Paisley Geothermal Project
Geothermal Boosts Our Energy Future
By: Lynn Culp
Surprise Valley Electric Member Service Manager
In Southern Oregon and North Eastern California we have energy waiting to be tapped into, energy found in water that is heated deep within the earth.
Over the past four years Surprise Valley Electric has been developing a geothermal power plant in Paisley, Oregon. In 1980 the Colahan Ranch in Paisley, Oregon drilled an irrigation well that intersected a fault. The result was hot water. Since 1981 the Colahans have used this water for irrigation a couple months of the year, but they always believed there were other uses for this water.
After completing a feasibility study in 2008, the Colahans, who are long time Surprise Valley Electric members, came to us to see if we wanted to develop the resource to produce electricity.
Our basic decision to develop the project was to sell this valuable renewable energy on the market for a number of years, and then when we need it, bring it back for our own members use to offset or reduce Tier 2 energy costs.
In 2009 we conducted a flow test on the existing irrigation well and began work on a number of resource studies to better understand the geology and the reservoir and determine the best options for development.
Along the way we received two major financial incentives. The US Dept of Energy is providing $2 million in American Recovery Act grant funds and the Oregon Dept of Energy has approved the project for a Business Energy Tax Credit for a value of up to $5 million. We have also been approved to convert a Cooperative Finance Corporation loan to clean Renewable Energy Bonds in the range of 1.25 percent. These funding sources have been invaluable to making this project a reality.
Our project consists of three geothermal wells which we drilled over the past couple years. Two of the wells will be used as production wells and the third for an injection well.
Well 1 is located at the base of a front range near the existing hot irrigation well and along a known fault. The goal was to intersect the fault at a deeper zone than the irrigation well to get hotter and more water for a production well. A second well drilled as the injection well.
When performing the first flow tests on Well 1, we discovered that it did not produce as much water or was as hot as projected. The flow test on Well 2 showed it produced more than twice the volume of water as Well 1 and is nearly as hot.
With two possible production wells we then decided to drill a third well for injection. Well 3 was completed this past August and it too produces a good flow of moderately hot water and will be an excellent injection well for the geothermal brine from the other two wells.
We are now in the process of designing and soon constructing the power plant, gathering system and transmission system for the project. The power plant is a binary system that uses an organic working fluid to capture the heat energy from the geothermal fluid. The geothermal fluid stays in a closed loop never leaving the piping system. Heat energy from the geothermal fluid causes the working fluid to vaporize and turn the turbine and generate electricity. The geothermal fluid is then injected back into the reservoir and the working fluid is condensed through a cooling tower and cycled back through the system.
Our plant will come online in the fall of 2013 and will produce 3MW of renewable, base load power. One of the benefits of geothermal energy is that it is available 24 hours a day, 365 days per year. Another benefit is that the spent geothermal fluid that comes out of the power plant still contains heat energy that can be used for other purposes. Some of the additional uses that are being investigated for our project are aquaculture, green house farming and district heating. The City of Paisley (250 population) is a small rural community that will benefit from any of this development.
We believe there are many opportunities within our service territory to develop energy sources to produce electricity. These are not easy projects, as we have said to ourselves as we have struggled along, “if it was easy, everyone would be doing it”, but the end result will benefit our members for years and even generations to come.
There are a numerous energy development opportunities throughout all of our service territories, some of them right beneath our feet.