How Solar Works in Homes

Lighting and heating homes with solar

by Wanda Jenifer
American University Interactive Journalism Program
Fall 2007

Photo by Wanda Jenifer
Jeff Gilbert teaches solar energy
classes at the Green Building Institute.

HOWARD COUNTY, MD. – The 2007 Solar Decathlon is well underway on the National Mall and everyone is talking about solar energy. The sun’s energy—a natural resource—is, now more than ever before, being used to heat and light our homes.Solar energy system designer and installer, Jeff Gilbert, Chesapeake Solar Chief Technical Officer says there are two types of solar energy systems we can use, solar thermal and solar electric.

Solar thermal collectors use solar energy to make hot water to heat the home. The panels are connected through “insulated pipes that have a mixture called glycol flowing through them that converts the sun’s energy to hot water for home heat.” Gilbert said.

Solar electric panels use solar energy to make electricity. The panels are wired from the roof to inside the house where they are connected to an inverter.

Photo by Wanda Jenifer
Meters measure temperature and
regulate pumps for hot water.

“The wires bring the electricity from the solar panel down to the inverter box. This inverter changes the direct current electricity, which the solar panels make and turns it into the kind of electricity that you would get from a regular wall socket, AC.” Gilbert said.To produce all of your solar electric needs, Gilbert said, “You would probably need about a 10kW solar system–a ten thousand watt system.” “It’s not very practical,” he said.

A common solar system for a homeowner is a 3kW system. Energy cost savings will vary according to customer usage, but after the initial cost of installation the energy source, the sun, will not cost anything.

According to Gilbert a 3kW solar system will require about 18 solar panels and an inverter box. This system typically cost around $25,000, he said.

To make solar energy use more affordable tax credits and incentives are available from federal, state and local governments.

In Howard County, there are three incentives to take advantage of, Gilbert said. “At first you’ll apply for a grant from the State of Maryland, and once it’s approved and you submit the paperwork you will get a check for up to $3,000.”

The two others are a federal and personal property solar energy tax credit that can total up to $10,000. Gilbert said, “Solar energy can be one of the best home improvement investments you make.” Because as energy cost continues to rise, you’re solar energy cost will not.

For a comprehensive list of solar energy incentive programs visit the state incentives for renewables and efficiency database.

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