E3: Is it energy or electricity?

Laur Hesse Fisher: [00:00:00] Hello and welcome to Today I Learned: Climate, this is Laur Hesse Fisher from the MIT Environmental Solutions Initiative. We’re in the middle of our energy and climate series which we’re running in collaboration with the MIT Energy Initiative.

We’ve been talking about how our electric grid works and where we get our energy from in the U.S., and we were just about to dive into a suite of clean energy options… But then… we thought it would be a good idea to take a second, take a breather, and get really clear what we’re talking about when we’re talking about energy.

So here is a mini episode on just that.

In everyday language, we often use energy and electricity interchangeably. But the difference between these two words is actually really important.

Energy is kind of a catch-all term, whereas electricity is a specific form of energy.

So… think of a fire, and think of the flames of a fire as energy. The flames can warm a pot a water for cooking pasta, or they can keep a room warm. Put a pan on top and melt down some metal. You could also boil water to create steam that turns a turbine and generates electricity.

So there are two things at play here. There’s what is being burned to produce the flames -- you know, wood, or coal, or gas -- and then there’s how the heat from the flames are being used -- like to boil water or warm the air.

So you see energy can be generated in a lot of different ways, and be used to do lots of different kinds of things, and making electricity is one of those things.

In fact, only about 40% of the energy that’s used in the U.S. is used to make electricity, which, you know, powers our lights, our computers, our appliances, our air conditioning units. Electricity is typically made in big power plants and then travels over wires to our buildings, like Harvey Michaels explained in our first episode.

So what about the other 60% of the energy that’s used in the U.S.? This isn’t used to produce electricity.

Some of it is used to produce heat for our homes and buildings, and to heat our water. There aren’t really heat power plants because heat is a really hard thing to transfer over a long distance. So instead, typically oil or natural gas is piped into buildings from refineries and burned on site. That’s what water heaters and furnaces do.

A lot of energy is consumed by industry and manufacturing plants, who use it to generate their own electricity or to produce heat to help create products, like paper, steel, plastics, and chemicals.

And about 30% of our energy in the U.S. is used to power our cars, trucks, planes, ships, and other forms of transportation. As John Reilly talked about in our last episode, we fill our tanks with oil [in the form of gasoline or diesel or jet fuel] and our engines burn this oil to power our vehicles.

So we have these big power plants generating electricity and producing CO2; and we have our furnaces and water heaters and cars that are like millions of sources of heat and power and also CO2.

As Harvey Michaels mentioned in our first episode, one strategy to reduce CO2 from energy is to electrify heat and transportation. This would get rid of these millions of sources of CO2... Instead of burning gas to heat water in our homes, we’d all use electric water heaters. Instead of oil to fuel our cars, we’d all have electric cars that we plug into electrical outlets. And then at the same time, we make it so that our electricity is being created in a way that doesn’t produce CO2.

So in the next set of episodes, we’re going to talk about these ways to generate electricity that doesn’t produce CO2. There’s a lot of work being put into areas of our economy that are hard to electrify, like making steel which requires super high temperatures or flying planes that use super powerful jet fuel, both of which would be really hard to get with electricity. But most of our energy use can be electrified, so that’s what we’ll be focusing on.

OK? OK! We’re good to launch into the rest of the season. Stay tuned for next week, where we dig into wind and solar power. And thank you for listening.