For the past 15 years, David Roll has lived off grid in a house in Blue Deer, south of Eureka Springs, that he designed and built into a berm with passive and active solar power. The passive solar design uses large windows to capture heat in the winter and the active solar panels provide electricity.
There have been great improvements in solar technology since Roll started out with four solar panels and some golf cart batteries. Panel prices have come down and battery storage of power has improved greatly. Recently he and his partner, Sherry Young, upgraded their system to replace old lead-acid batteries with saltwater batteries.
“Everything in the solar world has gotten cheaper,” Roll said. “The saltwater batteries are absolutely non-toxic. And you can run them down to zero charge which is a big no-no with the old school lead acid batteries. Those had to be kept charged, and there was a maintenance schedule with all that. We were waiting for the technology to move along and it did.”
The three saltwater batteries are columns three feet tall. Unlike the old lead batteries that have to have a toxic fume vented, it isn’t necessary to vent saltwater batteries.
“They are just beautiful,” Roll said. “These things are awesome.”
Conventional wisdom used to be that air conditioners used too much electricity to make it feasible to run them on solar power. But especially in humid summers, like this one, it’s important to control humidity to prevent the growth of mold.
There have also been improvements in the energy efficiency of air conditioners. Roll and Young recently purchased a mini-split air conditioner that runs on direct current (DC), making it even more energy efficient than the standard alternating-current systems.
“The DC air conditioner is the most efficient you can get,” Roll said. “We have 12 solar panels and it takes three to run the air conditioning. It is not some big, giant system.”
Roll has observed that the climate has been changing; the weather in Northwest Arkansas is different than it used to be.
“The issue that drove us to get air conditioning was the moisture in the house, the mold thing that sets in with this wet and hot weather,” Roll said. “We have to dehumidify now. That is essential. We let our needs drive the next step.”
Roll said for him, investing in solar power was not so much an idealistic choice as it was logical.
“The idealism follows behind,” Roll said. “The logical part is so beautiful. I’m not doing it in a reactive mode, but because of the logic of it and the joy I get from this system. All this time, it’s just a pleasure for me to stay in contact with weather, how much juice we have and what we can do. Someone else might do it because of wanting to help preserve the climate by reduce coal burning for electricity. Everyone has to be motivated in their own way for this solar stuff.”
Most people in the area who have installed solar systems are still on the grid. At times, they may be producing more power than they can use, which is then fed back into the grid. When the systems are not producing enough power for the homeowner, they can get power from the grid.
Roll said he’s sure what holds more people off installing solar is the initial cost.
“Now, if you hang in the game long enough, you could end up with cost savings,” Roll said.
The air conditioner cost about $2,000, and the three panels $1,000.
Roll initially went with solar power because his needs were simple and he had oriented the house perfectly to capture the sun. And while some people might hate not having access to as much power as they want, Roll found learning to live off the grid was a lot of fun.
“It has been very interactive,” Roll said. “There is kind of a formula with solar in terms of what you use and the amount of sun coming down. You are very connective and interactive. I immediately loved that part. In the early days, we might have had to burn candles at night if it had been cloudy a week. The system just grew organically through the years. We decided to add a few more panels because we needed a little more juice.”
They also now have well water pumped with its own solar system.
“The batteries and four panels for the water well are efficient stripped-down models,” Roll said. “All of these are what you would call stripped down models. They are really basic.”
The home also takes advantage of being earth sheltered. The house has a concrete wall on the north side bermed five feet into the hillside. Heat comes from windows and sliding glass doors facing south.
“In the wintertime, we get a huge passive solar gain,” Roll said. “When the sun is out during the winter we don’t have to heat the home until sundown. That is amazing. It is ten degrees outside, the sun is shining and the house is warm. The concrete wall against the back I painted with a sealant, and then put plastic along the outside wall. There are French drains and the area is backfilled with gravel allowing good drainage. That actually turned out to be essential with these big rains coming through.”
They also have water catchment off the metal roof of the house that initially was used as the water source for the home. Now both the well and rainwater catchment are used for the home and their garden.