Energy in the Residential Sector 2008 REPORT

Transcription

1 Energy in the Residential Sector 2008 REPORT

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3 Energy in the Residential Sector 2008 Report Report prepared by Fergal O Leary, Martin Howley and Dr. Brian Ó Gallachóir June 2008

4 Sustainable Energy Ireland Sustainable Energy Ireland was established as Ireland s national energy agency under the Sustainable Energy Act SEI s mission is to promote and assist the development of sustainable energy. This encompasses environmentally and economically sustainable production, supply and use of energy, in support of Government policy, across all sectors of the economy including public bodies, the business sector, local communities and individual consumers. Its remit relates mainly to improving energy efficiency, advancing the development and competitive deployment of renewable sources of energy and combined heat and power, and reducing the environmental impact of energy production and use, particularly in respect of greenhouse gas emissions. SEI is charged with implementing significant aspects of government policy on sustainable energy and the climate change abatement, including: Assisting deployment of superior energy technologies in each sector as required; Raising awareness and providing information, advice and publicity on best practice; Stimulating research, development and demonstration; Stimulating preparation of necessary standards and codes; Publishing statistics and projections on sustainable energy and achievement of targets. It is funded by the Government through the National Development Plan with programmes part financed by the European Union. Energy Policy Statistical Support Unit (EPSSU) SEI has a lead role in developing and maintaining comprehensive national and sectoral statistics for energy production, transformation and end use. This data is a vital input to meeting international reporting obligations, for advising policy makers and informing investment decisions. Based in Cork, EPSSU is SEI s specialist statistics team. Its core functions are to: Collect, process and publish energy statistics to support policy analysis and development in line with national needs and international obligations; Conduct statistical and economic analyses of energy services sectors and sustainable energy options; Contribute to the development and promulgation of appropriate sustainability indicators. Sustainable Energy Ireland REPRODUCTION OF THE CONTENTS IS PERMISSIBLE PROVIDED THE SOURCE IS ACKNOWLEDGED.

5 Highlights The observed ODEX (a measure of energy efficiency) for the residential sector in Ireland decreased by 15.2%, indicating an improvement in energy efficiency over the period 1995 to 2006 (1.5% per annum). The technical ODEX (an energy efficiency measure which excludes behavioural factors) decreased by 28% (2.9% per annum) from 1995 to This implies that significant additional efficiency gains would have been made if not for household behaviour. Comparing energy usage per dwelling in 2006, Ireland was 27% above the average for the UK and in 2005, 31% above the EU-15 average and 36% above the EU-27 average. General Context In 2006 the total amount of primary energy used by the residential sector was 3,965 ktoe, an increase of 32% (1.8% per annum on average) on The residential sector s share of total energy usage fell from 32% in 1990 to 25% in 2006 and was second only to the transport sector. The residential sector in 2006 used 2,990 ktoe of final energy. This represents 23% of Ireland s Total Final Consumption (TFC) and is a 32% increase (1.8% per annum) on With regard to CO2 emissions the residential sector s share of total emissions decreased from 35% in 1990 to 25% in 2006, despite actual CO2 increasing by 9.8% (0.6% per annum on average) to reach 11,896 kt CO2. The residential sector was the second largest after transport (35%). Average household electricity use per person in 2006 was 1,909 kwh, a 62% increase on 1990 (3% per annum). Household fuel use per person was 6,299 kwh in 2006, a decrease of 0.3% on 1990 (0.02% per annum). In 2006 the average dwelling consumed a total of 25,304 kwh of energy based on climate corrected data. This was comprised of 19,713 kwh (78%) in the form of direct fossil fuels and the remainder (5,591 kwh) as electricity. In 2006 the average dwelling was responsible for emitting approximately 8.1 tonnes of CO2. A total of 4.8 tonnes CO2 (59%) was from direct fuel use, the remainder being the result of upstream emissions from electricity usage. In 2006 average annual spend on energy by households was 1,767, an increase of 4% on 2005 and 70% on 1990 (3.4% per annum on average). Total spend on energy by the residential sector was approximately 2.5 billion in From June 2000 to January 2008 household electricity prices doubled (99% increase). The price of kerosene rose by 78% over the period and natural gas prices increased by 87%. From January 2006, when collection of data began, to January 2008 the price of bagged wood pellets increased by 12%. In 2004/2005 those in the lowest income decile spent on average 13% (compared with 14% in 1999/2000) of their disposable income on energy while the highest earners spend 1.7% (2% in 1999/2000). The average proportion of total disposable income spent on energy for Ireland as a whole was 3.6% (4% in 1999/2000 and 6.9% in 1987). 1

