Things In A Room

understanding of how many kilowatt hours a solar system will need to support a home. Some houses may use energy more judiciously or only use solar for specific equipment, while others opt for a system that offers a large reserve.

“The goal is to create enough power that you can consume it and maybe have more to spare. The extra will go to the grid — if you’re connected — where you can sell it to your neighbor or the city,” Bell explained.

Homes using solar needn’t be completely reliant on their own energy production. They can use power from the grid, or go off-grid completely with a supplemental generator.

“You don’t interrupt the land when you put in off-grid panels,” Bell suggested.

People typically consume about 80% of the power they produce and are able to sell back about 20%, he said. Owners of solar panels can essentially become private power producers with their excess through net-metering.

City of Fredericksburg Utility Billing Officer Daisy Schneider said for every kilowatt hour given back to the grid, a property owner is given a credit toward their utility bill at a wholesale rate. Compensation differs state to state.

Additionally, although not in the city of Fredericksburg, there is a federal tax rebate which accounts for 30% of solar expenses.

Battery support

When the power goes out due to severe weather or overuse on hot summer days, a typical solar system will go off, as they’re designed to work interactively with the grid. But, with a battery supply, properties maintain a steady stream of power.

“When we build a battery bank, we like to look at days of autonomy. We like to build in at least one day of autonomy, if not two,” Bell said of battery longevity. “We’ve had people go 21 days.”

Wells, septic systems and water tanks can be supplied with battery power. Battery backups, once 20% of Bell’s business, became 80% in recent years.

Batteries’ lifespans depend on their discharge but are about 10 years. New lithium ion batteries can last about 20 or 30 years, Bell said. Solar system inverters — necessary for turning captured energy into electricity — have about a 10-15-year lifespan.

Bell reported that he has managed systems that have been in place since the late ’90s, and said, “I have systems that have been in service for almost 40 years.”

Other than keeping a charge for a battery, maintenance is minimal. Only occasional cleaning may be necessary to remove dust and debris, Bell said.