As the popularity of renewable energy in the home grows, so too does the buzz around its technologies. There is a wealth of choice for property owners when it comes to powering a domestic building with renewables, whether it be for the purpose of generating heat, electricity, or both.
Solar PV and solar thermal panels have demanded the most column inches over the past decade, but there’s also a huge opportunity to use heat pumps and biomass boilers within a home. When coupled with the support of various government schemes and financial incentives (such as the RHI in Britain), these technologies are more accessible – and more appealing – than ever.
One popular technology is the ground source heat pump (GSHP). As many readers will already know, this is a heat pump system which uses the earth (or in some cases, water) as a heat source.
This diagram gives an overview of how it works:
In this article, I’ll seek to dispel some of the common myths about ground source heat pumps.
The myths of ground source heat pumps
So, where are the misconceptions and what is the truth about ground source heat pump technology?
“I need planning permission”
Typically this isn’t the case, as heat pump installation is considered a permitted development. However, the UK’s Planning Portal recommends that if you live in a conservation area or a listed building, you should contact your local council to be 100% sure about compliance.
“I need a huge garden”
Granted, you do need some outside space for a GSHP – but there are options. Loops of pipe are either laid in trenches or boreholes. A trench will require more space than a borehole, so if your garden isn’t large enough in width and length, boreholes might be a better solution. Those with insufficient outdoor space might wish to consider an air source heat pump instead, or a hybrid setup whereby a smaller heat pump operates in tandem with your existing heating system. An expert surveyor will inform you here.
“It’s too expensive”
Of course, this is relative to your situation. Firstly, given the incentive payments (in the UK) and increased efficiency, a GSHP is guaranteed to save you money in the long-term. It also adds value to a property. Furthermore, there are lots of attractive financing options available. Rarely do homeowners need to fork out a huge amount at the outset. I recently published an article about ground source heat pump installation costs, which makes for useful extra reading if you need to know more details.
“They’re only suitable for new-builds”
On the contrary. GSHPs are suitable for any building that meets efficiency and insulation standards, provided there’s sufficient space to install the system. If a building has too much “heat sink”, that might be a problem. But if your property is up-to-scratch, it doesn’t matter how old the building happens to be.
“GSHPs are inefficient”
In fact, ground source heat pumps are remarkably efficient when installed correctly in efficient buildings. Of course, the homeowner must ensure that the property is well-insulated (a condition for incentive schemes anyway), and maintain the heat pump over the course of its lifetime. See next point…
“They’re hard to maintain”
A heat pump compressor has a life expectancy of 20 – 25 years. Other elements of your GSHP, such as the ground arrays, will have an even longer lifespan. It’s certain to outlast a traditional boiler system, that’s for sure. Many heat pump parts need no maintenance whatsoever, but it’s beneficial to get a very simple yearly check-up to ensure the filters are clean and the system is efficient. If you’re in the UK and register with the governments MMSP metering system, this more than covers the cost of yearly maintenance.
“I need underfloor heating”
Whilst this is always a bonus for your domestic heat, a ground source heat pump doesn’t necessarily require underfloor heating. In fact, this system works fine with larger radiators. If you have small radiators, it may be the case that you need to replace them with oversized ones. This is due to GSHPs operating at around 40 to 50 degrees celsius as opposed to the 60 to 80 degrees celsius of a conventional boiler.
Summary
Ground source heat pumps aren’t without their complications. Indeed, careful preparation is needed to ensure long-term efficiency; before, during, and after installation. And not all properties are suitable. However, as these technologies mature, the process for installing and maintaining them becomes more simple for homeowners. Expertise is more widespread, services are more affordable, and the heat pump systems themselves get better and better. Renewable energy power is now accessible to the modern household, in a huge variety of forms.