6 Data from the Household Budget Survey indicates that, at least 144,171 homes were experiencing fuel poverty in Underlying Factors The most recent Census, carried out in April 2006, stated that there were 1,462,296 private households in permanent housing units. Over the period 1961 to 2006 the number of private households in permanent housing units increased by 116%. There was a 43% increase from 1991 to 2006 and a 14% increase from 2002 to Just under 50% of the housing stock were built before the first thermal energy insulation requirements came formally into effect in The total number of dwellings completed per year increased by 252% (11% per annum on average) from 1994 to In 2007, there was a 17% reduction in the number of completions on The most common house type in Ireland in 2006 was the detached house which accounted for 43% of the total. The average floor areas of new houses granted planning permission grew from 130 square metres in 1990 to 161 square metres in 2007 (an increase of 24%). The average number of persons per household declined by 29% over the period 1961 to 2006 and by 16% from 1991 to In addition CSO Census data reveals that the proportion of one person households has increased from 13% in 1961 to 22% in By international standards the average household size in Ireland remains high, at 2.81 persons per household in By comparison in 2004 in Germany the average was 2.1 persons per household while in Denmark it was 2.2 and in the UK in 2000 the average was 2.4. The proportion of homes with central heating has increased from 52% in 1987 to 91% in International Comparison Comparing electricity consumption per dwelling (climate corrected), in 2006 Ireland s electricity usage was 20% above the average for the UK, and in 2005, 17% above the average for the EU-15 and 29% above the average for the EU-27. Examining CO2 emissions per dwelling, the average Irish dwelling in 2005 emitted 47% more CO2 that the average dwelling in the UK. Emissions were 92% higher than the average for the EU-15, 104% more than the EU-27. Comparing ODEX indicators, where data are available, Poland experienced the largest improvement in energy efficiency from 2000 to 2005 at 28% while Greece recorded a deterioration of 3%. There was a 2% improvement for the EU- 15 as a whole (4% for the EU-27). Over the same period Ireland recorded a 10% improvement in energy efficiency. 2

7 Table of Contents Highlights... 1 General Context... 1 Underlying Factors... 2 International Comparison Introduction Energy and Environmental Context Energy Consumption and CO2 Emissions Underlying Causes The Housing Stock Number of Dwellings Type of Dwelling Period of Construction Estimated Floor Area Household Size and Occupancy Space Heating Expenditure on Fuel Additional Factors Energy Intensity and Efficiency Energy Efficiency International Comparison Going Forward Targets and Measures Forecasts of Energy Use Data Gaps Summary / Conclusions Data Sources References Residential Sector Final Energy Use 1990 to

8 Table of Figures Figure 1 Total Primary Energy Requirement by Sector 1990 to Figure 2 Residential Sector Energy Balance Figure 3 Residential Sector Total Final Energy Consumption by Fuel 1990 to Figure 4 Drivers of Energy Usage and CO2 Emissions... 9 Figure 5 Private Households in Permanent Housing Units (Selected Years) Figure 6 New Dwellings Completed by Type 1992 to Figure 7 Private Households in Permanent Housing Units Period of Construction Figure 8 Average Floor Areas of New Flats and New Houses 1990 to Figure 9 Average Floor Area of the Housing Stock 1990 to Figure 10 Penetration of Central Heating - Selected Years Figure 11 Central Heating / Thermal Unit Consumption Selected Years Figure 12 UK Internal Temperatures 1970 to Figure 13 Residential Sector Energy Prices 2000 to Figure 14 Average Spend on Energy per Permanently Occupied Dwelling 1990 to Figure 15 Ratio of Expenditure on Energy to Total Expenditure 1990 to Figure 16 Weekly Expenditure on Energy as a Proportion of Disposable Income Figure 17 Penetration of Electrical Appliances - Various Years Figure 18 EU Market Share of A Label Appliances, Selected Years - Various Years Figure 19 Estimated Electricity End Use Figure 20 Residential Energy Usage per Person 1990 to Figure 21 Unit Consumption of Energy per Dwelling (permanently occupied) 1990 to Figure 22 Estimated Energy Usage per Square Metre 1990 to Figure 23 Residential ODEX 1995 to Figure 24 Residential Energy Savings 1996 to Figure 25 Drivers of Change in Heating Consumption per Dwelling 1995 to Figure 26 Energy Usage per Dwelling Climate Corrected Figure 27 Final Energy Usage - Fuel Mix Figure 28 Electricity Consumption per Dwelling Climate Corrected Figure 29 CO2 Emissions per Dwelling Climate Corrected (Fossil Fuels) Figure 30 Residential Sector ODEX Variation 2000 to Figure 31 Residential Final Energy Demand by Fuel 1990 to 2020 (White Paper) Table of Tables Table 1 Growth Rates and Shares of TPER by Sector... 7 Table 2 Growth Rates and Shares of Final Consumption in Residential Sector... 8 Table 3 Private Households in Permanent Housing Units (Selected Years) Table 4 Stock of Private Households in Permanent Housing Units Type of Accommodation Table 5 Private Households in Permanent Housing Units Period of Construction Table 6 Growth Rates of Average Residential Floor Areas per New Dwelling Table 7 Growth in Average Floor Area -Stock Table 8 Average Number of Persons per Household Census Years Table 9 Penetration of Central Heating by Fuel Type Table 10 Impact of Building Requirements Table 11 Private Households in Permanent Housing Units Ownership 1991 and Table 12 Penetration of Electrical Appliances Various Years Table 13 Growth Rates of Residential Unit Energy Consumption and Unit CO2 Emissions Table 14 Estimated Energy Usage per Square Metre 1990 to Table 15 Residential Final Energy Usage - Fuel Mix Table 16 Projected Impacts and Further Potential Residential Sector Table 17 Energy Efficiency Savings -By Sector Table 18 Residential Final Energy Demand by Fuel 2005 to 2020 (White Paper)

