A Hot Future For Geothermal

[lupercal]

http://www.zerohedge.com/article/guest-pos...ture-geothermal

 

 

Capturing energy from the earth’s heat is pretty easy pickin’s for geologically-active areas of the world like Iceland, Indonesia, and Chile. In some locations, hot fluids are so near the earth’s surface that heat from naturally-occurring hot fluids can be directly circulated through buildings for heating. Iceland, in particular, takes advantage of this low-hanging energy fruit.

 

However, in most areas of the world where geothermal energy is captured, the heat is used to generate electricity.

 

Conventional Geothermal Energy

 

Unlike some of the more common alternative energies — hydro, solar, and wind — geothermal is impervious to weather conditions. This independence means it provides excellent base load electricity.

 

Is Geothermal Economically Viable?

 

A workable technology is one thing, and economic viability is something entirely different. As you can see from the chart below, not all energy sources are created equal when it comes to cost per kilowatt-hour.

 

In terms of production cost, geothermal certainly holds its own at 6.5 cents per kilowatt-hour — about the same as wind. Coal and nuclear power are still powering the way ahead with their 4-5 cent/kWh generation costs, but with natural gas at 7 cents and petroleum topping 10, geothermal has already proven itself to be a viable alternative, not only on the economic front but on the environmental front as well.

 

Given the fact that geothermal energy is only a minor player in the worldwide picture for energy, why are we still bothering with it?

 

Because in terms of economics, geothermal energy trounces solar and wind.

 

Here's what we mean:

 

 

 

1. Geothermal energy does not depend on weather. The sun doesn't shine around the clock or even every day; neither does the wind blow all the time. In contrast, hot rocks are there 24 hours of the day, seven days a week. The predictable amount of electricity makes it easy for geothermal companies to sign long-term energy contracts without worrying as much about underproduction or "wasted" production.
2. Lower capital costs. Even though solar panels have gotten much cheaper to make, the construction costs of a large solar farm are still extremely high. Recent estimates place the cost of solar energy to be upwards of US$10,000 per kilowatt-hour (kW) whereas wind is around $1,700-$3,000/kW. Geothermal is similar to wind at US$1,600-$2,800/kW depending on location, though due to reasons 1 and 3, geothermal is economically superior to solar and wind. In fact, these numbers put geothermal on par with building a coal plant under the new requirements for carbon capture. Geothermal capital costs are relatively low for two reasons. First, there's no need to sequester, or capture and stash, any carbon emissions. This requirement alone can add 40-60% to fossil fuel projects. Second, geothermal power plants enjoy the best of both worlds: they require less land than wind and solar projects, and fewer permits than coal and nuclear because they're less hazardous.
3. Higher load factor. Utility companies, and anybody buying power from them, have to consider load factor: the difference between nameplate capacity (how much the generator is designed to produce) and actual production. The smaller the difference, the higher the load factor, and the more money the utility will make. For a wind farm, the load factor is generally 30-40%, and even lower for solar farms. In contrast, geothermal power plants can generally operate near 90%, since, as we said before, hot rocks are always available.