Energy Facts

A communal system will have no impact on the way you heat your home. The system has similar controls and provision to program heating as a conventional system. This means that radiators can be supplied with hot water on demand as and when required, or according to a pre-set time schedule.

Within homes the gas boiler is replaced by a ‘Heat Interface Unit' (HIU) - an item similar in size to a gas boiler. This contains the incoming and outgoing heat mains, control values and metering. A heat exchanger within the HIU provides instant hot water by transferring heat from the community network to radiators in the house. The system can be designed with or without individual hot water cylinders in each home as required.

For more information on community heating networks, click here.

Yes, you will have full control in terms of when you would like to heat your home and to what temperature. A room thermostat can be used to set a demand or preferred temperature for your home. These work by sensing the air temperature and consist of a small dial, similar in size to a light switch, usually located in the living room. Some newer models may also incorporate a small digital display that shows the temperature setting. When the temperature in the home is below the thermostat setting, the heating is switched on and it is switched off when the set temperature is reached. As and when required the temperature setting in the thermostat can be raised or lowered depending on individual preferences.

There will usually be only one thermostat to control the temperature in your home. However, the radiators will be fitted with TRVs, or ‘thermostatic radiator valves', on either the flow or the return pipe connected to the radiator. These valves can be used to control the temperature in individual rooms by restricting the flow of water through the radiator.

For more information on community heating networks, click here. 

There will be no apparent difference in billing. You will be charged for the amount of energy or heat you consume as is the case with a conventional utility supplier. The control panel in your home will have a heat meter (much like a gas meter) that can be read manually or remotely by the company who manages the community heating network. 

Your bill will normally have two parts: a standing charge (covering fixed costs such as the availability of the system) and a unit charge (reflecting the amount of heat used).

For more information on community heating networks, click here. 

In both cases, you will pay for the heat generating equipment to be provided and maintained and for the amount of heat you use. In a house with a conventional individual boiler, the home owner will pay for the boiler as part of the purchase price (in the case of a new home) and normally enter into an annual service contract with the boiler manufacturer. The boiler would need to be replaced, say, every 10-15 years.

In contrast, the biomass CCHP plant and the communal heating network would be managed by an energy services company or what is generally referred to as an ESCo. Most ESCos will structure the overall energy services bill so that it is competitive or lower in price than the cost of heating a home using conventional means, such as through a gas boiler.

For more information on community heating networks, click here. 

Connecting to a community heating network means that as a homeowner or tenant you do not have the hassle of maintaining your individual heating system or paying for annual boiler servicing.

Also, the community system tends to be much more reliable as the central biomass CCHP plant will have a back-up system, such as gas boilers, to ensure a continuous supply of heat to your home even if the main biomass CCHP plant is down for maintenance.

There are also benefits in terms of future security of supply as community systems fuelled by local renewable energy sources will be less dependent on fossil fuels which we are running out of. The wider community benefits stem from an approach to energy production that is efficient, reduces carbon emissions and allows flexibility in terms of retro-fitting advanced technologies or alternative fuels in the future.   

For more information on community heating networks, click here.

A HIU or ‘Heat Interface Unit' (HIU) (control unit) replaces the gas boiler in your home. This is owned and maintained by the company that runs the central plant and community heating network. This means that, in effect, your energy supply company will maintain all the required equipment apart from the distribution pipes and radiators within your home and levy a connection charge and standing charge to cover these costs. You benefit in terms of avoided costs for annual gas checks, plus maintenance and replacement costs for the gas boiler.

For more information on community heating networks, click here.

The ESCo will be responsible for the maintenance of the community heating network and for any necessary repairs. Modern distribution networks can be designed to be much more reliable than the old systems were using advanced monitoring techniques that allow faults to be detected early. As with any other utility supplier, it is in the interest of your energy supply company (ESCo) to keep the network in good shape and to keep downtime to a minimum.

For more information on community heating networks, click here.

Community heating networks are very reliable. In countries such as Finland, district heating covers around 50% of the country's total heating demand and as much as 60% in Denmark. Modern networks can be designed with advanced monitoring techniques that allow faults to be detected early to avoid serious damage or major downtime. The Energy Intelligent Education project by the European Commission suggests that, on average, interruptions in large communal heating systems resulting from damages in the network and the consequent repair work leave the individual consumer without heat for only one hour a year.

