As the joint venture team constructs the new diesel and natural gas power plant, Mick Wasco, Marine Corps Air Station Miramar energy program manager, sheds some light on how this power plant will support the microgrid once operational. The steel erection for the power plant is scheduled for completion in March. Construction of the power plant is scheduled for completion in September 2018.
How did the project team decide the size of the backup generators for the microgrid?
The generators at the power plant are sized to cover critical loads in the case the microgrid’s renewable energy sources are not available. The diverse fuel and engines are in place to ensure that the generators can manage the critical loads.
What is the cost of energy and demand to utilize diesel as an economic alternative?
The microgrid control system has algorithms that will constantly analyze the costs and savings in order to dispatch generation. The usage of diesel to back up the landfill power plant is only a concept and the true operation of the microgrid may only use the natural gas to provide that support economically.
Demand charges can be around $13/kW per month, so if the landfill power drops offline during a peak period that is 3200 kW x $13 = $41,600 in one month. The cost of fuel can vary greatly, and the price of fuel and time to cover the load would be a factor in the design to run the generation to mitigate the peak. In the future, the microgrid will use energy storage to mitigate this issue.
What does the break-even point look like for converting diesel generators to natural gas in conjunction with establishing a microgrid?
Several factors drive these choices: air quality controls permitting (desired vs allowable run-time), availability and reliability of natural gas or diesel fuels, and evaluating their cost differences over time.