Heat Networks Industry Council
The Heat Networks Industry Council is made up of heat network industry companies which have gathered to support Government in achieving its vision of achieving a sustainable heat network industry.
The Council identifies measures Government can take to:
- create jobs and investment
- cut costs (for those investing in heat networks and for their customers)
- reduce carbon emissions
- create more liveable, smarter cities
- support grid balancing services
- improve air quality
- encourage excellence in customer service
The members of the Heat Network Industry Council:
ICAX supports the Heat Network Industry Council
ICAX is pleased to be able to work with the HNIC and its members to encourage the move towards Fourth Generation and Fifth Generation District Heating Networks:
Fourth Generation District Heat Networks
The long term trend towards lower temperature heat distribution in heat networks has contributed to higher efficiency and lower carbon emissions.
The first generation of district heating networks started in New York in the 1880s with heat distribution by pressurised steam at over 100°C.
The second generation from the 1930s was based on pressurised hot water with temperatures above 100°C.
The third generation from the 1970s was also based on hot water, but with temperatures below 100°C and usually incorporated prefabricated parts in construction. Many suffered from poor temperature control systems which led to wasted heat.
The fourth generation has been based on reduced temperature water distribution at around 60°C to limit installation costs and heat losses to the ground, together with a higher contribution from renewable energy and waste heat in order to limit carbon emissions and reduce air pollution. It has also been characterised by more sophisticated controls.
The critical new element of fourth generation district heating is the move toward the use of heat transfer for heat generation instead of combustion. Combustion of carbon compounds always releases CO2, which limits our ability to contain climate change, and also NO2 which is a major contributory to respitatory diseases. The alternative is to use heat pumps which issue no on-site CO2 and no NO2 either.
Fifth Generation District Heat Networks
The trend to lower distribution temperatures reaches its logical conclusion with fifth generation networks with distribution of water at close to ambient ground temperature. They employ distributed heat pumps: a heat pump in each building to transfer heat in to achieve heating when buildings need heating, and to transfer heat out when buildings need cooling. Heat losses to the ground are eliminated and the cost of installing the distribution circuit is radically reduced.
The key elements of a fifth generation district heating and cooling network include:
- ground temperature heat distribution circuit – (no need for expensive insulation)
- heating & cooling – (provided by a heat pump in each building)
- demand side response – (to reduce cost of electricity and reduce carbon emissions at peak times)
- thermal energy storage – (to extend the benefits of using Demand Side Response)
- integration of waste heat opportunities – (from any building that rejects heat above ambient ground temperature)
- flexibilty to expand (or contract) the network to meet changes in demand
The principal aims of the Heat Network Industry Council can all be achieved more effectively by the move toward heat transfer instead of combustion and by the move to Fourth Generation District Heating and, particularly, by the move to Fifth Generation District Heating Networks.
See also: Ten old myths surrounding ground source heat pumps that are simply untrue.
See also: Decarbonisation of the National Grid accelerates the case for electrification of heat and use of heat pumps.