The story of heating in Ireland

For centuries, the open fire or hearth was the principal means of heating and cooking in Ireland. From ancient times, wood and later peat were the main sources of fuel, and much later coal. Ranges were an improvement on open fires and in the second half of the 20^th century, with central heating the preferred option for those that could afford it. Coal and peat prevailed until the 1950s, with oil and towns gas becoming popular in the 1960s, then solid fuel returning from the mid-1970s to the late 1980s, with oil and natural gas (initially from Kinsale) very much the fuels of choice for most consumers over the past 25 years.  At the same time, our buildings have become better insulated and more comfortable, central heating was widely adopted by the 1980s, and our industrial processes have become more energy efficient. Looking ahead towards meeting our climate obligations, the twin priorities are to continue to passively reduce our demand for heat and to supply that heat with technologies that are smarter, cleaner, highly efficient and increasingly from renewable energy sources.  This will present many choices and may involve radical changes such as, for example, a major shift to heating by means of electricity or gas and solid fuels from renewable sources.

Up to the 19^th century, the need for, and means of, heat in Ireland were heavily determined by our relatively mild climate and the local availability of building materials and fuels.  With growing industrialisation and trade, heat demand for our homes, industry and other buildings became increasingly dependent on imported fossil fuel in the form of coal.

The 20^th century was an era of enormous expansion in economic activity, in our building stock, in the demand for heat and in the burning of imported oil and natural gas.  Irish consumers have experienced considerable fluctuations in fuel choices over the decades and steady progress in the quality and efficiency of our heating technologies and our home insulation levels in particular.  Coal and peat prevailed in the 1950s, oil and towns gas becoming popular in the 1960s, then solid fuel returning from the mid 1970s to the late 1980s, with oil and natural gas (initially from Kinsale) very much the fuels of choice for most consumers over the past 25 years.  But as a general trend, our buildings have become better insulated, more comfortable and our industrial processes more energy efficient.

Today, space and water heating of our homes accounts for half of Ireland’s heat demand, our industry for one third and our commercial and public buildings for the remaining one fifth.  The principal heating sources in non-domestic buildings are oil and gas, which in larger buildings are often through integrated heating and ventilation systems; electric heating is common in smaller buildings.  97% of homes in 2011 were centrally heated, with the preferred fuels being oil and gas. Coal and peat were first choice in only 10% of homes – a dramatic decline from the 1950s. In 2011 oil dominated in rural areas, while 54% of homes in larger towns relied on natural gas. Two out of every three homes in Dublin and Cork cities used gas. In contrast, the midlands had the highest incidence of peat and coal use.  Electrical storage heating accounts for around 9% of our home heating.  Wood and other renewables still account for less than 3% of heat supply to Ireland’s homes.  But from a near zero level a decade ago, and driven by regulations, incentives and promotion, biomass boilers (in industry, hotels and the like), electrical heat pumps and solar water heating have been growing slowly but steadily in popularity.

Looking ahead towards meeting our climate obligations under the Paris Agreement of 2015, with the imperative to transform from a fossil fuel based to a low carbon society, the twin priorities are to continue to passively reduce our demand for heat in our homes, public services, businesses and industry, and to supply that heat with active technologies that are smarter, cleaner, highly efficient and increasingly from renewable energy sources.  This will also present many choices, and may involve radical changes such as, for example, a major shift to heating by means of electricity or gas and solid fuels from renewable sources.  In any event, it is likely to lead to a variety of different systems for different circumstances –  dwellings versus businesses, urban versus rural, apartments versus homes.

A number of trends can be expected – in the level of demand for heat, in the sources through which we generate heat, in the infrastructure through which we deliver that heat and in the ways in which we operate and control the use of that heat.  These changes will involve a major cumulative investment across our society over a period of decades, and will need to be driven by a combination of policies:  regulation, incentives/ disincentives, technology development supports, and promotion.  The scale of change means both a significant investment cost, and significant benefits in the form of buildings and services which will be healthier, more comfortable, more affordable to run, more productive and more environmentally sustainable.

