Company to aid MECO handling of finicky power
The Maui News
July 18, 2009
By Harry Eagar
You don’t have to tell the windsurfers who flock to Maui that the island is windy. But what’s fun for boardsailers can be a headache for electric grid managers.
GE Global Research announced this week that it will be a contractor in the previously announced project to enhance the ability of Maui Electric Co. to manage increasing volumes of unstable alternative energy. “The real issue is that you have a high penetration wind environment” in the electric utility, says Juan de Bedout, the global technology leader for power conversion systems at GE Global Research in New York.
That means the amount of energy on the island that comes from unstable wind is very high in proportion to the total demand for power – 15 to 30 percent. Whereas Europe, even though it has lots of windmills, still gets a percentage in the “single digits” of its power from wind. Also, in Europe the huge electrical grid connects to vast generators running on stable fossil fuels.
But little Maui is all alone – and can’t connect with a larger grid like Europe. MECO will work with GE Smart Grid to figure out how to merge even more unstable wind (and/or solar) juice into its grid without crashing the system.
In a telephone interview Friday, de Bedout said what GE is bringing to the project is “industrially hardened” technology that has already been used extensively in the United Kingdom. Here, though, it will receive a test it doesn’t usually face. Only places like Maui, the Big Island and Ireland present the same “high penetration” problems for grid managers. “HELCO, MECO and HECO are truly leaders, blazing trails” for this technology, says de Bedout.
Smart Grid uses communications to enhance the ability of a power grid to respond to fluctuations in electricity flow.
It isn’t that grids are not already pretty smart, says de Bedout. In the vast continental grids, widely separated generators using varying technologies “have to maintain a rotor speed that is perfectly synchronized.” Smart technology can do even better, and, in the case of an isolated grid like Maui’s, handle even wilder swings in outputs.
GE will be a contractor in the partnership among MECO, the Hawaii Natural Energy Institute at the University of Hawaii and the U.S. Department of Energy to make unstable green sources more reliable. Most of the $7 million cost will come from the federal government.
MECO gets about 10 percent of its kilowatt hours from the Kaheawa Wind Farm, which can put out 30 megawatts on a good day – or, more likely, night, since that is when the wind blows hardest. The island demand for electricity peaks at around 200 megawatts, so Kaheawa could supply as much as 15 percent of peak demand, and double that at night, when use is down to around 100 MW.
However, an electrical grid cannot handle great fluctuations, at least with conventional controls. The situation is perhaps even more troublesome when Kaheawa is producing at low rates, because then the wind is likely to be fluky and the amount sent out varies beyond the capacity of the grid to manage. Or the wind output can drop to virtually zero in a brief moment.
Thus, MECO sometimes has to run a standby diesel generator to take over instantaneously if the wind fails, which means that the goal of cutting down on petroleum imports doesn’t get met.
GE claims its Smart Grid technology can control peak circuit demand, maintain adequate voltage and integrate intermittent (also called “unfirm”) energy resources. The project also contemplates work on storage systems (batteries or other forms of storage) to even out the flow of electrons.
In an interview in June, MECO President Ed Reinhardt said that the utility would consider using a system that gave even 15 to 30 minutes of backup power when the alternate source failed. That would give MECO enough time to ramp up one of its standby fossil fuel-powered generators.
De Bedout says: “While wind power has been around for some time, relying on a high percentage of wind for day-to-day power generation has been impossible.”
The reason the technology was used first in Britain is that there the regulations for reliability of the distribution system are more stringent than in the United States.