District Heating

Construction
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District heating is a system for distributing heat generated in a centralised location using a network of insulated pipes for residential and commercial heating needs such as space heating and water heating. 

District heating systems are widely used throughout Europe, with an estimated 24.5% all residential heat supply in the EU using district heating,  whereby communities' hot water and heat needs are supplied from a central source (Sayegh et al., 2018). Given the centralised nature of district heating systems they play an important role in reducing energy intensity and CO₂ and subsequently reducing climate change. 

There are many societal benefits of availing of high efficiency technologies and renewable energy sources such as district heating systems. These include security and flexibility of supply, reduced carbon emissions, decrease fossil fuel imports and greater use of local renewable and waste heat resources which also supports the local economy (SEAI, 2016). 

Ireland District Heating

Ireland has one of the lowest shares of district heating in Europe (<1% of the heat market). Advances in technology however, provide further possibilities for application of district heating in the future (e.g. smart heating controls and integration opportunities with the electricity sector, particularly for renewable energies). Moreover, as heat rather than fuel is supplied to end-users, a district heat network provides flexibility in fuel choice and the ability to adapt to changes in both the economic and policy landscape which may allow for a range of energy resources used at different times over the lifetime of a district heating network.

The growing number of data centres in Ireland, which produce significant amounts of excess heat as a by-product, means that there are opportunities to utilise this excess heat for district heating purposes. Specifically, Tallaght, Co. Dublin is expected to become the first major urban centre in Ireland where many buildings will be able to utilise district heating in the coming years. In this instance, excess heat waste from a large data centre in the area will be used to provide heat to a mix of public sector, residential and commercial buildings. This includes the provision of heat to up to 5,000 residential units once completed. Moreover, on completion it will reduce carbon emissions by nearly 1,500 tonnes per year (O'Sullivan, 2020). 

More strategically however, it is now recognised that Ireland has the potential for low-to-medium temperature geothermal energy resources (>400 m deep) suitable for large-scale or district heating and cooling in municipal, residential and industrial areas (Geological Survey of Ireland, 2020). In this context, in its Programme for Government in 2020, the Irish government committed to develop a scaled up programme for district heating in Ireland, including introducing requirements for district heating systems and developing a suitable regulatory environment to examine the rollout of such systems at a broader national level. Such systems will likely play an important role at a national level as we attempt to transition away from fossil fuel use.