Corporate Services Division Assurance and Forensic Department Contracted the University of Pretoria to execute this project Measurement and Verification Project Name: Measurement and Verification Guideline Residential Heat Pump Rebate Programme Project Number: 2010155 Report Type: Guideline (Draft) Reporting Period: December 2010 Report Issue Date: 09 JUNE 2011 Report Number: PM/M&V/UP-10/11-054 Revision Number: v1r3 COPYRIGHT IN THIS REPORT IS RESERVED. NO PUBLICATION OR DISSEMINATION OF ITS CONTENTS IS ALLOWED WITHOUT WRITTEN PERMISSION.
Compiled by: Date: 09 Jun 2011 Jiangfeng Zhang M&V Team Senior Engineer University of Pretoria Authorized by: Date: 09 Jun 2011 Prof. Xiaohua Xia M&V Team Leader University of Pretoria Submitted to:...... Date: Corporate Services Division Assurance and Forensic Department Eskom COPYRIGHT IN THIS REPORT IS RESERVED. NO PUBLICATION OR DISSEMINATION OF ITS CONTENTS IS ALLOWED WITHOUT WRITTEN PERMISSION.
TABLE OF CONTENTS 1 INTRODUCTION... 1 2 OVERVIEW OF THE RESIDENTIAL HEAT PUMP REBATE PROGRAMME... 1 2.1 INTRODUCTION... 1 2.2 PROJECT DESCRIPTION... 2 2.2.1 RHPR programme description... 2 2.2.2 RHPR M&V project description... 3 2.3 INTERNATIONAL M&V ACTIVITIES ON HEAT PUMPS... 4 2.4 HEAT PUMP PRINCIPLES... 7 3 M&V STRATEGY... 9 3.1 THE SCOPING STUDY... 9 3.2 THE M&V PLAN AND BASELINE... 10 3.3 IMPACT CALCULATION... 16 3.4 PERFORMANCE ASSESSMENT... 17 3.5 SUSTAINABILITY CHECKUPS AND PERFORMANCE TRACKING... 18 3.5.1 Sustainability checkups... 18 3.5.2 Performance tracking... 18 4 DISCUSSIONS... 21 5 REFERENCES... 22 APPENDIX... A1 PAGE III
NOMENCLATURE: COP RHPR EE ESCo FEMP GHP kw kwh M&V MW MWh PA PT R RLM SWH SABS yr Coefficient of Performance Residential Heat Pump Rebate Energy Efficiency Energy Service Company Federal Energy Management Program Geothermal Heat Pump Kilowatt Kilowatt-hour Measurement and verification Megawatt Megawatt-hour Performance Assessment Performance Tracking Rand Residential Load Management Solar Water Heating South African Bureau of Standards Year PAGE IV
1 INTRODUCTION The document provides a measurement and verification (M&V) guideline for the ESKOM Residential Heat Pump Rebate (RHPR) Programme. The purpose of this project is to measure and verify the monthly energy savings from the RHPR Programme. This Guideline describes how M&V is performed on this RHPR programme. Existing international activities on the M&V of heat pumps are reviewed, and a practically feasible M&V plan is developed for this RHPR programme. General procedures on the baseline development, savings calculation, performance assessment and performance tracking are provided in this Guideline as well. 2 OVERVIEW OF THE RESIDENTIAL HEAT PUMP REBATE PROGRAMME 2.1 INTRODUCTION ESKOM s Heat Pump Rebate Programme aims to reduce the load of residential water heating by replacing electric water heaters with air source heat pump water heaters. Savings impact from this programme is expected to be developed in this M&V project, that is, 24-hour power savings from installed heat pumps and the corresponding energy savings need to be found by this M&V project. To this purpose, energy consumption baselines for low priced 100 to 300 litres and high priced 301 to 500 litres electric water heaters at coastal and inland areas will be developed. The corresponding energy consumptions of low priced coastal heat pumps, low priced inland heat pumps, high priced coastal heat pumps, and high priced inland heat pumps are obtained to determine the power and energy savings from the heat pumps. Regional and national baselines and the power/energy savings will be given. Hot water usage profiles identified from existing studies in the Residential Load Management (RLM) programme are adopted in this project [7], [8]. These water usage profiles, together with the coefficient of performance (COP) of heat pumps and the 24-hour average weather data for 12 months from 34 major cities, are used to calculate the impact of heat pumps on energy savings. Metered electricity data are used to adjust the baselines. Since the heat pump installation will be spread out during the period from November 2010 to March 2013, the baselines and savings will be updated every 3 months in the performance assessment and performance tracking reports. PAGE 1
2.2 PROJECT DESCRIPTION 2.2.1 RHPR programme description In the RHPR programme, a total of 65,586 units of heat pumps will be installed during the period from 1 st November 2010 to 31 st March 2013. These heat pumps will replace existing electric geysers in all six ESKOM Distribution Regions and head offices. A large number of clients, including residential customers, lodges, and B&B s amongst others, are involved in the programme. The quantities of heat pumps that will be installed for different regions and categories are given in Table 1. Dx regions Unit per Region Category 1 Category 2 Central 9,542 2,701 Eastern 9,031 2,556 North Western 11,587 3,279 Northern 10,564 2,990 Southern 4,430 1,254 Western 5,964 1,688 Total 51,118 14,468 Table 1. Quantity of heat pump retrofit in different regions The rebate of heat pumps is determined according to the following two categories of heat pumps. Category 1: Low priced system with tank size from 100 Litres to 300 Litres; Category 2: High priced system with tank size from 301 Litres to 500 Litres. 51,118 units of Category 1 heat pumps and 14,468 units of Category 2 heat pumps will be installed, and 29% for the cost of Category 1 heat pumps and 27% for the cost of Category 2 heat pumps will be rebated through this RHPR programme. It is projected that a total of 54.16 MW (80.66 GWh) at a load factor of 17% will be saved from the installation of the 65,586 heat pumps. Prior to understanding the M&V process of the RHPR programme, the RHPR itself needs to be understood as it is different from a usual DSM project. The whole process can be summarised as below (see [6] for details): PAGE 2
Suppliers wanting to take part in the RHPR programme have to complete the necessary application forms and register each of their Heat Pump Systems with Eskom. Heat pump systems registered by the supplier must comply with a set of nonnegotiable factors. One of the non-negotiable factors is to undergo SABS tests and comply with all relevant SABS standards relating to Heat Pump Systems. After the application has been approved the Supplier/Esco can now sell heat pumps to any customer in any part of South Africa. Since the Supplier/Esco does not know which customer will buy a heat pump, pre-metering for baseline purpose becomes impossible. A heat pump system is installed provided that the customer has one or more electric geysers to be replaced by this heat pump. An installed heat pump might have or have not a back up electric heating element in the water tank. If a heat pump is purchased, the Supplier/Esco will keep book of the purchase and claim back the incentive from Deloitte. An M&V team will be supplied the corresponding bulk claim forms with relevant heat pump installation information by Deloitte, and then do the M&V for the impact savings of the RHPR programme. Reports on scoping, baseline, performance assessment and tracking will be issued. Metered data will be sent to M&V Teams, and each M&V Team needs to input the corresponding data in the RHPR Excel Application for baseline/saving update and performance tracking. The M&V Teams must ensure that metered data match correctly with the list of metered heat pumps. 2.2.2 RHPR M&V project description The objective of this RHPR M&V project is to measure and verify the savings that will occur due to the national retrofit of traditional electric geysers by 65,586 heat pumps in residential sector. This M&V project will produce a 24-hour average saving load profile for each month in the reporting period of the reporting year aggregated for both the Category 1 and Category 2 heat pumps for respectively the Central, Eastern, North Western, Northern, Southern, Western, and National regions. Since the RLM research developed hot water usage profiles for coastal and inland cities, the baseline for each region will be necessarily developed from the following four classes of hot water heating energy consumptions: Coastal Category 1; Coastal Category 2; Inland Category 1; Inland Category 2. PAGE 3
