4 Economic energy saving potential 62
4.1 Methodology 62
The economic energy saving potential for each beneficiary has been developed through the following main steps:
1. Collection of statistical data
2. Establishment of reference buildings 3. Identification of energy efficiency measures 4. Energy calculations
5. Cost-effective evaluation
6. Estimation of total and per m2 savings potential
7. Estimation of 2011 - 2020 aggregated investments and savings target Each step is described below.
1. Collection of statistical data Statistical data was collected:
• Building stock area, divided into building categories as available
• Initial determination of ratio between heated and unheated area for each building category
• Typical systems for heating and ventilation
• Typical operation and use patterns
• Distribution of energy consumption in the building sector into energy types (carriers)
• Tariffs for the different energy types (carriers), differentiated in residential and non-residential sector if applicable
Building stock area data have either been obtained from available official statistics or, for the building categories without statistics; extracted from other reliable sources (reports, studies etc.). Where no or limited information was available, basic assumptions was based on ENSI experience from the region and consultations with locals experts.
2. Establishment of reference buildings
To establish rough estimates of the national energy savings potential, the same types of reference buildings could be used as for the cost-optimum assessment.
63 If more accurate calculations are needed, more reference buildings would be needed, and it could be necessary to use more subcategories to reflect the cost of major renovations (depending on major construction types and technical systems).
There is not enough information available about the building stock in any of the beneficiaries to develop proper reference buildings reflecting the actual, average situation in each of the beneficiaries. Therefore, the following approach has been used to define reference buildings:
• Geometry: based on default building geometry different for each building category as developed and used by ENSI in other programmes in the region.
• Thermal properties: based on previous national building regulations/codes and ENSI experience the region (previous since this is potential for existing buildings, not new ones).
• Technical systems/installations: based on collected information and on ENSI experience and advice from local consultants from the region. The type of energy carriers used is also giving valuable information about what type of heating systems are used.
• Operational pattern: based on energy audit reports and/or ENSI experience from the region. Since there is limited information available, and to make it possible to compare the savings potential among the beneficiaries, the building stock has been divided into up to six building categories in the beneficiaries:
1. Family houses 2. Apartment buildings 3. Healthcare facilities 4. Hotels and restaurants 5. Education
6. Other buildings (offices, trade, etc.) 3. Identification of energy efficiency measures
The energy performance of a building can be improved by implementing a number of energy efficiency measures. From a long list of possible measures, we have selected those being most relevant, based on the following main criteria:
- Common practice in the countries;
- ENSI´s experience from the countries (e.g. energy audit reports);
- Use and availability of specific energy carriers.
The following energy saving measures with economic lifetime according to EU standards and producers, have been evaluated:
• Insulation of external walls (30 years)
• New windows (30 years)
• Insulation of roof (30 years)
• Heat recovery unit in mechanical ventilation systems (15 years)
• Energy efficient lighting (10 years)
• Solar heaters for DHW (15 years)
• Hydraulic balancing of heating system and installation of thermostatic radiator valves (15 years)
64
• New gas boiler (Central), incl. automatic control system (20 years)
• New biomass boiler (Central), incl. automatic control system (20 years)
• New coal boiler (Central) incl. automatic control system (20 years)
• New heating stoves, wood or coal (15 years)
• Replacement of split units/heat pump (15 years)
For specific country and building, only those measures that are relevant have been included into the evaluations of the savings potential. For instance new boiler is not relevant for those buildings connected to district heating. Gas boiler is not relevant for buildings without access to gas pipeline. Hydraulic balancing of heating system and installation of thermostatic radiator valves is not relevant in family houses using wood for direct heating.
4. Energy calculations
The ENSI EAB Software has been used for energy modelling of the reference buildings. The ENSI EAB Software is following the algorithms of ISO 13 790 with monthly quasy-steady state energy balance. System thermal losses (emission, distribution and generation) have been determined according to EU standards EN 15 316-X.
Energy calculations were performed for each building type and climate zone and including reference values for all the parameters as described for the reference building in chapter 3.3.5.
Calculations were performed for the following energy budget items:
• Heating and ventilation
• Domestic hot water
• Lighting
• Various equipment
Energy calculations included the following procedures and steps:
• Calculation of total actual (present) energy consumption for each country and building category (Used as baseline for the savings calculations – “actual baseline” without normalisation for design indoor climate or operation of technical installations):
For each reference building, the specific energy consumption in kWh/m2 of heated area was calculated.
Total actual energy consumption was calculated as the specific energy consumption multiplied by the corresponding heated area of the building stock.
To increase the accuracy of the established baseline, the calculated total actual energy consumption was compared to the actual energy consumption per energy carrier as presented in statistics or NEEAPs, and partly adjusted (calibrated) to balance these. Calibration was done for instance by adjustment of the input parameters for the calculations, ratio between heated and unheated area and/or shares of energy carriers.
• Calculation of total energy saving potential including economic evaluation for each building type:
Relevant measures were entered and energy savings calculated. Evaluation and selection of cost effective measures as described below.
65 5. Cost-effective evaluation
The cost-effective evaluations are based on:
• Energy savings calculated by the ENSI EAB Software
• Actual tariffs (partly averaged)
• Estimated investments for each measure
For each energy efficiency measure, based on unit costs incl. installation (per m2 of windows, walls, solar collectors, per kW for boilers, etc), we have established average unit investment costs in €/m2 (useful building area).
The unit costs were compared with data from Energy Audit reports and information from other studies in the region. Unit costs have also been compared with costs in the Bulgarian, Norwegian and Slovakian market. Other sources for unit costs are presented in the “Database with unitary costs for energy efficiency and renewable energy projects” (JASPERS Action Plan 2007; 169 HOR), the IEE- ROSH – Retrofitting of Social Housing project and Eurima Ecofys.
The energy tariffs for relevant energy carriers were based on the latest actual prices obtained from the web pages of the national energy regulatory commission’s, the available statistics, web pages of producers/suppliers, energy studies/audits and discussions with local experts. Energy prices vary depending on type of consumers, single or multiple tariff systems, regions, exchange rate, etc. Therefore, all data for calculation of energy savings potential have been converted, averaged and recalculated to €/MWh. A set of energy tariffs in tabular form have been prepared per energy carrier for each country. In case of significant difference in tariff of specific energy carrier for households and public/commercial consumers, both tariffs have been included. Based on calculated energy savings, actual tariffs and average unit investment costs, the payback for each measure has been calculated. For the purpose of establishing rough estimates in this Study, measures with a payback up to 10 years has been defined as cost effective if their economic lifetime (lifespan) is longer than 15 years and measures with a payback up to 15 years for measures with economic lifetime (lifespan) more than 20 years. All measures with longer payback periods than these limits were excluded when presenting the economic saving potential for each beneficiary.
When the contracting parties in the future are developing national savings potential for their country, which will be based on more accurate input values and evaluations done by national experts, more accurate profitability evaluations should be used (for instance by Net Present Value).
6. Estimation of total and per m2 savings potential
Using the approach as described above, total energy savings potential only including profitable measures are calculated (savings potential in %, MWh/year and €/year and corresponding investments in €).
The per m2 savings and investments are calculated by dividing the total savings by the building stock area, and the results are presented in tables like below, where those cost-effective measures that are included are listed, ranked based on “average profitability” for this specific building category.
66 Table 4.1-1 Example total and per m2 savings and investments potential
Education Savings Investment
Rank Measures kWh/m2 a €/m2 a €/m2
1 Energy efficient lighting 12,5 1,2 7,2
2 Replacement of coal boiler 3 Replacement of oil boiler 4 Insulation of roof
5 Hydraulic balancing + thermostatic valves 6 Insulation of external walls
Building stock area 6 279 000 m2 MWh/a € €
Total savings 20 % 78 300 7 800 000 45 466 000
The example numbers in the table above is the average savings potential and investment needed for the whole building category Education.
