Editor’s note: This story was originally published in January 2022.
Living a lifestyle off the power grid does not mean you have to compromise when it comes to electrical appliances and fixtures.
It does mean knowing how much power each appliance and fixture needs to run and being brutally honest with yourself and your power needs.
Homes that get electricity via a power company or utility are often referred to as “grid-tied” due to the connection to a large power grid. Those that get their power solely by producing and storing their own — using solar, wind, geothermal or other renewable sources — are called off-grid. Successfully living off grid means knowing exactly how much electricity it takes to run everything in your house.
“Living off grid means changing your relationship with electricity,” according to Danny Piper, owner of Sundog Solar in Searsport. “Being connected to the grid means you pretty much have endless power and you often don’t know how much you are using on any given day.”
Once you move off grid, according to Piper, you are living with a finite amount of electricity. That amount, he said, depends greatly on the amount of storage capacity in your batteries.
The good news is, you can design an off grid system to meet your needs.
“It’s really about sizing things correctly,” Piper said. “It all starts with understating what your load — or power consumption — is.”
That starts with looking at each appliance and fixture you plan to power with your off grid system. Every one of them is going to have a tag or sticker indicating how many electrical watts it takes to run.
It all comes down to those watts, according to Rob Taisey, owner of Assured Solar Energy in Yarmouth.
“When you think about the appliances, they are usually rated in watts,” Taisey said. “So your thought process needs to revolve around how many appliances you have, how many will be on at any given time and how long they will stay on.”
Using a simple mathematical formula of multiplying the appliance’s watts by the number of hours it will be running during the day gives you its load in kilowatt hours.
For example, a 1,000-watt water heater running an hour a day for a month will use 30,000 watts or, a 30 kilowatt hour load.
“You need to be honest with yourself and think critically about the appliances you have,” Piper said. “You are going to use that information to size the renewable power source and battery bank for your home.”
In addition to the watts used to power an appliance, some require a brief surge of extra wattage when they first start. It’s important to factor that in because if you are not careful, that extra boost can overload your system.
“Electric motors in general will surge for a few milliseconds using four to eight times more power during that time than they use when actually running,” Piper said. “It’s not a lot of time, but it’s enough time to shut things down if your system can’t handle it.”
A properly designed off grid system includes a power inverter that automatically shuts everything off before it can be damaged by an overload. And even the most well-planned systems can create an overload at times.
“I live off grid and it happens every once in a while at my house,” Piper said. “We are running the vacuum and then the well pump kicks in and the air purifier goes on and all of a sudden the whole system shuts down.”
After a minute or two, Piper said, the inverter resets everything and the power comes back on.
“As long as you are realistic with your electoral needs when you design your system, you can really do anything you want,” Piper said.