9 1 Introduction The residential sector accounted for just under a quarter of all the energy used in Ireland in 2006 and after transport it was the second largest energy using sector. It was responsible for 25% (11,896 kt CO2) 1 of energy related CO2 emissions. Energy use in the sector includes energy for heating, cooking, cleaning, washing, drying, lighting, cooling and for entertainment. The sector is one where considerable expansion has occurred in recent years with the number of permanently occupied dwellings increasing by 43% (2.4% per annum) to reach 1.46 million over the period 1990 to As a result, there is a clear incentive for policy makers to implement programmes and measures that reduce the sector s demand for energy. The purpose of this report, an update of the December 2005 edition, is to provide context and background to discussions regarding future policy options. In addition to an examination of overall residential sector energy usage and CO2 emissions trends the report presents an updated profile of the housing stock using new data from the Census and the Household Budget Survey. New indicators of energy efficiency have been added as well as forecasts of residential sector energy use to It also identifies key data gaps, such as the lack of robust, end use data and suggests areas for further study. Finally the report has been restructured to improve the presentation of data. The report is intended to be a further step in an ongoing process to develop and improve energy statistics in the residential sector and is structured as follows: The relevant trends in energy usage and CO2 emissions are outlined in section 2 to provide a context for the work. Section 3 profiles the residential sector and analyses the key issues that affect energy usage in Ireland. Section 4 examines energy intensity and energy efficiency trends. In section 5 trends in the residential sector in Ireland are compared with trends internationally, using data from the ODYSSEE project. Finally section 6 details Government targets, presents forecasts to 2020 and summarises the measures and programmes that have been announced to meet these targets. Conclusions and key data gaps in the sector are also included. The energy balance data for 2006 analysed in this report (and presented in tabular form on page 42) was frozen on 23 rd November Balance data are updated whenever more accurate information is known. To obtain the most up-to-date balance figures visit the statistics publications section on Sustainable Energy Ireland s website. A new energy data service is available at follow the links for Energy Statistics Databank. This service is hosted by the Central Statistics Office with data provided by SEI. Feedback and comment on the report are welcome and should be addressed by post to the address on the rear cover or by to mailto:epssu@sei.ie. 1 kilo tonnes carbon dioxide. 5

10 2 Energy and Environmental Context This section provides an overview of residential sector energy trends and the sector s share of total energy usage in Ireland, over the period 1990 to A more detailed discussion of energy trends in Ireland is available in the latest edition of Energy in Ireland 2. Ireland s energy supply is discussed in terms of changes to the total primary energy requirement (TPER), defined as the total amount of energy used within Ireland in any given year. This includes the energy requirements for the conversion of primary sources of energy into forms that are useful for the final consumer, for example electricity generation and oil refining. Figure 1 allocates Ireland s primary energy supply to each sector of the economy, according to its energy demand. The allocation is straightforward where fuels are used directly by a particular sector. Regarding electricity, the primary energy associated with each sector s electricity consumption is included to yield the total energy supply for each sector. Figure 1 Total Primary Energy Requirement by Sector 1990 to Mtoe Industry Transport Residential Commercial/Public Services Agriculture Source: SEI Table 1 tabulates the growth rates of the different sectors in terms of TPER and also provides the shares for 1990 and While the residential sector s energy usage has increased by 32%, its share of total energy usage fell from 32% in 1990 to 25% in This is largely the result of the 167% growth in energy usage for transport purposes. The total amount of energy used by the residential sector was 3,965 ktoe 3 in Available from 3 kilo tonnes of oil equivalent. 6

11 Table 1 Growth Rates and Shares of TPER by Sector Growth % Average Annual Growth Rates% Shares % Industry Transport Residential Commercial / Public Agriculture Total Source: SEI With regard to CO2 emissions the residential sector s share of total emissions 4 decreased from 35% in 1990 to 25% in 2006, despite actual CO2 increasing by 9.8% (0.6% per annum on average) to reach 11,896 kt CO2. The residential sector was the second largest after transport (35%). Figure 2 shows Ireland s residential sector energy balance for 2006 as an energy flow diagram. Figure 2 Residential Sector Energy Balance 2006 Source: SEI Fuel inputs on the left totalled 3,965 ktoe and include (pro-rata) the fuels 5 used to generate the electricity consumed by the sector. The energy transformation losses (mostly electricity generation) amounted to 1,009 ktoe (or 25% of residential TPER) resulting in the final energy consumption of the residential sector in 2006 reaching 2,990 ktoe. This represents 23% of Ireland s Total Final Consumption 6, and is the amount of energy for which households within the sector are billed directly. Referring again to Figure 2 the significant dependence on oil (38% of residential sector TFC) and electricity (23%) is noticeable. 4 Measured as kilo tonnes of carbon dioxide (kt CO2). 5 The total of each individual fuel used for electricity generation and oil refining is apportioned to each end use sector according to the final consumption of electricity and oil by that sector. 6 TFC is essentially TPER less the quantities of energy required to transform and distribute primary sources such as crude oil into forms suitable for use by consumers such as refined oils and electricity. 7

