Microgrids

[Surferbeetle]

During the course of my travels I had an occasion to work in an area where the UNDP had coordinated an electrical grid in which each house was limited to ~20 amps. This allowed for 24/7 power for all, but it of course limited the amount of electrical devices that could be run at one time in each household. A trip out to your residential panel in America, for a reference point, will typically reveal a ‘load center’ from 100 to 400 amp in size.

The 2007 RSMeans Facilities Construction Data provides bare material costs of $162 for an indoor 100 amp, 8 circuit residential load center and $1,150 for an indoor 400 amp, 42 circuit residential load center. Commerical 20 amp panels begin at $455.

Lowes does not list prices, but they do provide pictures of load centers.

Lawrence Berkley National Laboratory has been thinking about microgrids.

Instead of relying solely on large power plants, a portion of the nation's electricity needs could be met by small generators such as ordinary reciprocating engines, microturbines, fuel cells, and photovoltaic systems. A small network of these generators, each of which typically produce no more than 500 kilowatts, would provide reliable power to anything from a postal sorting facility to a neighborhood.

The May 2008 Edition of Popular Mechanics has an informative graphic on microgrids.

Microgrids will be small areas—like the residential and industrial neighborhoods shown here—where energy needs are roughly matched by local generation. A control station will juggle demand, buying and selling power to the main grid. During a regional blackout, a microgrid can run in “islanded” mode.

This was typical of what I observed in Iraq: