The story of renewable energy in Ireland

Renewable energy in Ireland comes in many forms. The primary sources are wood, water, wind, wave and some wastes. Others include tidal power, solar power (thermal and PV), biomass and biofuels. Electrically driven heat pumps are also considered renewable because, while they require energy to operate, they extract and produce more than they use from the air, water or the ground. Ireland is committed to 16% of energy from renewable sources by 2020, to be achieved by a combination of 40% renewable electricity, 10% renewable transport and 12% renewable heat. The heat target may be met using a combination of wood cuttings, chips or waste, incineration of biodegradable municipal waste, biogases or anaerobic digestion, solar thermal energy, or geothermal energy. Looking ahead towards meeting 2050 ambitions under the Paris Agreement of 2015 implies the continued transformation from a fossil fuel based to a low carbon society making optimum use of the available renewable energy sources subject to cost effectiveness, policy, and technological advancements.

Renewable energy in Ireland comes in many forms. The primary sources are wood, water, wind, wave and some wastes. Others include tidal power, solar power (thermal and PV), biomass and biofuels. Electrically driven heat pumps are also considered renewable providers because, while they require energy to operate, they extract more than they use from air, water and geothermal energy from soils and deeper rocks.

The earliest use of renewables in Ireland involved wood for fires for cooking, heating and metal work. After the last Ice Age, forests grew again in Ireland, and their wood was later used to make charcoal – a vital energy source for the smelting of iron ore. The production of flour from cereals was one of the earliest uses of hydro power. The energy in falling rivers was captured to drive water wheels. In areas such as Fingal, in north Co Dublin, windmills were used for grain milling in areas that were rich in cereals but lacked water power. By 1840, there were 250 windmills in operation in Ireland.

A major use of the renewable energy generated by wood takes place today in board mills and sawmills where waste wood and bark from the processing or trees is a source of process heat. The first Combined Heat and Power (CHP) plant to be fired on wood waste in Ireland was constructed in 2004 at Grainger Sawmills in West Cork. It feeds its electricity to the national grid.

In 1925, work began on planning the largest hydro-power station in Ireland at Ardnacrusha. Its dam raised the level of the river Shannon in order to produce enough electricity on which to base a national grid. It now provides about two per cent of Ireland’s electricity.

The first commercial wind farm in Bellacorrick, Co Mayo, started operation in 1992 and this heralded the era of wind power. By 2015, 23% of electricity used in the State came from renewable sources – with over 20% coming from wind.

To alleviate the hardship caused by oil shortages during the Second World War, bio-ethanol was made from potatoes by a state company, Chemicí Teoranta. This was an early renewable liquid biofuel and was combined with petrol to increase the available supplies of transport fuels. Bioethanol is used today and is blended in petrol under the Biofuels Obligation Scheme.

EU directives on renewable energy led to the development of a Biofuels Obligation Scheme for road transport fuels. The national target for renewable energy in 2020 is that it should account for 40% of electricity, 10% of transport energy and 12% of heat energy. The latter target may be met using a combination of wood pellets and wood chips, other wood waste, solar thermal energy and geothermal energy.

Water power

The availability of hydropower within the lower Shannon had been suggested by Robert Kane in his work on the industrial resources of Ireland as early as 1844. The use of hydropower in Ireland was first documented in the 1880s. It was mainly linked with harnessing the power of our rivers, initially in the form of mechanical energy. By 1883, the pioneering use of waterpower to provide electricity for the Portrush-Bushmills electric tramway had been demonstrated. In 1901, a private bill – the Shannon Water and Electric Power Act – proposed diverting water from that river into a canal to create a single fall.

However, the proposal to build a coal-fired power station alongside the hydro scheme led to opposition from fishery interests, and restrictions on the quantity of water eventually ended the initial ambitious scheme. If successful, its output would have been about twice the existing generating capacity in the State.

The passage of the Shannon Electricity Bill in 1925 led to the start of construction work on the Ardnacrusha hydropower station on the River Shannon. It became operational in 1929. The commissioning of an additional turbine in 1933 marked the final development at the Ardnacrusha station. Although its operation was weather-dependent, it became the backbone of the Irish electricity system, providing secure indigenous electricity until demand exceeded its capacity and the use of fossil fuels for power generation became more prevalent.

Since Ardnacrusha was built, the ESB has harnessed the majority of the country’s hydroelectric power potential. Hydro stations were built on the River Liffey and River Erne in 1937. Two others were constructed on the River Lee and one on the Clady River in Donegal. The ESB now has eight contracted and 59 connected hydro generators which provide 212 MW, 2.8% of the total generation capacity. While much of Ireland’s hydropower resource potential has already been tapped, some opportunities remain for small-scale decentralised generation.

In addition to river-based hydro, Ireland has one pumped hydro storage facility in Turlough Hill in Wicklow, which was built between 1968 and 1974 and at that time was the largest civil engineering project carried out in Ireland. It has a total capacity of 292 MW for load balancing during times of peak electricity demand. The scheme uses off-peak power (both fossil-based and renewables) to pump water to an elevated reservoir and converts the stored potential energy in the upper reservoir by letting the water down through hydraulic turbines to boost electrical generation during times of peak demand.

Hydropower was the largest contributor to renewable electricity in Ireland until the large-scale development of wind energy at the end of the 20th century. In 2014, its contribution to electricity production was 2.5%.

Wind power

Wind power was used as an early source of energy, with the earliest recorded windmill in Ireland dating back to 1281. In 1840, there were reportedly approximately 250 windmills in Ireland. Michael Faraday’s discovery of electromagnetic induction in 1831 made it possible to generate electricity from wind. A railway station master in Donegal built his own wind charger in 1885. In the 20th century, before the mid-century roll out of rural electrification, small wind chargers were widely used to provide energy for the batteries used in the radios of the time.

The further development of wind power in Ireland and elsewhere was eclipsed firstly by coal based steam power and then by electricity. By 1925, the main purpose of the windmills operating in Ireland was to produce mechanical power.

At the end of the 20th century, as a result of a concentrated research and development effort in Denmark, wind turbines were created that opened the prospect of an unlimited supply of renewable energy in windy regions of the world. The combination of several factors including technological advances, the indigenous nature of the resource, climate change concerns and other environmental benefits has resulted in wind farms becoming the main source of renewable energy in electricity generation in Ireland today.

Several demonstration wind turbines were installed in 1981 before the first commercial wind farm comprising 21 turbines was built in Bellacorrick, County Mayo in 1992. It had an installed capacity of 6.45 MW. At the time, Ireland was heavily dependent on imported fuels and the Government wanted to expand its energy portfolio. The development of wind farms in Ireland has accelerated since 20009. This expansion has been largely as a result of environmental commitments determined by the United Nations Framework on Climate Change (UNFCCC), including the Kyoto Protocol in 1997, and a strengthening, consolidated EU energy and environmental policy. The aim of Ireland’s latest National Renewable Energy Action Plan (NREAP) is that 40% of gross electricity consumption will come from renewable sources by 2020. Incentive schemes for renewable energy investment such as the Alternative Energy Requirement (AER ) 1995-2005 and Renewable Energy Feed-In Tariff (REFIT) 2006+) helped this process.

The first AER planned to install 75 MW of wind energy capacity by 1997. Successful applicants were granted a 15-year agreement that the ESB would purchase their electricity. Only 48.5 MW was commissioned, and in the third competition, 37.51 MW of wind capacity was developed out of a potential 137 MW.

A revised sustainable energy strategy in 1999 proposed to install 500 MW of renewable energy capacity by 2007; it made proposals on the opening of the electricity market, on planning processes and on the approach to grid connection. The Electricity Regulation Act and the establishment of the Commission for Energy Regulation (CER) in 1999 were two major steps to creating the framework for introducing competition into the electricity market. Installed wind capacity increased from 169 MW in 2003 to 744 MW by the end of 2006. With greater amounts of variable electricity supply, reinforcement of grid capacity was essential. The Single Electricity Market (SEM), a cross-border wholesale electricity market between Northern Ireland and the Republic of Ireland, was created in 2007.

The first REFIT programme was launched in 2006. Its aim was to more than double the contribution of renewable energy technologies to 13.2% in 2010. It was funded through a levy charged to all electricity consumers. Under the first scheme, 1,242 MW of renewable energy capacity was added to the system. By 2010, Ireland was producing almost 15% of its electricity from renewable sources. At the same time, broader economic concerns affected the rate of new wind installation while the drop in electricity demand contributed to curtailments where at times wind power had to be shut down for reasons of grid stability. The building of the electricity interconnector to Britain in 2013 was to help with this problem. There is now around 2,400 MW of wind energy installed and connected the Irish electricity network.

Solar energy

From 2000 to 2011, solar photovoltaic, or PV, was the world’s fastest growing renewable electrical power generation technology. However, its uptake in Ireland has been limited. In 1990, solar thermal contributed 0.3% to Ireland’s renewable energy. Active solar thermal for the production of hot water and heating grew from 1990 to 2004.

In 2013, it provided the primary energy equivalent of 1.2% of Ireland’s renewables. In 2013, there were about 150 PV installations, which functioned effectively as microgenerators, and even fewer grid-connected PV installations.

