Humanity’s demand for power is now around 16 terawatts. We’ve developed a desire for this high power consumption while ignoring the environmental and climate consequences. The correct energy and climate conversation should be far more nuanced than it is currently.
Humanity needs to choose a climate and temperature change that it can tolerate. On good climate models, you can expect a two-degree increase with some species loss, loss of coral reefs, a few million refugees–but “manageable” if we hit 450ppm. To stabilize at that CO2 concentration in the next 25 years, we’d need to ween our fossil fuel power production down to two or three terawatts, not the current 12-plus of our 16 terawatts. So we need conservation, and 10 or 11 terawatts from other sources.
People are inclined to believe and some industry zealots proselytize that with “green technology” we can have our cake and eat it, too: everyone in the world enjoying levels of energy consumption similar to those in Europe and North America. We need a much more intelligent and discerning conversation that considers the land use implications of massive renewable energy supplies. If we think two steps ahead in that way we realize things such as low efficiency solar cells will use up too much land, as will biofuels. Tidal and wave power is unlikely to ever supply significant amounts of our power. The land area to supply 10 or more terawatts of power to humanity is the size of a small continent, even with the best “green” technologies.
You need mostly solar, a lot of wind. Building 100 square meters of solar panels every second for the next 25 years will get you two of the 10 terawatts. You’ll need 50 square meters of solar thermal mirrors and a full 3MW wind turbine every five minutes. A nuclear plant every week. We can’t afford to make mistakes on low efficiency biofuels. We might have to consider massive carbon sequestration and storage systems. But mostly we have to look harder at the demand side, if for no other reason than to contain the challenge to around 16TW while allowing the rest of the world to increase their proportion of power consumption.
This challenge is serious and difficult. We can’t have reductionist or didactic views that support one or another technology. We need all at massive scale, and we need to choose them carefully and with an eye to high efficiency to minimize land use.
Saul Griffith is co-founder of Squid Labs and Makani Power, and has recently been working on www.wattzon.org.