Energy Efficiency and Savings Calculation, Top-down and Bottom- up Methods, CEN Task XXI experts meeting October 2010

Process Draft July 2010 not public available yet By end of November start of commending period (CEN enquiry) March 2011 start of revision July 2011 version for official approval

General information This draft covers both top-down and bottom- up calculation methods For bottom-up the standard builds on the results of the EMEEES project. This standard which is general in nature and applicable to a larger category of purposes and users than the EC-driven ESD.

Terms and definitions Baseline: energy consumption calculated or measured, possibly normalised, in the situation without an energy efficiency improvement action energy efficiency improvement action: achievement of technological, behavioural or economical changes providing a verifiable and measurable energy efficiency improvement

Terms and definitions gross energy savings: change of energy consumption following implementation of one or more energy efficiency improvement actions energy savings: gross energy savings corrected for selected parameters – NOTEDepending on the definition of energy saving used within a specific framework the gross energy savings can be corrected for elements not included in the adjustment factors. Examples of such parameters are technical interaction, double counting, multiplier effect and free-rider effect.

Characteristics of methods Top-downBottom-up Scope per method Sector, part of sector, technology Targeted energy use, policy measure EEI measure End-user actions (aggregated) End-user actions with/without facilitating measures Resulting energy savings Total Additional (policy) - Total Data usedStatistical Surveys, Test results on equipment, etc. System boundaryStatistically definedDependent on measure

Baselines There are two approaches for selecting the baseline situation: reference situation; for this the two most used ones are: – based on a stock situation – based on a market situation the “before” situation.

Calculation methos Calculation methods are generally composed of three main elements: a calculation model or formula including baselines and normalisation data collection techniques, for data needed to feed the calculation model a set of reference or default values.

4 Steps Step 1: unitary gross annual energy saving; Step 2: total gross annual energy savings; Step 3: total annual energy savings related to area, groups of end-users etc; Step 4: total remaining energy savings for target year.

Step 2: Calculation of total gross annual energy savings Step 2.a:Calculating the number of elementary units of action Step 2.b:Summing up the unitary gross annual energy savings Step 1: Calculation of unitary gross annual energy savings Step 1.a:Definition of elementary unit Step 1.b:General formula / calculation model Step 1.c: Baselines and specific formulas Step 1.d:Normalisation of energy consumption Step 1.e:Technical interaction Step 1.f: Application of conversion factors (when relevant) Step 3: Calculation of total annual energy savings Step 3.a:calculation of total annual energy savings Step 3.b:correction for double counting Step 3.c:correction for multiplier effect Step 3.d:correction for free-rider effect Step 3.e:correction for rebound effect Step 4: Calculation of remaining energy savings for target year

Step 1b:The general formula Specifies how energy consumption and the change in energy consumption are determined. Two approaches may be used: approach I for cases where consumption data is available; unitary gross annual energy savings = [GAEC] 0 * AF 0 - [GAEC] 1 * AF 1 approach II for cases where consumption data needs to be constructed. unitary gross annual energy savings = function (P 00, P 01 …P 0n )*AF 0 - function(P 10,P 11 …P 1n )*AF 1

Order of selection The preferred order for the selection of the parameters and the formula is: internationally accepted formula; national accepted formula; literature sources; self developed and documented.

Normalisation To this end energy consumption figures are normalised for external factors that should not enter the energy savings calculation. Examples of such external factors are: – weather conditions; – occupancy levels; – opening or operation hours for non-domestic buildings; – installed equipment intensity (plant throughput); product mix; – level of production, volume or added value; – schedules for installation and vehicles; – relationship with other units.

Step 1e: technical interaction Technical interaction may result from a relationship with other elementary units or with the surrounding physical system. Where energy consumption data is available (Approach I) adjustment for technical interaction is not needed if the consumption data used for calculating unitary energy savings is derived from metering at a place which reflects all relevant technical interactions In the case where energy consumption data is not directly available (Approach II) energy consumption is constructed using a set of parameters. In this case adjustment for technical interaction can be achieved by choosing for the case with implementation and for the baseline case different values for the parameters reflecting the interaction with the surrounding technical system or with other unitary elements of savings

Data handling and harmonisation Data scaleMain data sources Data processing and documenting Level 1 European default values existing/available European regulation, studies and statistics Reliability coefficient according to the data basis for the default value Level 2 National representative values up-to-date national statistics, surveys, samples, registries requirements = minimum set of data and justifications to be reported Level 3 Programme- or Participant-specific specific monitoring systems, registries, surveys, measurements requirements to report on the specific data and justifications in detail (standard report at least available)

Example boiler replacement Approach II, energy consumption data are not directly available, is used. unitary gross annual energy savings = (1/N 0 -1/N 1 )*SDH*A Where: N 0 is mean annual energy efficiency of the heating supply equipment before the replacement action (seasonal) N 1 is mean annual energy efficiency of the new heating supply equipment (seasonal) SHDis Specific Heating Demand {kWh/unit*yr] Ais average area of the space heated by the heating supply equipment (household, office, etc.) [m 2 ] 0is situation without action [baseline]; 1is situation with action. The formula is only applicable when just the boiler is changed and the other conditions remain the same. If more actions are taken, technical interaction (see step 1e) should be considered.

Example boiler replacement There is no need for an adjustment factor as the specific heating demand (SHD) is already normalised. There are several options to get the values for N 0 in the equation For the SHD there are three options for a (standard) value: – an EU average, – a national average – a building specific value For the average area of the space heated A there are the three options for a (standard) value: – an EU average, that could be more specific e.g. for type of building – a national average, that could be more specific e.g. for type of building – a building specific value

Baselines In the baseline approach with a reference situation (Approach A) one can use two options: market or stock. – The reference market for each could be the domestic market or the entire European Union. – The reference could be specified for non condensing boilers or for condensing boilers. The choice results in different values of N 0 in the formula and in different unitary gross annual energy savings In approach B the calcualtion N 0 is mean annual Energy efficiency of the old boiler (in the before situation)