12 Figure 3 shows the fuel mix contributing to the overall energy bill of the residential sector for the period 1990 to Figure 3 Residential Sector Total Final Energy Consumption by Fuel 1990 to Mtoe Coal Peat Oil Natural Gas Renewables Electricity Residential final energy use grew by 32% (1.8% per annum) over the period 1990 to Source: SEI As can be seen from Figure 3 and Table 2 natural gas experienced the biggest growth rate over the period (11% per annum on average) followed by oil (6.9% per annum) and electricity (4.3% per annum). Solid fuels (coal, peat and briquettes) all declined over the period. This reflects a significant change in the fuel mix over the period. Table 2 also contains the shares for 1990 and In 1990 coal and peat were responsible for 28% and 32% respectively of total energy usage in the residential sector. By 2006 coal and peat had declined to 7.3% and 9.5% of TFC. Meanwhile the shares of oil and gas increased from 17% and 5.2% respectively to 38% and 21% in Electricity also increased its share of residential sector TFC from 16% in 1990 to 23% in Due to the differences in energy conversion efficiencies associated with the different fuels, coupled with the differences in carbon content of fuels utilised, the energy use in the residential sector has become increasingly less CO2 intensive since Table 2 Growth Rates and Shares of Final Consumption in Residential Sector Growth % Average Annual Growth Rates % Shares % Fossil Fuels (Total) Coal Peat Briquettes Oil Natural Gas Renewables Combustible Fuel (Total) Electricity Total Source: SEI 8

13 3 Energy Consumption and CO2 Emissions Underlying Causes A number of factors shape the patterns of energy usage seen in section 2. This section analyses the significant variables which underlie the trends in residential sector energy usage and CO2 emissions. Some of the variables such as the number of dwellings will be expected to increase the demand for energy while other factors such as the Building Regulations will be expected to reduce demand. The variables are examined in this section, under 4 headings as illustrated in Figure 4: Figure 4 Drivers of Energy Usage and CO 2 Emissions The Housing Stock Numbers Type of dwelling Period of construction Floor area Household size Household occupancy Space Heating Penetration of central heating External and internal temperatures Fuel used Building regulations Economic Factors Energy prices Average spend Expenditure on energy as % of disposable income (fuel poverty) Other Factors Tenure / location Penetration of electrical appliances Market share of A label appliances Estimated electricity end use Penetration of energy efficient items Source: SEI 3.1 The Housing Stock As consumption of energy in the residential sector is dependent on the characteristics of the total stock of dwellings, it is therefore necessary to define this total Number of Dwellings There are many variables that can be used to track trends in the stock of housing, for example number of housing units, houses built, number of private households, number of private households in permanent housing units etc. The latter is one of the measures used in the Census of Population and is considered for the purposes of this report to be the indicator which best tracks the actual number of households in the country and the most useful in terms of impact on energy usage changes. The measure does not include temporary dwellings, holiday homes that are only occupied for part of the year and non-private households, defined as a group of persons situated in a boarding house, hotel, prison or ship, etc 7. 7 More details can be found in volume 6 (Housing) of the Census. Available from 9

14 The most recent Census, carried out in April 2006, stated that there were 1,462,296 private households in permanent housing units. The trend from Census data since 1961 is presented in Figure 5 and Table 3. Figure 5 Private Households in Permanent Housing Units (Selected Years) 1,600 Private Households in Permanent Housing Units ('000) 1,400 1,200 1, Source: CSO Over the period 1961 to 2006 the number of private households in permanent housing units increased by 116%, by 43% from 1991 to 2006 and by 14% from 2002 to Also shown in Table 3 is the average annual growth between periods, the acceleration in the trend in recent years is clearly evident. Table 3 Private Households in Permanent Housing Units (Selected Years) Year Number Average Annual Growth Rate Between Periods % , , , ,019, ,114, ,279, ,462, Source: CSO Type of Dwelling In addition to the number of households, a key variable impacting on energy consumption in the residential sector is the type of dwelling. Flats and or apartments, hereafter referred to as flats, are typically expected to have the lowest heat loss (as a result of their smaller size) while detached houses will have the largest as a result of having a larger surface ratio. It has been estimated that up to 25% of the heat from a dwelling can be lost through its walls 8. It follows that a dwelling with a larger surface area will be expected to have a greater potential for heat loss. If the proportion of flats in the stock is increasing it may therefore be assumed that the stock is becoming less energy intensive. 8 Source SEI. for more details. 10

