1. How does the system work?
District heating is one of the most efficient and cost effective ways to heat your home. A district heating system works like a domestic central heating system only on a larger scale. Water is heated using a boiler located in a central heating plant. The heat is distributed to the customer via an underground network of insulated pipes. The water in the network is continually circulating and therefore is always available to the householder. At the customers home the heating network is connected to the internal heating system (radiator and hot water network) by a heat distribution unit, which consists of two heat exchangers, a circulating pump, heat and flow meters, a temperature sensor, an expansion tank and control valves. The water used in the district heating network is not mixed with the water of the internal heating system of the dwelling, as heat is transferred across the heat exchangers. The district heating system is very reliable for many reasons due to professional operation and continuous monitoring of heat production and distribution. The district heating plant is designed to operate automatically and in general will only require fuel to be delivered.
2. How will the District Heating System be installed in the homes?
The installation of the system in your home is simple, and in fact it makes living in your home more comfortable. The internal temperature is electronically controlled, therefore maintaining a desired indoor temperature. Hot water is constantly circulating and is therefore available at the tap within seconds. Air is cleaner as there are no flue gases from oil or gas boiler, circulating around the house. Boilers and hot water storage tanks are not required, so a considerable amount of space is made free for other purposes. There is no need for an emersion heater as the district heating network acts as a giant hot water storage tank and can supply hot water 24-hours per day. The heat distribution unit is located at a convenient point within the home. The heat meter will allow the district heating operator to receive accurate information regarding the use of heat within the home.
3. What are the key benefits of the scheme – to the resident?
District heating is an efficient and economical way to generate, transfer and distribute heat and hot water to homeowners. It is a proven technology which has the following benefits: The customer is assured of a consistent and infinite supply of both space heating and hot water. Heat and hot water is available at a range between 16-24°C. Customers can regulate the temperature in their homes as desired. In addition the hot water for general domestic use, such as showers, is provided at a higher than usual pressure – this means you can enjoy a ‘power’ shower without having a noisy pump supplying the water under pressure. This adds to the comfort of your home. No more worries about making sure there is enough oil in the tank, or servicing the boiler; the district heating system supply’s heat from a centralised boiler, and it is the operator of the system who will maintain the boiler and all other associated equipment. A number of features have been built into the district heating system to ensure a high level of security of supply for customers. The principal feature is that a backup boiler will be installed in addition to a biomass boiler. Also electronic fault detection sends a signal to the operator if operating parameters go outside their normal range, which means they can be quickly fixed. As the system will be fired on both biomass (wood chip) and gas, this provides an extremely competitive heating solution. The use of different energy sources ensures price stability.
4. What are the key benefits of the scheme – to the environment?
District heating is an environmentally friendly solution. A centralised heating system reduces the emissions to the environment, compared to individual heating systems. Homes or commercial buildings can be assured that they are significantly reducing their carbon footprint. The system is extremely energy efficient. When hot water arrives at your home/facility, it’s ready to use. It means that district heating is 100 percent efficient “at the door,” compared with 80 percent or lower efficiencies when burning natural gas or fuel oil at a building. When you burn oil or gas you do so at 80% efficiency.
5. What are the expected average savings residents can make on their fuel bills?
Because district heating is a more efficient method of producing and delivering heat when compared to individual house boilers and because woodchips are cheaper than oil or gas, it is estimated that customers can save as much as 30% compared to heating with oil.
6. What type of fuel is being used?
The primary fuel used will be wood chips from renewable resources, such as willow or forest thinning. Wood chip is a renewable energy resource produced in Ireland and is continuously replenished through the cycles of nature. Unlike fossil fuels, their supply will never become exhausted. Renewable energy resources are indigenous resources. Ireland is heavily reliant on imported fossil fuels. We now import around 85% of the fuels we need for energy. By tapping our own renewable energy resources, we can reduce this reliance on imports and we can achieve a more secure and stable energy supply for the long term. As a back-up, and to ensure 100% security of fuel supply there will be a gas back-up boiler that will remain on standby.
7. How do you control the heat in your home and monitor usage?
The home owner will have full operational control over the heating system in your home, and can control the temperature through a digital control unit. This will allow you to heat your home or commercial building to a temperature range from 16-24 c. The digital control unit will also allow you to monitor the energy used in your home.
8. How will my heating bills be calculated?
The heating bills are calculated based on metered heat use and a standing charge, which will cover operational and maintenance costs. The heat meter in the home or commercial building will send an electronic signal to the management computer, which will contain technical data including energy units consumed.
9. How will I pay for the heating and who will I pay?
The residents can pay the bill, using direct debit in the same way they would pay utility bills. The residents will be billed bi-monthly by the company who will manage the district heating system.
10. Who will maintain the system and make upgrades / repairs as necessary?
The heating company will be fully responsible for the operation maintenance and repair of the heating system. There should not be a call out charge for technical problems with the system.
11. What are the environmental implications of using this system?
As there is a centralised heating centre, there will be a 90% reduction in fossil fuel use. There is one heating centre servicing the needs of an entire estate, and this reduces significantly the carbon footprint of the community. The use of a renewable energy solution to provide heating and hot water to the home/commercial building, in conjunction with energy efficiency measures (increased insulation etc.) contributes to sustainability as it reduces demand for and consumption of energy, whilst using a renewable form of fuel.
12. Are there any examples of successful schemes currently in place?
The following are examples of successful district heating systems around the world;
Danish Board of District Heating
Finish District Heating Association
Austrian National Association for District Heating
Swedish District Heating Association
Sheffield City Council – District Heating