I’d like to power our home with solar and take us off grid.  Can you help?

Paul Rosen is President of NorthBay Energy Services, Inc. He is a LEED Accredited Professional, licensed general contractor, and building performance consultant to architects, builders, and homeowners. Paul and his family live in a LEED Certified zero energy home they built in Sebastopol, California. He holds a BSE from the University of Michigan in Industrial Engineering and Systems Design.

Question: In the near future, we are planning to renovate, remodel and expand our older home. At that time I would like to install PV cells to power our home and take us off grid. I was hoping to tie onto the grid and sell back any extra kilowatts we do not use, but this being a relatively small area, I may be the first to do it and most do not have knowledge of this idea. I don't think I am searching in the right places or asking the right people. Can you help?

– Wendie Hall, Albertville, AL

Answer: Before buying a solar system, the best practice is to first "reduce, then produce" as I advised in a separate Ask A Pro article here. The relatively inexpensive recommendations in a Home Performance Audit will increase the energy efficiency, comfort, and health of your home, thus enabling you to invest in a more modest and effective photovoltaic system.

After that, take a look at your new reduced utility bills to help decide the size of the PV system you really need. Most homes will do well to aim to produce half to two thirds of their average electric consumption. This assumes that you have a utility grid to which you can remain connected to make up the difference. Check with your local utility company to see what programs are available. Many utility companies allow you to credit the excess electricity you produce during sunny days toward the electricity you need at night and days with insufficient sun. This is commonly known as net metering. The Database of State Incentives for Renewables and Efficiency (DSIRE) provides a list of net metering rules by state.

In general, there are more incentives for grid-tied systems than for off-grid systems, but a grid-tied system means you’ll be without electricity during a blackout or power failure. The only way to be completely independent of the utility grid is to have battery back up, but this is expensive and hard to justify unless you live in remote locations or really must have continuous power.

For more information:

The U.S. Department of Energy also has a details on its website about net metering.

GreenHomeGuide's Ask A Pro archive has answers to dozens of other green home questions from our network of the best and brightest green architects, designers, contractors and consultants across the U.S.