Achieving a retirement goal of an annual net-zero energy cost
As David prepared for retirement, he wanted to invest part of his pension lump sum into his home to reduce long-term energy costs and make a more environmentally responsible choice. Living in a three-bedroom end-terrace house in Didcot built in the 1980s, David’s 15-year-old gas boiler was nearing the end of its life, making it the right time to consider a future-proof solution.
Rather than replacing the boiler like-for-like, David chose a fully integrated heat pump, solar PV and battery system to help cut running costs, and protect against future rises in energy charges.
The Results
• Fast Payback: System pays for itself in just 5 years when factoring in an avoided boiler replacement
• Long-Term Value: Built to last more than 20 years; reliable technology with long term product warranties
• Peace of Mind: Energy bills cut by 95% to only £110 per annum*
* projections are based on historic bills vs the first 6 months with a heat pump installed
“ We chose Heat Horizons for their strong reputation, competitive pricing, and because they could deliver the entire solution in a single project — heating, solar, battery storage and insulation. They gave us confidence from the start — one team, one survey, and a complete integrated solution.”
David Baker, Didcot
The Solution
We designed and installed a 5kW Vaillant air source heat pump, supported by an 8kW solar PV system made up of 18 integrated panels across the east- and west-facing roof slopes. The integrated installation allows the panels to sit flush with the roof, improving appearance and preventing birds nesting underneath.
A Solax battery was also installed neatly in the utility room to store excess solar generation, while the heat pump was wall-mounted to the side of the property to allow for greater outdoor floor space and operates quietly with no disturbance indoors.
To optimise performance, ten radiators were upgraded, loft insulation was improved, and the hot water cylinder was replaced and relocated to the loft. This not only also improved heat performance, but additionally freed up the airing cupboard for storage space.
Installation Experience
The installation was completed over a three week period, which allowed some down time during the really hot May weather which was affecting the roof and loft work. through careful planning, we made sure that we me tour customer commitment guaranteeing a property is never without heating for more than one working day between the hours of 8am and 5pm.
“For the first time in 40 years we have a warm home.”
Comfort, Performance & Savings
The system now maintains a constant ambient temperature of 20°C, providing steady, comfortable heat throughout the home. It is of course capable of more, but this is more than warm enough for David. Compared to the previous gas boiler, the heating is more consistent and far quieter without the daily noise of a boiler firing on and off. Hot water is still supplied via a cylinder with full control over timings and temperature.
Before installation, annual energy costs were estimated at £1,330 with electricity making up 67% of the total annual bill. Since then:
• Electricity costs now average just £27 per month
• Meaning annual energy costs are projected to reduce to £336 * projections are based on historic bills vs the first 6 months with a heat pump installed
• But an additional £226 is being earned from exporting electricity back to the grid giving an annual heating cost of just £110.
In practical terms, the home is now operating at close to net-zero energy cost.
Investment & Outcome
The total system cost before grant support was £27,478. With current energy prices, the system is expected to pay for itself in under 5 years when the avoided cost of a replacement boiler is included. The equipment has an expected lifespan of around 20 years, with payback well within the standard product warranties.
By investing in an integrated renewable energy system, David has secured significantly lower energy bills, improved comfort, and long-term energy independence — making it a practical and sustainable choice for retirement living.
