The Carbon Impact of your off grid project

The Carbon Impact of your off grid project

Karl Bateman, Specifier Manager at Calor, looks at the different renewable options available for self-builds

You have a number of decisions to make when creating your dream home in the countryside, one being your choice of energy. In recent years, there has been more awareness of the carbon emissions emitted by rural fuel sources, with initiatives such as the Government’s Clean Growth Strategy prompting many self-builders to look to renewable energy systems to future proof their property.

Although renewables are a popular option for rural self-builds, you may have questions about the installation cost, reliability and efficiency of the different systems available. Air Source Heat Pumps (ASHP), Ground Source Heat Pumps (GSHP), Solar Panels and BioLPG are all viable options to help minimise emissions and make your dream home a greener home. But what are the pros and cons of these solutions?  

Air Source Heat Pumps

ASHPs can help to lower your carbon footprint by extracting heat from the outside air. The pump requires an electric source to process the air intake and transform it into a useable energy source.

There are two types of ASHPs, with an air-to-water system able to produce hot water – unlike its air-to-air counterpart. An ASHP can deliver its highest efficiency levels at low temperatures over a large surface area, which is ideal for underfloor heating. 

However, according to E On, ASHPs have a high initial installation cost of around £11,000, and the network of qualified engineers to fit and maintain the system is limited. Also, the system’s set-up and commissioning can be difficult to install. 

The system is also reliant on a secondary energy source during the winter months, with ASHP not being able to work optimally in cold conditions. It’s also unable to deliver instantaneous hot water and will require a hot water cylinder to be installed into the property. 

Ground Source Heat Pumps

GSHPs utilise the natural energy from the ground, in comparison to its air counterpart. Ground source provides a consistent energy all year, as the temperature underground has less fluctuation than the air. 

A GSHP extracts its energy using a ground collector through the heat pump and into a thermal-store in the home. For optimum performance, installing larger radiators and under-floor heating is beneficial. 

The ground collectors require a large space underground, twice the total amount of your floor space at a depth of one metre, which can be a barrier to installation if you are building on a relatively small plot.  

There is an alternative method if space is at a premium, which involves boring a hole, however this normally requires planning permission. The systems are around £10,000 – £18,000 to set-up and will involve excavating your garden.

A secondary energy source may still be required as a back-up during extreme cold weather, and providing hot water will also affect the efficiency of the pump so a separate electric heater may be required to help meet all of your heating and hot water needs. 

Solar PV

There are two main types of active solar panel systems, Photovoltaic (PV) solar panels and solar water heating. Solar PV converts the energy from sunlight using semi-conducting materials to energise and produce electricity for your home. 

You should take into consideration the size of your roof to the type of solar panels you require as there are four varying types with different efficiencies. Currently, solar panels cannot store energy, so a backup energy source is required for 24-hour electricity. Solar batteries are an option, but they are an expensive add-on at £2,000 per battery. 

An initial investment of £4,000 – £6,000 for a 3kW unit can power a family home. However, research suggests that properties with a solar panel system reduces the home’s value. 


Available exclusively from Calor, BioLPG is a renewable fuel that shares an identical chemical structure to LPG but is created from a mix of renewable and waste materials. BioLPG is made from renewable materials and will reduce a homeowner’s carbon footprint for home heating by 38 per cent compared to heating oil and by 15% vs standard LPG . 

It’s classed as a drop in fuel, so it’s compatible with current LPG heating systems and appliances, and the system requires no additional upgrades or adjustment. This makes it a very cost-effective option in terms of both installation and ongoing maintenance, and it’s also very reliable as its performance is not dependent on certain environmental conditions.

BioLPG is almost identical to being on mains gas, to cater for all of your cooking, washing and heating needs, making it familiar for self-builders that are locating from a mains gas grid property. 

There are a number of tank storage options, including above-ground tanks, underground tanks and compact cylinders to cater for projects of all sizes. Having an underground tank can preserve your gardens aesthetics and maintain your rural views.  

Many A-rated LPG boilers have also been proven to achieve efficiencies of 90 per cent or more. This energy efficiency makes them kinder to both the environment and your bank balance. LPG boilers also save on space as they are a compact option and can be wall mounted to take up less space, which is ideal for builds where space is at a premium. 

What’s more, Calor works with a large network of installers who are fully qualified to fit and service an LPG boiler. The ‘Find an Installer’tool on the Calor website provides you with a database of installers who are qualified to work with LPG and BioLPG.

Auto-ordering is also available on BioLPG tanks, meaning Calor will monitor your gas levels and automatically schedule a top up when needed – plus you don’t have to be at home for the delivery.

For more information on Calor’s renewable BioLPG visit; call 0808 159 7864.