Green energy at the grass roots, living off-the-grid of big electric utilities

An estimated 750,000 American households have chosen to live “off the grid,” generating their own electricity through renewable sources. These are the greenest of energy pioneers in the campaign against global warming (for a related story, click here). But their choices also point to a larger issue in the drive to tap noncarbon energy sources: how can electricity from solar and wind best be delivered to consumers who decide to stay on the public utility grid?

Even with progress in renewable energies, the big electric utilities will be around for quite some time. And they will still need to rely on coal, oil, or gas, although perhaps in forms that emit fewer greenhouse gases. But the push for clean energy in many states and in Congress is also running into the need to build some 5,000 miles of transmission lines to carry electricity from the wind-rich Midwest and solar-intense Southwest to heavily populated areas.

This is no easy task. The obstacles could prove to be a bottleneck for the growth of renewables. The taking of land for new lines by governments, for example, could be as big an effort as the construction of the Interstate highway system. Another issue is the cost burden: should consumers pay for new electric lines or the companies that generate power from renewables?

One alternative to erecting new high-voltage lines across America are local, self-contained “green” producers of electricity that are tied together into so-called microgrids. Cities such as Austin, Texas, and Sacramento, Calif., are venturing toward these “home-grown” islands of power. And the US military also plans to have some bases generate their own renewable power.

Microgrids can supplement big utilities, but their main purpose is to improve the reliability of electricity, enhance security from terror attacks, and support green energy as a solution to climate change.

Alas, many public utilities are using their political clout with the states and Washington to continue the reliance on big “base load” generation and long-distance distribution of electricity. Their arguments are often technical, such as the variability of solar and wind.

But microgrids are being helped by better technologies, such as more efficient solar panels and new ways to store electricity in order to overcome the intermittent nature of wind and solar. According to a report from Pike Research, the number of microgrids worldwide will grow from fewer than 100 today to more than 2,000 by 2015, with the United States leading the way.

With other climate-change bills stalled in Congress, the ability to generate local power that won’t add to carbon pollution can’t be ignored.