Sustainable Off-Grid Living with Onsen Energy and Kensa’s Shoebox NX
Sustainable Off-Grid Living with Onsen Energy and Kensa’s Shoebox NX
Entering A New Era of Ground Source Heat Pumps and Access to Renewable Energy’s Efficiency and Sustainability
Onsen Energy, in partnership with award-winning ground source heat pump designers and suppliers, Kensa, has provided an innovative ground source heat pump solution for a self-builder's vision of sustainable living - and the UK’s first installation of Kensa’s revolutionary new kind of heat pump.
The Shoebox NX, a compact yet powerful heat pump, is at the heart of this energy-efficient two-bedroom bungalow, helping to minimise environmental impact and reduce reliance on traditional energy sources.
Key Facts
- Property: Modern 2-bed new-build bungalow
- Heating system: 5kW Kensa Shoebox NX ground source heat pump
- Renewable features: Solar panels and electric battery storage
- Ground array: 2 shallow boreholes
- Heating: Underfloor heating and high insulation
Background
Retired electrician Mr. James aimed to create a home that would allow him to live off-grid while maintaining energy efficiency. To achieve this, he installed a range of renewable technologies, amongst them - in a UK first - the innovation that is the Shoebox NX ground source heat pump. With 12 solar panels and a 13kW battery, the energy generated helps power the heat pump, providing heating and hot water throughout the property.
Prefabricated frames were delivered to the site and erected in just a week to expedite the construction. The bungalow's rustic wooden cladding met local planning requirements, completing the sustainable aesthetic.
Groundwork & Heat Pump Installation
Onsen Energy’s team worked with Mr. James to install the ground source system, drilling two shallow boreholes due to the limited outdoor space. The geological surveys highlighted the high water table, leading to the choice of shallow boreholes to avoid the risk of tapping into an underground stream. This space-saving solution fits seamlessly with the property’s design.
Installer’s Expertise
Onsen Energy, a trusted Kensa Partner Installer, brought over a decade of expertise in borehole drilling and heat pump installation to the project. Managing Director Gareth Berry shared insights into the challenges of borehole installations and the adaptability required to manage varying site conditions.
He explains, “Boreholes are a great option if your property has limited outside space. If you’ve got a bit more room, then slinkies or horizontal pipework can be installed instead. At this site, geological surveys revealed the region has a high water table so drilling two shallow boreholes instead of one deeper borehole mitigated the risk of releasing a powerful stream of water from the ground below. Every ground source heat pump installation is different, and we’re ready to adapt to any potential challenges.”
Performance & Efficiency
Mr. James' design incorporates high-quality insulation, ensuring the home retains the heat generated by the Shoebox NX. This is complemented by underfloor heating throughout the property, creating a consistent and comfortable indoor climate year-round.
The Shoebox NX, with its exceptional efficiency (producing 5.35 kilowatts of heat for every 1 kilowatt of electricity), keeps energy bills low. Mr. James also took advantage of the UK Government’s Boiler Upgrade Scheme (BUS) to offset the installation cost. His projected annual heating and hot water costs are now as low as £800.
Gareth comments:
“By switching to the Shoebox NX, Mr. James not only benefited from the latest technology but also enjoys quieter operation and improved efficiency. The running costs for heating and hot water are significantly lower than with conventional systems.”
Conclusion
This case study demonstrates how Onsen Energy and Kensa’s Shoebox NX ground source heat pump can support homeowners in creating sustainable, energy-efficient properties. Mr. James’ self-built bungalow is a prime example of how modern technology and renewable energy can work together to achieve off-grid living, with minimal environmental impact and long-term cost savings.