Power to the People

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Moreover, residential fuel cell systems will be sized to not only meet, but beat the peak demands of the average home (most homes generally function in the 1to 2 kW range). Plug Power's 7kW system, for instance, will come equipped with a built-in battery bank giving it a 15kW surge capacity, while American Fuel Cell's 3kW system will incorporate a battery pack allowing it to meet I0kW peak loads. Which means you'll be able to cut ties from the grid—and still run your air conditioner and toast bread at the same time.

And with systems designed to run on natural gas, propane and/or methanol slated for commercialization within the next few years, no matter your fuel of choice, you won't be left in the dark.

Efficiency at Work

Fuel cells are extremely efficient power producers. They create electricity in one simple step, with no moving parts and—at least in the case of PEM fuel cells—at a very low temperature. (Compare this to the combustion process employed by traditional power plants: A fuel is burned at high temperature to create heat, the heat energy is then converted to mechanical energy and that mechanical energy is finally converted into electricity.)

Plug Power's 7kW system will run at about 40% efficiency (a standard being matched virtually industry wide), meaning that four-tenths of the fuel it takes in will be converted to electricity, while the remainder will be converted to heat. Most coal-fired plants are lucky to see efficiencies of 35%—and then they lose another 7% to 8% during transmission across the grid.

Newer, natural gas turbine plants can achieve efficiencies of 40% or more, and some combined-cycle plants can even get up into the 50% range, but again, these plants still have to get that power to your house, and so suffer the attendant transmission losses.

The end result is that, when it comes to producing electricity efficiently, fuel cell systems will top most and match even the best power plants on the grid. But electricity production is only half the picture. The real potential for upping efficiency lies in harnessing the collateral heat and using it, for example, to heat your hot water or part of your house. Once this happens and it will happen according to virtually every fuel cell developer out there efficiencies will reach 85% to 90%.

"When you make electricity, no matter what the method, you always make some heat," notes Acker. "Power plants can't do anything with that heat; it just warms up the Hudson River or whatever happens to be nearby."

Calling this another "huge advantage" to on-site power generation, Acker predicts, "The ability to capture and use the waste heat is what makes it absolutely inevitable that this technology will eventually be better than central generation."

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