How Ireland can utilise renewable heat
Sarah Rigney
Staff Writer

Generating electricity from renewable sources has become more commonplace in Ireland in recent years, but what about renewable heat? Here we look at what options there are for renewable heat generation and how Ireland can take advantage of them.

While significant progress is being made in generating renewable electricity, one area Ireland is lagging behind in is renewable heat generation, which has so much potential. 

Renewable heat generation could dramatically contribute to a greener, more sustainable future for Ireland and help us reach net zero emissions.

In this guide, we take a look at what renewable heat is, how much renewable heat Ireland currently generates, what measures the Government has put in place, and how renewable heat can be generated and utilised. 

What is renewable heat? 

By now we’re all familiar with renewable energy, however in Ireland, this is primarily associated with generating electricity and is less focused on heating.

Renewable heating technology uses sustainable sources to deliver a constant supply of heat to a property. While costly to install initially, renewable heating systems can result in lower running costs. 

Renewable heating can help in carbon footprint reduction and protect households from future fuel price rises.

Examples of renewable heat sources include:

The renewable heat market in Ireland

In 2021, only 6.8% of Ireland’s heat was generated by renewable energy, a stark contrast to the EU average of 23%. While progress is being made, significant action is needed to transform our energy sector to a high-renewable, low-carbon system on a way to net zero emissions by 2050.

In fact, Ireland’s renewable heat generation was the worst in the EU last year. Belgium and the Netherlands also had low rates - both 8% - while Iceland had a rate of 80%. This is primarily due to its use of geothermal energy. 

Most of Ireland’s heating needs are in the domestic market, which in 2020 accounted for 45% of the market, according to figures from the Sustainable Energy Authority of Ireland (SEAI). 

Domestic Irish households still heavily rely on solid fuels, such as oil and gas, for heating. According to the Central Statistics Office (CSO), in urban areas, gas is the predominant source of heat, at 54%, and in rural areas oil is the primary source, with 53% using kerosene. In Dublin, gas usage is particularly high, at 69%.

Government measures

In November 2022, the Minister for the Environment, Climate and Communications, Eamon Ryan announced that the Government will introduce an obligation on the heat sector to include renewable heat by 2024.

Up until this point, several policy measures aimed at decarbonising the heat sector have already been implemented. 

Building regulations

Building regulations have been updated and a share of the energy demand - around 20% - in new buildings now must come from renewable sources, according to the SEAI. 

Incentives

The provision of incentives, such as the residential and community energy efficiency upgrade schemes from the SEAI, support domestic heat users to increase the energy efficiency of Ireland’s housing stock. 

Through the SEAI’s upgrade schemes, homeowners can avail of grants for the installation of solar panels, heat pumps, and other retrofits. 

The Support Scheme for Renewable Heat 

This Government-funded scheme offers support for the adoption of renewable heat systems by non-domestic heat users. The scheme aims to bridge the gap between the installation and operating costs of renewable heating systems and conventional fossil fuel alternatives.

The scheme is open to commercial, industrial, agricultural, district heating, public sector and other non-domestic heat users.

How Ireland can better integrate renewable heat 

The main solutions to Ireland’s low renewable heat generation are electrifying heating through the use of heat pumps, and developing district heating systems.

1. Electrifying heating

By electrifying heating, the electricity grid is responsible for heating homes. This, in turn, is more sustainable as the electricity grid is becoming more renewable faster than heating itself is becoming environmentally friendly. 

The main way of electrifying heating is through the use of heat pumps, which are modern alternatives to an oil or gas boiler.

Heat pumps

A heat pump is a renewable energy technology that extracts heat from low-temperature sources (e.g. air, water and ground) and upgrades it to a higher temperature, before releasing it to heat homes. Heat pumps have become more popular in recent years and over half of new homes in Ireland are being built with heat pumps installed.

In order to run, a heat pump requires electricity. However, according to the ESB, they typically produce three to four units of heat for every unit of electricity consumed.

One of the main benefits of heat pumps is that they make temperature control a lot easier. They give households the ability to keep their homes at a specific temperature, making them much more efficient.

As renewable energy generation expands, more and more of the electricity used by heat pumps is coming from renewable sources, such as wind.

Heat pumps and geothermal heating

Geothermal heating is another form of renewable energy, which uses a heat pump to harness the temperatures below ground. 

Ireland has excellent shallow geothermal energy reserves all over the country, however our geothermal resources are currently under-utilised and not fully understood.

According to Geological Survey Ireland (GSI), Ireland’s shallow groundwaters provide a stable thermal energy resource, which can be used to provide heating at very high efficiencies. Ground Source Heat Pumps (GSHPs) are becoming increasingly popular and with sufficient insulation, they can be a very efficient method of heating our homes and businesses.

According to Government publications, research to date indicates that there is significant potential for the increased development of geothermal resources onshore in Ireland. Wicklow, Wexford, Waterford and Cork show the presence of deep untapped reservoirs of geothermal heat that could be harnessed. 

To support the greater deployment of geothermal energy in Ireland the Government is currently developing a policy regulatory framework to facilitate the exploration and development of geothermal energy resources. 

2. District heating

The other main way Ireland can better integrate renewable heat is through district heating. District heating systems deliver heat for both space heating and water heating needs to buildings through a network of insulated underground pipelines.

This method of heating is commonly used in other European countries, such as Denmark, where 60% of heating is delivered this way. 

This method can also be made renewable, and benefits scale as heating multiple homes together is more efficient than individual properties needing their own heating systems.

District heating can harness waste heat from energy production. During energy production, 60% of energy is wasted and let off in the form of steam. In Sweden, 97% of their district heating system is from recoverable heat energy. 

According to statistics from Eurostat, as of 2020, Finland has the most district heating by Km in the EU, with nearly 14,500km of pipes. The next highest is Romania with 7,800km of heating, followed by Austria, France, Italy and Bulgaria. 

In Ireland, data centres consume vast amounts of energy, which results in heat that is released. Instead of being released, this heat could be harnessed by a district heating system to provide public benefits from Ireland’s data centres. This would also make Ireland’s rapidly growing data centre sector more sustainable. 

District heating would only be applicable in densely populated areas. This means 70% of Dublin’s households would qualify for district heating, utilising recycled heat from energy production, data centres and geothermal energy. 

Tallaght’s district heating system

In 2021, construction on a project in Tallaght started to create a district heating system using heat being distributed from the local Amazon Web Services (AWS) data centre. 

Through this project, those in the catchment area will have reliable heat and hot water, without needing a boiler or immersion in their homes. 

The cost of heating in the homes will be reduced and will be 100% renewable. The project will also improve the Building Energy Rating (BER) of the homes in the area. 

Along with the Tallaght district heating system, there are also plans for a district heating system around the Dublin harbour area, powered by the Poolbeg Waste to Energy facility. Similarly, another data centre district system is being scouted in Blanchardstown. 

Discover more about renewable energy

If you found this article interesting, make sure you take a look at our other informative renewable energy pieces:

Don’t forget, you can stay up-to-date with the latest news on our blog and guide pages. 

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Main sources

cso.ie, ec.europa.eu, gov.ie, gsi.ie, seai.ie