Part of Future Homes- Avoiding unintended consequences

2. Cost Implications

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You did a great job telling me how the heat pump was better for the environment, but you never said it would cost me an arm and a leg to run.

We do not know what will happen to future energy prices and whether current differences between electricity and gas costs will even out.

The real concerns about fuel poverty and escalating energy costs attract lots of media and news interest. As we move towards electrical transport and heating there is further uncertainty about how the substantial upgrades to the existing grid infrastructure will be funded. This may be through further increases in energy bills.

At today’s prices, based on Ofgem’s information for the current price cap, gas is currently a quarter of the price of electricity. Unless a heat pump can achieve a seasonal coefficient of performance (CoP) of between 3 and 4 in use, a very good performance, a home could be more expensive to heat with electricity than with gas. There are anomalies in the energy market* that make this comparison unfair to heat pumps and this will surely need to be reversed if we are to be encouraged to move away from fossil fuels voluntarily.

Efficient operation of the system, including the heating and storage of hot water, will be essential. Hot water usage accounts for a large proportion of energy used in the home especially if the home is extremely well insulated (see NHBC NF87 The Future for Home Heating). The hot water design may entail running the heat pump for periods at a higher temperature (70°C) which is less efficient or supplementing the heat pump with direct electric heating through an immersion heater. The system must be designed carefully by qualified designers who understand the technology and the design guidance. 

Heat pumps are a proven and efficient technology. If things go wrong, it may not be the heat pump itself that is the cause of bills that are higher than expected.

* Government has committed to publishing proposals on how to re-balance social and environmental costs away from electricity bills in 2022. 

Things that can go wrong:

  • Higher than expected heating bills;
  • Reduced consumer confidence;
  • Overuse of direct (immersion) heating for hot water.

Future-proofing recommendations:

  • DESIGN: Systems designed for specific house types to Microgeneration Certification Scheme (MCS) design standards;
  • INSTALL: Avoid product substitutions and deviations from the design;
  • COMMISSION: Commission all components and the completed system;
  • DECOMMISSION: Be aware of the requirements for decommissioning equipment with refrigerants for managing F-gas and ozone depleting substances;
  • MAINTAIN: Provide a demonstration of systems at handover and back this up with information for householders and clear guidance on maintenance.

Further Reading

  • Analysis from the Energy Saving Trust’s heat pump field trial

    Energy Saving Trust heat pump field trial (2008-2013) showed many installations could be improved with a range of interventions. As a result the MCS installation standards were updated. (, Department of Energy & Climate Change, Analysis from the Energy Saving Trust’s heat pump field trial, 7 August 2013)

    Demand reduction should be first priority
  • Energy Saving Trust, blog post

    In 2019, 27,000 heat pumps were installed – compared to the 100,000 additional homes connected to the gas network and the 1.7 million replacement boilers installed. (Energy Saving Trust, blog post 28 May 2021)

    Demand reduction should be first priority
  • Ofgem, press release 3 February 2022

    Energy prices are not fixed. February 2022 Ofgem announced a 54% annual increase in the default energy tariff price cap. (Ofgem, press release 3 February 2022)

    Demand reduction should be first priority

Find below relevant NHBC standards/reports for further reading:

NF87 The Future for Home Heating

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