I'll be posting a series of blogs as I travel for a three-week fellowship through the East-West Center, based in Hawaii. The trip will include a look at what's happening with clean energy in California and China. The first stop is Hawaii, where the particular energy challenges of this island state are driving a push to develop renewable energy.

Hawaii relies heavily on oil (which has to be imported) and as a result electricity prices are roughly two to five times the average price on the mainland. Hawaii is also home to multiple military bases and the headquarters for U.S. Pacific Command, which overseas military operations throughout Asia and the Pacific, over half of the world's total area. Like the state of Hawaii, the military also has special energy needs. In the field, it's reliance on fossil fuels requires expensive and vulnerable supply lines. Its bases also depend on the aging power grid in the U.S., which likewise is vulnerable to attack.

Tomorrow I'll write more about what the state of Hawaii is doing to reduce its use of oil. Today, the focus is on the military, which is planning to reduce its fossil energy use in Hawaii by about 70 percent by 2030 (not including the fuel used by tactical vehicles, like troop transports) through a combination of renewable energy, biofuels and energy efficiency. A lot of what it's doing is conventional stuff, such as installing solar panels and energy analysis of buildings to identify wasted energy.

But it's also doing some unusual things. The U.S. Navy has paid Lockheed Martin $9.32 million to develop Ocean Thermal Energy Conversion (OTEC) technology, which uses temperature differences between warm surface waters and deep, cold water to generate power. (It can use a Rankine cycle that involves a liquid with a low boiling point. Warm sea water boils the liquid, producing steam that drives a turbine to generate electricity. Cold water condenses the coolant to a liquid to be reused.) The idea behind OTEC isn't new, and the potential to generate electricity is vast, but it hasn't been used commercially because it's expensive. It requires costly infrastructure to deliver cold water from the depths, and it doesn't produce much power for the amount of equipment required because the temperature difference between the cold and warm water isn't very much. The hope is that tricks can be found to lower the energy needed to deliver the cold water, lower materials costs, and to make the whole system durable enough to eventually pay for itself. The technology is risky--in addition to its high initial capital costs, the systems are vulnerable to storms. But it's attractive to the military because it could produce power day and night--it's not intermittent like solar and wind.

The military is also investing in solar-powered hydrogen production. This is in part to produce hydrogen for vehicles (either fuel cell cars or internal combustion engines made to burn hydrogen). What's more interesting is the potential of hydrogen as an energy storage medium. A large part of wind power produced in Hawaii is wasted because the power is generated at night, when demand is low, and storing that energy as hydrogen, which can be used to generate electricity when it's needed, could be cheaper (though much less efficient) than using batteries. The military could use solar powered hydrogen generation in the field to power its bases, without the need for supply trucks to deliver diesel for generators.

Both hydrogen energy storage and OTEC are expensive technologies that aren't going to be used for large scale power any time soon. But in investing in these technologies, the military may be performing a very useful service for clean energy. Companies with new energy technologies have a problem. For many other new technologies--better flat screen televisions, say--companies can count on a cadre of early adopters to pay exorbitant prices, which can pave the way for larger scale production to drive down costs. But in general, electricity consumers won't pay much more, if any, for clean energy. Certainly not if the costs are several times that of conventional power. Without the early adopters, solar and wind companies have relied on government mandates and subsidies, but now that those technologies are becoming cheaper, alternatives like OTEC, which have a lot of potential and have the advantage of being more reliable than solar or wind, might not be able to compete, even under the mandates and subsidies (in states with renewable energy mandates, utilities typically turn to solar and wind). The military is stepping in as an early adopter--with immense purchasing power. Of course, it's risky, but the pay off could be big.

GM and The Gas Company, based in Hawaii, have announced an initiative that will provide hydrogen to fuel cell vehicles that the automaker plans to roll out there as soon as 2015.

The Gas Company currently converts waste products from petroleum refining into methane, hydrogen, and some liquid fuels, and pumps these gases around Oahu in a pipeline. About five percent of that gas stream is hydrogen. The new initiative will see the company install devices that can separate that hydrogen at fueling stations, and pump it into the pressurized tanks that store the gas on board GM's vehicles. The devices cost about a quarter as much as installing a new hydrogen fueling station, the company says.

The new approach is meant to address one of the biggest challenges with hydrogen fuel cell vehicles: the lack of widespread infrastructure for refueling. In some ways, Hawaii is the ideal place to start using these vehicles widely, since you only need a couple dozen fueling stations for the whole island of Oahu. The new approach could also be environmentally friendly, especially if The Gas Company follows through with its plans to make hydrogen out of plant and animal oils, and to capture it from landfills.

In another way though, Hawaii makes less sense for hydrogen fuel cell vehicles. Hydrogen fuel cell vehicles are best suited for driving involving high loads, high speeds and long distances, continuous driving. But most people on Oahu live and work and play in an area just 5 miles long and 25 miles wide. That's perfect for electric vehicles, which can be affordable if they only need to store enough energy to trot around a small area.

Electric vehicles can also be more energy efficient than fuel cell vehicles. It's hard to say what's better in this situation, but if the electricity comes from wind turbines on the island, then charging a battery and using that electricity to power a car is probably going to be more efficient than extracting, pressurizing and distributing hydrogen, which also has to be converted it into electricity in the car.

In its 2010 budget, the Obama administration put an end to funding for hydrogen fuel cell vehicle research, but Congress is putting that money back in. In the last two days, the relevant committees in both the House and the Senate have issued their versions of the Department of Energy budget. Both reduce investment in renewable energy compared with the president's budget, and direct money to research into hydrogen programs that the administration deemed too far away from reality to merit funding.

In an interview with Technology Review, Energy Secretary Steven Chu said that hydrogen fuel cell vehicles would require four "miracles" to become practical. Chu supports research into better biofuels and batteries instead.