (and wind) are amongst the few hopeful things I see in global energy statistics.  Here are the growth rates in solar capacity:

73% in 2010!  That's awesome.  Over the last decade, the average growth rate is 39%, which corresponds to roughly doubling every two years.  If we were able to continue those growth rates for another decade or two, it would make a real difference.  To give you some idea, if you extrapolate out the growth in percentage of electricity generation for the last decade to 2025, here's what you get:

So by the 2025-2030 timeframe, you are approaching the point where all electricity generation could be solar.  That's how fast solar is growing.  Of course, I stress that this is a scenario, not a forecast.  There are massive barriers to continuing this level of growth, and in particular it implies the ability to either store large amounts of solar electricity overnight, or trade it around the world between the sunny regions and the dark or cloudy regions.  The latter is a lot more feasible, since it can largely be done with existing technology.

To me, that's really the way we should be thinking about climate change.  "How do we pass carbon trading treaties now?" is utterly the wrong question.  The right question is "How do we build a global renewables grid?"

In the meantime, readers who haven't signed up for renewable power are urged to do so!  In the US and Canada, Green-e has helpful information.  Feel free to add other useful resources in comments for international readers (I actually would quite like to create a periodic post summarizing useful resources for consumer renewable options around the world).

Update:  If you don't think rapid growth is going to continue for a while at least, check out what's happening to solar costs via this piece at Grist:


James said...


Typical capacity factors for PV in sunny Colorado are 20 percent, not 30%, and they would be about 15% in Germany.

It is amazing: the Germans have installed more solar PV in each of the last 2 years than Americans have since we invented the stuff in the early 1950s.

Your solar scenario would please me, but obviously each successive doubling gets, from a physical standpoint, more difficult, even as, from an economic standpoint, each watt gets cheaper.

The capacity factors above are for untracked, southfacing PV. Concentrated solar farms would do better, as do tracking arrays, but at a complexity cost.

But low capacity factors are an issue. For example, my local rural coop has a 280 MW peak load, and sells about 1.1 B kwh each year.

80 MW of PV, costing about $400 million, would provide just 10 percent of the energy they need.

Stuart Staniford said...


My assumption is that most solar is in big installations and is tracked. However, even if the right capacity factor answer was 20% rather than 30%, it doesn't materially change the situation - just wait another year.

I see the really big barrier as going from providing supplemental power to help meet peak load in sunny places, which doesn't require a lot of grid, to having sun/wind do everything, which requires a ton of grid.

I don't disagree that growth will slow down at some point, of course. I just think we should do everything possible to keep it from slowing down.

Fixed Carbon said...

Stuart: What is your view of rooftop PV installs? Jacobson and Delucci give rooftop PV a prominent position in a renewable future.

Nick G said...
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Nick G said...

I still have a copy of the 1980 Scientific American article which projected a decline from 30Wp in 1980 to $3Wp in 2010 in a nice exponentially declining curve.

And...that's how it worked out, and even a bit ahead of schedule.

It's a striking example of the predictability of manufacturing cost reduction.

Stephen B. said...

It's just amazing how far ahead Europe is pulling ahead of the US in terms of installed renewable power.

This is even more amazing when one considers that the US enjoys generally much higher insolation levels then does Europe.

Tony said...


In November 2010, The Oil Drum posted an analysis of German solar PV (which would be the largest contributor to European PV), which gave German capacity factors of 0.115 for theoretical maximum, and 0.095 for actual achieved value.

The author, Willem Post, portrayed the German Feed-In-Tariff system as primarily a lucrative investment vehicle for wealthier German homeowners, and of little value for energy generation, carbon reduction, or job creation. Also, because most systems were grid-tied, they would not provide backup power in the event of grid failure. As you might expect, the author’s position was disputed by solar advocate comments.

Here are some excerpts from the article:

“The purpose of this analysis is to show the impact of Photovoltaic (PV) Solar Feed-In-Tariffs (FITs) in Germany. It has the largest installed base of grid-connected PV solar systems in the world, and much data is available about it.

