Much of the electric infrastructure in the US is dated bordering on chewing gum and piano wire constuction relative to current needs. The superstorm Sandy has forced towns and institutions to rethink local infrastructure as waiting for utilities is no longer practical. Combined heat and power - CHP - projects are popping up throughout the Northeast.
Then there are the micro grids within the micro grid, known as "clusters," each connected to several types of electricity generators. These sources, say solar panels and a natural gas generator, are paired together to ensure there will always be electricity. So, when the sun goes down or the wind stops blowing, another power source kicks in. The locations of each cluster will be determined by the power needs in that section of the grid. A cluster containing cogeneration, for instance, might be situated near an apartment building, where the inhabitants use energy day and night, whereas a cluster containing solar panels might be located near an office building, which uses electricity mostly from 9 A.M to 5 P.M.
Each local power source can switch from one grid to the other because it essentially has two sets of wires: one that connects it to PS&G's grid and one that connects it to the micro grid. A power source will never be connected to both grids simultaneously. In fact, the power source must first be disconnected from one grid before it can be connected to the other.
That's no accident. One of PS&G's concerns all along has been power coming into their lines unexpectedly. What if they had a power outage and shut down a section of their grid in order to work on it? If the two grids were connected, power from the micro grid could flow back into PSE&G's lines and blow a transformer—or worse, electrocute a worker. "Their lines will not be attached to our lines," says Ananda Kanapathy, director of electric and gas asset strategy at PSE&G. "Their grid will be separated and isolated from us."
At this time most are supplementary, but there is a chance this may disrupt utilties down the road.