HAWI, Hawai’i – Down a dirt road on America’s southernmost island, 16 windmills tilt their sleek blades toward the ocean, as dependent on the whims of Hawai’i’s tropical breeze as residents are on the electricity they help produce.
The Hawi wind farm on the Big Island makes clean and affordable energy, but the 100-foot-tall wind turbines stop when the air is still.
Most forms of renewable energy face a similar difficulty nationwide – they’re cleaner than oil and coal but fall short on reliability and convenience.
“Everyone is trying to increase their renewable energy,” said Greg Barbour, lead technician at the Big Island wind farm, which can generate enough electricity for more than 1,200 homes. “Demand for power keeps going up, not down. At some point in time, something will have to be done.”
Hawai’i seems like a perfect candidate for energy independence because its Pacific gusts, ample sunlight and a continuously erupting volcano can be used to make electricity. Its fertile soil also holds potential for biofuel.
But the islands rely on imported fossil fuels more than any other state, with about 90 percent of Hawai’i’s energy sources coming from foreign countries and most of the rest from renewable resources in 2005, according to state data.
By comparison, the United States as a whole imports 30 percent of its energy, with 6 percent from renewables, according to the Energy Information Administration.
During one recent afternoon, the calm trade winds were only strong enough to turn eight of the 16 wind turbines at Hawi, forcing the local electric utility to compensate with other sources to avoid power shortages.
“If the wind stops, that’s a large decline in power that has to be made up for with generating units,” said Jose Dizon, engineering manager for HELCO, the Big Island’s utility company. “We’ll do whatever we can to try to remove our dependence on fossil fuels in a way that’s economic and reliable to our customers.”
In Hawai’i, a law passed last year calls for one-fifth of the state’s energy to come from renewable sources by 2020.
“The utilities are in a tough spot,” said Mike Gresham, vice president of UPC Hawaii Wind Partners, which runs the state’s largest wind farm on Maui, with 20 turbines. “Our community understands the time is now to think about these things, and yet we demand that they keep the lights on.”
The chief challenge is the lack of adequate technology.
If there were better ways to store wind energy, the utilities wouldn’t need significant fossil fuel generators to always stand ready in case the wind dies down. If solar power were more affordable and efficient, it could supplement the grid.
One reliable source of clean energy is the heat deep within the Earth’s crust – the geothermal energy generated by steam that drives a turbine to spin a generator.
The main drawback of geothermal energy nationally is that it’s accessible for power in so few states – mainly Hawai’i, California, Alaska, Oregon, Idaho, Arizona, Nevada and Utah. More than 20 countries worldwide have geothermal facilities.
“We’re really looking to take ourselves off the oil standard,” said Barry Mizumo, a consultant for Puna Geothermal Venture, which contributes 15 percent of the Big Island’s peak power capacity. “Unlike wind, geothermal is just like fossil fuel. We keep on producing.”
Because geothermal energy is stable, it doesn’t create the same hurdles to the electricity utility companies as wind, Mizumo said.
For every megawatt of inconsistent energy the utilities take on, they need that much electric generating capacity in reserve, said Karl Stahlkopf, president of Renewable Hawaii, a subsidiary of Hawaiian Electric Co.
“The problem is there’s no accurate method of forecasting wind,” Stahlkopf said. “You need a storage method that can come in and back that up.”
Solar power faces a similar quandary because the sun sets when customers need power the most, between 5 p.m. and 9 p.m., said Rick Reed, president of the Hawaii Solar Energy Association.
Photovoltaic systems could become far more widespread if there were better ways to save the energy from the sun’s rays for nighttime hours, he said.
Other abundant natural resources for the islands, such as wave energy and biofuels, also hold potential but are far from developed as electricity sources.
Several companies are working on early efforts to harness the power of the tides, and Hawai’i’s electric utilities plan conversions of existing plants to biodiesel fuel by 2009, Stahlkopf said.
Two promising storage technologies could make renewable energies more feasible, Stahlkopf said. Hydroelectric storage uses excess electricity to pump water to a reservoir and then release it when needed to power generators. Also, several companies are working to develop large battery systems that could absorb, save and release electricity.
“In the long-term view, we need to figure out how to store energy being made by these renewable sources so that we have the power when we need it,” said Rep. Hermina Morita, D-14th (Hanalei, Anahola, Kapa’a), chairwoman of the House Energy Committee.
With more renewable energy sources soon becoming available – including a new $200 million Maui wind farm that will power 15,000 homes – it’s unclear how much wind electricity the islands’ isolated utilities can take on, Stahlkopf said.
States on the Mainland are better suited to inconsistent forms of energy because larger electric grids need less stabilization from fossil fuels, he said.
“The potential is huge. We’re not lacking the resources,” said Maurice Kaya, chief technology officer for the Department of Business, Economic Development and Tourism. “There may be technological solutions to this intermittence, but we’re not there yet.”
How quickly these energy sources become more practical and cost-competitive will determine how widely they are used.
Warren Bollmeier, president of Hawaii Renewable Energy Alliance, is not optimistic.
“Some of us like to think that the odds of the sun coming up tomorrow are greater than the next tanker coming in,” he said.
By Mark Niesse
8 April 2007
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