Executives in the solar industry say they are seeing an increased demand for solar power from homeowners.

However, it’s still a relatively expensive endeavor, and in some cases homeowner associations and the presence of tall trees can prevent some owners from utilizing solar energy, according to the Charlotte Business Journal.

Many are opting for solar water heaters, which are the most economical, as nearly a quarter of a home’s energy costs go to heat water.

A typical solar water-heating system for a single-family home consists of two 4-foot by 10-foot panels mounted on the roof. The panels are connected to a 40- or 80-gallon tank, where the heated water is stored. The average cost for a residential system is between $6,500 and $7,000, says Jon Goode, the Charlotte operations director for Southern Energy Management.

Goode says his company is installing systems just about every day in Raleigh, N.C., and that things are picking up in Charlotte.

“Solar thermal has been a huge growth market,” says Erik Lensch, president and co-founder of Argand Energy Solutions, which installs solar systems for commercial, government and residential customers. “There’s been some interest in PV systems, but because the price point is higher, it hasn’t taken off in the Charlotte area.”

Lensch says the increase in demand for solar energy comes mostly from homeowners, not builders. But that’s likely to change — earlier this year, the National Association of Home Builders announced a green-home certification program that includes solar options.