Pre-1900s

Irish society’s need for heat and means of heating has been historically conditioned by two factors:  our mild maritime climate and the availability of local or indigenous resources in the form of materials – for building construction and as fuel.  Our climate has meant that, unlike many countries, we had to cope with neither extreme cold nor extreme heat, so that the insulation of our homes and means of heating were more a matter of health and comfort than of immediate life or death.  Plentiful local materials, in the form of stone, wood, mud or peat were suitable for building construction and influenced the nature of local trades and industry over the centuries. Traditionally, our buildings were often positioned to respond to climate, so that for example location, orientation were chosen to protect against cold prevailing winds.

For centuries, the open fire or hearth was the only means of heating and cooking in Ireland. From ancient times, wood and then peat were the main sources of fuel for these activities.  The discovery and mining of indigenous coal reserves fuelled the production of iron from ore using coal conversion into the coke necessary to produce iron.  Once established, coal was used for heating and cooking by households and craft industries close to the mines.  In parallel, coal was also imported for use in homes and industry – at first in coastal towns, but eventually throughout the country as demand increased.  With growing industrialisation and trade, heat demand for our homes, industry and other buildings became increasingly dependent on imported fossil fuel in the form of coal.

The settlement and plantation period in the 16^th and 17^th centuries marked the beginning of large- scale harvesting of natural forests for wood for fuel and timber for building. As population grew in the early 1800s and into the Famine years, the woodlands became more depleted, and a peat fire was a common means of cooking and heating.  The prominence of peat and coal continued to the end of the 19^th century and in many industrial facilities of the period these fuels were used to raise steam to supply heat at high temperatures to various production processes.

20th Century

The 20^th century was an era of enormous expansion in economic activity, in our building stock, in the demand for heat and in the burning of imported oil and natural gas.

By the 1900s, new fuels and appliances had begun to arrive:  oil for lighting, coal for heating in open fires or closed stoves, and coal-gas for gas-fired heaters.  Gas manufactured from coal was known as ‘towns gas’.  People were just starting to use electricity in towns in the 1900s and it was quickly adopted as a convenient new energy source, primarily for lighting. In the early years of that century, solid fuels were still the most widely used and large numbers lived in uncomfortable, congested, unhealthy conditions; nearly 10% of dwellings had 10 or more rooms, but there were over 50,000 one-room dwellings and almost half of these had three or more persons living in the dwelling.  Practically all relied on open fires.

In 1922, the AGA cooker or ‘range’ was invented in Sweden.  With controlled and more efficient burning of solid fuels, it provided energy for cooking and was itself a source of heat in the home.  But open fires and closed stoves remained commonplace in both homes and commercial premises.  With little or no insulation in our often draughty homes until the 1980s, inefficient open fires provided little more than Dickensian standards of thermal comfort.  In areas adjacent to bogs and in public services such as schools and hospitals, peat continued to be a popular source of solid fuel. From the mid-1950s, peat briquettes were manufactured by Bórd na Mona and they are still used today in open fires and closed stoves, frequently as a supplement to gas or oil-fired central heating.  From that period also, oil fired appliances made a strong entry into the market and began to predominate in commercial and public buildings such as modern offices, shops and supermarkets, schools and hospitals.

1960s to 2000

The invention of central heating boilers fired on ‘gas oil’ (diesel), natural gas or LPG offered a greatly improved standard and convenience of heating in the home, in commercial buildings and industrial processes.  In homes from the late 1960s onward, traditional fireplaces began to be replaced with central heating as the principal source of heat. Boilers were used to heat water with oil, then gas and, in some instances, electricity.  Hot water was circulated through radiators to heat the house.

