In the US, 2016 saw a number of major milestones on the power grid, almost all of them in the field of wind energy. Now the Energy Information Administration confirms that this is because of a major overall trend: wind power is now the largest source of renewable energy generation capacity, surpassing hydropower in 2016. And since the two sources produce electricity at nearly the same rate, we’ll soon see wind surpass hydropower in terms of electricity produced.
Wind energy capacity has been growing at an astonishing rate (as shown in the chart above), and 2016 was no exception. As companies scrambled to take advantage of renewable energy tax breaks, the US saw 8.7 Gigawatts of new wind capacity installed in 2016. That is the highest number since 2012, the last time the tax breaks were due to expire. This has pushed the U.S.’s total wind capacity to more than 81 GW, pushing it past hydroelectric power, which has remained relatively stable at about 80 GW.
Note that this is capacity only; since generators cannot run non-stop, they generate only a fraction of the electricity their capacity allows. That fraction, called a capacity factor, is close to 34 percent for U.S. wind, lower than most traditional sources of electricity. But the capacity factor of hydropower is not much better, usually 37-38 percent. As a result, wind doesn’t have to grow much to consistently outpace hydropower.
In fact, that happened for part of 2016. As hydropower began its normal late-summer decline, increased wind production in the early fall made it the largest source of renewable energy in the US for several months. During that time, the wind set some rather dramatic records. On a February night, wind accounted for more than half of the power produced in a region serving several states in the Central Plains. The Texas roster (called ERCOT) also regularly sets new records, with wind penetration reaching 47 and 48 percent last year.
These figures mainly came during periods of low demand, but they do indicate that a well-managed grid can integrate significant amounts of intermittent power.
While wind will inevitably overtake hydropower in terms of electricity produced, 2017 is unlikely to be the year it does. For starters, the tax credit for new wind power will be lower in 2017 as it decreases toward a planned phase-out in 2020. While wind will still be cheaper than any source of generation other than natural gas, the reduced benefits will still change the economy enough to slow down installations.
But the biggest factor is probably the high production of hydropower. After several years of catastrophic drought, California has received so much rain that at least one dam was in danger of failing. This will allow for much higher hydroelectric production late into the summer, and it will increase the overall capacity factor of hydroelectricity. This should be enough to keep hydro power ahead despite the smaller overall capacity.
But since wind can be installed quickly, more cheaply and with a much smaller impact on the environment, the delay is certainly temporary.
List image by Bureau of Ocean Energy Management