Full Renewable Retrofit for a 3-Bed Bungalow in Cockermouth
Client: Private Homeowner
Location: Cockermouth, Cumbria
Property Type: 3-Bedroom 1970’s Bungalow (Retrofit)
Project Type: Air Source Heat Pump, Solar PV, Battery Storage & EV Charging
Estimated energy generation: 5,150kWh per year
Estimated cost savings: Up to £1,339 per year
Overview
This 3-bedroom bungalow in Cockermouth underwent a complete renewable energy retrofit to replace an ageing fossil fuel heating system and significantly reduce running costs.
With a calculated heat loss of 7.5kW at -3.7°C. The property required a carefully designed system to ensure reliable performance through colder Cumbrian winters.
Rather than upgrading individual elements in isolation, the homeowner chose a fully integrated approach, combining:
- Renewable heating
- Solar generation
- Battery storage
- EV charging.
The goal was ultimately for a comfortable, low-carbon home built for efficiency, resilience, and long-term savings.
“Prior to our move we researched various companies and felt comfortable that Geowarmth stood out from the rest and qualified to supply all renewable energy systems that we required.” – Customer (see below for full testimonial)
The Solution
1. Air Source Heat Pump & Heating System
A Vaillant 10kW air source heat pump was installed to meet the home’s 7.5kW design heat loss.
The system was engineered to operate at a 50°C flow temperature. It provides an effective balance between retrofit practicality and seasonal efficiency.
“…the team worked efficiently causing very little disruption to the household and following the commissioning of the system we have had a very cozy home.” – Customer (see below for full testimonial)
Key upgrades included:
- Installation of new designer radiators, correctly sized for 50°C design flow
- System optimisation to maintain comfort at -3.7°C external temperatures
- Careful commissioning to maximise long-term performance
By upgrading the emitters, the system achieves efficient operation while retaining a familiar radiator-based setup.
2. Hot Water System
A Joule 200L unvented hot water cylinder was installed in the loft to deliver strong and reliable domestic hot water performance.
Designed for heat pump compatibility, it ensures:
- Efficient reheating cycles
- Excellent hot water availability
- Seamless integration with the new heating system
3. Solar PV & On-Site Generation
To reduce grid dependency and offset heating costs, the roof was fitted with:
- 14 × 440W all-black solar PV panels
- 6.16kW peak generation
- Estimated annual generation of 5,150kWh per year
If all generated electricity is consumed on site, this could equate to savings of up to £1,339 per year, depending on tariff rates.
One of the main advantages of solar systems is that they significantly reduces imported electricity. This is particularly true during spring and summer months, when generation is strongest.
4. Battery Storage & Smart Energy Use
“The car charger and solar system together with a Tesla Powerwall 3 were installed over one week during the spring. The team worked efficiently causing very little disruption to the household. Scaffolding was put up on the day stated and promptly removed following completion of the work.” – Customer (see below for full testimonial)
To maximise the value of solar generation, the solar had installed a Tesla Powerwall 3. We expanded it with an additional 13.5kWh expansion unit, providing two 13.5kWh battery units to allow:
- Excess daytime solar energy to be stored for evening and overnight use
- Greater self-consumption of renewable electricity
- Reduced reliance on peak-rate grid electricity
During winter, when solar generation is naturally lower, the system can purchase low-cost off-peak electricity from the grid, store it in the batteries, and use it during higher peak-rate periods.
Crucially, both stored solar energy and off-peak electricity help offset and reduce the running costs of the heat pump, improving overall system economics.
5. Electric Vehicle Charging
An EV charger was installed to complete the renewable package, allowing the homeowner to charge their vehicle using:
- Self-generated solar electricity
- Stored battery energy
- Off-peak grid electricity.
This ensures both home heating and transport are electrified and optimised for low-carbon operation.
A coordinated retrofit strategy
What makes this Cockermouth project particularly effective is the joined-up design. Heating demand, solar generation, battery capacity, and tariff strategy were all considered together.
Key Outcomes
- Heat pump correctly sized for 7.5kW demand at -3.7°C
- Radiators upgraded for efficient 50°C operation
- 5,150kWh annual solar generation reducing grid imports
- Up to £1,339 potential annual PV savings (if fully consumed on site)
- 27kWh total battery storage enabling smart tariff optimisation
- Lower heat pump running costs through solar and off-peak energy use
- Fully electrified heating and transport
Why this matters for retrofit homes in Cumbria
Many bungalows across Cumbria rely on traditional radiator systems.
This project demonstrates that, with correct design and emitter upgrades, air source heat pumps can perform in colder climates easily.
By combining renewable heating, solar PV and battery storage, homeowners can reduce exposure to rising energy prices whilst lowering carbon emissions.
Customer Outcome
“The entire process has future proofed our home, added value and certainly changed the EPC grading for the property.” – Customer (see below for full testimonial)
This Cockermouth bungalow is now a modern, energy-resilient home.
It delivers reliable comfort in winter, maximises solar generation in summer, and strategically uses battery storage year-round to reduce costs.
The result is a future-ready property with lower running costs, reduced carbon emissions, and greater energy independence.
Considering a heat pump Retrofit in Cockermouth or Cumbria?
At Geowarmth Heat Pumps, we specialise in:
- Air source heat pump retrofits
- Solar panel installation
- Battery storage
- EV charging systems.
We work across Cumbria and the North of England.
If you’re planning to upgrade your bungalow or reduce your energy bills, contact us to discuss a tailored renewable solution.
Full customer testimonial
Having had a survey carried out on the property we were buying and aware that the previous owners had added substantial insulation and greatly modernised the home. We therefore arrived with our 12 month old EV and straight away needed a car charger to be installed. We had had solar panels at our previous property and we were naturally keen to have them installed at our new home. The property had gas central heating and a combi boiler but we were keen to consider installing an air source heat pump.
Prior to our move we researched various companies and felt comfortable that Geowarmth stood out from the rest and qualified to supply all renewable energy systems that we required.
The car charger and solar system together with a Tesla Powerwall 3 were installed over one week during the spring. The team worked efficiently causing very little disruption to the household. Scaffolding was put up on the day stated and promptly removed following completion of the work. We then had a glorious spring / summer of sunshine and were delighted with the system and at that point decided to go ahead with an air source heat pump.
The heat pump was installed during late September as we wished to have the property cozy 24/7 during the winter. Again the team worked efficiently causing very little disruption to the household and following the commissioning of the system we have had a very cozy home. While the Powerwall 3 battery has met our needs I took the opportunity of a Tesla offer to add an expansion unit for further battery storage.
The entire process has future proofed our home, added value and certainly changed the EPC grading for the property.