Heating fuels supply twice the energy demand of electricity in Ireland, providing a significant opportunity for decarbonisation in the heating sector, writes John O'Shea.

As Ireland’s economy recovers, the country’s energy demands continue to grow and, as a result, Ireland faces the challenge of meeting this increasing demand while simultaneously reducing its carbon emissions.

Decarbonisation of electricity sector

The decarbonisation of the electricity sector is often discussed, but what tends to be overlooked is that heating fuels supply twice the energy demand of electricity in Ireland, providing a significant opportunity for decarbonisation in the heating sector.

In Ireland, heating has traditionally been the most difficult sector to decarbonise. It is currently the worst performing sector in relation to our 2020 renewable energy targets. It is behind electricity and transport, with renewables supplying a mere 6.5% of heat demand.

One technology that can play a key role in moving Ireland towards low-carbon heating and reducing our reliance on imported fossil fuels is district heating (DH). A 2019 study by the Heat Roadmaps research partnership estimated that almost 60% of Ireland’s heat demand could be met by DH systems.

District heating involves a network of super-insulated pipes that deliver heat from a centralised energy source and provide space heating and hot water to multiple buildings connected to the network. DH is, in itself, often referred to as being technology agnostic.

It has the inherent flexibility to utilise multiple, diverse, locally available and low-carbon heat sources. Typically, in electrical power plants, between 50% and 70% of the energy output is heat.

Heat local homes and businesses through DH network

In Ireland, this heat is currently dumped into rivers or vented into the atmosphere, but it could easily be utilised to heat local homes and businesses through a DH network.

Lower temperature heat sources, such as the heat from river water, geothermal heat and heat expelled from data centres or other cooling systems, can also be used to feed district heating networks.

These more advanced, lower temperature networks are commonly referred to as fourth generation district heating networks (4DHC) and often utilise heat pumps to raise the temperature to a usable level.

Codema is the lead partner in an EU Interreg project called HeatNet NWE, which promotes the development of 4DHC across six countries in northwest Europe (NWE).

District heating can provide numerous environmental, economic and social benefits. It can contribute significantly to EU and national energy targets, through a reduction in carbon emissions and a greater uptake in renewable energy. It can also improve building energy ratings and lower energy and maintenance bills.

It creates local jobs, provides greater security of supply and a better level of indoor comfort, while helping reduce fuel poverty for tenants. Further benefits can be found in the HeatNet NWE Guide for Public Sector Organisations brochure.

Electric heat pumps

Heat networks that utilise electric heat pumps can be used to balance the electrical grid. These act as large thermal batteries, which reduce the curtailment of intermittent renewables, such as wind, during low demand periods (e.g. night-time).

This is done at a fraction of the cost of electrical battery storage. The flexibility to use multiple sources also improves reliability and continuity of service, as the system is not dependent on any one source.

The network allows for easy integration of future heating technologies at a much faster rate than would be possible with individual building-level installations, while minimising disruption to customers.

District heating has a proven track record as a cost-effective technology in other countries such as Denmark and Sweden. In cities like Copenhagen, 98% of buildings are connected to DH networks.

Here in Ireland, DH represents less than 1% of the total heat market. Establishing DH in a new market such as Ireland has its own challenges; one of the main barriers is the lack of knowledge and awareness of DH.

This is the case across all sectors; from DH’s absence from national energy models in academia, to lack of experience in DH for semi-state utility companies, to the awareness for customers.

Local authorities' low level of autonomy

There are currently very few local authority-led utilities in Ireland, and local authorities have a low level of autonomy compared with those in other European countries. This leads to difficulties in developing policy and regulations for a local issue like heating.

Some unintended barriers have arisen from policy being developed without DH in mind. There are currently no incentives or grants for customers to connect to district heating systems, unlike those given for heat pumps and other technologies.

At the moment, we do not have a national-level heat plan similar to what exists for electricity and transport. However, Codema is working with national-level stakeholders to overcome some of these issues.

A DH policy framework is now being developed as part of the 2019 All of Government Climate Action Plan, and the Eastern and Midland Regional Assembly is empowering councils to carry out feasibility assessments for DH.

Heating is a challenge that cannot be solved only by a top-down approach. Public sector organisations can play a leading role in the development of DH by supporting, implementing and connecting to district heating networks in their region.

As one of the leading local authorities in this area, South Dublin County Council (SDCC) has implemented planning policies which promote the use of waste industrial heat, local energy partnerships and prioritise the development of low-carbon district heating in the county.

A Transition Roadmap has also been developed to provide a step-by-step guide to further develop the county’s DH potential into the future. SDCC is also responsible for developing the first not-for-profit, publicly led utility in the country – the South Dublin District Heating company.

This innovative scheme, supported under the HeatNet NWE project, utilises waste heat from a local data centre to provide low-carbon, low-cost hot water and space heating to buildings in the Tallaght area.

So how can local authorities get started on their journey towards adopting low-carbon DH networks? A good place to start is the South Dublin Transition Roadmap, which draws on the experience gained by SDCC and Codema in bringing the Tallaght District Heating Scheme project from initial concept through to final development.

The roadmap suggests actions to be taken in the short, medium and long term to catalyse and promote the development of DH networks in the county.

It discusses the development of heat demand and heat source maps and also provides high-level guidance in areas such as policy options for local authorities, identifying suitable locations for starting a DH scheme, identifying and engaging effectively with stakeholders, techno-economic analysis, and choosing the right business model and procurement method.

This roadmap is further supplemented with guides developed as part of the HeatNet NWE project on areas such as retrofitting existing buildings for 4DHC and procurement.

As part of the Department of Communications, Climate Action and Environment’s Climate Action Fund (CAF), two DH projects were selected for funding in 2019 - the Tallaght District Heating Scheme and the Dublin District Heating Scheme (DDHS).

Recycles waste heat from data centre

The TDHS, as discussed above, recycles waste heat from a data centre through a large-scale heat pump to supply heat to public sector buildings, a college campus and new residential and commercial developments.

This scheme is due to begin construction in the coming weeks, with heat being supplied in early 2021. The Dublin City DH Scheme will utilise waste heat from a waste-to-energy plant in the docklands area of the city, which has up to 90 MW of heat capacity, to feed new and existing developments nearby. This project is currently progressing through its procurement phase.

For those interested in exploring the latest opportunities for developing DH in Ireland, including existing and planned schemes, national policy and finance, and experience from international markets, Ireland’s second national conference on district energy will be held in the Radisson Blu Royal Hotel, Golden Lane, Dublin on Thursday 30th April 2020. Please register here.

Author: John O’ Shea is energy systems analyst with Codema – Dublin’s Energy Agency. He has worked in the district heating and cooling sector since 2013, and has been involved in many heat planning, feasibility and design projects across Ireland, Europe and the Middle East. He has also acted as a technical and policy adviser and is the lead author of the South Dublin Transition Roadmap.