15 Data on accommodation type is available from a number of sources such as the Census of Population, INSHQ and the CSO Quarterly National Household Survey (QHNS). For this report the Census data was used as it is the most recent. Table 4 illustrates that the most common house type in Ireland in 2006 was the detached house which accounted for 43% of the total. Table 4 Stock of Private Households in Permanent Housing Units Type of Accommodation Dwelling Type 2006 Number 2006 % of Total Detached House 625, Semi-Detached House 398, Terraced House 257, Flat / Apartment 9 139, Bed-sit 8, Not Stated 31, Total 1,462, Source: SEI While the above refers to the stock of houses data are also available for the number of completed dwellings by type. Figure 6 illustrates the number of house completions by type from 1992 to 2006, 1992 being the earliest year data are available. Data are sourced from the Department of the Environment, Heritage and Local Government (DEHLG) which in turn is obtained from dwellings connected to the electricity supply. A comparable dataset is not available before 1994 and from 2005 data are categorised differently 11. While this precludes an analysis of dwelling type over the full period it can be seen that apartments have increased their share of annual new dwellings from 19% in 1994 to 24% in The total number of dwellings completed per year increased by 252% (11% per annum on average) from 1994 to In 2007, there was a 17% reduction in the number of completions on Figure 6 New Dwellings Completed by Type 1992 to ,000 90,000 80,000 70,000 60,000 Number 50,000 40,000 30,000 20,000 10, * 2006 * 2007 * Flat /Apartment Bungalow Detached House Semi-D House Terraced House Individual House Scheme House Source: DEHLG 9 This refers to both converted and purpose built flats and apartments. 10 Percentage totals in this report may not sum to 100 as a result of rounding errors is classified as follows:" Individual House" is where connection is provided to separate detached house. "Scheme House" is where connection is provided to two or more houses. "Apartments" is where all customer metering for the block is centrally located. 11

16 The European Housing Review 12 stated that in 2006 Ireland had the highest per capita building rate in the EU. Completions per capita were over 50% higher than Spain, the country with the second highest building rate. The Housing review goes on to state that: Demographic and other factors suggest the need for more housing in the years to come but it is rare indeed for an advanced economy to absorb such a high level of housing investment on a sustained basis Period of Construction A key factor in determining the energy profile of the housing stock is the period of construction. Newer houses must conform to stricter energy efficiency standards and therefore they will be expected to use less energy per square metre than older dwellings. However, improvements in insulation standards in the existing stock through retrofitting will be expected to have offset some of the energy losses that would otherwise have occurred. Figure 7 and Table 5 illustrate the age profile using data from the 2006 Census. Figure 7 Private Households in Permanent Housing Units Period of Construction % of Dwellings Constructed by Period Before to to to to to to to or later Not stated Source: CSO It can be seen that 28% of the total housing stock has been built since These dwellings should be more energy efficient as they have been subject to more stringent Building Regulations. By contrast 50% of the stock were built before the first thermal insulation requirements came formally into effect in It can be reasonably assumed that pre-1980 housing stock has a poorer standard of insulation than those built after the introduction of the thermal building requirements. According to the European Housing Review, , Ireland has the youngest dwelling stock in the EU. 12 Royal Institution of Chartered Surveyors, European Housing Review. Available from 13 Royal Institution of Chartered Surveyors, 2008, European Housing Review Page 65. Available from 14 It can be seen that data are shown to 1980 as opposed to 1979 but this shouldn t significantly alter the point. In addition there were some elementary building thermal energy requirements from Royal Institution of Chartered Surveyors, European Housing Review. Available from 12

17 Table 5 Private Households in Permanent Housing Units Period of Construction Period in which Built Number % of Total Before , to , to , to , to , to , to , to , or later 249, Not stated 69, Total 1,462, Source: CSO Estimated Floor Area A dataset is published by the CSO which shows the average floor area of granted planning permissions for flats and houses. Not all dwellings that are granted planning permission are built but the figures provide a plausible proxy for the trend in new flat and house size. The trend is shown in Figure 8 for the period 1990 to 2007 with percentage growth rates shown in Table 6. Table 6 Growth Rates of Average Residential Floor Areas per New Dwelling Growth % Average Annual Growth Rates % New Houses New Flats Source: CSO and SEI Average floor areas of new houses granted planning permission grew from 130 square metres in 1990 to 161 square metres in 2007 (an increase of 24%). The average declined slightly in the early 1990s and grew at a rate of 2% per annum in the latter half of the decade saw an increase of 1.5%. Average floor areas of new flats showed a stronger growth over the period from 64 square metres to 82 square metres (27%). The average floor area of flats increased by 1% in Figure 8 Average Floor Areas of New Flats and New Houses 1990 to Average Floor Area of Granted Planning Permission (square metre) Average Floor Area Per New House Average Floor Area Per New Flat Source: CSO and SEI 13

