What is a District Heating System?
A district heating system is where heat in the form of hot water is supplied from a central source to provide both hot water for use and for space heating to a number of domestic and/or commercial properties. It is very common in northern Europe and there are examples locally in Aberdeen and Methlick.
What area will it cover?
It is proposed initially, to cover the adjacent communities of Port Elphinstone and Inverurie. It may also be possible to extend the system to Kintore and Blackburn.
Who will be eligible to receive it?
All properties within the catchment area will be eligible, including domestic, commercial, industrial and public sector premises.
Will the heat be cheaper than gas or electric?
The actual costs of the project are not yet known. However, the source of heat energy is to be ‘gifted’ to the community by the developers of the proposed Energy from Waste Plant at the site of the former paper mill. There will be significant costs to install the network however, it is expected that the heat will be sold to users at a cost less than gas or electricity. Hot water and space heating account for 81% of the energy bill for the average home. Even the best and most modern combi boilers are only around 80% efficient when new and working optimally. That means you pay for 100% of the gas that you use and lose 20% of the potential heat in its conversion to heat. In district heating you only pay for the heat you use.
Will there be up-front costs of installing the district heating in homes?
Yes. In the same way that there are costs involved in installing, maintaining and replacing all systems, there is an initial investment required. The actual amounts are not yet known for the distribution network or for individual connections to it.
What if I am interested in taking part but cannot afford the initial up-front costs?
It is accepted that this could be an issue for many. Consideration will be given to what arrangements can be made to address this issue.
Governments are committed to challenging carbon reduction targets and have, from time to time, made grants available to householders and businesses to help with such installation costs.
Will I need to change the current central heating system in my home?
It is proposed that any system to be adopted should be compatible with existing gas-fired, hot water central heating systems.
When will the system be up and running?
As it depends on using residual heat from the Energy plant at Kirkwood Industrial Park, it cannot start until that plant is operational. It is estimated that it will be 2025. The District Heat Network will be installed in phases over a further period of time.
Will installation of pipework cause disruption?
Inevitably, there will be some temporary disruption while the underground pipes are installed. This will be kept to a minimum. Roads and streets are regularly being dug up for a number of reasons such as water, sewerage, electricity, telephones and more recently, modern fibre optic communications. Efforts will be made to try to co-install other new systems at the same time.
How will the hot water be piped to my home?
An individual supply connection will be required in the same way that gas, water, electricity and sewerage is supplied at the moment.
I have a Combi boiler installed at the moment. Will it require to be removed?
In most cases the existing boiler will be removed primarily for space saving reasons but it can be retained.
What is used instead of my existing boiler?
Boilers are replaced by a heat interface unit – a device similar in size and shape as a boiler whose job is to transfer heat from the heat network into the home via the pipes and radiators that make up the home heating system.
How big is the heat interface unit?
A standard heat interface unit is slightly larger than a modern combi boiler. Like a combi boiler, it provides ‘instant’ hot water and space heating and does not require a hot water storage tank.
How long will a heat interface unit last?
It is estimated that the heat interface unit will last for over 20 years in comparison to a modern combi boiler which has a life expectancy of around 15 years.
Annual Maintenance Contracts
Heat interface units are less complex than combi boilers and have fewer parts. Accordingly, they require less maintenance and consequently, have lower operational maintenance costs.
What if the heat source plant breaks down?
There are several layers of resilience built into the system which will last for hours or days depending upon demand. There is a heat storage capacity built in at the energy plant and within the district heating network itself which can accommodate a shut down at source. Additionally, the heat suppliers have built into their proposals the ability to ensure continuity of heat supply by means of supplementary gas boilers. In the very unlikely failure of these various systems, users would be in no worse a situation than they would be, if their own primary system failed. i.e. If your gas boiler fails, you usually have access to electrical ways of providing hot water and space heating.
What are the environmental benefits ?
A district heating system avoids the need for individual gas boilers, each with a flue emitting gases to the atmosphere. This will lead to a significant improvement in air quality within the community and equally importantly, it significantly reduces the carbon footprint of every user.
What are the economic benefits?
There are several significant, economic benefits –
What about fuel poverty?
The reduction in the basic cost of heat and hot water is expected to reduce the amount of fuel poverty in the area. In addition, it will be part of the community consultation to determine if more should be done in that issue.
What price will the heat be set at?
ICESL trading as Garioch District Heat, is a non-profit distributing organisation registered with the Financial Conduct Authority. The price of heat will be set to cover the Capital and Operational costs, repay any loans taken out and to provide a fixed rate of return to investors. Any further ‘profit’ may be used to address priorities set by the community such as tackling Fuel Poverty, insulating homes and establishing an Environmental Grant Fund.
