Monday, June 13, 2011

Wind and Solar Global Stats

On Friday, I discussed the BP statistics for global solar installations.  Today, I compare that to the wind installation capacity from the same source.   As you can see above, the world has installed significantly more wind than solar capacity.

Before we go further, a reminder that both these sets of numbers are for nameplate capacity, and all renewables suffer from intermittency issues meaning that the fraction of full power they produce, averaged over time, is a lot less than 100%.  Several readers corrected me on Friday that my assumption of solar capacity factor of 30% is probably too high.  I still haven't found any good global statistics, but it does seem likely they are right, and solar capacity factors are probably more like 15-20%.  Wind capacity factors are in the range 20-40%.  So in terms of actual delivered energy, the difference is probably greater than the capacity graph above would suggest.

However, in recent years, solar has been growing much faster:

Wind has been growing in the range 20-35% for 15 years now, and had a not so great 2010 (we've already discussed the collapse of US wind installation last year).  Solar was growing in the same range until the early 2000s, but has lately taken off and had an unbelievable 2010.


Mike Aucott said...

In New Jersey, PV capacity factors average about 15%.

John said...

Even at 20%, 200 GW of Wind is equivalent to 40 average nuclear power stations @ 100%.

I like Google's mantra, RE < C. Renewable energy less than the price of coal. And hence less than the more expensive, public-insured nuclear option.

Tom Gardner said...

There is a recent report analysing the actual energy generated in all the UK's wind farms. This is of interest since the UK has significant potential for wind energy, and since large-scale long-term measurements are much more valuable than sets of presumptions.


To whet your appetite, here are some snippets...

-- text omitted --

This analysis uses publicly available data for a 26 month period between November 2008 and December 2010 and the facts in respect of the above assertions are:
1. Average output from wind was 27.18% of metered capacity in 2009, 21.14% in 2010, and 24.08% between November 2008 and December 2010 inclusive.
2. There were 124 separate occasions from November 2008 till December 2010 when total generation from the windfarms metered by National Grid was less than 20MW. (Average capacity over the period was in excess of 1600MW).
3. The average frequency and duration of a low wind event of 20MW or less between November 2008 and December 2010 was once every 6.38 days for a period of 4.93 hours.
4. At each of the four highest peak demands of 2010 wind output was low being respectively 4.72%, 5.51%, 2.59% and 2.51% of capacity at peak demand.
5. The entire pumped storage hydro capacity in the UK can provide up to 2788MW for only 5 hours then it drops to 1060MW, and finally runs out of water after 22 hours.

have emerged in the course of this analysis in addition to the Principal Findings which
related to the testing of five common assertions. These Other Findings are listed below.
1. During the study period, wind generation was:
• below 20% of capacity more than half the time.
• below 10% of capacity over one third of the time.
• below 2.5% capacity for the equivalent of one day in twelve.
• below 1.25% capacity for the equivalent of just under one day a month.
The discovery that for one third of the time wind output was less than 10% of capacity, and
often significantly less than 10%, was an unexpected result of the analysis.

-- text omitted --

Nick G said...


That report is badly biased. It claims

It challenges five common assertions made regularly by wind industry and the Scottish Government

These are strawmen. Sure, some of them are sometimes asserted, but this presentation is misleading. For instance, the following:

Britain does not cover a large area,

This study mostly just covers Scotland. That's not very large. The example given in Appendix A of an assertion that large geographical coverage is important says the following:

"Extreme lows or highs in wind speed are a natural feature of the UK wind climate; however a diversified wind power system would be less affected
as it is rare that these extreme events affect large areas of the country at the same time."

Note that they don't claim that low output never happens, and more importantly the geographical coverage is the whole UK.