18 The ratio of new houses to new flats granted planning in 1990 was approximately 9 to 1 whereas in 2007 it was approximately 3 to 1. While the above only refers to new dwellings it is also possible to estimate the trend in the stock as a whole using the CSO dataset and a model of the stock of dwellings derived using, inter alia, data from DEHLG studies in the mid 1990s 16. Data from this model is updated incrementally, using planning permission data from the CSO minus an estimate of demolitions 17. Table 7 summaries the growth rates during the period. Over the period 1990 to 2007 the estimated average floor area of the stock of dwellings increased from 100 square metres in 1990 to 117 square metres in Table 7 Growth in Average Floor Area -Stock Growth % Average Annual Growth Rates % Average Floor Area Source: CSO and SEI Average floor area has increased steadily over the period as larger dwellings are added to the stock. Growth of 1.2% was recorded in The increasing trend in floor area has been offset somewhat by the growing number of flats. However, overall the dominant driving force is the number and size of large one off or non estate dwellings that have been built in recent years. For example in the fourth quarter of 2007 average floor areas granted for non estate houses was 242 square metres compared to 136 square metres for houses in estates and 91 square metres for flats 18. The evidence suggests that there has been a trend towards larger dwellings. Taken in isolation, this should have had a significant impact on the amount of energy demanded in the residential sector as bigger dwellings tend to have a larger demand for heating as they have a proportionally greater wall surface area and therefore higher heat loss. This is expected to have been offset, somewhat, by the increasing insulation standards promoted through iterations of the Building Regulations in recent years. Figure 9 Average Floor Area of the Housing Stock 1990 to Average Floor Area of Stock of Houses (Square Metre) Source: CSO and SEI 16 Kevin O Rourke, Personal Communication. 17 ESRI have estimated in the Irish National Survey of Housing Quality that 0.06% of the housing stock is lost through demolitions each year. 18 CSO (2007), Planning Permissions Quarter Available from 14

19 3.1.5 Household Size and Occupancy While the number of dwellings and the average size of these dwellings has been increasing in recent years Table 8 shows that the number of persons making up a household is declining. This is important as, other things being equal; two people living in two separate households will typically consume more energy than two people living in the same household. Table 8 presents the average household size for selected years from 1961 to Table 8 Average Number of Persons per Household Census Years Average Number of Persons per Household Source: CSO The average number of persons per household declined by 29% over the period 1961 to 2006 and by 16% from 1991 to In addition CSO Census data reveals that the proportion of one person households has increased from 13% in 1961 to 22% in By international standards the average household size in Ireland remains high. For example in 2004 in Germany the average was 2.1 persons per household while in Denmark it was 2.2 and in the UK in 2000 the average was Another factor which would be expected to affect the demand for energy in the residential sector is occupancy. Dwellings which are empty for extended periods during the day should require less energy for heating and lighting than those which are constantly occupied. Data on occupancy is not directly available but the rate of female participation in the workforce can be used as a proxy and in recent years there has been a significant increase in the number of women working. In 1997 the employment rate for women of working age was 42%. By quarter 3, 2007 this had increased to 55% 20. The number of vacant dwellings is also on the increase. In 1991, 12.7% of dwellings were not occupied (on the night of the Census) 21. In 2006 there were 266,000 vacant dwellings representing 15% of the total housing stock. Of these, 175,000 were houses, 42,000 were flats and 50,000 were classified as holiday homes 22. Furthermore NCB stockbrokers in 2006 estimated that more than 10,000 second homes are constructed annually 23. This number can reasonably be expected to have declined in 2007 and Space Heating Another significant factor in residential sector energy usage is the system of space heating. Central heating systems are predominantly more energy efficient than individual room heating appliances for example, open fires with backboilers, so for a given requirement of space heating less energy would be expected to be used. On the other hand, a considerable increase in the level of comfort, in the form of higher temperatures and a move towards whole house heating, is often associated with the introduction of central heating. There may also be greater convenience using timer controls, particularly with oil and natural gas fired systems, which has the potential to result in greater usage. Therefore an improvement in energy efficiency associated with a switch to central heating can be 19 Housing Statistics in the EU CSO, various years, Quarterly National Household Survey See 21 Fitzgerald, John The Irish Housing Stock: Growth in Number of Vacant Dwellings. Available from 22 CSO, 2007, Census Volume 6. Available from 23 NCB Stockbrokers, January The Irish Housing Market. 15

20 offset somewhat by increased energy usage through greater convenience and comfort levels. Current data availability does not permit a quantification of this last point and it is an area where further study is required. Figure 10 and Table 9 show the percentage of dwellings with central heating from 1987 to 2005 using data from iterations of the CSO Household Budget Survey (HBS) 24. It can be seen that the proportion of homes with central heating has increased from 52% in 1987 to 91% in In 1974 it has been estimated that less than 25% of the 740,000 households in the country had central heating 25. For comparison, in the UK in 2004, 92% 26 of homes used some form of central heating compared to 31% in Figure 10 Penetration of Central Heating - Selected Years % With Central Heating Solid Fuel Electricity Oil Fired Gas Fired Dual System Source: CSO Table 9 Penetration of Central Heating by Fuel Type Fuel Type % Solid Fuel Electricity Oil Fired Natural Gas Fired Dual System Total Central Heating Source: CSO It can be seen that the share of solid fuel has declined while central heating systems fired by oil and natural gas have increased. It is worth noting that the Economic and Social Research Institute (ESRI) in the Irish National Survey of Housing Quality (INSHQ) 27 state that over 80% of dual 28 systems use oil. In the coming years however, it is anticipated that solid fuel may increase again due to increasing use of biomass systems. For comparison, in the UK the predominant form of central heating was natural gas which increased from 10% of homes in 1970 to over 77% in By contrast the use of solid fuels fell from 9% to 1% over the same period CSO, Various Years. Household Budget Survey Kevin O Rourke, Personal Communication with Energy Policy Statistical Support Unit. 26 Building Research Establishment, Domestic Energy Fact File Available from 27 ESRI, Irish National Survey of Housing Quality. A full copy of the report or an executive summary can be downloaded from 28 The INSHQ defines duel systems as central heating systems which can be run from either solid fuel or oil, or two separate systems. 29 Building Research Establishment, Domestic Energy Fact File Available from 16

