The Power of Ground Source Heat Pumps: In Conversation with Gareth Berry, MD of Onsen Energy
For over a decade, Onsen Energy has been at the cutting edge of renewable energy installations, driven by a mission to deliver sustainable solutions to homes and businesses across the UK. With expertise in vertically drilled borehole solutions and heat pump installations, Onsen Energy has become a trusted partner to leading consultants in the renewable energy sector.
Gareth Berry, Managing Director of Onsen Energy and board member of the Ground Source Heat Pump Association, recently sat down with our partners, Kensa, to discuss our recent collaborations, Onsen’s origins, and the growing role of ground source heat pumps (GSHPs) in the UK’s energy landscape.
We’re pleased to share that conversation in this month’s article.
Making the Leap: How Onsen Energy Got Into Ground Source Heat Pumps
Onsen Energy wasn’t always focused on GSHPs as a specialism. Our shift toward renewable energy was driven by market demand as well as the clear imperative for the UK to decarbonise heating and cooling. Gareth reflects on our journey:
“We first got into ground source heating a few years back while working in the construction industry, installing traditional heating systems. We saw an increasing demand for ground source heating and decided to jump into the industry with both feet! We bought a drilling rig, founded Onsen Energy, and approached Kensa for guidance.”
Kensa’s support was pivotal to Onsen’s early success, providing the training and resources needed to navigate the complexities of MCS compliance.
Acknowledging the invaluable role Kensa has played, Gareth commented that the “partnership has been instrumental in getting us where we are today as a Kensa partner installer."
Onsen at Work - Installing the First Kensa Shoebox NX
One of our company’s most recent highlights was the UK’s first installation of the Kensa Shoebox NX—a compact and efficient ground source heat pump designed to broaden the accessibility of renewable energy to a wider range of properties.
Gareth shared the key benefits of this new technology:
“We recently installed the Shoebox NX for a self-build project, providing heating and hot water to a two-bedroom bungalow. There are several standout features that we’ve noticed. For example, the top connections make it much easier and faster to connect the heat pump, speeding up the installation process. It also features a screen, similar to Kensa’s Evo range, making the interface more user-friendly. One of the biggest highlights is how quiet the Shoebox NX is in operation. That’s a major bonus for the homeowner.”
Why the Shoebox NX is Easy to Install
One of the standout features of the Shoebox NX is its straightforward installation process. According to Gareth:
“It’s quick to install because the service valves are more accessible, and all the connections are on the top. We’re not using flexible braided hoses because the flexible joints are built directly into the heat pump. This makes it very easy to fit. There are also no covers to remove, which reduces the risk of any vibration issues, contributing to the quietness of the system.”
Outstanding Energy Efficiency
The energy efficiency of the Kensa Shoebox NX is another reason why it’s quickly becoming a preferred option for many homeowners. Gareth explains:
“Under its design criteria, the Shoebox NX delivers a Seasonal Coefficient of Performance (SCOP) of 4.49, which means it generates 4.49 kW of heat for every 1 kW of electricity. However, we’re seeing even better results in practice.
Since the ground temperature where we installed the system is around 10°C—much warmer than the 0°C assumed in the design—the SCOP is actually 5.35. That means the system is delivering 5.35 kW of heat for every 1 kW of electricity.”
This impressive performance translates to substantial savings for homeowners, reducing heating and hot water bills.
The Ideal Property for the Shoebox NX
When asked what type of property benefits most from the Shoebox NX, Gareth points to smaller, well-insulated homes.
“The Shoebox NX is ideal for properties like bungalows, apartments, or any well-insulated home. It also works well in a shared ground array setup for blocks of flats. Its compact size and quiet operation make it perfect for properties with limited space or multiple residents.”
GSHP Advice for Installers and Homeowners
For installers interested in breaking into the ground source heat pump market, Gareth offers valuable advice:
“If you’re thinking about getting into the industry, definitely reach out to Kensa’s installer development team. The support they’ve given us as a business has been extremely valuable. Their training, guidance, and continued support have helped us grow and succeed in the renewable energy sector.”
And for homeowners considering installing a ground source heat pump, Gareth emphasises the importance of working with knowledgeable professionals who will ensure the right system modelling is done to guarantee efficient heating. “We always check that the heat emitters can meet the heat demand of the property to ensure the client is warm and comfortable year-round,” he explains.
He addresses a common misconception about GSHPs as well:
“A common myth is that heat pumps can’t heat homes efficiently, but this simply isn’t true. With the right design and installation, any home can benefit from ground source heating. It’s essential to work with an installer who understands heat pump design and ensures the system is modelled correctly for the property’s needs.”
Final Thoughts: Ground Source Heating is the Future
Looking ahead, Gareth sees enormous potential for ground source heat pumps, especially for large-scale projects as more of our recent work demonstrates.
“There’s huge potential in the market, especially with large projects that use shared ground arrays to serve multiple homes. This approach could drive down costs for homeowners, making ground source heating more accessible. I think the industry will see rapid growth if it’s adopted in the right way.”
Ground source heat pumps are a forward-thinking solution for heating and cooling, offering significant reductions in energy consumption, greenhouse gas emissions, and long-term costs. Their appeal spans both residential and commercial projects, making them a key player in the shift towards sustainable energy.
As the technology continues to evolve and costs come down, GSHPs are positioned to become a key player in the shift toward more sustainable energy solutions.
For homeowners and businesses alike, ground source heating offers an eco-friendly and cost-effective alternative that significantly reduces energy consumption and greenhouse gas emissions.
If you're interested in learning more about how Onsen Energy can help you benefit from ground source heat pumps, Gareth is available to discuss your project: gareth@onsenenergy.com