News

Enhancement and expansion continuing at San Emidio geothermal plant in Nevada

San Emidio geothermal power plant, Nevada (source: U.S. Geothermal)
Alexander Richter 25 Oct 2017

U.S. Geothermal commences its enhancement program of the San Emidio I geothermal power plant in Nevada, and continued with well testing at its San Emidio II expansion project.

In a release today, U.S. Geothermal provides an update on various activities, including its enhancement program at the San Emidio I geothermal power plant in Nevada, as well as the expansion at San Emidio II.

San Emidio II, Nevada

During September, a 59-hour, multi-well flow test was conducted using three of the recently drilled Southwest Zone wells. Total flow from the wells was approximately 1,590 gpm.  Testing included a step rate program with four-hour increments, whereby one well, then two wells, and finally all three wells were flowed for the 51-hour duration of the test.  Flowing temperature from the three wells ranged from 319°F to 325°F.  Pressure was also monitored on the flowing wells, which experienced pressure drawdown from 7.7 psi to 43.0 psi.  A monitoring well in the Southwest Zone, located 1,700 feet from the nearest flowing well, had a pressure drawdown of 4.3 psi.  Five additional monitoring wells located in the Phase I reservoir area recorded pressure changes of 0.9 psi to 3.2 psi.

These results continue to support the previously announced Probability Power Density model resource estimate of 25.9 megawatts at a 90% probability.  The 50% probability level estimate of 47 megawatts remains unchanged because all of these wells are inside the originally defined Southwest Zone resource area.  Future drilling to expand the resource beyond the currently defined area is planned, but cannot be implemented until the Environmental Assessment for the Phase II power plant development is approved by the BLM.

San Emidio I, Nevada

At our operating San Emidio I project, we are evaluating an enhancement program to increase generation from the power plant.  There is approximately 1 megawatt annual average that remains available under the terms of the PPA at full price, and several more megawatts that could be sold at the excess energy price.  One megawatt at full contract price is worth approximately $800,000 in additional annual revenue and each megawatt of excess energy is worth approximately $425,000.

A permit has been filed with the Bureau of Land Management (BLM) in order to drill a full-sized twin of observation well 25-21 in the Southwest Zone.  The new production well would be connected to the Phase I plant and provide 1,200 to 1,500 gpm of 320°F fluid.  Developing production from the Southwest Zone in 2018 would not only result in an increase in revenue, but would provide a long-term flow test of the Southwest Zone that will be critical to understand its full development potential.

Source: Company release by email