At IMS, we’re committed to helping homeowners cut their energy bills and reduce their carbon footprint. One of our customers, Steve, has closely monitored his energy usage since we installed his Vaillant Arotherm+ ASHP in early 2023.
Steve lives in a four-bedroom detached stone-built house in Bakewell, Derbyshire, and has since integrated his heat pump with solar panels and battery storage. His data offers an excellent demonstration of how these technologies work together effectively.
In this blog, we’ll explain how each system functions, why they complement one another, and share Steve’s real-life experience as proof of their combined efficiency.
An air source heat pump (ASHP) extracts warmth from outdoor air, even in colder temperatures, and compresses it to generate heat efficiently for heating and hot water inside your home.
Solar panels convert sunlight into electricity, offering a clean, renewable energy source during daylight hours. This electricity directly powers household appliances and the heat pump, significantly reducing dependence on grid electricity.
Battery storage captures excess solar energy generated during daylight, storing it for use during low sunlight periods. Additionally, batteries can charge from the grid overnight using cheaper, Time of Use (TOU), or Off-Peak tariffs, further reducing electricity costs.
Together, these systems form what we call the ‘Golden Trio,’ maximising energy efficiency, reducing electricity bills, and lowering your home’s carbon footprint.
Why Heat Pumps Are an Ideal First Step
An ASHP provides an energy-efficient way to heat your home by drawing warmth from outdoor air. Even in cold weather, ASHPs deliver reliable indoor comfort.
Based on our expert advice, Steve opted for a 12kW Vaillant Arotherm+ ASHP installed by IMS. The system efficiently provides heating and hot water through a refrigerant-compression cycle.
Key Performance Results for Steve’s Heat Pump
In 2024 alone, Steve’s heat pump:
- Consumed 4,568 kWh of electricity
- Delivered 14,613 kWh of heating
- Provided 2,090 kWh of hot water
This equates to an impressive efficiency rating (Coefficient of Performance, or COP) of 3.7—meaning for every unit of electricity used, the system produced 3.7 units of heat energy.
The Limitation: Energy Costs
Although ASHPs are efficient, they still require electricity. Without additional measures, electricity costs can increase, especially during colder months. This is where solar panels and battery storage significantly enhance savings.
Adding Solar Panels
Steve installed 14 solar panels with a total capacity of 5kW to offset his electricity usage. These panels generate electricity during daylight, directly powering household appliances and the heat pump.
Maximising Solar Power with Battery Storage
The graph below shows the monthly variations between Steve’s solar panel output (both consumed and fed back into the grid) and his heat pump’s electricity demand throughout 2024, highlighting the complementary nature of these systems:
As solar panels only produce energy during daylight, Steve installed a 5kWh battery to store excess energy. Using an OVO Energy Economy 7 tariff, he strategically charges the battery overnight at a reduced rate (16.5p/kWh). This stored energy primarily benefits Steve in the morning before sunrise when the ASHP warms the house, enhancing cost savings further.
Steve’s Results: Significant Energy Savings
The following table clearly illustrates Steve’s energy consumption before and after installing the ‘Golden Trio’ (ASHP, Solar Panels, and Battery Storage), demonstrating substantial reductions in overall usage. Note: EV refers to ‘electric vehicle,’ which Steve leases to further reduce his carbon footprint—covering around 10,000 miles for only 270 kWh of electricity:
By combining his ASHP, solar panels, and battery storage, Steve achieved remarkable results:
- Total energy consumption fell from 21,974 kWh in 2022 to 10,147 kWh in 2024—a reduction of over 50%.
- Carbon footprint reduced by approximately 2,350 kg CO₂.
- During sunnier months, Steve’s solar panels generated excess power, earning £147 in feed-in tariffs in 2024.
Steve’s annual energy bills dropped from an estimated £2,366 (adjusted for 2024 rates) to just £1,756. With an upcoming tariff reduction to 15p/kWh for ASHP users, Steve expects his 2025 bills to fall even further to around £1,054.
Understanding the Bigger Picture
Although Steve’s journey began with a heat pump installation, adding solar panels and battery storage unlocked greater savings. By adopting this ‘Golden Trio’, Steve has:
- Maximised energy efficiency
- Reduced reliance on the grid
- Significantly lowered his carbon footprint
Why the ‘Golden Trio’ Makes Sense for Homeowners
If you’re considering installing a heat pump, combining it with solar panels and battery storage can greatly improve your results:
- Solar panels significantly reduce daytime electricity costs for your ASHP.
- Battery storage allows the use of solar power during evenings or cloudy days.
- Off-peak charging tariffs further enhance cost savings when paired with battery storage.
Thinking About a Heat Pump, Solar or Battery Storage for Your Home?
Contact us today to explore how we can help you maximise your home’s energy efficiency and savings.