Nestled in the mountains of Las Sendas in east Mesa, a builder and buyer are collaborating on an 18,000-square-foot home that will be one of the largest in the Valley to rely almost exclusively on solar energy.

Built with a panoramic view of the Valley, the $4 million home is located at the Peaks, a multimillion-dollar neighborhood.

The custom home is expected to be finished by summer and will include nearly 140 solar panels that will provide 70 percent of the home's power. The panels will be recessed into the roof so they do not distract from the design, a concern for some homeowners.

"Almost every home we've done over the past two years relies on solar electricity," said Tom Fitzgerald, who owns Belmont Homes in Mesa.

His company has built six homes, averaging $3 million, and he now is tapping into the solar business with a new company called Solar Energy of Arizona, a solar installation and consulting business for residential and commercial properties.

Chen Liu, who is buying the four-bedroom mansion with a guesthouse, could potentially become Salt River Project's largest residential applicant to benefit from the utility company's EarthWise Solar Incentive Program, said Chico Hunter, an SRP engineer.

"Having customers like this is an example of how our program is encouraging the local solar industry and helping our customers who do solar," he said.

The Liu home will be powered by a 20.16-kilowatt system. Currently, the largest home that SRP services is a 20.08-kilowatt system in Florence, Hunter said. Most homes with a solar system have a capacity of 4 to 9 kilowatts.

Hunter said if a customer needs more energy than is produced from the solar system, he or she can purchase additional energy from SRP. But whatever energy that's not used can be sold back to SRP or used as credit toward the next billing cycle.

Liu's home could potentially become self-sufficient.

Installing solar panels on roofs is not new, but looking for ways to be energy-efficient has become popular.

"It's growing very quickly, especially here in the Southwest because of how much sun we have," said Greg Pitz, a Tempe-based solar architect hired to design the system.

To purchase and install a solar system is costly and could start at $28,000 for a 4-kilowatt system, depending on the usage and size of the home, Hunter said.

Liu, who is buying the home, is looking to receive an estimated $120,000 in local and federal incentives for installing the solar system.

He also is considering using geothermal energy to heat the home's pool.

This will be the second home in Las Sendas for the Liu family, which includes his wife and two children.

Building an energy-efficient home is a natural step for him, considering his line of work, Liu said. He runs Sunrise Lighting in Gilbert, an 11-year-old company that manufactures and distributes compact fluorescent light bulbs, which can save up to 75 percent of energy use.

"So anything related to energy savings, I'm interested," Liu said.