Green Homes Network

Philippa lives in a detached, timber frame property in Stirling. She has made various improvements since purchasing the property in 2009, all with the intention of reducing her household’s carbon footprint.

Within the first year in her new home Philippa had upgraded the loft’s insulation, filled the cavity wall sections and fitted insulation under the ground floor. She installed solar photovoltaic (PV) panels in 2015 and combined this with an electric vehicle (EV) chargepoint. The chargepoint initially required plugging in when excess power was being generated by the panels, but Philippa upgraded it so that charging now takes place automatically.

Installing an air source heat pump

Philippa next focused on tackling her heating system. She was keen to reduce her reliance on gas heating which makes up a significant amount of her household’s carbon footprint. In 2021 she contacted Home Energy Scotland, a free and impartial energy advice service funded by the Scottish Government, to discuss her heating requirements. She spoke to a specialist renewables advisor about the practicalities of an air source heat pump and soon decided to contact installers.

Finding a suitable heat pump installer

Home Energy Scotland advised Philippa to use a Microgeneration Certification Scheme registered installer. She spoke to five local installers but because some were too busy to take on more jobs, this narrowed her choices to three installers. Each installer provided information over the phone and carried out site visits.

Philippa’s final decision was based on the type of refrigerant that would be used. Most heat pumps use fluids with a global warming potential (GWP) and Philippa wanted to mitigate this as much as possible by opting for a fluid with the lowest GWP. She found it difficult to explain her preference to one installer but felt it was an important aspect to consider.

Philippa was very impressed with how quick it was to install the heat pump. Her Vaillant Arotherm Plus 7kW heat pump and Vaillant 250l cylinder were installed in just two days - this even included installing full-bore pipework and fitting new radiators, including two extra units. Philippa explains that “all our existing radiators were replaced with larger versions. We had an extra radiator installed in our kitchen dining room to compensate for lower heat generation and we had an additional radiator fitted on the landing too, an area which didn’t previously have a radiator”.

Getting ongoing support

Philippa recalls that some people thought her decision to install a heat pump during wintertime was “crazy!”. However, the cold weather prompted her to figure out and manage the system sooner rather than later.

She points out that ongoing support from the installer is very important and advises other householders to confirm how their chosen installer will respond to issues. For example, she says that “when the pressure dropped in our system overnight, I sent the installer a text message at 7am to let him know. He replied straight away and then talked through the actions we needed to take while he was out walking his dog. All was fixed by 8.30 am”.

Getting financial support to install

Philippa was able to spread the cost of her new heat pump with a Home Energy Scotland Loan for £10,000, of which £7,500 was a cashback grant. She says she probably would have waited if the funding hadn't been available but would still have applied if there had been less available.

Philippa says that “in the first month of using the heat pump, the combined amount we spent on gas and electricity was the same or less when compared to the same month in the previous year, which is a good start”.

She says it’s not always easy to compare energy bills because you need to take other factors into account (such as EV charging) but says that “I’d say that we spent less on gas and electricity for heating, cooking and hot water following installation than in the previous year.” Philippa is already making the most of her cheap overnight tariff to charge her EV and heat water for the morning.

Making the most of the energy generated

Philippa’s solar panels continue to be put to good use and she is conscious of when to use this electricity to maximise its effect. For example, “on a sunny day the panels can provide some of the electricity needed for the heat pump. We raise the temperature of the house slightly so that the pump doesn’t have to increase the temperature as much later in the day, when the outside temperature drops, and the solar panels stop generating”.

Philippa is considering adding a battery “now that we can see how much we are exporting in the summer months”. She also hopes that the battery “might help with storing energy generated during the day for using the heat pump when we’re not generating”.

Philippa adds “we're really pleased to have been able to make such a significant step in reducing our carbon footprint".

Feeling inspired?

If you too want to research different types of renewable technologies, our Home Renewables Selector will help you discover your options and calculate your savings. You can also use the Renewables Installer Finder to find accredited installers in your area.