As for the biomass CCHP plant, this will be designed with adequate back-up, such as gas boilers, to ensure an uninterrupted supply of heat when the main system is down for maintenance.

For more information on community heating networks, click here.

The size of the main plant will depend on the how big the community is that it is serving. For a community of a few thousand homes, the plant could be 3-6 storeys high, located away from the main residential areas and with good access for delivery of fuel.

Attached to it will be a chimney that will be much higher than the surrounding buildings to ensure that any smoke is discharged high into the atmosphere. Modern plants are very efficient and are designed to the strictest environmental standards. This makes sure that any emissions are kept within regulatory limits. Plumes of gases often visible on a cold day mostly consist of water vapour. This happens especially when the humidity in the air is high, and as more water vapour is added it condenses into water and appears as a trail of fog. This is much like the smoky exhaust seen from the flue of your gas boiler on a cold day.

Architecturally, the building exterior doesn't have to look industrial. It can be designed in a way that is aesthetically pleasing - the choice of materials and architectural style can reflect or compliment the type of buildings that surround it.

For more information on community heating networks, click here.

Considering the issues regarding security of supply from fossil fuels and therefore rising fuel costs in the future, it is possible that homes that are supplied by locally sourced renewable fuels (and are therefore largely self-sufficient in terms of energy generation) will be more appealing to home owners.

Also, as the environmental or climate change agenda becomes stronger, the true costs of carbon will be reflected in the goods and energy we consume. This has already started to happen, for example, for non-domestic consumers where fuel bills also include a climate change levy on all energy generated from fossil fuels. This may mean that homes supplied by low carbon or renewable energy will be cheaper to run than those supplied by energy generated from fossil fuels. These savings in fuel costs may eventually be reflected in the cost of the property.

Recently introduced government policies will require all buildings to be rated from A-G in terms of their energy performance much like appliances such as fridge-freezers. These ratings may also potentially influence buyer preferences and therefore property costs.

For more information on community heating networks, click here. 

Homes with micro-renewables, such as solar panels, do not necessarily have to look different from conventional alternatives. The design of homes will compliment existing local buildings, and will be partly influenced by the extent and type of solar passive features such as large south-facing windows, solar shading etc. 

Low-carbon technologies such as ground source heat pumps are totally concealed and have no visible external equipment.  Air source heat pumps are located outside the house, preferably in the back garden, and may be either floor or wall-mounted. In either instance, the visual impact can be reduced using appropriate landscape features or other design elements.

Solar technologies such as photovoltaic and solar hot water panels are usually roof-mounted. Alternatively, at the expense of some loss in efficiency, these could be wall-mounted in locations where the panels are free from obstructions that can cause overshading. For these technologies, orientation is the key to maximizing efficiency and this may influence the roof or façade design. For instance, in case of a dual pitched roof, only half the roof area is effectively available for solar technologies. This can be increased by designing a mono-pitched roof which faces south.

For more information on micro renewables, click here. 

The ground-source heat pump is best located inside the home, close to the hot water cylinder to minimise heat losses from the pipework. Ot it could be housed in a utility room or garage. Air source heat pumps are generally located outside the house, preferably in the back garden. These could be mounted on the floor or on the wall. In case of an air-to-air system, an additional wall mounted indoor unit will supply warm air inside the home. 

Heat pumps are generally designed with comparatively large hot water storage to make best use of cheaper night-time electricity tariffs, so this may need to taken into account when allowing for space within the house.

For more information on heat pumps, click here.

The running costs and plant replacement requirements will depend on the technology. Solar technologies are generally low maintenance with no or few moving parts. Solar PV systems will require inverters to be replaced every 10 years or so.

For more information on micro renewables, click here.

All micro-renewables described in this website are tried and tested technologies, and are extremely reliable. Most manufacturers offer warranties on their products and on-going maintenance support through a service contract.

Also, back-up systems such as the main heating system for hot water in case of solar thermal, and grid back-up for electricity supply in case of photovoltaic panels will ensure uninterrupted energy supply to your home. Heat pumps systems are designed with electric immersion heaters for back-up and to supplement heat supply during periods of high demand.