What changes are happening or likely in terms of space heating?
No one can predict the future but we do know that governments have stated that they will ban individual gas boilers in new homes in the near future. It is only a short step to a ban on replacement gas boilers. Additionally, concerns over global climate change and government commitments to carbon reduction targets mean that not only will price stability of fossil fuels be at risk but their actual continuation has to be under serious doubt. As at October 2021, we are already seeing significant increases in the price of natural gas with more predicted. Concern is also being expressed nationally, about the security of gas supply in the UK.
How will the project be funded?
At the moment the local volunteers who have agreed to work to start the project, are looking for grant funding to kick-start the community awareness and consultation aspects. The main Capital Funding – known as Capex, is expected to come from a share issue. It is expected that local residents will receive initial preference in taking up shares in the company. Thereafter, the shares will be available publicly. Given the number of large pension funds etc., known to be looking to move away from fossil fuel and other investments, we envisage that the share offer will be over-subscribed. The Operating costs – known as Opex, will be covered by the sales of heat.
That has not yet been decided and is one of the issues that we want to gauge local opinion on.
Will there be any other benefits?
Subject to community consultation, we want to give consideration to, for example, establishing an Environmental Grant Fund within the community.
It seems incongruous to provide cheaper heat to houses which are poorly insulated. Accordingly, it may be appropriate to consider improvements in the insulation of properties supplied by the DHN. This could be done as part of the DH programme or in partnership with other organisations specialising in that work.
How common or innovative is District Heating?
District Heating has been around for many decades and there are examples locally, in Aberdeen and in Methlick. Utilisation of waste heat from Energy from Waste – EfW plants is very common in northern Europe especially in Denmark. A district heating scheme has been running in Lerwick, Shetland using heat from the local EfW plant and there is a waiting list to be connected. Reports from Lerwick show significant financial benefits within the community as a result of the scheme.
Why here?
It is an opportunity presented by the proposed development of a EfW plant on the site of the former paper mill. The developers have offered to ‘gift’ the heat normally vented to atmosphere, to the local community for the purpose of creating a community- owned District Heating Network.
Why now?
The proposed EfW plant is a commercial, merchant development, designed to treat the ‘residual’ waste from businesses in the north east which currently goes to landfill. In Scotland, landfilling of mixed waste was due to be banned from 31 Dec 2020 but the date has had to be extended due to lack of alternative treatment facilities.
Will the source of heat be regarded as ‘Green’?
The heat from an EfW plant is regarded as ‘renewable’ on the basis that it is treating / recovering the energy, from waste which is classed as ‘residual’ – and cannot be recycled due to Technical, Environmental, Economic or Practical reasons – TEEP. The primary output from the plant will be in the form of electricity sent to the national grid. However, to increase the efficiency of the plant the lower grade heat is utilised in a system called Combined Heat and Power. In the past such heat was vented off into the atmosphere.
How will using District Heating reduce my carbon footprint?
Using the surplus heat from the plant avoids the need to use other fossil fuel sources of heating, especially gas. This enables users to significantly reduce their carbon footprint without having to make drastic changes in their lifestyle such as getting rid of their car or no more flying on holiday.
Will the District Heating Network be extended to cover rural properties?
The logistics and economies of scale make this unlikely. However, the concept of Heat Batteries is developing and it may be possible to deliver heat to rural properties in a similar way that oil and LPG are delivered today.
My Boiler will need to be replaced soon, so when will this all take place?
The plant will take some 3-4 years in construction and commissioning with completion expected in 2025. We hope that installation of the District Heating Network infrastructure,will be started in parallel with the later stages of the plant construction to be ready to start around the same time.
The DHN will be developed in several stages over a number of years. The initial efforts will concentrate on delivering the core loop network around Inverurie, to supply the commercial, industrial and institutional customers. This is known the ‘Anchor load’ and is necessary to provide the financial viability to attract the investment required to develop the future stages.
There will be ‘opportunity’ domestic installations during this phase. However, the majority of individual domestic installations will be in future phases.
What would happen if the Energy plant goes out of business or reaches the end of its planned life?
The plant is designed for 25years of operation with potential to continue for a further 25 years
Part of our long term planning is to look at additional sources of heat available within the community. Geothermal heat is understood to be available in the area. In other areas of Scotland rivers and sewage treatment works are being harnessed as sources of available heat.
We will also investigate the potential for bulk heat storage in summer when demand is low, for use in winter.