When used to generate power or move vehicles, fossil fuels kill people. Particulates and ozone resulting from fossil fuel burning cause direct health impacts, while climate change will act indirectly. Regardless of the immediacy, premature deaths and illness prior to death are felt through lost productivity and the cost of treatments.

Typically, you see the financial impacts quantified when the EPA issues new regulations, as the health benefits of limiting pollution typically dwarf the costs of meeting new standards. But some researchers from Lawrence Berkeley National Lab have now done similar calculations—but focusing on the impact of renewable energy. Wind and solar, by displacing fossil fuel use, are acting as a form of pollution control and so should produce similar economic benefits.

Do they ever. The researchers find that, in the US, wind and solar have health and climate benefits of over $100 for every Megawatt-hour produced, for a total of a quarter-trillion dollars in just the last four years. This dwarfs the cost of the electricity they generate and the total of the subsidies they received.

Avoiding damages

The new work, done by Dev Millstein, Eric O'Shaughnessy, and Ryan Wiser, was inspired in part by recent work done on estimating what's called the social cost of carbon. The social cost of carbon is a way to attach a dollar value to every ton of carbon emissions that represent its share of the total damage that will result from global climate impacts. The US government currently uses a value of about $50/tonne, but recent research places it at $185/tonne. Similarly, there has been additional research into the health impacts of SO₂ and nitrogen oxides emitted during the burning of fossil fuels, which produce particulate and ozone pollution.

So, the researchers decided to create new estimates of the benefits of renewable power, taking these updated estimates into account. They also chose to do so in a way that will make it easier to keep their estimates up to date, by focusing on regional-level changes in US electricity generating, rather than waiting for data on individual power plant production, which tends to take a while to gather. (So, the work sacrifices some resolution in order to make data available sooner.)

The basics of the analysis are pretty simple. They started by dividing the 48 contiguous states into 11 regions, as defined by the US Energy Information Agency (you can see a map of them here). Then, they determined whether wind or solar were contributing at least 3 percent of the electricity to each region. One region, centered around Tennessee, was under 3 percent for both wind and solar, so wasn't included; a few of the others fell below 3 percent on wind or solar, so only a single power source was considered there.

From there, the analysis involved finding out how much renewable power was generated within that region. In the absence of wind and solar, that demand would likely have been met using fossil fuels (given the pace of nuclear and hydroelectric construction, this is a very reasonable assumption). A regression analysis was used to match renewable production to alterations in fossil fuel generation, and the fuel that would have been used to meet the demand in the absence of renewables (either coal or natural gas) was assumed to match the existing mix in that region.

Since we have estimates of the climate and health damages caused by both coal and natural gas, it's easy to convert these changes into dollar values. And those values can be viewed as co-benefits to switching to renewables. They don't accrue to anyone involved in operating the plants but instead are enjoyed by society at large in terms of reduced environmental degradation and lower health expenses.