Homeowners Take Complete Control Over Energy Costs

Introduction

When Tommy and Joan Finn set out to build their forever home in Ballymote, Co. Sligo back in 2018, they had a clear vision: create a comfortable, future-proof home that would combine modern living with long-term energy efficiency. Their main priority was to have a "a low running cost house"

Having previously lived in a 200-year-old property, they wanted a home that would be bright, practical and easy to maintain in later years, with ground-floor accommodation providing additional convenience and accessibility to serve them in later life. They were also keen to achieve a more comfortable and consistent indoor environment than they had experienced in their previous home. As Joan recalls, their former house "was warm, but it wasn’t a constant heat."

Challenge

Like many homeowners, Tommy and Joan wanted to protect themselves from rising energy costs without compromising on comfort. Prior to moving into their new build in 2018, they were determined to install a future-proof heating system that would operate efficiently year-round and make the most of renewable energy. The 260m², four-bedroom property was designed to be highly insulated and airtight, but its exposed location presented additional challenges. Subject to strong winds and heavy rainfall, the site demanded a heating solution capable of maintaining consistent comfort regardless of the weather outside.

At the same time, electricity prices were becoming increasingly unpredictable, reinforcing the importance of energy independence. Tommy and Joan wanted a system that would not only minimise running costs but also maximise self-sufficiency, reduce reliance on fossil fuels, and deliver reliable, long-term performance.

To further enhance comfort and flexibility, a Mitsubishi Electric Multi-Split Air Conditioning System was also installed, providing additional heating and cooling where required.

Having experienced the benefits of living with a heat pump for several years, the Finns expanded their renewable energy strategy in 2023 with the installation of a 7.8kW solar PV array. As Tommy explains, "we went down the solar route because we could see straight away that solar would suit a house that is totally heated by electricity."

The system was further enhanced in 2025 with the addition of 24kWh of battery storage, enabling excess solar energy to be stored for use when solar generation is lower and further reducing reliance on grid electricity.

Results

The integrated energy system has delivered exceptional comfort, sustainability and financial benefits for Tommy and Joan.

At the heart of the home is the Mitsubishi Electric Ecodan heat pump, which maintains a steady indoor temperature of 22°C throughout the heating season, from October to March, while producing approximately 200 litres of domestic hot water each day.

For Tommy, the consistent comfort is one of the most noticeable benefits. "The whole house just runs at the one temperature," he says. As an all-electric home, the property requires no oil, gas, open fires or solid fuel appliances, significantly reducing carbon emissions while eliminating reliance on fossil fuels.

The reduced running costs have changed the way the family uses energy day-to-day. "Nobody stops anyone from turning on a tumble dryer anymore," Tommy jokes. Looking ahead to the summer months, he adds, "We won't have bills."

In addition to reducing costs, the system also improves energy resilience. In the event of a power outage, the battery storage system can be charged via a generator, ensuring continued comfort and operation during grid disruptions.

For Joan, however, the greatest benefit is the comfort of the home itself. Reflecting on what the house means to her, she says: "I'll drive anywhere, once I can come home. I always want to come back here." It's a testament not only to the efficiency of the technology, but to the warm, comfortable living environment it has helped create.