In 1974, while all large commercial and public buildings were centrally heated, just 25% of households in the country had some form of central heating.  Most domestic heating still came from the use of solid fuels in open fires, cooker ranges, stoves and back boilers (usually providing hot water only).  Following world oil price crises in the 1970s, and often subsidised by grants, a form of central heating using solid fuel back boilers supplying radiators became prominent.  But after the drop in oil prices in the mid-1980s, the piping of indigenous Kinsale natural gas to the largest cities and towns, and a diminishing popularity of solid fuel in urban areas –  including progressive smoke and sulphur control regulation during the 1990s – oil (increasingly in the form of kerosene) and gas central heating grew to become the preferred form of heating in over 90% of buildings.  Even traditional solid fuel cooker and stove designs were adapted to oil or gas models.  A further trend was the prevalence of night storage electric heating in the emerging modern apartment sector.  A parallel positive development from 1980 onwards has been the introduction of minimum insulation standards for buildings and their gradual strengthening over the years, plus retrofitting of attic insulation, more efficient glazing and some forms of wall insulation to existing buildings.  Apart from more efficient boilers, we also saw the market uptake of improved automatic controls – including smarter programmer time switches and thermostats, and thermostatic radiator valves.

The scale of market change is seen in the fact that solid fuels were the principal heating source in over three quarters of homes in 1990 but this figure had declined to 15% by 2004, with oil and gas taking their place.  Electric storage heating was installed in about 5% of homes at that point.

Overall, the 20^th century was one of dramatic change overall in the direction of more comfortable, convenient and efficient systems of heating in Ireland’s buildings, but also predominantly with imported fossil fuel.  A rise in national energy use for heating over the decades was driven by a series of forces – rising income, population, housing stock, dwelling sizes, and major expansion in commercial office and retail space, public buildings and industrial premises.

Between 1960 and 2000, the population grew from 2.8 million to 3.8 million, while household numbers grew by 87% from 670,000 to 1.25 million (resulting in a decline from 4 to 3 persons per household).  This rise in total volume of energy use was however accompanied by a general improvement in energy efficiency, i.e. in useful service provided from each unit of energy consumption.  For example, between 1987 and 2000 dwelling numbers grew from less than 1 million to 1.25 million, but energy usage per household declined. There were two main reasons for this – the switch from solid fuels in open fires to more efficient oil and natural gas boilers, and improved insulation standards.

In contrast with much of central Europe, and following the decommissioning of the heating network in the original Ballymun high rise housing development, district or group heating is rare in Ireland, with just a small number of centralised communal heating installations in modern apartment blocks, heated by either gas or biomass.

To summarise:  Irish consumers have experienced considerable fluctuations in fuel choices over the decades but also steady progress in the quality and efficiency of our heating technologies and our home insulation levels in particular.  Coal and peat prevailed in the 1950s, oil and towns gas becoming popular in the 1960s, then solid fuel returning from the mid 1970s to the late 1980s, with oil and natural gas (initially from Kinsale) very much the fuels of choice for most consumers over the past 25 years.  As a general trend, our buildings have become better insulated, more comfortable and our industrial processes more energy efficient.

21st Century

The trends of the late 20^th century have continued through the first decade this century.  By 2011, 97% of Ireland’s homes had some form of central heating.  The principal sources of space heating were oil (44%), gas (34%), electricity (10%), coal and peat (5% each), with the balance being from wood and other renewables.  Notably, our average dwelling size has grown from less than 100 m² in the 1970s to reach almost 120 m² by 2011, which is 39% above the EU average.  Over the same period, due to improved insulation levels and heating efficiencies, the amount of energy required to provide a modern standard of comfort and amenity has fallen considerably.  A new home built to the standards of the Building Regulations of 2011 will need less than 10% of the space heating fuel requirement of its 1970s equivalent.  The same degree of progress in heating efficiency has not yet, however, been evident in the commercial buildings sector.

Today, space and water heating of our homes accounts for half of Ireland’s heat demand, our industry for one third and our commercial and public buildings for the remaining one fifth.  The principal heating sources in non-domestic buildings are oil and gas, which in larger buildings are often through integrated heating and ventilation (and sometimes air conditioning) systems; electric heating is common in smaller buildings.  97% of homes in 2011 were centrally heated, with the preferred fuels being oil and gas, but coal and peat were first choice in only 10% of homes – a dramatic decline. Oil dominated in rural areas, while 54% of homes in larger towns relied on natural gas. Two out of every three homes in Dublin and Cork cities used gas. Moreover, in homes built since 2000 natural gas had a higher share of heating than had oil.  In contrast, the midlands had the highest incidence of peat and coal use.  Electrical storage heating accounts for around 9% of our home heating.

