The prominent role of GSHP in the UK geothermal sector – Tamsin Lishman, CEO of Kensa
The prominent role of GSHP in the UK geothermal sector - Tamsin Lishman, Kensa / Part of the Voices of Geothermal UK series
Carlo Cariaga
2 Oct 2025
As part of the Voices of Geothermal UK series, Tamsin Lishman of Kensa discusses pioneering efforts for networked heat pump systems and advancing GSHP use.
Deep geothermal may be a relatively new frontier for the UK, but the country already has decades of experience in the field of shallow geothermal, specifically in the use of ground source heat pumps (GSHP). In this context, leading ground source heat pump manufacturer and installer Kensa represents an important part of the geothermal industry as a member of the Geothermal UK coalition.
In this interview, Kensa CEO Tamsin Lishman tells us how the company has pioneered networked heat pumps in the UK, the barriers to wider adoption of heat pump technology, and their outlook on the growth of the ground source heat pump sector. This interview is part of the ongoing ‘Voices of Geothermal UK’ series highlighting key geothermal industry players in the UK. Check out the other interviews in this series:
- Anne Murrell, Geothermal UK
- Jordan Weddepohl, Arup
- Karen Spenley, Celsius Energy
- David Townsend, TownRock Energy
- Stuart Sinclair, Consortium Drilling
- Gus Grand, Eden Geothermal
As a leader in ground source heat pump deployment in the UK, how has Kensa adapted to an evolving heating market in the UK through the years?
Since 1999, Kensa has been at the forefront of heat decarbonisation, initially through the design and production of best-in-class individual ground source heat pumps (GSHPs) and latterly through pioneering innovative networked heat pumps (NHPs). NHPs work in the same way as single-home GSHPs, using liquid-filled underground pipework to absorb the ground’s 10°C temperature and transfer it to a heat pump indoors, but leverage shared boreholes and pipework, installed across multiple properties simultaneously, therefore reducing the cost per property. This ‘fit and forget’ solution is highly efficient and low-maintenance, with ground loops lasting up to 100 years, making the decision to decarbonise much simpler.
We developed NHPs because we noticed the able to pay environmentally conscious market, although vitally important, would not deliver the growth Kensa was looking to achieve, whilst there wasn’t an efficient low carbon system readily available for “complex to decarbonise” homes such as flats and terraced houses.
Kensa, therefore, introduced NHPs to the market in 2011 with the aim of unlocking a scalable, cost-effective and efficient way to utilise GSHPs with a particular focus on so-called “complex to decarbonise” homes like terraced houses and flats. In order to penetrate this market, Kensa had to innovate by designing a product small enough to fit into these properties but efficient enough to deliver bill savings. So, in 2012, the award-winning Shoebox GSHP was launched. This product is small enough to fit in a cupboard yet powerful enough to deliver efficient heating and hot water. It’s the perfect choice for homes where space is limited and can be connected to NHPs.
What are the biggest barriers homeowners face when considering ground source heating?
We understand that one of the most significant barriers to heat pump uptake is the upfront installation cost. This is why we have developed a finance option to go alongside our innovative NHP solution.
Indeed, by introducing third-party finance into the installation process, Kensa or a third-party financer, such as a pension fund, can finance and install the networks in the roads, and residents then connect to these networks in exchange for a small monthly fee, similar to an existing gas standing charge. This pays for the upfront infrastructure cost, which means a homeowner only has to pay for the heat pump itself, which in turn receives a government subsidy.
We took this approach at our pioneering ‘Heat the Streets’ project at Stithians, Cornwall, where we installed the world’s first in-road retrofit NHP to 98 private and social housing homes. Here, there was no upfront cost for residents; instead, they signed a 20-year service agreement for use of the infrastructure for just £25 a month. Meaning local residents had no financial outlay and were able to enjoy an average annual bill saving of £628, whilst carbon emissions reduced by over 70%.
How does Kensa engage with local authorities and housing developers to promote geothermal solutions?