German solar PV in 2009 produced only 1.1% of total German electricity, but issues of grid stability are already being raised, as is the issue of excessive cost.

Prior to 2000 PV solar, FITs did not exist and there were almost no PV solar systems in Germany, because Germany’s annual PV solar capacity factor for true-south-facing, fixed-tilt, correctly-angled systems is about 0.115, which makes it a very poor candidate for unsubsidized PV solar power.

By 31 August, 2010, German households and businesses installed about 700,000 grid-connected PV solar systems with a total capacity of 14,680 MW, because of the subsidies and generous FITs in effect starting in 2000.

The FITs are lucrative for the households and businesses with grid-connected PV solar systems. They get to sell all of their PV solar power to the utilities at generous, but declining, FIT rates for 20 years from date of installation. The average FIT rate was $0.54/kWh in 2009. Households buy power for their own consumption from the utilities at about $0.28/kWh, for a gain of $0.26/kWh. Businesses buy power for their own consumption at $0.20/kWh, for a gain of $0.34/kWh.

In 2009, Germany’s PV solar capacity factor was 6,578 GWh/(7,890 MW x 8,760 hr/yr) = 0.095. The low capacity factor may indicate the PV solar panels are aging, dusty, partially shaded by trees, partially snow-covered, etc., and, as about 80% of the PV solar systems are roof-mounted, many roofs may not be true-south-facing, and the panels may not be correctly angled.

Based on this analysis, it is difficult to justify Germany's decision in 2000 to undertake the PV solar subsidy based on a review of economic, air pollution or global warming considerations. Instead, it is an extremely expensive way to subsidize an industrial sector, create jobs and reduce CO2.

Because of the large gap between the FIT rates and utility electric rates, it is easy for German households and businesses see that a decision to “go solar” makes economic sense, much to the delight of PV solar vendors, financiers and developers who call this (for them) a success. Spain is having a similar disastrous experience with its PV solar FITs. See this article.

If we are to mitigate climate change at a reasonable cost, we must use technologies that provide the greatest reduction in CO2 per dollar invested. As a renewable, PV solar is among the highest in capital cost per installed kW and the lowest in power production and CO2 reduction per dollar invested.”

Stuart Staniford said...


There's no question that solar was not cost competitive in the past, particularly in Germany. The point of subsidies was to increase the size of the market and support further technological development, thus lowering costs. The graphs above suggest this has been working out brilliantly. Now solar is approaching cost parity in some places, and there seems hope that the learning curve will continue (it's been the fastest learning curve of any energy technology for several decades). This will allow it to reach cost parity in more places.

I think the German government has done the entire planet an enormous service in driving this process forward.

Greg said...

The NZ Government has a useful site for householders:

The Energy Efficiency and Conservation Authority, which operates the Energywise site, has other useful info, for example an introductory PDF on micro-generation (PV, hydro, wind) at

But be quick -- the current government is on a cost-cutting binge, and seems to want to keep us firmly in the fossil fuel era, so the EECA may be pruned back.

Tony said...

I hope you’re right about the future potential of solar. I read your Jan 2008 TOD story about world solar power, and was a little unnerved by the terrorist etc security problems for the worldwide network of grid cables, E-W for diurnal sharing, and N-S for annual sharing (summer insolation being 3x winter around here, for example).

Interestingly, the Archdruid has recently advocated the use of simply-built thermoelectric generators down the road, when he thinks the complexity to manufacture PV won’t be available. The TE generators could be powered in daytime by a simple solar concentrator, or at night by direct heat from a stove, say. He recommends PV plus batteries, however, as today’s bridge to TE.

Wikipedia mentions the following combination of PV and TE (unreferenced):

“Solar cells use only the high frequency part of the radiation, while the low frequency heat energy is wasted. Several patents about the use of thermoelectric devices in tandem with solar cells have been filed. The idea is to increase the efficiency of the combined solar/thermoelectric system to convert the solar radiation into useful electricity.”