Battery or Generator?
"Horrorshow.” That’s how one co-op member described the scene in his freezer when he returned home from a two-week summer vacation. He didn’t know it, but a storm struck during his time away, causing an extended power outage.
“When I stepped into the house, the first thing I noticed was an odd smell, like something was off,” John Seidenberger says.
Tracing the odor to his refrigerator-freezer, he reluctantly opened the door—and gagged. Blood puddled around his stockpile of once frozen game. Parasites, found naturally in unprocessed meats, swarmed the rancid mess.
Thankfully, most power outage experiences aren’t so horrific, but they can be bone-chilling, sometimes sweltering, and always inconvenient. In a state averaging 45 to 60 thunderstorms a year, and some 151 ice storms in the past 10 years, most Oklahomans have an outage story. While the discomfort of losing power is temporary, it is prompting a growing number of homeowners to consider a secondary power source.
Typically, an off-grid system capable of running everything in your home would include a propane, natural gas, or diesel-fueled generator that kicks on automatically after your home loses power. But as the price of solar panels plunges and battery storage technology improves, more consumers find the idea of a clean, renewable system appealing. Adding to the allure, a 2019 ruling by the Oklahoma Corporation Commission helps consumers recoup a small part of their investment by requiring regulated utilities to buy their excess power at the going wholesale rate.
So, which system is best for you? It depends.
“There’s an education process going on with both types of systems. Both come with advantages and disadvantages, and neither option is cheap,” says Gary Roulet, CEO of Western Farmers Electric Cooperative (WFEC). The generation and transmission (G&T) co-op has the fifth-lowest wholesale power rates of any G&T in the nation, thanks in part to its investment in zero-carbon generating sources, including long-term purchase agreements for 957MW of wind and 53MW of solar, currently in commercial operation. Another 570 MW of solar is expected to come online in 2023.
Due to the sizable upfront costs for battery or generator backup for the home, Roulet says it pays to do your research before buying. Needs, expectations and budget should weigh carefully in your decision. Be sure to get multiple bids and visit with neighbors with similar systems. Above all, talk to your cooperative energy adviser before making a decision.
At his home near Newcastle, Roulet relies on a 30kW generator for backup power. The system cost roughly $20,000. Since 2018, he has used it once. Is it worth it?
“Depends on when you ask the question,” Roulet says, laughing. “If you ask me when the power is off, I’d probably say yes.”
Generating Peace of Mind
When an ice storm hammered southwest Oklahoma in 2010, Binger-based CKenergy Electric Cooperative kicked off a program to help their members finance the cost of a whole home backup generator. The offer included an incentive rate that allowed the co-op to turn the generators on during peak usage periods when power costs are high. Due to changes in the structure of regional wholesale power rates, they’ve since discontinued the incentive but continue to sell, install and maintain generators for members. Today, 1,100 CKenergy households enjoy uninterruptible power via backup generators, compared to 35 homes with solar-plus-battery storage.
Boyd Lee, vice president of strategic planning for the co-op, says for members seeking no-brainer backup power that requires little to no adjustment in lifestyle, “a generator isn’t just the best option; it’s the only option.”
Yes, generators are loud, require routine maintenance to ensure reliable startup, and burn emission-emitting fuels that cost money. On the upside, they provide robust, steady power for the home, kick on within seconds of detecting an outage, and cost significantly less than a solar-plus-storage system with similar capabilities.
For example, a 22kW generator capable of running a 2,500-square foot total electric home starts at roughly $14,000. A homeowner looking at a solar-plus-storage system with equivalent capability can expect to pay from $30,000 up.
For members looking to lower their energy costs and recoup their solar investment, Lee recommends a smaller solar setup capable of running the water heater, a swimming pool pump, or other high-usage appliances.
Construction underway on the solar farm and learning center collaboration between OEC and Norman Public Schools. | Photo courtesy of OEC
Located in Norman, Oklahoma Electric Cooperative (OEC) serves an increasingly suburban membership with a growing interest in solar power. As OEC’s manager of system engineering, Nick Shumaker oversees the co-op’s renewable programs, including a 2.5MW community solar project, a future solar farm and learning center in collaboration with Norman Public Schools, and a federally funded research project studying the feasibility of using repurposed EV batteries for residential energy storage. He also serves on the board of the Oklahoma Photovoltaic Research Institute.
Shumaker says 250 OEC households rely on grid-tied solar; fewer than 15 have battery backup. While some solar users like the independence of being off-grid, most prefer the comfort of knowing they can still draw power from the grid when their panels aren’t producing.
“People don’t think about it, but homeowners with grid-tied solar can still lose power. During an extended outage, the renewable asset will shut down to prevent it from back-feeding onto our lines,” he says.
Batteries provide a short-term solution to this problem, but enough storage to power the home for an extended period requires sacrifices by the homeowner, either in lifestyle or pocketbook. Shumaker says most consumers can expect to pay about $1,000 per kWh of needed capacity. At OEC, the average residential member uses roughly 40 kWh/day.
“Do the math, and you’ll see why we don’t have a ton of people doing it yet,” he says.
Still, he agrees the potential is there, and batteries offer distinct advantages—instant transition of power with no lag time, little to no maintenance, and quiet, emissions-free operation. As technology continues to improve, Shumaker believes the price for solar-plus-storage will begin to make more sense.
“The technology’s not there yet, but it will be,” he says. “I think it’s the future.”
Grid-Tied Solar- Plus-Battery Storage
- Quiet operation
- Seamless transition from grid to battery
- Clean, emissions-free energy
- Very little maintenance
- Excess generation may be sold back to your cooperative at wholesale rates
- High upfront cost
- Requires sunshine to operate or charge the battery. Optimum charge time is 10 a.m. to 4:30 pm.
- Requires multiple batteries to power the home
- Lower upfront cost than solar-equivalent systems
- Higher capacity provides longer run times
- Needs no refueling if connected to propane or natural gas
- Requires routine maintenance
- Requires propane, natural gas or diesel