The costs and realities of making your own energy

Cost of making your own energy
Are solar panels a bright idea?
"Wood-burning biomass systems are old-school technology with a new-school twist"
  • | by Dave Jenkins

Generating your own heat and electricity from natural resources is a dream for many households, particularly when there’s uncertainty around where fuel will come from in the future.

But how can you do it? And, crucially, how much does it cost to install?

Here’s a breakdown of each domestic renewable energy source available today, with approximate prices for kit and installation.

Air Source heating


Photo: 51 Stud

How does it work?

Heat from the air is captured via an evaporator coil. It’s then condensed to the temperature needed in your heating system using mains electricity.

Air source pumps provide a low-but-constant heat that keeps a consistent air temperature. As a result they work best with under-floor heating or very large radiators.

Benefits: Small, easy to install and can heat water at a much lower cost than other technology

Drawbacks: The irregular UK weather isn’t great for air pumps. When the temperature drops below 7 degrees celcius there’s a danger you’ll be using more electricity to power the pump than a regular boiler.

Best suited to: Off-grid homes, new builds and smaller homes. Due to their low-but-constant heat delivery, both air source and ground source pumps are best for dwellings that are constantly inhabited.

Cost: £10,000


Biomass fuel

Photo: DW Global Ideas

How does it work?

Wood-burning biomass systems are old-school technology with a new-school twist, and much more efficient than traditional open fireplaces where most of the heat was lost up the chimney.

You can burn logs, chips or pellets in two types of system: a dry stove that works as a heater for one room or, for the full renewable experience, a wet boiler system, which is around £7,000 more expensive.

Benefits: Some wet systems are up to 80% efficient and the fuel is very cheap. The large boilers have their own self-serving hopper system which top their own fuel levels up to provide a consistent heat. 

Drawbacks: You'll need to buy a lot of wood, and have space to store it. If you’re installing a full boiler then your entire plumbing system will have to be re-routed to your flue. If you live in a Smoke Control Area, you’ll need to invest in expensive smoke-free appliances.

Best suited to: Wet systems are best suited to off-grid homes, new builds or larger households. Any house with a flue will benefit from a smaller dry stove heater.

Cost: £10,000 for a full boiler, £3,000 for a stove heater.

Micro CHP

CHP generator

Photo: Tognum OTU

How does it work?

Micro CHP harnesses steam, combined heat and power (hence 'CHP') to create electricity as a byproduct. The technology has been used commercially since the 1970s in large hotels and hospitals (as pictured above), but recent developments mean CHP can be used in domestic-sized boilers.

There’s also talk of biomass CHP boiler development in the future which will make this wholly renewable. For now, though, micro CHP relies on gas.

Benefits: You can make electricity while you heat your house. And the boilers themselves are efficient even when they’re not making electricity.

Drawbacks: You probably can’t justify making electricity through your heating system during the warmer months…

Best suited to: Commercial businesses and very large households that require some form heat throughout the year.

Cost: £10,000

Ground Source heating

Ground source heating

Photo: Energy Saving Trust

How does it work?

Like air source technology, ground source heat pumps take already available natural heat and condense it to a temperature that can be used to heat your house. This involves coils buried in a two metre-deep trench or, if space is limited, a borehole up to 100 metres deep.

The looped coil contains a water and anti-freeze solution which takes the heat from the ground to be extracted and pumped to an effective temperature.

Benefits: Once you’ve dug deep enough, the heat in the ground is consistent so your consumption will remain steady.

Drawbacks: Expensive and extensive construction work is necessary.

Best suited to: Off-grid or new-build homes. Like air source hearing, ground source pumps are best for dwellings that are in constant use.

Cost: £15,000

Solar PV

Solar panels

Photo: Energy Saving Trust

How does it work?

Solar photovoltaic (PV) systems use the sun to generate electricity. Contrary to popular belief, the panels still generate electricity during overcast days.

Benefits: A full 4kW nine panel system can generate up to 3,000kW/h per year, which is a sizeable chunk of an average household’s electricity usage.

Drawbacks: You’ll need south-facing roof space which is free of shade. Installation is the most expensive part; if you’re installing two or nine panels, the actual build cost is the same.

Best suited to: Any house with a south facing roof can benefit from solar PV. However, houses with nine metre square or more of roof space will get the most out of this renewable system.

Cost: £8,000. However, Swedish retailer Ikea has just got in on the act and started selling Solar PV panels. Apparently, you'll be able to fit out a semi-detatched house with solar panels for £5,700, including installation. 

Solar Thermal

Solar panel

Photo: Energy Saving Trust

How does it work?

Instead of capturing light to generate electricity, these roof-bound puppies grab the heat for use in your water and heating system.

Benefits: Heating hot water means you store the energy you’ve created, allowing you to use it when you want. Many households with solar thermal panels rarely use their boiler between spring and autumn. They also take up very little space; two panels are all you need.

Drawbacks: If your domestic system doesn’t use a water storage tank then the installation will cost more. Many combi boilers don’t like pre-heated water, so you may need to change your boiler, too.

Best suited to: Most UK houses.

Cost: £3,000


Wind turbines

Photo: iStockphoto

How does it work?

As their name suggests, wind turbines harness the power of the wind. Which is great for the UK: we generate about 40% of Europe’s wind-derived electricity.

Unfortunately, wind generation remains a contentious issue for many - just look at that windfarm above.

Benefits: Generate electricity day and night and throughout every season, which can be stored in batteries.

Drawbacks: While roof-mounted systems are available, there’s a danger they’ll impact your house’s foundations. As wind is so unpredictable, connecting to the grid is much more complex than with a solar PV system. They also require regular maintenance.

Best suited to: Houses on the coast, on high ground or in wide open rural spaces. For a full 10 metre 4kW system your house needs to be neighbour-free for 80 metres.

Cost: A smaller turbine system can be as low as £12,000 but for a full system you’re looking at £30,000.