Maui Electric Co. (MECO) has implemented operational improvements to further increase its use of wind energy.
MECO says it is now using about 91% of available wind energy, compared to an estimated 72% prior to making the changes. The increased use of wind energy results in estimated savings of more than $22 per year for a typical Maui, Hawaii residential electric bill. With additional changes, Maui Electric expects to increase the amount of wind energy from roughly 95% to as much as 98%, which could save a typical residential customer another $7 to $10 per year.
To ensure reliable electric service, MECO notes that it uses some of its generators to balance the output from renewable energy sources, such as wind farms and photovoltaic systems. This output varies from moment to moment, depending on a number of factors including wind speeds, wind direction, cloud cover, weather conditions and time of day.
In a report filed with the Hawaii Public Utilities Commission (PUC), MECO laid out its plan to increase its reliance on wind by modifying some of its generator control systems, reducing the use of the four generating units at the Kahului power plan and incorporating a battery energy storage system at the Kaheawa Wind II wind farm.
MECO is also planning to deactivate two of the four generating units at the Kahului power plant in 2014, retire all four Kahului generating units by 2019 and modify the use of generating units at the Maalaea power plant.
The filing also covered other likely options, such as implementing demand response pilot programs, installing a battery energy storage system or beginning measures to shift customer usage to certain time periods, upgrading transmission lines, and implementing Advanced Metering Infrastructure.
MECO's growing use of renewable energy includes wind power, biomass energy from Hawaii's last working sugar plantation, hydroelectric power and energy from photovoltaic systems. As of the end of 2012, 21% of the electricity used by Maui Electric customers came from renewable sources.