Highballs are better than lowballs.

[UPDATE: I left something very important out of this post. So when you’re done with it, read this.]

Last month, Michael Noble of Fresh Energy put up a fascinating list of projections made by energy experts around 2000 or so. (I got there via Brad Plumer.) Suffice to say, the projections did not fare well. They were badly wrong, and all in the same direction — they underestimated the growth of renewable energy. It’s worth quoting the whole list:


  • 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 gigawatts 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 gigawatts of solar photovoltaic in China by 2020, but China reached almost double that mark — 900 megawatts — by 2010.

What should we take from this?

Well, mainly that fossil-fuel energy was really cheap in 2000. Oil was about a third the price it is now, coal for electricity about half. That colored those projections. But that’s a boring lesson. Let’s speculate about some others.

Image courtesy of Shutterstock.

The projections weren’t just off, they were way off. You can find similarly poor projections from the ’70s that underestimate the spread of energy efficiency and other demand-side technology solutions. (They thought they were going to need hundreds of nuclear plants. See Alexis Madrigal on this.) Similarly terrible projections were also common in the early years of cell phones.

What do cell phones, energy efficiency, and renewable energy have in common? One, they are dynamic areas of technology development and market competition, which makes straight-line projections pretty useless. And two, they are distributed, with millions of loosely networked people and organizations working on them in parallel. Distributed, human-scale technologies come in small increments. They replicate quickly, so there’s more variation and competitive selection, and thus more evolution.