If you have an electric car, and you want to try to reduce the greenhouse gases that are created in order to power that car, when should you charge it?
Megan Hall: Welcome to Possibly, where we take on huge problems like the future of our planet and break them down into small questions with unexpected answers. I’m Megan Hall.
Today we’ve got a question from our show’s founder Stephen Porder. Stephen and his family have an electric car, and he wants to try to reduce the greenhouse gases that come from charging that car. So he wants to know, when should he charge it?
We had Nat Hardy and Will Malloy from our Possibly Team look into this.
Nat Hardy: Hi, Megan!
Will Malloy: Hey!
Megan Hall: So actually I’ve got an electric car too, and I’ve been wondering the same thing!
Nat Hardy: Yeah it’s a good question! But first, it’s important to say that driving a fully electric car will always cut down on emissions compared with a gas car.
Will Malloy: But how much your emissions are reduced comes down to where you live, and the time of day you’re charging your car.
Megan Hall: Why does the time of day affect emissions of the electricity we use?
Nat Hardy: Right. So, it’s easy to think of electricity as a consistent source of power. You plug in your car, or run your clothes dryer, and it just works.
Will Malloy: But the truth is, the electric grid is a mix of lots of different energy sources, and the amount of electricity from these sources is constantly changing – throughout the seasons, and by the second!
Nat Hardy: And where your electricity comes from makes a big difference on your emissions! If your car gets charged with electricity entirely from renewable sources like wind and solar power, there are no greenhouse emissions from powering your car!
Megan Hall: But if that electricity came from a fossil fuel source?
Will Malloy: Then there are emissions from creating that electricity – even though the total emissions will still be lower than if you drove a gas car!
Megan Hall: Okay got it. But how can I figure out where my electricity comes from?
Will Malloy: Well lucky for us, there’s someone you can ask!
Nat Hardy: Different parts of the country have their own electric grids, and each grid is managed by an organization called an Independent System Operator, or ISO for short.
Will Malloy: So to figure out where our electricity is coming from here in Rhode Island, we called up ISO New England. Here’s Matt Kakley, a spokesperson for the ISO.
Matt Kakley: Right now, we’re seeing it as about half natural gas, about a third or so nuclear, and then, you know, renewables and imported electricity from neighboring regions. You know, in large part Canadian hydro power.
Nat Hardy: Most of the energy sources Matt mentioned, generate electricity consistently throughout the day. But the exception is New England’s solar panels, which generate power during the middle of the day. So midday is a great time to charge your car in New England.
Megan Hall: But what if you live somewhere else?
Will Malloy: Well luckily you don’t need to call up your local ISO to ask, most ISOs have websites that show you a live feed of where your electricity comes from.
Nat Hardy: And in some parts of the country, things will look different. If you live somewhere that has more wind turbines, like the midwest, they tend to make more energy at night.
Megan Hall: So, charge in the day if your region uses more solar, charge at night, if there’s more wind power?
Nat Hardy: Yeah! But there’s one more thing to consider, and it’s probably the most important thing – the demand for electricity.
Will Malloy: When people use more electricity than normal, our electric grid has to turn to extra sources of energy that can quickly be turned on or off. And those sources are usually fossil fuel plants.
Megan Hall: Which means they’re creating extra greenhouse gas emissions?
Will Malloy: Exactly.
Megan Hall: So, when are these spikes in demand?
Nat Hardy: Matt says-
Matt Kakley: Those fossil fuel units that don’t operate very often are operating on the hottest and coldest days of the year, and they’re doing so during the peak hours of those days.
Megan Hall: When do these peak hours usually happen?
Nat Hardy: It depends on the season. In the winter, electricity demand peaks in the morning before work, and in the evening after work.
Will Malloy: But in the summer electricity use peaks when everyone’s using their ACs, around 5 to 6 pm.
Megan Hall: Okay. That’s a lot of information to juggle. Can you just make it a little easier for me?
Nat Hardy: Sure. No matter where you are in the country, the best thing you can do is to charge your car when people are less likely to be using electricity. During the middle of the day, or at night.
Megan Hall: Great! Thanks, Nat and Will!
That’s it for today.
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Possibly is a co-production of Brown University’s Institute for Environment and Society, Brown’s Climate Solutions Initiative, and the Public’s Radio.
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