Most people who set up “grid-tied” energy systems for their homes—solar cells and wind generators, mostly—think of the excess energy that they pump back into the grid as pay-back to the utilities, to offset their own energy costs and save them money. But it’s more than that. Grid-tied systems help support the energy grid during stress or peak load periods, often keeping them from failing.
An Earth Techling article describes the current Australian heatwave, which is greatly taxing the power grid in order to keep up with energy demand. The article highlights homes with their own solar cell rooftops, which feed their excess energy back into the grid during these peak-stress periods, and thereby take some of the load off of the struggling network.
The same article points out a number of occasions, during this past January’s record cold spells in the U.S., when privately owned wind generators (windmills) generated enough excess power to dump back into the grid and bolster it during peak load periods of heating homes.
Peak demand periods, such as the dead of summer (or winter) are of great concern to utilities: They have to construct everything with an eye towards handling that load, even though that load is only present less than 5% of their online time. That means larger and more expensive systems. Still, they rarely design for the absolute worst loads, which means that rare 110 degree day might strain their systems beyond their capacity to handle.
Studies in Australia, where a great deal of the country’s power is generated by private residential systems, have shown clearly that the residential power pumped into the grid during peak demand periods helps to ease the demand on the utility networks, lessening the likelihood of a system failure. This means that private power systems not only provide power to their owner’s homes, but they help insure their neighbors’ power will stay up, too.
Considering today’s concerns in places like the U.S. that terrorists may strike at us through our power grids, it would seem to make sense for as many homeowners as possible to generate as much of their own power as they can… essentially decentralizing the power grid for security reasons. Not only would it save them money in the long run, but a loss of grid power would not be as catastrophic; private power sources could continue to provide minimal power until the mains were brought back online.
Also, centralized power systems so backed up do not have to build as heavily to manage peak demand times. That means less infrastructure at less cost, and lower bills to the consumer to support that infrastructure.
All future home construction in the U.S. should take this, essentially a safety and money-saving feature, into account; every roof that is replaced or repaired should be considered a potential place to put up solar cells, and every yard with enough clearance should be considered a place for a wind generator.
Save the planet… save money… save your neighbor. Is there a more noble set of goals?