The Real Cost of Heating

The Carbon Emission Reduction Target (CERT), approved by the Department of Energy and Climate Change (DECC) have released figures showing the cost per kilowatt of energy for the various ways of heating your home.

The below chart shows the costs:

This assumes a gas boiler efficiency of 80%

An air source heat pump efficiency of 3:1 and ground source of 3.5:1

To view this information on the Energy Saving Trust page, click here

Electricity, not on this chart, is the most expensive form of heating. This ranges from 9.08p (economy 7) through to 15.32p for standard rate.

The reason why air and ground source heat pumps are the cheapest is because their efficiency is a multiple of the energy used.

To explain this we can use the example of gas, which is normally around 80%. When 1kW worth of gas is burnt to heat your home, around 20% is lost due to inefficiencies within the boiler. Examples include a less than perfect fuel mix and inefficiencies within the heat exchanger.

The same can be said of LPG and oil burners. In fact it is only electric heaters which operate at 100% efficiency – all the electricity is used to create heat, none is lost as a by-product.

Air and ground source heat pumps take their energy from the atmosphere; either the air temperate or ground temperature. They are therefore taking more energy than they are using. In the case of an air source heat pump they need 1kW of electricity to take 3kW of energy from the atmosphere. So the cost of energy is 1/3 of the electricity used to generate that energy.

Introduction to Our Eco House – Part 1 – Ground Source Heat Pump

After several months designing and building our eco home, we’re starting to see some real progress.

We decided that an old poorly insulation bungalow in Purleigh near Maldon in Essex would be a great opportunity to demonstrate all the services/product we provide in one place. The original bungalow was demolished, leaving only the foundations. These foundations were extended to form the base of our new building.

It was decided that a ground source heat pump installation would suit the house best. The reason for this is that the building will be well insulated, underfloor heating will be fitted and the garden is large. Firstly we dug trenches 1.2 metres deep in the garden and laid our pipework. We decided to opt for a horizontal array, but if you’re tight for space or don’t want to dig your garden, then a borehole may suit you better.

For more information on our ground source heat pump installations visit the ground source heat pump section of our site

The heat pump used is a Vaillant 6kW Geotherm, this is able to generate approximately 4kW to heat the house for every 1kW used.

We then constructed a small shed to house the heat pump itself and a buffer tank. These can be located within the house, but as we have a large garden we decided to save space in the house. The ground source heat pump is a great way of using the natural warmth of the ground (which doesn’t fall below 5⁰C even during winter) to heat your home. The set-up will also provide a large part of the hot water requirements. The heat pump can provide 100% of the required hot water, but we’re also installing solar thermal.

The ground source heat pump is eligible for the Renewable Heat Premium Payment, which provided a £1,250 payment from the government after installation. Also, starting next spring we’ll be able to claim for the Renewable Heating Incentive, which will pay out for each unit of heat generated.

To heat the house itself the underfloor heating system draws heat from the buffer tank and pumps this around its network. Unlike traditional heating systems the ground source heat pump is most efficient when operated at a fixed temperature, i.e. the house’s temperature is maintained throughout day and night. This creates a very comfortable environment within the house, which is no longer subject to fluctuating temperatures.

The heat pump was installed several months ago and was able to comfortably warm the house despite the exceptionally cold and prolonged winter. We’ve also notice a very significant saving when compared with the old oil based heating system used previously.

The Future of Gas Prices

Alistair Buchanan, chief executive of Ofgem has recently warned of ‘rollercoaster’ energy supplies. Buchanan references three main contributing factors; the closure of power plants, decreasing supplies of foreign energy and greater domestic demands.

In fact Buchanan noted that this January the 16th, the National Grid fell short to the measure of around one million homes. An old oil-fired power plant in Fawley made up the difference, however by next year this plant will be closed.

Looking to the future of energy generation Buchanan notes that ‘Wind has … been hit by the financial crisis and it will take time to reach a critical mass; nuclear will not be with us until well after 2020; and carbon capture and storage technology is still in its infancy. So that leaves gas’

Currently gas provides around 30% of our energy generation needs. Looking forward to 2020 this could rise to 60-70%. This will force Britain to ‘compete for it’s gas on a world-wide market’

With all this speculation and uncertainty over gas prices, we’ve noticed an increasingly large number of our customers opting for ground and air source heat pumps. Often these customers also have the option to utilise gas. However after taking a long term view, our customers have opted to avoid exposing themselves to the ‘rollercoaster’ of future gas supplies.

If you’d like more information on reducing your exposure to fluctuating gas and electricity prices call us on 01621 827015