Geothermal

Geothermal energy is a clean, safe and reliable energy source that has the potential to be generated right in Western Washington. It has the ability to provide constant “baseload” energy from the heat of the earth. Geothermal energy also is an established, well-understood technology that’s improving all the time. It has one of the smallest overall footprints for renewable energy resources.

Why Geothermal?

The PUD is evaluating geothermal energy and other carbon-free resources – including tidal, wind, solar and biomass energy – as part of its effort to meet growing energy needs through conservation and renewable energy. Customers have long supported PUD efforts to include green, carbon-free energy sources in its power supply.

The region offers many opportunities for geothermal energy thanks to the many inactive volcanoes, hot springs, geysers and other geological conditions. If developed, the PUD’s geothermal energy project would be the first in Washington state.

Benefits of Geothermal Energy:

  • Clean, safe , reliable and consistent “baseload” energy
  • Can be generated locally in Western Washington and easily integrated into electrical grid
  • Diversifies power supplies and promotes greater national energy independence
  • Geothermal has one of the smallest overall footprints of any energy source. A 20-megawatt project could provide energy for up to 15,000 customers.
  • Development in the Cascade Mountain region could provide immense value and benefits for the Pacific Northwest as well as advance geothermal technology.

The energy resource also could help utilities meet the requirements under Washington’s renewable portfolio standard.

What’s the current status of the PUD’s research and development?

The PUD is only engaged in exploration currently. It has worked with two independent geothermal consultants to evaluate geothermal feasibility in or around Snohomish County. After drilling a series of test wells, and evaluating sites with consultants, the PUD determined that the site at Garland Mineral Springs was the only one that warranted further exploration. In fall 2011, the utility began drilling a 5,000-foot deep well to establish temperature gradient profile below 700 feet (previous drill depth). The information gathered was valuable for researchers and provided additional experience in geothermal development. However, the temperatures and permeability conditions at this site do not warrant additional exploration. The PUD will be broadening its assessment of geothermal potential beyond Snohomish County. Numerous sites in and around the Cascade Mountains and in Oregon could be considered for additional research.