Pond mats

How much will a ground source heat pump with pond mats cost?

In this example, a single Kensa Evo ground source heat pump fed by a pond mat ground array could cost in the region of £14,500 and £16,500, and earn between £24,000 and £28,000 income from the Domestic Renewable Heat Incentive (RHI).

For more heat pump prices, call Kensa on 0845 680 4328.

Example: Project & Finances

Based on the above schematic, Kensa has calculated example costs below to illustrate the upfront finance required and the expected running costs and income generated via the Domestic Renewable Heat Incentive (RHI) over a 20 year period, compared to an LPG system. For a bespoke quote please click here.

Heat Pump Specification

System architectureSingle heat pump
Heat pump capacity13kW
Equipment type13kW Evo
Design conditions0/40°C
Potable DHW temp60°C
Integral immersion heatersNo (DNO friendly)
Ground array typePond Mats
Pond mats requiredx4
Lake area required - no flow1000sq/m


Total Project Costs, Savings & Returns vs LPG

 Kensa Ground Source Heat Pump & Ground ArrayLPG Boiler
Lifetime Expectancy: ApplianceUp to 20 yearsUp to 10 years
Lifetime Expectancy: InfrastructureUp to 100 years-
Carbon Saved (over 20 years)28 tonnes0 tonnes
Local NOx emissions*0kg NOx/y1.31kg NOx/y
Appliance & Infrastructure Cost**£14.5K to £16.5K£1.5K
Running Costs (over 7 years)***£9K to £11K£14K to £16K
Servicing Costs (over 7 years)****£0£700
RHI Income (over 7 years)*****£24K - £28KNot eligible
Net cost (after 7 years)******£0.5K profit£16.2K - £18.2K cost
*NOx emissions based on 56mg/Kwh for gas and liquefied petroleum gas (LPG) boilers (1800 run hours) **Costs are for the supply and installation of the Kensa heat pump and ground array only, and the supply and installation of the LPG boiler equipment only. Costs for supply and installation of internals such as radiators, underfloor and heating controls are not included, please speak to your plumbing contractor. ***Based on electric at 15p/kW/hr and COP of 3. Based on LPG at 40p a litre and 85% efficiency ****Ground source heat pumps have no requirement for annual maintenance. However, it is good practice for the heating distribution system to be proactively checked and maintained to ensure optimum performance. *****The DOMESTIC RHI is a 7 year index linked funding stream which assumes inflation at 3%. ******Net cost for LPG does not include an additional LPG boiler, which will likely need to be  factored in during the 20 year comparison period due to the LPG’s 10 year average lifetime expectancy.

Example: Schematic

For illustrative purposes only

Case study: River House

Mr Clarke replaced his gas boiler with a Kensa 24kW Single Phase Twin Compressor to harness heat energy from a nearby lake to provide space heating and hot water to his Grade II listed farmhouse.

Key facts:

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