The corresponding savings from the replacement of heat pumps will be determined for the above four classes. The RHPR M&V project will be led by the University of Pretoria M&V team which is responsible for the development of questionnaires, M&V methodology, the corresponding RHPR Excel Application, and also the M&V for the north-western region. Other M&V teams will be responsible for the remaining five regional M&V projects which includes the M&V site visits, data processing and reporting. The contact details of each M&V team are given below in Table 2. M&V Company Name & Region University of Pretoria (UP) M&V Contact Person: Prof X. Xia Phone: 012 420 2165 Fax: 012 362 5000 Cell: 082 747 7986 Email: xxia@postino.up.ac.za M&V Company Name & Region Stellenbosch University (SU) M&V Contact Person: Prof Johan Vermeulen Phone: 021 808 4326 Email: vermeuln@sun.ac.za M&V Company Name & Region University of Cape Town (UCT) M&V Contact Person: Ms Mascha Moorlach Phone: 021 650 2825 Email: Mascha.Moorlach@uct.ac.za M&V Company Name & Region University of Forthare (UF) M&V Contact Person: Prof Edson Meyer Phone: 040 602 2086 Email: EMeyer@ufh.ac.za M&V Company Name & Region Tshwane University of Technology (TUT) M&V Contact Person: Prof O. D. Dintchev Phone: 012 799 9512 Email: dintchev@icon.co.za M&V Company Name & Region Cape Peninsula University of Technology (CPUT) M&V Contact Person: Prof Ernst Uken Phone: 021 460 3127 Email: ukene@cput.ac.za Table 2. Information of M&V teams 2.3 INTERNATIONAL M&V ACTIVITIES ON HEAT PUMPS International M&V activities on heat pumps focus exclusively on geothermal heat pumps (GHPs). The working mechanisms of GHPs are different from the air source heat pumps, however, the study of existing GHP M&V procedures will be very helpful for the RHPR programme. PAGE 4
The Federal Energy Management Program (FEMP) at the US Department of Energy issued a revised M&V guideline in 2008 which has a new subsection on the M&V of GHPs ([2]). Option D-Calibrated Computer Simulation is suggested as a usual approach for GHP retrofit projects, and energy analysis programmes such as DOE-2, TRACE 700, TRNSYS, or any programme including subcomponent models for GHPs are recommended. The FEMP M&V guideline advises to collect every 5-minutes the data such as the water temperatures entering and leaving the heat pump, ambient outdoor air temperature, heat pump unit input kw, the supply and return dry-bulb air temperatures for water-to-air GHP units, and the supply and return load water temperatures for water-to-water GHP units. The measured input kw readings are compared with manufacturer s performance data to estimate the energy savings. Important tips of this comparison are also given in this guideline ([2]). Although the GHP M&V Guideline was given only in 2008 in [2], a practical M&V project for GHPs already took place more than10 years before this GHP guideline. In 1995, the US Army and a private energy service company developed a comprehensive energy efficiency project to upgrade the family housing at Fort Polk, Louisiana (see [3], [4], [5], [9], [10]). This project included converting the space heating/cooling systems of 4003 housing units to GHPs, and Oak Ridge National Laboratory (ORNL) led the M&V for this project. GHPs were applied to replace existing air-source electric heat pumps and combinations of natural gas furnaces and central electric air conditioners. The M&V approach was still Option D which applied building management software similar to what was recommended in the FEMP M&V Guideline. The field measurement included three nested levels of site monitoring, with each level building on the preceding level of measurement. Level 1 addressed the housing community as a whole; Level 2 isolated the information for individual apartments from sampled Level 1 buildings; and Level 3 focused specifically on the performance impacts of the GHPs via end-use measurements in a subset of the Level-2 apartments. All three levels were designed to record electrical energy and demand data before the retrofits occur (pre-retrofit) and after (postretrofit). Buildings were classified in terms of age and size, and a very limited number of selected buildings were performed site surveys by site engineers. The reason for the limited number of surveys was due to the strict privacy regulations protecting residents of military family housing. Data collection for the three level buildings included the following information. Level 1: Project impact using community-wide electric energy and demand data, outdoor dry bulb temperature, and relative humidity; Level 2: Housing unit impact using total-residence and HVAC electric energy and demand data; Level 3: Separation of GHP from total impacts using additional electric end-use energy and demand data. PAGE 5
