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Green Energy: Top 10 Questions

November 2007

Thanks to Professor Jon Van Gerpen, University of Idaho, and Robert Neilson, Idaho National Laboratory for the answers.

1: Why is it called "green" energy rather than another color like yellow or orange?

Green is the color that many people think of when they think of renewable energy and environmentally-conscious efforts. So people just started calling it "green energy." It reflects the idea that this kind of energy is easier on the environment than traditional energy sources. (From Pedro in Mrs. Whitesell's class at Gooding Elementary)

2: Does ethanol pollute the air more than gasoline?

No, basically it's doesn't. The components that go into the air when you burn ethanol are typically friendlier than the components you burn with regular gasoline. The difference with ethanol is that when you burn ethanol, you do get small concentrations of some chemicals going into the air that you don't typically see with gasoline. Is it a significant enough difference in the pollutants that we should all be using ethanol versus gasoline? Well, gasoline is getting harder and harder to find. But since ethanol comes from growing plants, it is basically a way to convert solar energy into liquid fuels. With ethanol, what carbon dioxide comes out into the air while you're driving your car is about the same as the carbon dioxide that the plant took out of the air while it was growing. Carbon dioxide is a greenhouse gas. Because of climate change, we want to reduce the amount of carbon dioxide introduced in the air. That's why some folks are concerned about ethanol. (From Mikayla from Victory Star School)

3: How much energy does a regular family use in a year?

We use a lot of energy in this country. While we've got 5% of the world's population, we use about 25% of the world's energy. So we use a huge amount of energy in that regard. It is hard to say how much an individual family uses each year, but it is easy to say we all use too much. (From Carly in Post Falls)

4: How big a difference can changing incandescent bulbs to fluorescent bulbs make?

A lot. It uses about one-quarter the energy of an incandescent light bulb. People have talk about how much energy you would save if every house just changed one normal light bulb to one compact fluorescent and the amount saved is huge. Compact fluorescent bulbs also last maybe five or six times longer, so you don't have to change the light bulbs as frequently. (From Joan in Boise)

5: How do electric cars use or save green energy?

Electric cars save energy or are more "green" because they typically don't use gasoline or diesel or other fossil fuels. There are at least three different kinds of cars: those that are pure electrics that just use batteries; those that use hybrid electric engines - vehicles that use batteries and also have small gasoline engines; and vehicles that use fuel cells. Fuel cells are a little different because they typically use hydrogen to generate electricity that generates the power that turns the wheels. There is one thing to remember about electric vehicles. The electricity that you use to recharge the batteries has to come from someplace. In most cases, it comes from the electric socket in your house, which comes from a power plant someplace. To make electric cars are truly "green," we have to make sure that the power plants, which create the electricity to charge the batteries, aren't adding to the energy crisis too. (From Veronica in Mrs. Kerr's Class at Roosevelt Elementary in Boise)

6: How is sunlight converted into green energy?

Sunlight is really the source of most of our energy, either directly or indirectly. Sunlight is what powers the wind and it's a source of energy that plants use to survive. Plants are what we use as sources of energy, either directly when we make ethanol or biodiesel, or when we burn wood, or even when we burn petroleum and natural gas that's coming from fossilized plants and biological material that was laid down millions of years ago. But it's still all originating from the sun. Solar panels convert the sun into energy. Photovoltaic, solar cells, use special materials that create electricity when placed in sunlight. The sun causes electrons to move around in the material. Those electrons then are collected and made into an electric current that can be used to power a light bulb, or a radio or television set. (From Shawn in Mrs. Whitesell's class at Gooding Elementary)

7: Can we run out of energy?

Certainly the energy that we get from dams that produce electricity, what we call hydropower, doesn't usually run out because the water used to turn the generators is replenished every time it rains. But sources of energy like petroleum that we pump out of the ground are another matter. We're not really going to pump out every bit of oil that's down there. It just becomes more and more difficult to find the oil and more and more difficult to pump it out. So if we want to pay $15 a barrel for oil, there may not be very much of that kind of oil left. But if we're willing to pay $90 per barrel for the oil, there's more at that price. And if we have to pay $200 per barrel for the oil, then there's quite a bit of that oil available. So you have to look at how much money you're willing to pay to look for and to find and to pump out the oil and then decide how much oil is actually available for us. You also have to consider the cost to the environment to get the oil and decide if are we willing to pay that cost as well. (From Sara in Mrs. Hunt's class at Cynthia Mann Elementary in Boise)

8: Where would be the best place in Idaho to put a wind farm?

Wind farms are found in areas where you have mountains because typically what you're looking for are places where the wind accelerates as it moves past mountains and mountain ridges. So the Snake River Plain, for example, is an excellent conduit for wind blowing west to east. That's why we have some wind farms in southeast Idaho. They pick up the energy as the wind rises up over the mountains in that part of the state. You don't put a wind farm where there isn't much wind, and since most of us don't like to live in windy spots, most wind farms aren't close to populations. (From Hugo in Mrs. Schweitzer's fourth grade class at Riverside Elementary in Boise)

9: What is the main cause of air pollution?

The main cause of air pollution is typically from the burning of fossil fuels. Typically you're looking at hydrocarbons, carbon monoxide and other things that come from petroleum and coal-based products. Cars, factories, and power plants are some of the main sources of burning fossil fuels. Burning wood can add to pollution levels too. (From Evan in Mrs. Hunt's fourth grade class at Cynthia Mann Elementary in Boise)

10: What is the cheapest form of green energy?

The answer is easy. It's conservation. It's always a lot cheaper to not use energy or use less of it than have to create more energy in the first place. But if you want to know what's the cheapest form of energy that we might use, I might vote for wood. Burning wood, if you can do it cleanly, is actually quite inexpensive. It is also renewable, but does have an environmental cost to consider. One other form we are lucky to have here in Idaho is cheap hydropower. But when you think about it, the reason that hydropower is so cheap is that very large, very expensive dams and hydroelectric plants were built 40 and 50 years ago. Now they're paid off, but they're robust in the sense they can operate for many, many, many years. In the same sense the cost of nuclear power may some day be inexpensive. They may be expensive plants to build today, but they may give you cheap power in years to come. (From Brandon in Filer)


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