From the Fresh Energy blog and a good reminder that most experts have trouble thinking exponentially.
- In 2000, the International Energy Agency (IEA) published its World Energy Outlook, predicting that non-hydro renewable energy would comprise 3 percent of global energy by 2020. That benchmark was reached in 2008.
- In 2000, IEA projected that there would be 30 gigawatts of wind power worldwide by 2010, but the estimate was off by a factor of 7. Wind power produced 200 gigawatts in 2010, an investment of approximately $400 billion.
- In 1999, the U.S. Department of Energy estimated that total U.S. wind power capacity could reach 10 gigawatts by 2010. The country reached that amount in 2006 and quadrupled between 2006 and 2010.
- In 2000, the European Wind Energy Association predicted Europe would have 50 gigawatts of wind by 2010 and boosted that estimate to 75 two years later. Actually, 84 gigawatts of wind power were feeding into the European electric grid by 2012.
- In 2000, IEA estimated that China would have 2 gigwatts of wind power installed by 2010. China reached 45 gigawatts by the end of 2010. The IEA projected that China wind power in 2020 would be 3.7 gigawatts, but most projections now exceed 150 gigawatts, or 40 times more.
- In 2000, total installed global photovoltaic solar capacity was 1.5 gigawatts, and most of it was off-the-grid, like solar on NASA satellites or on cabins in the mountains or woods.
- In 2002, a top industry analyst predicted an additional 1 gigawatt annual market by 2010. The annual market in 2010 was 17 times that at 17 gigawatts.
- In 1996, the World Bank estimated 0.5 gigwatts of solar photovoltaic in China by 2020, but China reached almost double that mark—900 megawatts by 2010.