With Denver city and county seeking to reduce energy consumption 30% by 2030, the Denver Housing Authority (DHA) began installing rooftop solar panels on 665 properties in 2005; another 2,335 were eligible, but were ultimately deemed unsuited due to issues of excessive shading, rooftop conditions, or redevelopment plans.
With approval from Xcel Energy, the local utility, the DHA took the next step, establishing the nation’s first housing authority developed, owned, and operated solar garden, a 2 megawatt facility with an array of 5,958 panels. Located on 10 acres in a Denver suburb, it serves some 500 low-income homes.
The solar farm, launched in 2017, is “out of sight, out of mind,” says Chris Jedd, the DHA’s portfolio energy manager. “You don’t have to worry about damage on the roof, or if you want to sell or demolish a building. There is no debt on it, no equipment on it, and it gives a lot more flexibility and optionality within the portfolio.”
In some regions and climates, community solar is not in play and a combination of rooftop solar and natural gas continues to dominate home building and remodeling.
“There is no perfect panacea in one energy source,” said Bill Owens, founder and president of Owens Construction, in Worthington, Ohio, in a recent webinar sponsored by the Propane Education & Research Council (PERC). “It doesn’t make sense to do fully electric for whatever reason. That’s a mandate I just can’t see coming to fruition.”
“A common misconception is that to get to zero energy or zero energy-ready, your homes have to be all-electric," says Bryan Cordill, director of residential and commercial business development at PERC. “The truth is that getting to zero doesn’t mean giving up desirable, high-performing gas systems,” such as those used for cooking and water heating.
Still, in California alone, 42 municipalities have adopted all-electric building codes. With that, the state's Title 24 energy code requires that all new homes must be zero net energy by 2022, essentially mandating the use of solar panels either on individual homes or from community-wide arrays.
In the city of Davis, Calif., “New construction has been getting solar even before the statewide mandate,” says Aaron Nitzkin, who chairs the California city’s solar task force and is founder and CEO of Solar Roof Dynamics.
Denver’s Thrive Home Builders sells homes with rooftop solar arrays as standard, and recently committed to an all-electric option, including cooking appliances, HVAC equipment, and fireplaces to replace those powered by natural gas.
Bill Rectanus, Thrive’s VP of operations, notes “health risks” associated with natural gas, such as leaks that can lead to explosions and worse. Still, he adds, many homebuyers prefer their gas fireplaces and stoves. “You watch any cooking show, they’re all cooking over gas,” he says.
Storm-driven electrical power outages and grid reliability are other deterrents to going all-electric. “Propane generators and appliances that use minimal electricity make homes more resilient and dependable,” Cordill says.
But as solar has grown in popularity, so have backup batteries to guard against power grid reliability problems and to provide power for a few critical systems, such as a refrigerator, heating or cooling equipment, or Wi-Fi and a computer. In fact, part of Thrive’s optional all-electric home package includes backup batteries that collect and store energy from the home's rooftop solar array.
PERC and other fossil fuel industry stakeholders, meanwhile, have been lobbying to curtail local authorities' efforts to reduce emissions and advance solar.
Industry supporters have introduced such measures in Indiana, Kansas, Mississippi, Missouri, Texas, and Utah. Last year four other states—Arizona, Louisiana, Oklahoma, and Tennessee—passed laws preventing localities from adopting zero-emission building codes that essentially ban new natural gas service hookups for new buildings, including homes.
Cordill also points to Colorado builder Andrew Michler’s MARTaK project, the state’s first certified International Passive House. Although electricity is provided solely from photovoltaics, the house relies on a traditional propane water heater to meet its minimal heating and domestic hot water requirements. It also uses propane-fueled kitchen appliances.
But even in progressive communities, expanding solar can be divisive. In Montgomery County, Md., adjoining the District of Columbia, a plan to allow additional solar farms on up to 1,800 acres inside a 93,000-acre agricultural preserve was reduced by more than 70%. Critics argued that more community solar would threaten the prized farmland economy. Advocates noted farmers are paid to lease the land, and animals can graze beneath the solar panels.
The original proposal would have powered 50,000 homes elsewhere in the county, but the measure ultimately adopted by the Montgomery County Council reduced that to 2,000, according to Hans Riemer, an at-large member of the council and a leading proponent of the solar farm initiative in its original form.
Another amendment added more procedural requirements that Riemer said would further hamper solar farms in the reserve. “This is a prohibition,” he says. “Frankly, it’s devastating. If combined with additional restrictions, there’s nothing left.”