Article: Clean Energy from Filthy Water
Author: Jane Braxton Little
Years ago, Calpine Corporation, an energy company, and Santa Rosa became partners in what is now the world's largest geothermal wastewater-to-energy project. In this project, effluent is used to generate clean energy. The Santa Rosa Geysers Recharge Project pumps millions of gallons of water from Santa Rosa through a pipeline to a mountain where it is injected into an underground aquifer. The water is processed in 3 stages: "physical treatment in sedimentation tanks to remove grease, oil and other impurities; biological treatment to break down organic matter and remove nutrients and additional compounds; and sand or activated carbon filtration to remove remaining organic matter and parasites". After that, it is exposed to ultraviolet light to kill any lingering bacteria. Then, hot rocks boil the water into steam. From there, the steam is piped to the surface to electricity-generating turbines to produce clean energy. This is a clean, sustainable way to provide energy in the future; it doesn't release any greenhouse gases or other pollutants into the atmosphere. According to the U.S Department of Energy, this technique could supply 10% or more of the nation's electricity by 2050. The partnerships formed between Calpine, Santa Rosa, and Lake County has solved 3 problems with one solution. Calpine entered the geothermal business in 1989; today the company owns 19 of 21 geyser power plants. By generating 200 megawatts of electricity from wastewater, Santa Rosa and Lake County have effectively reduced greenhouse gas emissions by two billion pounds a year. However, there are some downsides to this technique. Ever since Calpine began injecting effluent into the ground, local residents have experienced an increase in earthquakes; activity at the Geysers increased by 60% since 2003. Most of those cause no damage, but some are still troubled by the planned expansions of Santa Rosa and Lake County; it is speculated that injecting greater volumes of water could trigger a big earthquake.
This technique seems to be the solution to our increasing demand of energy. We wouldn't have to use freshwater for steam-generated electricity, we could just treat our waste. It's a clean and sustainable way to provide energy in the future, and best of all, it doesn't release any greenhouse gases or pollutants in the atmosphere! 2 BILLION pounds of greenhouse gas emissions were reduced in Santa Rosa and Lake County alone; think about what would happen if these geothermal power plants were all around the world. Our waste could be used to make something that is becoming more and more in demand. In addition, the reduction of dumping of effluent into bodies of water would eliminate the need to build new storage and treatment facilities. And there would be more freshwater in streams for fish if wastewater is used instead of drawing out freshwater from tributaries to be used. There are so many benefits to this technique, I think they outweigh the disadvantages. Also, it's not likely that expanded production will increase the amount of earthquakes. An earthquake with a high magnitude would need a major fault, but if these geothermal power plants are only located near geysers, then we're safe since geysers only contain small fractures. We should really consider using this technique around the world. If we do, our future's looking bright.
Author: Jane Braxton Little
- Santa Rosa and Calpine Corporation, an energy company, are partners in the world’s largest geothermal wastewater-to-power project
- Uses effluent (human waste) to generate clean energy, improving life for humans and fish
- Santa Rosa Geysers Recharge Project pumps millions of gallons of water through a pipeline to a mountain where it is injected into an underground aquifer and boiled into steam using hot rocks
- From there, it's piped to the surface to drive electricity-generating turbines
- Generates electricity without discharging any green-house gases or pollutants into the atmosphere
- According to U.S Department of Energy, this technique could supply 10% of our nation's electricity by 2050, or even more
- Extracting steam can trigger small earthquakes/increased ground shaking
- "In 1993 Santa Rosa was facing a cease-and-desist order and the threat of a building moratorium because of the city's illegal wastewater discharges into the Russian River"
- Lake County officials were under a mandate to halt illegal discharges into Clear Lake, California's largest body of freshwater; even when treated to legal standards, wastewater still contained nutrients harmful to aquatic life
- Calpine's production of electricity was depleting the steam faster than it could be replenished; power plants were running out of water and were searching for a source of water to inject into the steam fields and reinvigorate them
- Partnerships formed between Calpine and Lake County and Santa Rosa solved all three problems
