Creating Your Personal Power Plant

In my blog series on creating your personal power plant, we discussed how investing in solar energy can help reduce your carbon footprint, lower your energy costs, and give you control over your energy usage. Before I installed solar and backup, I had NES install air-source heat pumps (ASHPs), specifically mini-split systems. Given recent supply chain issues, I thought it wise to take the opportunity to have them installed while they were available. Mini-splits represent another fantastic way to further reduce fossil fuel usage and achieve even greater energy savings.

As I write this, we’ve just experienced a volatile month of weather, with more on the way. A Nor-easter swept through in mid-March, blanketing New England with wet, heavy snow. Hundreds of thousands of people lost power. I did a lot of shoveling last month but never lost power — and was glad to have backup. The solar panels were generally clear of snow within 36 hours, producing power again for my home. At each National Weather Service (NWS) warning or watch, my backup power was initiated by Storm Guard, the feature I described in my last post. I was all set. I am thankful for a backup system that ensures absolute resilience against these evolving weather threats.

Even though it is early April, we are anticipating temperatures to jump into the 80’s in the coming days. Throughout this year’s wild temperature and weather swings, the one constant has been the mini-splits I installed last October that have kept my home comfortable in all weather. As I look ahead to summer, I am reminded of how well my mini-splits will keep my house cool and dry. My primary reason for installing mini-splits was to stabilize my long-term energy costs. Adding mini-splits to my solar power plant allows me to heat and cool my house at no cost. My solar power plant will produce more energy than the mini-splits will consume, which eliminates the impact of fluctuating heating bills on my budget.

As it does with solar installation, Northeast Solar takes clients through the entire process of mini-split installation. Our lead ASHP technician, Fana, works closely with clients to first design a mini-split system that works seamlessly within the client’s home and habit energies — and then install the system taking the same care to create convenience and comfort. He designed my system to be simple, efficient, and aesthetically pleasing. Each unit’s location was carefully thought out to reduce the line-set runs and avoid multiple bends. He centered each condensing unit aesthetically inside each room so they look good and efficiently condition the room. The total installation time was about 12 hours spread out over two days.

Fana’s design included two Fujitsu mini-splits, (NES installs Fujitsu and Mitsubishi ASHPs) — one 12,000 BTU single-head unit upstairs in the master bedroom, and one 15,000 BTU single-head system on the first floor. Upstairs there are four rooms and one full bath. The downstairs is an open floor plan with a living area, dining area, kitchen, and half bath. The two units have made the entire home comfortable even when the outdoor temperature bottomed out at -13 degrees in early February. The one concession is that all the room doors should be left open so the heat can flow into each room. In my situation, that is not an issue for me, but for families with privacy-conscious tweens or teens, you might want to incorporate those considerations into the design, and provide them with their own condensing unit. The system I installed is considered a partial home system by MassSave. It is not designed to provide whole home heating and cooling — even though it does. A partial home system is eligible for a MassSave rebate of $1,250 per “ton.” A ton is 12,000 BTU. My system is 2.25 tons.

As a partial home system, I still have a fuel oiler boiler as backup. For whole-home ASHP systems, MassSave offers a $10,000 rebate. To qualify for a whole-home system rebate, the primary heating system might need to be disconnected, or the homeowner might need to attest to not use it except in emergencies. There are also other conditions that must be met for the whole-home rebate, which are outlined on the MassSave website. Feel free, too, to call our offices and speak to Fana.

As I mentioned, I didn’t use the boiler to heat my home this winter, but I did use it to heat water. During a typical winter heating season (October – April), my home would use approximately 600 gallons of fuel oil. This heating season, I have only used 100 gallons — an 80% savings! This was the energy stabilization I was looking for. For example, a year ago, before I had mini-splits installed, from October 2021 through March 2022, I consumed 5.4 MW of electricity and used 630 gallons of fuel oil to power and heat my home, respectively. Combined, that was $3,528 of energy expense. A year later, after installing mini-splits, from October 2022 – March 2023, I used 2.5 MW of electricity and 100 gallons of fuel oil for a combined expense of $1,180. This translates into a 66% savings, or $2,348. Add these savings to the $2,812.50 MassSave rebate and $2,000 ASHP federal tax credit, and my ASHP system will be paid back in less than four years. After that, the system will be putting money back into my savings account.