While traditional utility infrastructure for gas and electricity is still very much in demand for new-build developments, a new type of bespoke, low-carbon energy solution is becoming ever more popular across the UK.
The main driver for housebuilders and developers is to future-proof new communities.
This helps with making the developments more attractive to prospective homeowners.
Low-carbon energy solutions, such as district heat and combined heat and power (CHP) can help to deliver sustainable developments, meeting the challenges of the most stringent emissions targets and planning stipulations.
CHP engines generate electricity and capture waste heat that is produced during this process.
This waste heat is fed into a district heating network to supply homes and businesses.
District heat is when heat harnessed during the power-generation process is delivered locally to homes and business by a network of pipes.
The combination of CHP and district heat is an energy-efficient method of powering and heating communities, which benefits from economies of scale.
The saving is two-fold as first, the waste product (heat) is used, and secondly, just one community plant is required, rather than individual boilers in each home.
The homeowner can control the heat input and is individually metered for the energy used.
Accordng to figures from the Association for Decentralised Energy, CHP plants provide a saving of approximately 50 per cent in terms of carbon emissions, compared to more traditional generation processes like a combined-cycle gas turbine.
Conventional electricity generation in the UK may deliver as little as 30 per cent of the power generated to end users.
This is because up to 70 per cent of energy is lost as heat at the plant and in the journey to the homes from the power station, which is generally located in a remote area.
The efficiency for CHP plants, located in local energy centres, is rated at around 80 per cent.
“Conventional electricity generation in the UK may deliver as little as 30 per cent of the power generated to end users”
Communities tend to use their heat in cycles, with a pattern set by similar daily routines.
Energy centres therefore include thermal stores, so that when there is no demand for heat from the communal network, it can be stored for later use.
This means that CHP engines can be run even more efficiently, creating even greater savings in carbon emissions.
Any electricity that is created over and above the need of the community can be sold back to the grid.
The community can thus benefit from local electricity generation, yet local businesses and residents are still able to choose their electricity supplier in the normal way if it is operated on an open-access basis.
The energy centre on a large development will consist of a number of CHP engines.
This means that a new engine can be installed with each new phase of the development, allowing the heat network to be extended as required.
Each new building can, quite literally, be plugged in to the heat network as it is finalised.
The availability of this phased approach means that the plant is increased in line with demand, making both energy and monetary savings, as well as assisting with the developer’s cashflow.
Heat networks can make use of heat from a wide variety of sources, not just CHP engines.
As the UK decarbonises, district heat can be fed from ground-source or river-source heat pumps, energy-from-waste plants, fuel cells, bio fuel and waste heat from industry.
The key future-proof element is having the heat network in place - the heat source can evolve with time.
These energy-centre and heat-network solutions are being delivered on a range of developments throughout the UK, for both high-density, inner- city, mixed-use developments, and suburban schemes seeking low-carbon solutions.
The pioneering King’s Cross development with CHP and district heat networks operated by Metropolitan, is one example, where CHP and district heat networks will help to meet the massive electricity demand under strict planning regulations on the permitted levels of carbon emissions.
John Marsh is heat and water director (operations) at Metropolitan Infrastructure