Improved grid and less diesel for Kodiak Island

Kodiak Electric Association's (KEA) aimed at doubling their wind project’s capacity to 9 MW. Given the inherent intermittency of wind power, KEA performed a detailed study to investigate the possible impact that adding 4.5 MW of wind would have on grid reliability. While the hydroelectric facility provided an excellent source of clean energy, it was not responsive enough to maintain grid frequency in the event of a sudden loss of wind power. In order to maintain the same level of reliable power delivery, KEA faced the unfavorable prospect of bringing more diesel generators online to provide frequency regulation and spinning reserves during high wind generating hours.

This additional diesel generation would require curtailing available wind power and consuming more diesel fuel – effectively increasing the cost of delivered energy and diluting the percentage of energy sales from renewable resources.

Not satisfied with the idea of increasing wind capacity only to run more diesel generators, KEA set out to find a more efficient solution. After investigating various technologies and companies, KEA selected Younicos, an energy storage company that was acquired by Aggreko in 2017, to design, build, install, and commission an integrated 3 MW battery-based energy storage system to provide robust and reliable frequency regulation – enabling the full 9 MW green promise of the Pillar Mountain Wind Project to be delivered to its customers.

Since its commissioning in November 2012, the Younicos ESS has successfully responded to over 253,000 frequency events – an average of approximately 165 events per day. This fast-acting, accurate response has helped to avoid multiple potential power losses and in some cases, prevented island-wide blackouts due to sudden drops in grid frequency.

Younicos ESS allows KEA to take full advantage of the 9 MW of wind capacity without increasing diesel fuel consumption. Overall, phase I and phase II of the wind project, coupled with the addition of the ESS has allowed KEA to deliver 114 million kWh of wind energy, and save 8 million gallons of diesel fuel – delivering on its commitment to reliable, affordable and renewable power for its customers.