Electricity Providers
Liberalisation
European Union directives aim to create a single European electricity market. Ireland has progressively liberalised the market and energy commencing with the Energy Regulation Act 1999, followed by the European Communities (Internal Market in Electricity Regulations 2000.
In 2005, the full market was opened up to competition.  Bord Gáis initially entered the market for business customers. Once ESB reached 60 per cent share, deregulation took take place for residential customers.
All Island Market
The single electricity market project was launched in 2007 between the Republic of Ireland and Northern Ireland governments. The initiative created a single electricity market for the Island of Ireland.
There is a mandatory pool to which almost all electricity has to be bought and sold throughout the island of Ireland. The purpose of this is to combine two smaller markets to create greater competition and improve reliability and efficiency. If it is a stepping stone towards a European energy market with closer harmonisation with Great Britain and ultimately Continental Europe.
Coal and Gas
Most of the electricity capacity in Ireland is produced by gas-fired CCGT combined cycle gas turbines. The proportionate reliance on heavy oil-fired stations has decreased significantly since the 1970s. In 2010, Bord Gáis opened its first major gas-fired plant at Whitegate Cork, generating 500 megawatts.
Four new gas-fired turbine power stations were opened in the period 2010 to 2015, bringing in an extra 400 megawatts capacity.
Approximately 5-10 per cent of capacity is generated by coal. The large Moneypoint station accounted for almost half of electricity generation (915 megawatts) in the past. Moneypoint is the only coal-powered plant.
There were once minor coal resources in Ireland but none has been economically mined for many years. The station can use heavy fuel oil as an alternative. This station undertook significant capital investment in recent years, which included steps to reduce pollutants significantly.
Peat
Starting in the 1930s, the Electricity Supply Board was obliged to use a proportion of peat in its fuel production on the basis of security of supply. Formerly, it was as high as 40 to 50 percent in the 1950s and ‘60s
Peat is effectively the only indigenous fuel. As of 2010, the percentage of mega wattage generated by peat was approximately six per cent. The ESB  employed a range of peat-fired stations over time.
Two peat generating stations in West Offaly and Lough Ree were commissioned in 2005. They replaced older stations at Shanonbridge and Lanesborough. There was an independent 120-megawatt peat station in Edenderry.
The newer plants used more advanced technology than their predecessors and which delivered efficiency and reduced emissions. In 2010, 15 per cent of Ireland’s electricity could be generated through peat under the EU decision.
The Edenderry 120-megawatt peat-fired power station was the first non-ESB plant to come into existence. It was protected to some extent from competition by a long-term agreement for the purchase of power with ESB. It is a large peat and biomass-fired power station.
 It has been owned by Bord na Móna since 2006 and is part of the Powergen Division. It was purchased from E.ON in December 2005. Trials of co-fuelling the plant with biomass commenced in 2007 and were successful.
As of 2020, the plant is co-fired with about 62% biomass (delivered by around 60 heavy goods vehicles per day), of which 336,000 energy tonnes (or 80%) is Irish. The station has a target of 100% biomass by 2023. The ash is sent by rail and deposited at the adjacent Cloncreen bog near Clonbullogue. In 2021 the plant was still burning peat from stocks but was not allowed to cut more.
Most peat-fired stations closed in 2020.
Renewables
Renewable capacity has increased dramatically in the last twenty years, increasing from 5% in 2006 to 36-43% in 2020. Renewables are approximately 85 percent wind and 15 percent hydroelectric.In 2030, 80% of Ireland’s electricity should come from renewable sources.
ESB
Until recently, the Irish electricity sector has been dominated by state sponsored body, Electricity Supply Board. The ESB is a publicly owned corporation. ESB was established in 1927 as a statutory corporation in the Republic of Ireland, and the majority of shares are held by the Irish Government.
The Board was a monopoly or near monopoly supplier of electricity in Ireland from its establishment in the 1920s until the liberalisation of the electricity market and certain EU directives in the 1990s.
The transmission function has been transferred to EirGrid as of 2006. ESB Networks is the distribution system operator.
Electric Ireland is the retail division of ESB (Electricity Supply Board). Previously known as ESB Customer Supply and ESB Independent Energy, the retail division of ESB was rebranded to Electric Ireland in 2012. Recognised as Ireland’s leading energy provider, Electric Ireland supplies electricity, gas and energy services to over 1.2 million households and 95,000 businesses in the Republic of Ireland and Northern Ireland.
Devesting
In 2007, the ESB and the Commission for Energy Regulation entered an “Asset Strategy Agreement.” It was designed to address the dominant position of ESB by purporting competition and maintaining the security of supply.
Under the agreement ESB was required to divest itself of 1300 megawatts of mid-merit plant and 200 megawatts peaking capacity on the phase basis of 2010. It must make sites available to others interested in entering the markets. As part of this agreement, ESB was authorised to build 430 megawatts at Aghada, County Cork.
On 6 July 2010, Viridian agreed to sell Northern Ireland Electricity – including NIE Powerteam, but excluding NIE Energy – to the Electricity Supply Board in the Republic of Ireland. The acquisition was completed in December 2010.