Kensa has hard-working teams dedicated to engaging with local authorities, social housing providers and the new build sector. These teams have successfully developed partnerships with organisations such as GTC, the UK’s leading provider of multi-utility networks, which will deliver NHPs to tens of thousands of new-build homes each year.
On top of this, Kensa has secured another partnership with Sureserve, a leading provider of energy efficiency services for social housing, which aims to deliver thousands of heat pump installations over the next two to three years.
What financial or policy incentives are most effective for accelerating heat pump uptake?
The introduction of the Future Homes Standard, which is expected to mandate that any new home built from 2028 must have a heat pump, is the most effective policy measure the government has to incentivise heat pump uptake. At a single stroke, this one policy will triple the size of the heat pump market virtually overnight, from 100,000 to 300,000 a year.
Importantly, the Government is set to unveil its Warm Homes Plan this autumn. To incentivise heat pump uptake, it is vital that subsidy schemes such as the Social Housing Fund focuses more on heat pump deployment, moving away from its historic focus on fabric installations and ring-fence funding for the removal of the least efficient heating systems. Indeed, with 2.4 million electrically heated homes in the UK, over 20% of which are in fuel poverty, twice the UK average, these properties should be a priority for heat pump deployment.
In the private retrofit market, the Warm Homes Plan should look to introduce an area-based approach to heat decarbonisation, where whole streets or neighbourhoods coordinate their switches to clean heat. This is an important policy that could substantially increase heat pump deployment. There are numerous benefits to this approach, including coordination of heat decarbonisation with grid upgrades, creating local pipelines/supply chains, addressing the skills gap, economies of scale, and building consumer confidence in clean heat. Critically, an area-based approach is essential to the deployment of communal heating technologies like NHPs in the private retrofit sector.
Are there international models that could inspire the UK to accelerate geothermal heat pump deployment?
The UK is at the forefront of NHP deployment. However, that doesn’t mean we can’t learn from international models.
France, for example, has a dedicated geothermal strategy that focuses on significantly increasing the deployment of both deep geothermal and surface geothermal projects, such as NHPs, to achieve energy sovereignty, carbon neutrality, and reduce fossil fuel dependence. Whilst the US Department of Energy has released very interesting reports on the applicability of NHPs in the USA, highlighting the bill savings, system cost savings and emissions that can be achieved when this technology is deployed at scale.
What partnerships or collaborations have been most important in accelerating Kensa’s rollout?
In 2023, Kensa secured £70 million in investment from Legal & General and Octopus Energy. This allowed Kensa to retain operational independence and increase manufacturing capacity to over 23,000 GSHPs annually by the decade’s end.
Kensa’s largest markets are the new build and social housing sectors, so to accelerate deployment in these sectors, Kensa has announced a series of partnerships with key industry stakeholders. As I mentioned previously in June 2024, we announced a partnership with GTC, the UK’s leading provider of multiutility networks, which will deliver NHPs to tens of thousands of new build homes each year. As part of this agreement, GTC funds the ground array along with the design, borehole drilling, and network installation at new build developments, which can be implemented alongside other utility networks as part of a one-stop shop. While Kensa supplies GSHPs to each home, the costs of GSHPs at these sites will be lower than those of equivalent ASHPs.
Kensa’s partnership with Sureserve will deliver an end-to-end solution from feasibility, design, and funding support to quality installation and long-term servicing and maintenance for social housing. This partnership aims to support up to 2,250 GSHPs by 2027/28.
What role do you envision will the ground source heat pump sector play in the growth outlook of the overall geothermal sector in the UK?
I believe the GSHP sector will play a very prominent role in the future growth of the overall geothermal sector. Indeed, Kensa has scaled up its manufacturing capabilities, plans to increase its workforce substantially and the number of heat pumps we produce to meet expected demand.
We are not the only ones envisioning a bright future for GSHPs. The National Energy System Operator’s Future Energy Scenarios 2025 predicts that 11% of homes will be heated with GSHPs/NHPs by 2050. This equates to 3.8 million homes and means over 250,000 homes a year would need to be connected to either an individual GSHP or NHP between 2035 and 2050.
