Simpler Solar Power

Enlarge Image Image Gallery Kristin and Mark Sullivan's super-efficient solar home in Capitola, Calif. Catherine Wanek

Many of us dream of tapping alternative energy sources so we can live “off the grid.” But you don’t need to unplug from the utility grid in order to use solar panels to produce your own power. For most of us, a simpler grid-tied system is a better choice than an off-the-grid setup. Instead of costly batteries, you can use the grid to “store” your excess solar power. In most states, net metering laws require your utility to credit you whenever your system produces more power than you use. This means that when the sun is shining, your electric meter may spin backwards!

What follows is a guide to grid-tied solar systems — the simplest way to switch to renewable energy for your home.

Net Metering

The most important factor in deciding to install a grid-tied solar system is whether your state or area has net metering. Net metering means the utility will trade electricity with you, giving you credit for any excess power your renewable energy system produces for the grid. When your grid-tied system is producing more than you use, the excess power automatically flows back to the grid, literally spinning your electricity meter backward and adding credits to your account. Net metering is so important that you probably don’t want to consider a residential grid-tied system in a location that doesn’t offer it, unless you aren’t concerned with saving money.

If your area doesn’t have net metering, write your state policymakers urging them to change the regulations.

Many states (37 and counting) do offer net metering. Not all locations have the same regulations, though; go to www.dsireusa.org to learn more about net metering policies in your area. This Web site also is a great source for information about renewable energy rebates and other incentives available in your area.

You should pay close attention to your local net metering regulations because they will affect the sizing of your system. Some states calculate net metering monthly, while others figure it annually. Most home solar systems produce a surplus of power in the summer and run a deficit in the winter, so an annual billing period usually is a better deal.

In many states, any net excess electricity credits you accumulate during your billing cycle can be sold to the utility — but usually at a significantly lower price than the retail rate. So it probably wouldn’t be cost-effective to produce more electricity than you use; the goal is to choose a system sized to produce only the power you think you will use in a given net metering period.

Go Without Batteries