Endesa / SSE
Endesa Ireland Limited, a subsidiary of a large-scale Spanish utility/ energy company, was established in 2009. It purchased the ESB plants at Great Island in Co Wexford and Tarbert in Co Kerry in a €450 million deal, which had a power-generating capacity of 1,068 megawatts (MW), about 16 per cent of Ireland’s total installed capacity.
Endesa also purchased two plants on two sites for power stations at Lanesborough and Shannonbridge. Endesa proposed, as of 2012, to decommission Tarbert and Great Island and replace them with gas power plants.
Endesa Ireland was acquired by SSEÂ in 2012. from Endesa Generacion SA through its subsidiary SSE Generation Ltd. Endesa’s plants at Tarbert Power Station in County Kerry, Great Island Power Station in County Wexford, Tawnaghmore Power Station in County County Mayo and Rhode Power Station in County Offaly effectively passed to SSE. Following the completion of the acquisition, SSE became the third-largest electricity generation capacity owner in Ireland.
SSEÂ completed the construction of a new combined cycle gas turbine generating station at Great Ireland.
SSE Airtricity’s  28 onshore wind farms have a combined generation capacity of 720MW, making it the largest generator and provider of renewable energy in the all-island Single Electricity Market. This includes Ireland’s largest onshore wind farm, the 169MW Galway Wind Park, which was jointly developed with Coillte.
Energia
Energia Group (formerly Viridian Group) was formed in 1998 as a holding company for Northern Ireland Electricity plc; the purpose of the reorganisation was to “step up the move into unregulated markets and for expansion overseas.” NIE was a public utility which was privatised in 1993. Formerly a vertically integrated monopoly, NIE’s power stations were demerged and sold prior to privatisation.
Energia became the first independent supplier in Northern Ireland, and within a year, it had entered the Irish business electricity market. By 2003, Energia had established itself as Ireland’s leading independent energy business supplying over 30% of large industrial electricity requirements. Energia now supplies over 250,000 homes in the Republic of Ireland.
On 6 October 2006, Viridian’s board agreed on the acquisition of the group by Electric Invest, a company owned by the international investment firm Arcapita. The acquisition, which valued Viridian at £1.62 billion, was completed on 8 December 2006
Energia has 550MW of operational renewable electricity capacity contracted within its renewable energy portfolio. This portfolio includes power from our own wind farms or from Power Purchase Agreements where we agree to buy the power from the wind farm, thus securing the funding for its development. Energia Renewables continues to have an aggressive development strategy, with a further 230MW of wind farm projects currently in development across Ireland.
Energia Group owns and operates over 300MW of onshore wind assets across 15 different sites on the island of Ireland. We are currently developing both onshore and offshore wind energy, solar technology, green hydrogen production, bioenergy plants and battery storage projects. Our ongoing €3bn ‘Positive Energy’ investment programme will double our renewable energy capacity to help reach our climate action goals.
Energia is developing two offshore renewable energy projects off the coast of counties Waterford and Wexford; its North Celtic Sea and South Irish Sea projects.
Huntstown Power Company was a  fully owned subsidiary of Veridian PLC and commenced operations in 2002, with a  243 megawatt power plant situated in north county Dublin.  A second power station on the Huntstown site was completed with h 440 megawatt capacity.
Bord Gais Energy
The market was deregulated in 2007. On 18 February 2009, Bord Gáis Energy entered the residential market, joining Airtricity and ESB Customer Supply.
A condition of the EU/IMF bailout programme for Ireland required the Irish government to sell off some state-owned assets to help pay down loans and reduce Ireland’s debt burden. In March 2014, Bord Gáis Éireann confirmed it would sell its customer supply arm Bord Gáis Energy to a consortium made up of Centrica, Brookfield Renewable Energy and iCON Infrastructure to the value of €1.1 billion.
The sale involved the splitting of the group’s retail unit among the three buyers. The main retail division would be bought by Centrica, while its wind assets under SWS would be acquired by Brookfield Renewable Energy Partners and iCON infrastructure acquiring Northern Ireland based Firmus Energy.
Bord Gáis Éireann was subsequently renamed Ervia.
Bord Gáis Energy is a private limited company that is part of the Centrica Group and no longer associated in any way with Ervia or any of its subsidiaries (Irish Water or Gas Networks Ireland). In July 2014, it became part of the global Centrica plc Group.
Whitegate was Bord Gáis’ first major electricity-generating station, opened in 2010 with a capacity of 445 megawatts. It is a CCGT plant. It is powered by natural gas augmented by the supply of refinery gas adjacent to the Conoco Philips Refinery.
Others
Tynagh Energy developed 400 megawatts of combined cycle gas turbine power based on natural gas with backup from distillate oil. Its shareholders are Gamma Energy International 40 per cent, GE Energy Financial Services 40 per cent Mountside Properties 20 per cent.
Aughinish is a combined heat and power plant at the Shannon Estuary producing 160 megawatts. It provides all electricity required by the Aughinish plant, around 40 megawatts and two-thirds of its heat requirement.
Aghada was constructed by EBS under the Asset Strategy Agreement. A 430-megawatt combined CCGT plant, it replaces an existing 528 megawatt plant on the site.