21 The relationship between unit consumption, (usage of energy per dwelling), and the penetration of central heating is examined in Figure 11 (for more on unit consumption see section 4). Only thermal (fuel) usage is shown, i.e. electricity is excluded, as it constitutes such a small proportion of central heating and as noted in Table 9 the majority of central heating is fuelled by oil, natural gas or solid fuels. Unit consumption here is climate corrected, using degree day 30 data, to filter out the variations due to hot and cold years. Central heating data are only available in this series for 1987, 1995, 2000, and 2005 so the comparison with energy usage is limited to these years. Figure 11 Central Heating / Thermal Unit Consumption Selected Years ,000 % of Households With Central Heating ,000 21,000 20,000 19,000 18,000 17,000 16,000 kwh / Dwelling Central Heating % Residential Thermal Energy (Climate Corrected) 15,000 Source: CSO Figure 11 suggests that the increase in the penetration of central heating, and associated increase in comfort and energy use, was offset by gains made through energy efficiency. This is illustrated by the decrease in thermal unit consumption (climate corrected) from 1987 until This decrease in energy usage is due, in part, to the switch from the use of solid fuels in open fires and backboilers to oil and natural gas central heating, as seen in Figure 10. A number of other factors such as the increased insulation standards arising from revisions of the Building Regulations will also have had an impact through improvements in building fabric performance and more recently as a result of heating control requirements. The trend was reversed from 2000 when the increase in the penetration of larger dwellings, central heating, and associated increase in comfort and energy use, was no longer offset by gains made as a result of energy efficiency improvements. This coincides with increased disposable income during the Celtic Tiger years. This is known as a comfort effect whereby the convenience of automated controls, whole house heating, larger houses and higher internal temperatures outweigh lower energy consumption gains achieved as a result of fuel switching to cleaner fuels. In summary, Figure 11 intimates that while thermal energy consumption has decreased per dwelling, total energy savings were reduced by increased comfort. The last point does not take into account the social and health benefits arising from increased household comfort and convenience. 30 Data are climate corrected using degree days where degree days are a measure or index used to take account of the severity of the weather when looking at energy consumption in terms of heating (or cooling) "load" on a building. A degree day is an expression of how cold (or warm) it is outside, relative to a day on which little or no heating (or cooling) would be required. It is thus a measure of cumulative temperature deficit (or surplus) of the outdoor temperature relative to a neutral target temperature (base temperature) at which no heating or cooling would be required. 17

22 Data on comfort levels or internal temperature is currently not available for Ireland but estimates are available for the UK and are presented in Figure 12. Data are sourced from the Building Research Establishment (BRE) 31 and are based on a number of surveys carried out at irregular intervals. Their data indicates that homes heated by central heating tend to be 2.5 Celsius warmer than those heated by stand alone room heating systems. The internal temperature increase over the period 1970 and 2004 was 4.4 C for both centrally and non-centrally heated dwellings in the UK but the weighted average temperature rose by 5.9 C because of the increasing numbers of dwellings which have central heating. It may be reasonable to assert that there has been a similar increase in Ireland given the comparable increase in central heating. However the actual internal temperature levels may be different between Ireland and the UK. Figure 12 UK Internal Temperatures 1970 to Degree Celsius Centrally Heated Homes Non-Centrally Heated Homes Weighted Average Source: BRE The increasing penetration of central heating and electrical appliances will be expected to increase the use of energy significantly, but as will be shown in detail in section 4 energy usage per dwelling fell by 8.9% over the period 1990 to This implies that the stock of buildings has become more energy efficient. A key reason for this has been the various iterations of thermal energy standards. Table presents a basic comparison of normalised heating energy usage of different age cohorts of Irish housing arising from progressive improvements in thermal standards introduced by the Government since 1979, accompanied by the installation of more efficient heating systems. 31 Building Research Establishment, Domestic Energy Fact File Available from 32 SEI, Home Energy Rating Scheme Programme Strategy, Consultation Draft. 18

