Rooftop solar array powers hilltop home, electric cars of Fayetteville entrepreneur

Entrepreneur and environmentalist Terry Tremwel, board chairman of solar technology startup Picasolar Inc. and energy consulting firm Trem|Wel Energy LLC, has used less electricity at his three-level, 2,750-square-foot home than his rooftop solar panels have generated over the past two years. And he charges two electric vehicles, a Chevrolet Volt and a Tesla Model 3, as the home has charging stations for six electric vehicles.

Tremwel, who teaches sustainability in business at the University of Arkansas, said the home’s 14.82-kilowatt solar system has generated 38.4-megawatt hours of electricity since he and his wife, Margaret, moved into the home. As a result, the energy savings have been about $3,840 so far under a 20-year net metering agreement with utility Southwestern Electric Power Co. (SWEPCO). Including a more than $10,000 federal tax credit, the payback period should be about 13 years on the nearly $35,000 system, comprising 52 Yingli solar panels and two 7.6-kilowatt SolarEdge inverters with optimizers on each module. The roof has the capacity for 18 more modules, and since he purchased the system in late 2016, costs have declined from 72.4 cents per watt to nearly 51 cents per watt.

Tremwel’s electric bill for February shows usage of 0-kilowatt hours for the past 12 months, and the only charges are an $8 monthly customer charge and taxes. He considers his home to be net zero plus, with the plus being that he charges his electric vehicles using the generated electricity.

He explained his fuel costs per mile to be about 3 cents for the Tesla, which is charged by the solar system, and by comparison, the fuel cost per mile is 7.33 cents for a vehicle with a fuel economy of 30 miles per gallon, based on fuel costs of $2.20 per gallon.

Tremwel’s price will be stable over the 20-year net metering agreement as opposed to the frequent price fluctuations in gasoline or diesel. Also, he said electric vehicles have zero tailpipe emissions because they don’t have a tailpipe, and maintenance costs are low because they don’t require oil changes and use battery regeneration, reducing wear on brakes.

Tremwel most enjoys the view overlooking downtown Fayetteville and the UA from his home on Mount Sequoyah, the highest point in the city. The home was completed about two years ago after nearly $1 million worth of work, including the purchase and demolition of a former home and the construction of the new home at the 0.33-acre site, south of the overlook with the cross.