Hillary Clinton has suggested a goal of half a billion solar panels in the United States. The target number, 500 million, was probably selected because it sounds big, but it is less of a stretch than it sounds.
The United States is already installing solar panels at an impressive pace. There are about 75 million already, and there could be 125 million by the end of 2016. That would be already one fourth of the way to the goal Clinton has proposed for 2020.
Prices for solar panels decline every year and the pace of installation picks up accordingly. Based on an extrapolation of the trends, 500 million will occur on its own without policy intervention, if not in 2020, then by 2022. Solar has its limits, but the goal of half a billion does not venture near any practical limit. It might take up the roofs of one eighth of the country’s houses. It will supply about one twentieth of the electricity for the country, not enough to require a large-scale adjustment in the electric grid. The plan falls far short of the ideal of energy independence that occasionally gets mentioned. The cost will be about one week of GDP, not such a large sum of money after you divide it up among millions of owners and investors. It is similar to the previously proposed cost to build one new nuclear power station, a project that has fallen by the wayside in part because it would take 20 years to do. To look at the solar plan another way, at 500 million the number of solar panels will exceed the number of automobiles in the United States, but still fall short of the number of privately owned firearms.
It is not so hard to be a leader in solar power among U.S. presidential candidates. After all, four years ago, one major-party candidate campaigned with a proposal to abolish solar power, calling it a fraud. Of course, that was a losing position, but the winning candidate promised only to “expand” solar power, something that was happening already. If those positions seem timid, it helps to remember that the cost of installed solar capacity has been cut in half since then. It is the price decreases that make solar power so easy to support this year and into the future.