By George Harvey
Most readers of Green Energy Times may know that Green Mountain Power (GMP) has been working to make Rutland the solar capital of the area. Their effort has been extended, however, into the development of microgrids. They are partnering for this effort with NRG, which has developed both equipment and software.
A microgrid is an area with its own generating capacity, capable of supplying itself with power. It typically has some backup power or storage if the generating equipment cannot supply power around the clock. It may consist of a single building, or it could encompass an entire community. It is usually grid-tied, sending excess power to the grid or drawing electricity as needed. It is intended to be independent in the event of general grid failure.
The pilot project is being established in Rutland, but GMP has a clearly-stated intention of establishing microgrids throughout the state of Vermont. There are important implications of this.
Community microgrids make it possible for communities to have their own generating equipment, as they see fit. Generating power locally means keeping local money to cover power costs in the local economy. This can decrease costs because the community owns the equipment and the fuel for solar and wind power is free. Since the generating equipment may pay taxes, it can ease municipal financial burdens. It can also create local jobs.
One very important aspect of a community microgrid is security of the electricity supply. In the even of a grid failure, a microgrid can usually come online more quickly than the grid. If local infrastructure is not damaged, it can come online almost instantly. Without microgrid capabilities, a community would have to wait for the grid to be reestablished, and this can mean delays of weeks, as happened in New Jersey and New York after hurricane Sandy. Also, people who are not in the microgrid system can benefit from it; the initial microgrid in Rutland includes Rutland High School, which is an emergency shelter for the entire community.
GMP and NRG are providing more to customers in the microgrids than just security. Personal energy management is being offered to customers. This makes it possible for a consumer to control household power remotely. Electric vehicle charging stations are also made more possible, as are small multi-purpose generators developed by NRG.
The microgrid being developed also enables demand response, which is almost certain to be very important in the future. In a demand response system, a piece of equipment that uses large amounts of power, such as a water heater, can be programmed to use power when it is available at low cost and not when the price is high. An electric vehicle in a demand response system can even charge at low rates at night and sell power back to the grid during the daytime. In a test of this in Delaware last year, a Tesla made $150 per month just because it was responding to the prices of power, buying low and selling high, automatically as the prices changed.
The initial pilot program should be in operation in 2015.