For more information on micro renewables, click here. 

Solar technologies such as solar thermal and photovoltaic panels do not produce any noise. 

For heat pumps, the noise produced by the compressor can vary for different manufacturers but is similar to a large refrigerator. This is usually not an issue but can be reduced by housing the heat pump in a utility room or garage. Air source heat pumps have an air handling unit that draws air through the evaporator or heat exchanger. These are located outside the home and the noise generated is similar to the fan noise for an air conditioning unit. Its impact can be reduced by locating the unit a few metres away from your home or locating it away from noise-sensitive rooms.

For more information on micro renewables, click here. 

Yes, it will continue to work as normal. The temperature at some depth beneath the earth remains largely constant and does not fluctuate as much with changes in air temperature. The heat pump will therefore continue to extract heat form the ground and heat your home.

For more information on heat pumps, click here. 

The system will continue to heat your home and any remaining demand, if required,  will be met through top-up electric heaters that are built into the system. It will, however, affect the systems overall efficiency as the heat pump has to work harder to extract heat from the air, which means that it will consume more electricity to provide the same output.

For more information on heat pumps, click here.  

In overcast conditions, the output from your solar panel will drop. And needless to say that no electricity or heat will be generated during the night time. However, this will not affect they way your home is heated, or the way you light your home or use appliances.

Solar thermal provides a proportion of the hot water demand for the home and any remaining demand would automatically be met by the main heating system. This will also be the case during overcast conditions when the solar panel is not producing enough hot water and during evenings. In case of photovoltaic panels, any excess electricity generated during the day is exported to the grid. Similarly when no electricity is produced you would continue to use electricity from the grid as normal.  

For more information on solar panels, click here.

Most of these technologies are low maintenance and are quite reliable. If things do go wrong for some reason, most technology suppliers provide on-going support to customers as is the case with gas boilers or any other appliance that you buy for your home.

Solar thermal panels are sized to provide, on average, around 50-60% of the annual hot water needs of your home. This will be closer to 100% in the summer months and much less during the winter period. On average, over the year, solar hot water will save around £40-£120 depending on the fuel displaced.

For photovoltaic panels, the fuel cost savings depend on the system size. A 1kWp installation or 8m² of panels will deliver savings of around £75 in energy bills.  

For more information on solar thermal, click here.

For more information on solar PV, click here.

This may well be the case. The additional costs for such a home will reflect the benefits these technologies will provide to the resident/ owner in terms of reduced energy bills and as a safeguard against potential future increases in energy prices.

For more information on micro renewables, click here.

Large scale wind turbines are located well away from residential areas to keep noise to a minimum. The optimum distance is determined by the design of the wind turbine and the existing noise levels in the area.

Also, modern turbines are designed to be much quieter and efficient than some of the earlier models. Direct drive turbines have no gearbox, and consequently no high speed mechanical (or electrical) components. Direct drive turbines are therefore much quieter than gearbox machines as they do not produce mechanical or tonal noise. Variable speed turbines rotate more slowly or quickly depending on the wind speed. These can therefore blend with the background noise that also tends to increase or decrease depending upon wind speed.

For more information on wind power, click here.

The issue of visual impact will depend on the local context. In some instances a single large turbine may be preferable to multiple smaller ones or vice versa. A 600kW turbine, for example, is around 50m in diameter with 50-75m hub height.  However, in terms of carbon emissions, this will produce enough renewable electricity to reduce carbon dioxide emissions by as much as 600 tonnes a year on a site with good wind potential - the equivalent to roughly 13,500 m² of photovoltaic (solar) panels. Again, turbine sizes do not increase proportionately to generation capacity and a 1MW turbine is only marginally bigger with around 55m diameter and around 70-85m hub height whilst a 2MW wind turbine might have a rotor diameter of 70m and a hub height of 110m.

For more information on wind power, click here. 

The wind turbines would feed renewable electricity directly to the national grid, which in turn would supply electricity to your home. Electricity supply to your home would therefore be unaffected during periods when the wind turbine is not generating any electricity.

For more information on wind power, click here.