Wood and other renewables still account for less than 3% of heat supply to Ireland’s homes.  But from a near zero level a decade ago, and driven by regulations, incentives and promotion, biomass boilers (in industry, hotels and the like), electrical heat pumps and solar water heating have been growing slowly but steadily in popularity.  Combined heat and power plants have a significant presence in the industrial and services sectors, with over 250 installations operating in 2014 and supplying 6% of national heat and 7% of national electricity supply.  These are fired predominantly on natural gas, with a small number using oil, biogas, biomass or other solid fuel.

Changes in policy have played an important role in recent years.  Developments include:  the prohibition on bituminous coal in Dublin in 1990,  extending to other urban areas since; the successive strengthening of the Building Regulations Part L, most recently in 2011;  the EU Energy Performance of Buildings of 2002 and 2010 which has led to the establishment of Building Energy Rating certification of over 750,000 buildings since 2007;  the EU Eco-Design and Energy-Using Products Directives;  programmes for insulation and other improvements to homes of low income householders;  and other incentive programmes for renewable energy retrofitting of buildings, and the current Better Energy scheme which has supported energy efficiency upgrades to homes, businesses, public sector buildings and now includes a Better Energy Communities scheme.  Over 300,000 buildings have received such energy efficiency upgrades over the past decade.  Since 2008, the Building Regulations have required new homes to have some form of renewable energy source – typically a solar water heating or solar electrical system, a heat pump installation or a biomass installation.

Looking ahead

Looking ahead towards meeting our climate obligations under the Paris Agreement of 2015, with the imperative to transform from a fossil fuel based to a low carbon society, the twin priorities are to continue to passively reduce demand for heat in our homes, services and industry, and to supply that heat with active technologies that are smarter, cleaner, highly efficient and increasingly from renewable energy sources.  In any event, it is likely to lead to a variety of different systems for different circumstances –  dwellings versus businesses, urban versus rural, apartments versus homes.

A number of trends can be expected – in the level of demand for heat, in the sources through which we generate heat, in the infrastructure through which we deliver that heat and in the ways in which we operate and control the use of that heat.

Most fundamentally, the demand for heat is set to fall in all sectors, with space heating declining more than hot water heating.  A drive towards ‘nearly zero’ energy (and carbon) buildings, and for major energy efficiency renovation of existing buildings, is already being mandated by EU directive.  This will also present many choices, and may involve radical changes such as, for example, a major shift to heating by means of electricity from renewable sources.  It will also present challenges, such as providing ventilation systems which are both healthy and energy efficient, of which there are a growing number of product examples already available.

As a source of heat generation, the dominant share from oil and gas is set to steadily decline.  Decarbonisation of energy supply will entail recourse to several already relatively mature renewable energy technologies, such as solar thermal, electrical heat pumps and biomass.  As a major transitional trend towards a more sustainable energy system, there are indications that heating and ventilation powered by electricity increasingly generated from renewable sources (wind, biomass and possibly solar) may become a preferred option over current forms of boiler central heating.  For new urban district or community developments, centralised heat and/or combined heat and power providing district heating from biomass or biogas may offer a solution.  New technologies, such as gas fired heat pumps and fuel cell combined heat and power at individual building level, may also begin to have a presence in the market.  Developments in ICT are set to facilitate convenience and economy, with ‘building management systems’ already well established in services and industrial buildings, while there are products already on the market to allow remote control of domestic heating systems.  Such technologies, along with smart metering of electricity and gas and other ‘smart grid’ technologies, are set to transform the way we experience and interact with the heat technology supply and control systems within our buildings.

These changes will involve a major cumulative investment across our society over a period of decades, and will need to be driven by a combination of policies:  regulation, incentives/ disincentives, technology development supports, and promotion.  The scale of change means both a significant investment cost, and significant benefits in the form of buildings and services which are healthier, more comfortable, more affordable to run, more productive and more environmentally sustainable.  For sure, how we heat (or cool) our homes, offices, shops and industry are set to change rather radically from how we do it today.  Those decades ahead will be challenging and exciting.