Wednesday, 26 September, 2001

Is Local Power Generation Feasible?

Is it still more efficient to have a centralized electric power infrastructure than it is to have each building generate its own electricity?  Until recently, the answer to that question was an unequivocal "Yes."  But today, especially in rural or semi-rural areas, I'm not so sure.  Consider the GE HomeGen system.  This fuel cell runs on natural gas or LPG and is designed to provide 100% of a home's energy needs.  Current systems vent the waste heat, but systems now under development will use the waste heat to heat your water, or for other purposes.  This system is more efficient at extracting energy from the fuel than is a traditional coal- or gas-fired power plant, and doesn't incur the 8% or 10% additional loss from transmitting the power from the generating station to your house.  True, you still need some way to get gas to your house.  Absent a pipeline that means trucking it in, which could be less efficient than power transmission--unless everyone in the neighborhood had one of these things.  Then a weekly neighborhood gas delivery service would make sense and you could keep your tank topped off.

There is still something of a centralized infrastructure in that the trucks delivering the gas have to get it from somewhere, but there could be many of those somewheres, so that a failure at any one wouldn't completely disrupt the entire system.  In addition, with a tank outside your house that holds a month's worth of gas, most people should be able to withstand a week or more interruption in service.  What's more, with a little extra effort it'd be possible to build a neighborhood power distribution system in which those who have excess power could put it "on the grid" in times of emergency.  Think of a smaller-scale version of the power distribution grids that are formed by today's large power plants.  Every house is both a producer and a consumer.  It's an interesting possibility. 

I'm not completely discounting the possibility of solar, mind you, but it has some significant drawbacks.  Solar power generation depends on abundant sunshine and huge storage batteries.  A week or more of cloudy weather can render even the best solar energy system inoperable, and the last time I checked storage batteries of this size involved lots of dangerous chemicals, with the associated environmental hazards throughout their lifetimes from manufacture to disposal.  Solar may be a good supplemental system for non-essential needs like heating a swimming pool or running an outdoor barbecue, but it's not yet practical as a primary power generation system for most applications.