Friday, June 10, 2011
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: