So how do you know what's in the mix?
Take a look at this map. If you live in one of the colored regions, your electricity is sold on a wholesale market regulated by an organization called a regional transmission organization (RTO) or independent system operator (ISO). Distribution utilities like Con Ed often buy their energy through these markets, based on availability and cost.
Still, it's pretty easy to figure out where your energy comes from. Just look up the ISO or RTO website (such as NYISO or CAISO). Usually, these organizations will provide energy supply information in near-real time.
That's exactly what Con Edison (which buys energy on the NYISO marketplace) suggested. As of Friday morning, roughly 40% of the energy on the market place was natural gas or other fossil fuels, 34% was nuclear, and about 22% was hydro.
If you live in another region governed by an ISO or RTO, such as in most of California, you can do the same thing. Like NYISO, CAISO has a dashboard that shows (again, as of Friday morning) about 36% of the energy on the market comes from natural gas and more than 20% comes from renewables.
In the map linked above, you'll notice that some of the ISOs and RTOs like MISO encompass enormous regions. That means that even if you figure out where the energy in your market comes from, it's not going to be geographically specific. But there are a couple of ways to drill down even further.
Use one of these tools to find slightly older, more localized data
The Environmental Protection Agency has a straightforward tool called Power Profiler. You can enter your zip code to see the fuel mix in your area. But it's not perfect. The data are from 2016 and, in some regions of the country like the upper Midwest, they aren't much more localized.
The World Resources Institute also has a tool that allows you to see the electricity mix by state, based on 2017 data from EIA. These numbers represent power generation, not the electricity actually flowing into your sockets, but they offer a rough idea of what energy resources are operating in your state.
What to do if you want to switch to renewables without having to buy new hardware
One option is to check with your utility to see if it has a "green power" offering. Over 600 utilities across the country have one, according to the Climate Reality Project, though they often come at a slightly higher cost. It's typically on the scale of just a few more cents per kilowatt-hour.
There are also independent, consumer-facing companies like Arcadia and Green Mountain Energy that allow you to source renewable energy, by virtually connecting you to community solar projects or purchasing Renewable Energy Certificates, or RECs, on your behalf.
"RECs measure an investment in a clean energy resource," Ratz said, in an email. "The goal of putting that resource on the grid is to push out the need for dirtier resources."
The good news: Even if you do nothing, your energy mix will get cleaner. Coal production has fallen to lows not seen since the 1980s, while renewable electricity generation has doubled since 2008. So whether you like it or not, you'll be roped into the clean energy boom one way or another.