Pollution

For learning purposes we shall split the pollution from geothermal energy into air and water pollution...

Air

The most airborne pollution from geothermal energy is in the form of hydrogen sulfide and carbon dioxide that come from geothermal brine. Luckily in the eighties they started using crystal clarifying technology which captures the hydrogen sulfides and carbon dioxide and puts it back into the geothermal reservoirs. This is a method of cleaning the little pollution there is from geothermal energy. Overall, Geothermal energy prevents 22 tons of carbon dioxide, 200,000 tons of sulfur dioxide, 80,000 tons of nitrogen oxides, and 110,000 tons of particulate matter from getting into the air. Carbon dioxide and nitrogen oxides are huge contributors to the problem of global warming, so this resource is one of the best for our environment. 

Water

Bioaccumulation can happen when the steam extracted from the geothermal reservoirs contain high amounts of boron, arsenic, mercury and lead. If the water is dumped into streams, these elements when eaten by fish, and then bigger fish, and then us, get into our system, and can have drastic health consquences. The USA has regulations that say the geothermal water must be re-injected and reused as opposed to being dumped into streams, therefore eliminating this as a threat.

Thermal pollution occurs when hot water gets into creeks and streams and it can't carry as much dissolved oxygen to the fish. These fish suffocate and die without the oxygen they need to breathe. Once again, we have regulations that require geothermal power plants to return this warm water back into the geothermal reservoirs. This not only keeps water clean, but it makes Geothermal energy one of the most sustainable sources of energy there is!

History

Ancient Times-Hot Springs, Geysers and even Volcanoes have been used for energy for thousands of years
Used for cooking, bathing, heating ect*
1830- In Hot Springs, Arkansas, Asa Thompson charges three dollars for use of hot springs bath, the first commercial use of geothermal energy
1864- Hot Lake Hotel is opened, the first grand scale use of geothermal energy in heating
1904- Geothermal Energy was experimented and pioneered at Lardello thermal field in Italy
1913- 205 kilowatt generator is installed at the site*
1921- John Grant attempts to produce electricity using The Geyers in California
1940- The first use of geothermal heating for residential use begins in Reno
1960- The Geysers, the world’s most developed geothermal plant, begins generating
1970- The Steam Act is passed which regulates geothermal production and allows the federal government to use public lands for geothermal energy production*
1982- Crystallizer clarifying technology is developed and put in place at Salton Sea geothermal plant to control geothermal brine*
1998- Geothermal Energy represents .4% of world’s electricity generation

*Event Featured in Geothermal Through the Ages

See How It Works

http://www.youtube.com/watch?v=kjpp2MQffnw&feature=related

The Basics

There are 2 Main types of Geothermal Energy

1. Conventional

Natural ancient heat from the earth's core comes from friction when continental plates slide over each other, from radioactive elements decomposing and from recent volcanism. 

The groundwater then becomes heated by this heat, but does not turn into steam because of the immense pressure. This extremely hot water travels upwards until it becomes trapped by the earth's crust. 

This hot water can be drilled for much like oil and natural gas is drilled for. Released from the pressure, the water becomes steam in a "flash" process and power a turbine in flash power plants.

A dry steam plant is very similar to the flash power plant except that the water underground i already in the form of steam.

In a binary power plant, the hot water heats another liquid which powers the turbine.

This turbine is connected to a generator, which then is wired to take the electricity to your home.

The leftover water can be re-piped down into the underground reservoirs, where it can be sustainably reused again and again.

2. Hot Dry Rock

Geothermal energy is limited to where geothermal reservoirs are, however, scientists are looking into a way to produce geothermal energy using hot dry rock.

They drill into hot dry rock and then use hydraulic pressure to fracture it, creating a reservoir similar to ones found underground at conventional geothermal plants. 

Similarly, the water is then heated by the rock, becomes steam and spins a turbine connected to a generator to produce electricity.

Currently, technology is not advanced enough to be produced commercially at a reasonable price, but keep checking our blog for the latest news.