Pump-up the carbon savings from heat

Heat pumps provide a proven and effective solution to the complex challenge of decarbonising heat, says Luke Bannar-Martin of Centrica Business Solutions. In this article he explains how organisations can take a giant step towards delivering on their net zero ambitions.

Heat pumps can provide heating from 35°C to 120°C and do not emit any direct emissions, significantly reducing or replacing an organisation’s need to burn fossil fuels on-site. Relative to a natural gas fuelled boiler, they can reduce overall greenhouse gas emissions by as much as 80%.

There is potential to couple heat pumps with other on-site generation technologies to improve cost and carbon performance, e.g. in combination with solar PV, heat pumps become carbon neutral, whereas adding CHP into the mix can enhance heat generation and accelerate cost returns.

Financial support for heat pumps

Technology costs are reducing, making heat pumps more cost-effective. Importantly, several UK Government funded green stimulus grants are available to support organisations in switching to sustainable heat generation, such as the Public Sector Decarbonisation Scheme, and the Industrial Energy Transformation Fund (IETF).

As approved suppliers to both government funding schemes, Centrica Business Solutions is helping public bodies and industrial businesses to deliver heat pump projects. We can also provide project finance to spread out the cost of installing a heat pump.

As a proven, scalable technology, that’s rapid to deploy, it comes as no surprise that the UK government is targeting a massive 20-fold rise in electric heat pump installations – from just 30,000 today to 600,000 by 2028.

In its recent Energy White Paper, the Government signalled its commitment to gradually removing and replacing gas boilers with cleaner alternatives. It is hoped that by the mid-2030s at the latest, all newly installed heating systems will be low carbon, such as heat pumps.

Another driver is the proposed update to SAP (SAP10.1), which will reduce the carbon factor of electricity by 75%. This change will likely take effect when the Part L planning document is updated this year. As the new build market segment moves away from natural gas and towards electrically driven heating solutions, heat pumps offer the most efficient way to electrify heat.

Despite being a proven and mature technology, heat pumps currently only satisfy around 5% of global heat demand from buildings, but the market is growing rapidly. The International Energy Agency forecasts that, in the absence of a large build out of hydrogen infrastructure, over 50% of heating in Europe could be supplied by heat pumps in 2050.

How do heat pumps work?

Heat pumps extract natural warmth from the ground, air, water, or other source (even in winter) and use it to provide heat for space heating, hot water and certain industrial processes. This operates similar to an air-conditioning unit running in reverse. This process will typically deliver between 3 and 5 units of heat for every 1 unit of electricity it uses. When configured to provide chilled water to supplement cooling, they can operate at a ratio of 5-9 units of heat /cooling per 1 unit of electricity. 

How to choose the right Heat Pump?

There are a range of heat pump options, so which one is right for your organisation? How do you choose between an air, ground, water or waste-source pump? What factors should you consider in the selection and feasibility process?

1. Air-source heat pumps

Capable of supplying hot water to any site under most conditions, this option is the least intrusive and most capital cost-effective option. Normally fitted to the side or on the roof of a building, the heat pump draws air from outside and transfers the heat by means of compression. By utilising a waste heat interface, the heat pump can recover waste heat from chillers or waste water, thereby improving the performance and financials.


  • Lowest Capex and maintenance cost option; currently eligible for government grants
  • Simple, scalable and straightforward installation
  • Possible to increase efficiency by utilising waste heat
  • Potential to integrate heat storage to load shift and enable the possibility to generate revenue from Demand Side Response services


  • Efficiency is highly dependent on ambient conditions
  • Reduced thermal energy management
  • Low efficiency of the system can impact business case
  • Lowest lifetime carbon savings of all heat pump source options

2. Ground-source heat pumps

Heat from the sun as well as from the core of the Earth keeps the ground at a reasonably consistent temperature all year. Ground-source Heat Pumps can use thermal boreholes as a heat source for a year-round reliable and predictable source of stable temperature heat. The heat recovery loop can be used to store heat in the ground during the hotter months for drawing off during the cooling months.


  • Greatly increased seasonal efficiency and performance over air-source
  • Larger reduction in associated carbon emissions
  • Ground loop system enables seasonal thermal balancing
  • Improved cash flow and eligible for green stimulus grants


  • Increased Capex, relative to an air source system
  • Process to drill boreholes can be disruptive
  • Retrofit projects can be challenging due to space required
  • More complex to retrofit on an existing site than air-source

3. Water-source

A similar system to a ground-source, they extract heat from a body of water and convert it into useful heat using submerged pipes containing a working fluid to absorb heat. If available to your organisation, an open body of water (e.g. reservoir, lake, sea), a flowing body of water (e.g. river, wastewater) or underground water (e.g. aquifer) source, can provide more an even more advanced heating solution.


  • Seasonal performance similar to, or better than, ground-source
  • Larger reduction in associated carbon emissions
  • Capex and land requirement lower than a ground source
  • Can use the water source to provide ‘free cooling’


  • There is no ‘one-size-fits-all’ with water source systems
  • Unlike ground source systems, thermal energy management may not be possible
  • If needed, obtaining abstraction licence can be a lengthy and complex process

 Specialist heat pump support

As heat pump specialists, Centrica Business Solutions provides a complete design, installation, operation and maintenance service – with flexible financing to ensure that projects can be kept off balance sheet, if necessary.

Further information: www.centricabusinesssolutions.com

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