23 Table 10 Impact of Building Requirements Date of Introduction Change Cumulative Change Fuel Use for Heating, Relative to Base % % -44% 56% % -58% 42% % -71% 29% % -76% 24% Source: SEI It can be seen that there has been a significant decrease in the amount of energy required for heating over the period. It is important to note that this does not mean that dwellings constructed in 2003 or later use 76% less energy that those built before 1979, the figures in Table 10 refer only to the technical improvements relating to energy requirements for heating. Just under 50% of dwellings therefore were built before the introduction of energy specific building requirements (see Table 5). Some of these dwellings, however, will have since been improved thermally by retrofitting insulation or by using energy efficient items. It is important to note that while thermal standards have been improved, the actual amount of energy savings may be less than that stated in the Building Regulations due to factors such as non compliance and behaviour of household occupants. Draft Building Regulations were published in September 2007 which are designed to result in a 40% improvement in energy efficiency and a 40% reduction in CO2 emissions for new homes. The intention is that the new rules will apply to all new housing planning applications after 1 st July A commitment was also made to review and improve regulations in 2010 with the ultimate aim of achieving a zero carbon standard for new houses in the medium to long term. 3.3 Expenditure on Fuel Price is clearly an important factor in discussing energy usage and Figure 13 presents the trend in residential energy prices (current prices) for electricity, natural gas and heating oil (kerosene), and wood 35. These were chosen as these fuels make up the majority of central heating systems which, in turn, are present in 91% of dwellings. The different fuels are compared by examining delivered costs per kilowatt hour (kwh). It can be seen that from June 2000 to January 2008 household electricity prices doubled (99%increse). The price of kerosene rose by 78% over the period and natural gas prices increased by 87%. From January 2006, when collection of data began, to January 2008 the price of bagged wood pellets increased by 12%. 33 There were further regulations issued in 2005 but these were concerned with the specific heat loss rate and therefore it is not appropriate to compare them with the older regulations. 34 See for full details. 35 Data are sourced from Fuel Cost Comparison sheets available from For simplicity only one tariff per fuel is presented with the electricity tariff being Nightsaver (as it is heating that is being compared in this case), Natural Gas is the New Standard Rate from October 2007 and High User Commitment before., oil refers to kerosene. Note that discounts are available by purchasing oil and wood in bulk quantities. The electricity prices presented here do not include the standing charge. 19

24 Figure 13 Residential Sector Energy Prices 2000 to Jun-00 Sep-00 Dec-00 Mar-01 Jun-01 Sep-01 Dec-01 Mar-02 Jun-02 Sep-02 Dec-02 Mar-03 Jun-03 Sep-03 Dec-03 Mar-04 Jun-04 Sep-04 Dec-04 Mar-05 Jun-05 Sep-05 Dec-05 Mar-06 Jun-06 Sep-06 Dec-06 Mar-07 Jun-07 Sep-07 Dec-07 Delivered Energy Cost cent/kwh Oil Night Saver Electricity Natural Gas Bagged Wood Pellets Source: SEI Figure 14 presents the average spend (current prices) on energy per permanently occupied dwelling from 1990 to In 2006 average annual spend on energy by households was 1,767, an increase of 4% on 2005 and 70% on 1990 (3.4% per annum on average). Total spend by the residential sector was approximately 2.5 billion in Figure 14 Average Spend on Energy per Permanently Occupied Dwelling 1990 to ,000 Spend per Permanently Occupied Dwelling ( Currnet Prices) 1,800 1,600 1,400 1,200 1, Source: CSO Figure 15 illustrates the ratio of household energy expenditure to total expenditure 37. It can be seen that the proportion of total expenditure spent on fuel and power decreased over the period 1991 to The direction of the trend changed in 2003, which coincided with increasing fuel prices (see Figure 13) and increasing thermal unit consumption (see Figure 11). Overall in 1990, 3.8% of total household expenditure was spent on energy, falling to 2.5% by This means that energy now forms a smaller proportion of our spending than it did in Data on expenditure on energy (fuel and power) is taken from CSO s National Income and Expenditure Accounts. 37 Total expenditure is defined as personal consumption of goods and services less taxes on personal income and wealth. 20

25 Figure 15 Ratio of Expenditure on Energy to Total Expenditure 1990 to 2006 Ratio of Personal Expenditure on Energy to Total Personal Expenditure Source: CSO Figure 16 examines expenditure on energy 38 as a percentage of disposable income in 2004/2005. Disposable household income is defined in the HBS as gross income less direct taxation. The Household Budget Survey (HBS) provides this data for 10 income deciles. The income deciles are constructed by ranking all incomes and then grouping them into ten equal groups. For example the lowest income decile contains the households with the lowest 10% of incomes. Figure 16 Weekly Expenditure on Energy as a Proportion of Disposable Income % of Disposable Income Spent on Energy Weekly Expenditure ( ) 0 1st Income Decile 2nd Income Decile 3rd Income Decile 4th Income Decile 5th Income Decile 6th Income Decile 7th Income Decile 8th Income Decile 9th Income Decile 10th Income Decile Energy as a % of Disposable Income 99/00 Energy as a % of Disposable Income 04/05 Average Weekly Spend on Energy 04/05 State 0 Source: CSO It can be seen from Figure 16 that as income decreases there is an increase in the proportion of disposable income spent on energy. Those in the lowest (or 1 st ) income decile spent on average 13% (compared with 14% in 1999/2000) of their disposable income on energy while the highest earners spend 1.7% (2% in 1999/2000). The average 38 The actual variable in the HBS is Expenditure on Fuel and Light, here referred to as energy. 21