If it weren’t for electricity, life as we know it in the United States would grind to a halt. But how much do you know about where all the electricity you’re using comes from? In rough numbers, 67 percent of our electricity comes from fossil fuels: coal (33 percent), natural gas (33 percent), and oil (1 percent). The problem with using fossil fuels to produce electricity is that they generate a huge amount of pollution.
Let me give you a quick example. Your neighborhood utility company has to burn about 700 pounds of coal to keep a single 100-watt light bulb lit for a year. (Okay, I know you don’t keep your lightbulbs lit all year without turning them off, but you get the point, right?) Besides keeping the light on, burning that 700 pounds of coal produces five pounds of sulfur dioxide (which causes acid rain) and another five pounds of nitrogen dioxide (which causes smog), according to the non-partisan website howstuffworks. But the biggest problem is the more than 1,800 pounds of carbon dioxide, which is the major culprit behind global warming.
Wait, what? When I first looked at these numbers I thought there was a misprint. How could burning 700 pounds of something generate 1,800 pounds of waste? Well, it’s all about the chemistry. Each molecule of carbon from the burned coal combines with two molecules of oxygen that are already in the air. The result is carbon dioxide—CO2—which weighs something.
Anyway, back to our light bulb. Powering it by burning natural gas would generate far, far less pollution. But there are other problems associated with natural gas production. Hydraulic fracturing (fracking) has released huge reserves of natural gas, but many opponents of the practice say that it’s causing earthquakes and polluting groundwater supplies.
Because of the nasty environmental fallout from fossil-fuel–produced electricity, scientists and entrepreneurs have been frantically experimenting with low-polluting, renewable alternatives, including hydropower, hydrogen fuel cells, wind, geothermal, and solar. Of these, solar is the only one that’s being marketed directly to consumers.
Should you take advantage of one of those enticing offers to install solar panels on your house? The answer is a resounding “maybe.” Let’s take a quick look at some of the pros and cons of solar energy.
The Pros
- It’s everywhere and we aren’t going to run out any time soon. There are very few places on the planet that never see the light of day. According to the U.S. Department of Energy, “more energy from the sun strikes the earth’s surface in one hour than all the energy consumed on the planet in a year.” Best of all, since the sun will be around for another few billion years, we can use as much solar energy as we want without stressing about depriving our grandchildren.
- It’s quiet. Most other methods of producing electricity are pretty noisy. Solar power is nearly silent. And because there are very few moving parts in solar panels, they’re pretty cheap to maintain.
- It can save you money. Solar panels may allow you to produce your own electricity more cheaply than your utility company can. And if you generate more than you use, many municipal utilities are required to purchase the surplus from you.
- The technology is getting better all the time. That means more efficiency and lower costs.
The Cons
- It’s still expensive. Prices for solar panels are a fraction of what they were 10 or 15 years ago, but if it weren’t for rebates, tax credits, and other government incentives, they would still be out of reach for a lot of people. Unfortunately, many of those incentives are being discontinued, thereby making solar more expensive. In addition, some of the minerals and other materials used to manufacture the panels are extremely rare, and since future demand would exhaust world supplies, prices will surely increase.
- It’s intermittent and hard to store. On overcast days, you’re not going to get much from your solar system. And the technology to efficiently and economically store any extra power you capture when the sun is up is still in development.
- It takes up a lot of space. You need a lot of real estate to produce power. Putting panels on the roof doesn’t take much usable space, but we need a lot more acreage than we have on roofs.
- There is still some environmental impact. Capturing solar radiation doesn’t produce much pollution, but the process of manufacturing the actual panels does.