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As the grid gets cleaner and ‘greener’ James Parker looks at the benefits of heat pumps

Among all the current generally grim news, one thing which provides a crumb of comfort is the UK’s success in decarbonising its electricity grid.

Thanks to embracing renewables such as offshore wind, the UK has in fact reduced CO2 emissions in its electricity economy faster than any other G20 country in the 21st century.

However, when it comes to heating buildings, we are lagging behind when it comes to decarbonising.

Many sustainability-oriented architects and specifiers are looking to electricity rather than gas as the way forward, when it comes to meeting our challenging 2050 net zero greenhouse gases target.

But gas remains the vastly preferred option at the moment in mainstream construction, so something big is needed to change this status quo.

It sounds utopian, but perhaps it’s doable, with the right intent and pragmatic political

James Parker James Parker Editor of Architects Datafile

Gas is not the future

There is little doubting the words of senior product manager for Mitsubishi Electric, James Chaplen, in a recent webinar presented by the company, that “gas is not the future.”

With the 2025 Future Homes Standard (FHS) being one major driver, the push in heating and hot water is clearly away from fossil fuels and towards more sustainable alternatives, one of which of course is the heat pumps which the company manufactures.

FHS is not the only thing that will be needed – being a more industry ‘push’ – what is perhaps more useful is the realistic application of tariffs for customers which incentivise renewable heating.

The Renewable Heat Incentive has been attacked for having applied the wrong baseline, and for costing taxpayers too much, and the Government is to replace the domestic version with a Clean Heat Grant in March 2022 (the non-domestic RHI’s being replaced with a Clean Heat Grant in April 2021).

A heat pump tariff

Good Energy is thought to be the first provider to launch a tariff specifically for heat pumps.

Somewhat confusing the issue, given the presence of the Clean Heat Grant, there’s also now a Green Homes Grant offering homeowners up to £10K to make improvements in energy efficiency (including covering up to two-thirds of the cost of heat pump installations).

Quick on the uptake, Good Energy’s tariff will not only give customers a cheaper rate for the electricity they use to produce heating via heat pumps, they’ll also get a further reduction for specific times of the day, when there’s higher renewable output to the grid, and when there’s less stress on it.

This should all make it attractive to more customers (and therefore architects) to back heat pumps, particularly at a time when Covid is making seemingly non-essential investments in technology seem more daunting than they might have been.

It won’t be long before more energy providers are jumping on the wagon and providing specifiers with further levers to help clients reduce both their monthly bills, and their carbon footprint.


Unfortunately, gas and oil prices haven’t been rising in any kind of predictable way recently, and their fluctuating nature have meant that some consumers have been reluctant to give up oil and gas boilers.

The Future Homes Standard’s big ambition is a 31 per cent reduction in carbon emissions for new homes, based on installing technologies such as PVs and heat pumps, in addition to better fabric standards.

Heat pumps will be key to what will be need to be a small revolution in housing specification to achieve this in five-year’s time, but as their efficiencies can be over 300 per cent, they have the credentials if the right incentives are there.

Cheaper heat

Air source heat pumps act like a fridge in reverse, taking heat out of the external air, to warm the water for both heating and hot water.

The boxes which house them are located on the exterior of buildings, and while they’re not enormous, they do have an aesthetic and potential noise impact which needs to be considered, and space needs to be left around them for air to circulate.

However, much more important is that ASHPs potentially offer the cheapest way to heat a home, using only electricity to power the fan.

There are some limitations, for example the unit ideally needs to be left on, also heat supplied is at a relatively low level, so buildings need to be well insulated.

In commercial applications, inefficiencies identified with using higher flow temperatures are being addressed with product innovation by companies like Mitsubishi Electric, however.

Driving the future

Despite what the industry is doing, Government could be doing more to drive forward the use of such technologies.

Part L has not been updated since 2012. The Part L 1a consultation has concluded, but the consultation on the 2a and 2b elements isn’t even due to start until the end of 2020.

Local initiatives such as Sadiq Khan’s bold move to make London net zero by 2030 is possibly an example of the ambition that’s needed.

Officials should be able to ‘work closely with’ (ie lean on) local firms and installers, and vice versa, in order to make sure things happen on the ground – to make the investment leaps needed to get the right technologies specified.

The Carbon Trust estimates that by 2030 there will be 120,000 heat pump installations per year. It sounds like a utopian idea, but perhaps it’s doable, with the right intent and pragmatic political will to intervene where needed.

James Parker is editor of Architects Datafile