- Lake County was the world's first recycled-water-to-electricity, while Santa Rosa is the largest
- John D. Grant built the nation's first geothermal power plant at the Geysers in 1921
- Calpine entered the geothermal business in 1989 and operates 19 of 21 geyser power plants today
- Water processed in 3 stages: "physical treatment in sedimentation tanks to remove grease, oil and other impurities; biological treatment to break down organic matter and remove nutrients and additional compounds; and sand or activated carbon filtration to remove remaining organic matter and parasites"
- Then it is exposed to ultraviolet light to kill any lingering bacteria
- Ever since Calpine began injecting effluent into the ground, local residents have experienced an increase in earthquakes; activity at the Geysers increased by 60% since 2003
- Most earthquakes cause no damage, but some shake items off shelves and even crack building foundations
- Some people are troubled by the expansions planned by Santa Rosa and Lake County; speculate if injecting greater volumes of water could trigger the "big one" (earthquake)
- By generating 200 megawatts of electricity from wastewater, Santa Rosa and Lake County have effectively reduced greenhouse gas emissions by two billion pounds a year
- Stopped dumping effluent into Russian River and Clean Lake, and have eliminated the need to build new storage and treatment facilities
- Since Calpine is using wastewater instead of withdrawing water from Russian River tributaries, there is more freshwater in the streams for fish
- "Treated effluent is a commercially viable alternative to freshwater for steam-generated electricity"
Years ago, Calpine Corporation, an energy company, and Santa Rosa became partners in what is now the world's largest geothermal wastewater-to-energy project. In this project, effluent is used to generate clean energy. The Santa Rosa Geysers Recharge Project pumps millions of gallons of water from Santa Rosa through a pipeline to a mountain where it is injected into an underground aquifer. The water is processed in 3 stages: "physical treatment in sedimentation tanks to remove grease, oil and other impurities; biological treatment to break down organic matter and remove nutrients and additional compounds; and sand or activated carbon filtration to remove remaining organic matter and parasites". After that, it is exposed to ultraviolet light to kill any lingering bacteria. Then, hot rocks boil the water into steam. From there, the steam is piped to the surface to electricity-generating turbines to produce clean energy. This is a clean, sustainable way to provide energy in the future; it doesn't release any greenhouse gases or other pollutants into the atmosphere. According to the U.S Department of Energy, this technique could supply 10% or more of the nation's electricity by 2050. The partnerships formed between Calpine, Santa Rosa, and Lake County has solved 3 problems with one solution. Calpine entered the geothermal business in 1989; today the company owns 19 of 21 geyser power plants. By generating 200 megawatts of electricity from wastewater, Santa Rosa and Lake County have effectively reduced greenhouse gas emissions by two billion pounds a year. However, there are some downsides to this technique. Ever since Calpine began injecting effluent into the ground, local residents have experienced an increase in earthquakes; activity at the Geysers increased by 60% since 2003. Most of those cause no damage, but some are still troubled by the planned expansions of Santa Rosa and Lake County; it is speculated that injecting greater volumes of water could trigger a big earthquake.
This technique seems to be the solution to our increasing demand of energy. We wouldn't have to use freshwater for steam-generated electricity, we could just treat our waste. It's a clean and sustainable way to provide energy in the future, and best of all, it doesn't release any greenhouse gases or pollutants in the atmosphere! 2 BILLION pounds of greenhouse gas emissions were reduced in Santa Rosa and Lake County alone; think about what would happen if these geothermal power plants were all around the world. Our waste could be used to make something that is becoming more and more in demand. In addition, the reduction of dumping of effluent into bodies of water would eliminate the need to build new storage and treatment facilities. And there would be more freshwater in streams for fish if wastewater is used instead of drawing out freshwater from tributaries to be used. There are so many benefits to this technique, I think they outweigh the disadvantages. Also, it's not likely that expanded production will increase the amount of earthquakes. An earthquake with a high magnitude would need a major fault, but if these geothermal power plants are only located near geysers, then we're safe since geysers only contain small fractures. We should really consider using this technique around the world. If we do, our future's looking bright.