Within this building category, there could be large differences in pr. m2 savings and investments depending on type of energy carrier used for the different buildings, type of heating system, age, etc. Since the building stock area includes both heated and unheated building area, the savings potential for the heated area is larger than those specific figures presented in the table.
The presented energy saving potential is a result of rough calculations and therefore need to be adjusted for specific applications.
In these rough estimations, all profitable measures were included; some of them with payback period up to 15 years (due to their long economic lifetime). As a result of this, the average payback period for the package of measures is quite long. From an overall economic policy point of view, this could be acceptable. From a company financial point of view, only measures with shorter payback, or better return on investment could be included. This in turn will reduce the savings potential.
7. Estimation of 2011 – 2020 aggregated investments and savings target
We did not have enough data to calculate the energy savings potential for the period 2011 – 2020. However, regarding aggregated investments and savings, this has been estimated based on the assumption that the target is to achieve 1% energy saving per year in the building sector, accumulated to 9% by 2020.
To estimate the aggregated savings and investments for 2011 – 2020, the following approach was used, based on the total savings as presented above for each building category:
• If the total savings potential in one building category is 25%, the aggregated savings and investments for 2011 – 2020 is 9/25 = 36% of the total savings and investments.
67 The results are presented in tables as follows:
Table 4.1-2 Example aggregated investments and savings target
Building category Savings Investment
MWh/a €/a € Family houses 345 500 31 623 400 169 530 700 Apartment buildings 165 700 14 910 300 135 220 500 Healthcare 17 800 1 503 400 12 536 300 Education 35 900 3 575 300 20 843 000 Hotel 122 700 10 335 000 73 770 200
Other (offices, trade, etc.) 37 900 3 265 200 21 804 900
Total 725 500 65 212 600 433 705 600
These figures are aggregated investments during the 9 year period; 1/9 of the total investments in year 1 (47,7 mill. Euro), which generates 1/9 of the total savings in year 2 (7,2 mill euro), additional 1/9 of the total investment in year 2, which generates additional 1/9 of the total savings in year 3, etc. For the example above, this means that at the end of year 2020, the accumulated investments will be 433,7 million euro, which will generate annual savings of 65,2 million euro.
The accumulated savings will of course be much higher than the total savings as given in the example above:
Table 4.1-3 Example accumulated savings
Year Savings in mill euro
New savings Total savings Accumulated savings 1 2011 2 2012 7,24 7,24 7,24 3 2013 7,24 14,48 21,72 4 2014 7,24 21,72 43,44 5 2015 7,24 28,96 72,40 6 2016 7,24 36,20 108,60 7 2017 7,24 43,44 152,04 8 2018 7,24 50,68 202,72 9 2019 7,24 57,92 260,64 10 2020 7,24 65,16 325,80
For this example, at the end of year 2020, the 433,7 mill euro investments has generated accumulated savings of 325,8 mill euro.
The aggregated investments and savings as presented in table 4.1.2 are based on the average potential estimated for each building category. Within each building category there will be several projects with better profitability than the average. If the target of 9% savings remains and the most profitable projects are implemented first, the aggregated investments needed to achieve the savings presented for 2011 – 2020 will be less than what is presented for each country (better profitability).
68 The profitability of these investments could be further improved by including energy efficiency measures when renovating buildings (since some of the costs for the energy efficiency measures will be covered by the renovation “component”). In most of the beneficiaries, there is a need for substantial renovation of a large number of buildings, incl. hospitals, schools, kindergartens, etc. To combine renovation with implementation of energy efficiency measures is a very good approach, and this should be promoted and stimulated by national authorities.
Considering the scenario with implementing the most profitable projects a first priority as well as combining renovation and energy efficiency projects, it might be possible to achieve the 9% savings target with investments 20-30% lower compared to what is presented in tables based on the average potential.