However, the Greener Homes Scheme of 2006 and the introduction of renewable energy requirements in the revision (2008) to the Building Regulations Part L, stimulated investment in renewable heat in the residential sector and solar thermal was supported with government grants.

In 2013, the main contribution from solar thermal installations to the final consumption of renewable energy was in the residential sector, accounting for 0.4% of the total residential sector energy requirement.

Geothermal energy and heat pumps

Heat, classed as renewable, can be extracted from a variety of sources. Air source heat pumps extract heat from the outside air and deliver it at a higher temperature for home heating. Water source heat pumps can be used to extract heat from groundwater, rivers and lakes. Heat from soil or within rocks can also be extracted using heat pumps or by heating water directly against hot underground rock in areas where this is present. Only a part of the energy recovered in this way can be deemed renewable because most heat pumps require electricity to run. At this time (2016), most of the country’s electricity comes from fossil fuels. However, under suitable conditions, heat pumps can deliver much more energy than they require to operate. The Coefficient of Performance (CoP) is the ratio of the heat delivered to the energy input so that it is common to get 3-4 kWh of heat for every 1 kWh of electricity used to run the heat pumps.

Wood and biomass

Biomass refers to a wide range of organic materials that have the potential to be converted into either heat, electricity or transport fuels. The technologies used to generate useful energy from biomass include wood stoves, kilns, combined heat and power (CHP) plants, gasification units, anaerobic digesters, gas engines (Otto cycle as in diesel engines with spark ignition) and Elsbett engines.

Wood was the original source of energy in Ireland, with the initial settlers utilising native forests to source fuel for heating and cooking. Today the biggest use of wood for energy purposes is in the wood processing industry where wood waste is used to generate heat and in some cases heat and power (CHP). The heat is used to dry timber in large steam heated kilns.

During the 1990s, bioenergy grew at a rate of 3% per year, mostly due to greater use of solid biomass as a source of heat in sawmills and related wood processing. The use of solid biomass for energy generation expanded dramatically with the partial conversion of the peat-fired electricity generating plant at Edenderry to co-firing with biomass. Aside from that, biomass use is still today dominated by the sawmilling and wood-based panel sectors where wood is used to generate heat and electricity for drying and processing. Ireland’s first solid biomass-fuelled CHP plant began operating in late 2004 producing heat for timber drying. The bulk of electricity generated by the wood-fired CHP unit was sold under the sixth AER competition.

In the residential sector, many householders still use chopped and seasoned wood for heating. Wood pellets are increasingly in demand, with just over 1,000 tonnes of pellets imported into Ireland in 2006. Switching to biomass as a heat source was supported through various sustainability-based policy programmes, including the Greener Homes Scheme in 2006, the Reheat programme in 2007, the renewable energy requirement in the 2008 Building Regulations Part L and the Combined Heat and Power grant scheme.

In electricity generation, solid biomass is primarily used in co-firing with peat in existing power plants or in industrial CHP plants. The increasing use of biomass in the industry sub-sectors led to increasing industrial biomass use since 1990. However, the use of renewable heat in industry has remained relatively static since 2005 while the utilisation of biomass in the residential sector has increased by 182% in the period 2005 to 2013 after a decrease from 1990 to 2001. This growth is a result of two factors – less use of solid wood in open fires and the increasing popularity of biomass boilers and solid fuel stoves that are more energy efficient than open fires. The introduction of stoves and boilers led to the use of wood pellets and chips as a fuel source. Notwithstanding the technology advances in wood boilers and stoves, the residential sector still only accounted for 14% of the final consumption of solid biomass (including renewable wastes) for thermal energy in 2013.

Biofuels for transport

Under EU legislation, all member states must now ensure that road transport fuels contain a minimum level of renewable energy (biofuels). In Ireland, these are increasingly used in both petrol and diesel. The target for 2020 is that 10% of energy in transport will come from renewable sources.

Renewable gas

Biogas is another source of renewable heat and electricity. There are seven landfill gas electricity generating plants contributing to bioenergy use. At present, biogas from landfill generates more electricity than solid biomass. As of 2012, Ireland had 39 MW of electricity generation capacity running on landfill gas. This contrasts with 10 MW of co-firing capacity attributable to the biomass portion of the fuel in peat-fired stations. There was a further 12 MW of power production from biomass renewables (from solid and anaerobic) CHP capacity.

Research is being carried out on the viability in Ireland of the production of biogas from feedstock including grass. It is examining the potential for renewable gas as a transport fuel using the natural gas transmission network to distribute the energy to centres of greatest demand.