HAVERHILL — With the air conditioner cooling and pool heating, Paula Komola's electric bills were about $600 a month in the dead heat of the summer. That was until she got solar panels placed on her home five years ago.

Now things are a little different. 

"For four to six months of the year I don't have an electric bill, and I might actually get a credit," she said. "Any bill I do have is cut in half, at least in half." 

As of Wednesday, Komola has a $166 credit to use towards her next electric bill. If she paired her solar system with a battery she might save even more.

Five years ago, when Komola installed her $65,000 system, pairing it with a battery wasn't an option. 

Tax incentives brought down the cost of her solar panels by about $20,000. Komola has been able to pay off the loan in the past five years using the money she saves and paying with the money she gets from selling her power, also called a Solar Renewable Energy Certificates (SRECs), for every megawatt of power sold.

"It wouldn't have been worth our time if we didn't have it — you need the incentive," she said. "There should be some sort of option for people (who can't afford it), because you are saving energy and money in the long run."

Now there's a new incentive program offered by local electric companies: batteries for solar panel systems. These programs are meant to spur the use of a batteries to store the energy homes produce and also sell it back to electric companies.  

There are also federal tax incentives to buy storage batteries, and Massachusetts offers incentives as well. Currently there are no New Hampshire incentives.

Reduce demand, reduce cost

Electric companies in New Hampshire and Massachusetts transmit or distribute power they don’t create it themselves. They pay for electricity based on the price to produce it at those peak times during high demand, explained John Shore, senior manager of marketing and communications for Liberty Utilities.

“If there is a way to reduce overall demand we can reduce overall cost,” Shore said. “If we can shift some of that spike down customers can be charged less for transmission. We don’t make money off of the transmission piece, so the savings goes directly to the customer.” 

That shift is the use of batteries.

Typically solar systems are tied to the power grid, because solar systems create direct current energy not the alternating current that homes use use. The power grid takes the direct current energy and converts it to alternating current. The battery systems can also make that change, as well as store energy. 

This is why electric companies and the government are offering incentives for their use.

In New Hampshire, Liberty is piloting a battery program. The company is offering to lease home storage batteries to customers for $30 a month. The program will combine battery storage with time of use rates, so customers enrolled in the program will be charged less per kilowatt during peak use.

Liberty is offering batteries to all customers, whether they have solar panels or not, because of their storage ability. Though often paired with solar systems, storage batteries can kick on as generators in the event of a power outage. Batteries alone are part of the companies' solution to lessening the load on the electrical grid during peak use.

Liberty's program was full and had a full waiting list soon after it was announced, Shore said. He added that customers want programs of this sort because oftentimes they can't afford the equipment themselves.

These batteries cost between $6,000 and $8,000 to purchase and install. The Liberty program is offering to defray that cost by leasing them to customers for the monthly rate and charging customers a time-of-use rate.

Batteries will charge overnight when demand is lowest, and people will be able to use that stored power during the peak usage times. Customers enrolled in this program will be charged 7 cents a kilowatt for overnight use between 8 p.m. and 8 a.m., while they will be charged 23 cents per kilowatt during the critical peak times of 3 to 8 p.m.

In Massachusetts, National Grid is partnering with Tesla to allow customers to be part of the solution. The Tesla Powerwall is one battery storage option that homeowners can install, and if they choose to allow National Grid to tap into the battery for peak demand times, like when air conditioners are being used, they will get paid.

The power from the battery will be deployed during that critical peak time, hopefully saving the customer money, Shore said. 

Cleaner energy

Energy usage tends to tick up on the hottest of hot summer days. It creates what those in the energy industry call "peak demand."

“Peak days account for 1% of the hours in the year, but cost 10%” of what consumers pay for electricity,” said Malcolm Sonnett, a solar design team manager for Revision Energy, a company that specializes in solar and energy efficient appliances.

That’s why the solar designers at Revision Energy are working with people to pair batteries with solar systems, maximizing the batteries’ effects. 

“It will lessen the load on power that’s coming out of the state,” Sonnett said, explaining that New England is reliant on other states for electricity. “And that is anti the New England spirit of independence and self reliance."

The batteries can also work to help ensure people are using cleaner energy options, he added. He explained that when there is peak electricity demand that’s when dirtier options like coal and oil are burned for electricity are typically used.

“With battery storage you are meeting a personal need and at the same time benefiting and cleaning the grid to lessen the cost for all,” Sonnett said.

Sonnett added that while the company has stores in New Hampshire, Massachusetts and Maine, Massachusetts is the fist state to make battery storage part of its energy plan. He said that state incentives to participate in getting battery storage and solar systems have been effective for people buying systems from Revision Energy.