Eco-friendly heat pumps do not work as well as gas boilers for warming up homes
EARTH SOURCE HEAT PUMPS (£ 14,000 – £ 19,000)
Geothermal heat pumps use pipes laid in the garden to extract heat from the ground, which can then heat radiators, hot air heaters and hot water.
They circulate a mixture of water and antifreeze around an earth loop pipe. Heat from the ground is absorbed into the liquid and then passes through a heat exchanger.
Installation costs range from £ 14,000 to £ 19,000 depending on the length of the loop, and operating costs depend on the size of the house and its insulation.
Users may be able to receive payments for the heat they produce through the government’s incentive for renewable heat. The systems usually come with a two or three year guarantee – and function for at least 20 years, with a professional test every three to five years.
AIR SOURCE HEAT PUMPS (£ 11,000)
Air source heat pumps absorb heat from the outside air at low temperature into a liquid to heat your home and hot water. You can still extract heat from a cold of -15 ° C (5 ° F), whereby the liquid flows through a compressor, which heats it and transfers it to a heating circuit.
They extract renewable heat from the environment, ie the heat output is greater than the amount of electricity used – and are therefore considered energy-efficient.
There are two types, air-to-water and air-to-air, and a system costs £ 9,000 to £ 11,000 to install, depending on the size of your home and its insulation.
A typical three bedroom house is said to save £ 2,755 in ten years when used in place of a gas boiler.
HYDROGEN BOILER (£ 1,500 – £ 5,000)
Hydrogen boilers are still in the prototype phase, but are being developed in such a way that they can be operated with hydrogen gas or natural gas – that is, they can be converted without the need for a new heater.
The main advantage of hydrogen is that it does not produce carbon dioxide at the point of use and can be made either from water using electricity as a renewable energy source or from natural gas with carbon dioxide capture and storage.
A hydrogen-ready boiler is said to be an equivalent swap for an existing gas boiler, but the cost is unknown, with estimates between 1,500 and 5,000 pounds.
The boiler is constructed and functions essentially like an existing condensing boiler. Worcester Bosch – which is making a prototype – says it will take a trained engineer about an hour to convert a hydrogen-ready boiler from natural gas to hydrogen.
SOLAR PHOTOVOLTAIC PANELS (£ 4,800)
Photovoltaic solar panels generate renewable electricity by converting solar energy into electricity, with experts saying it will cut electricity bills.
Options include panels on a sloping south or flat roof, free-standing panels or solar tiles – each suitable for different environments. They are made of layers of semiconducting material, usually silicon, and electrons are released when light shines on the material, creating a flow of current.
The cells can work on a cloudy day, but generate more electricity when the sun is more intense. The electricity produced is direct current (DC), while household appliances typically use alternating current (AC) – and therefore an inverter is installed with the system.
The average private PV system is 3.5 kilowatts peak (kWp) – the rate at which energy is generated at peak power, for example on a sunny afternoon. A 1 kWp set of panels produces an average of 900 kWh per year under optimal conditions and the cost is £ 4,800.
SOLAR WATER HEATING (£ 5,000)
Solar water heating systems or solar thermal systems use the heat of the sun to heat hot water.
A conventional boiler or immersion heater can then be used to make the water hotter or to provide hot water when solar energy is not available.
The system works by circulating a liquid through a plate on a roof or on a wall or open-air system.
The panels absorb heat from the sun, which is used to heat water in a cylinder, and those with the system require a significant amount of roof space that receives direct sunlight for most of the day to make it effective.
The cost of installing a typical system is anywhere from £ 4,000 to £ 5,000, but the savings are less than other options because it is not as effective in the winter months.
BIOMASS BOILER (£ 5,000 – £ 19,000)
Biomass, a renewable energy source, is obtained from burning wood, plants and other organic substances such as liquid manure or household waste. It releases carbon dioxide when burned, but much less than fossil fuels.
Biomass heating can burn wood pellets, wood chips or split logs to heat a single room or to run central heating and hot water boilers.
A stove can also be fitted with a rear boiler to heat water, and experts say a wood-burning biomass boiler could save up to £ 700 a year compared to a traditional electric heating system.
An auto-fed pellet boiler for the average home costs between £ 11,000 and £ 19,000, including installation, fireplace and fuel storage. Manually fed log boiler systems can be slightly cheaper, while a smaller household biomass boiler starts at £ 5,000.