Wind and solar power are subsidized by just about every major country in the world, either directly or indirectly through tax breaks, mandates, and regulations.
The main rationale for these subsidies is that wind and solar produce, to use the economic term of art, “positive externalities” — benefits to society that are not captured in their market price. Specifically, wind and solar power reduce pollution, which reduces sickness, missed work days, and early deaths. Every wind farm or solar field displaces some other form of power generation (usually coal or natural gas) that would have polluted more.
Subsidies for renewables are meant to remedy this market failure, to make the market value of renewables more accurately reflect their total social value.
This raises an obvious question: Are renewable energy subsidies doing the job? That is to say, are they accurately reflecting the size and nature of the positive externalities?
That turns out to be a devilishly difficult question to answer. Quantifying renewable energy’s health and environmental benefits is super, super complicated. Happily, researchers at the Lawrence Berkeley Lab have just produced the most comprehensive attempt to date. It contains all kinds of food for thought, both in its numbers and its uncertainties.