With the metered data, energy usage E for a day was approximated by the following piecewise linear function: E0, ( T < T1 ) E = E0 + c( T T1 ), ( T T1 ) where E0and c are constants, T is the average temperature for that particular day, and T 1 is the cooling change point. The above model was used to estimate energy consumptions for pre-retrofit and post-retrofit stages and thus to derive the corresponding energy savings. It is important to note that the above GHP project is different with the RHPR programme in the following sense: The GHP project retrofitted space heating/cooling systems, while RHPR retrofits only water heaters; GHP systems are usually more complex than the heat pumps in the RHPR programme; GHP project had no existing baselines for pre-retrofit energy consumption and had to measure both pre-retrofit and post-retrofit energy consumption, while RHPR can use existing baselines for electric geysers developed by the RLM project; GHP project had to use Option D approach with the aid of building energy simulation software tools, while RHPR can use Option A since RLM project results can be used it is noted that RLM is also based on Option D. Locally gained experience and knowledge from RLM lend themselves to a simplified approach for RHPR; GHP project has installed 4003 heat pumps, while the RHPR will install 65,586 heat pumps which is a very big project; The project organisation structure, e.g. finance and technical support, of GHP is different from that of the RHPR as the former focuses more on military family houses while the RHPR focuses on residential houses; The heat pumps in the GHP project were installed during the period 1995-1996, and the savings calculation was based on the measurement of pre-installation and postinstallation energy consumptions, while the heat pumps in the RHPR programme are installed gradually in a 3-year period and the M&V reports on impact savings at each installation stage within the 3 years must be issued, this implies that the RHPR will need to dynamically update its baseline and savings at different installation stage which is quite different from the GHP project; and The accuracy of the GHP M&V results depends on its 3 levels of metered data, while the accuracy of the RHPR M&V results depend on the dynamically updated baselines, tested COPs, and metered data of heat pump samples. PAGE 6
It is also noted that only Level 3 buildings in GHP project had metered data for GHPs, and metered data from Level 1 and 2 buildings in GHP project could not tell accurately the energy consumptions of GHPs. Therefore, the RHPR project will directly measure the heat pump energy consumption to improve accuracy. To the best knowledge of the UP M&V Team, the above M&V activities on GHPs are the only information available related to the M&V of heat pumps needed in the RHPR programme. 2.4 HEAT PUMP PRINCIPLES A heat pump is a device that moves heat from one area to another. This is achieved by pumping a refrigerant fluid around in a closed circuit. During this process the fluid is compressed into liquid at one end and then vaporised by evaporation at the other end. Heat is absorbed in the evaporator and transported around the circuit by another fluid to the condenser where it is released. This circuit is called a vapour-compression cycle and is used in most fridges and air conditioners today. The technology can save up to 67% or more depending on the coefficient of performance. Typically it absorbs heat from the air outside a house and transfers the heat to a heat exchanger that warms water or air inside the house. A typical heat pump diagram is given in Fig. 1. Fig. 1. Typical heat pump diagram PAGE 7
The actual energy consumption of an air-source heat pump water heater can be calculated from its COP and the load of the electric geyser that is replaced by this heat pump. Note that the COP is determined by ambient and indoor temperature and humidity, and the inlet/outlet water temperature. Assume that the electric geyser load during the 48 half-hour periods is given by Pi at the i -th half-hour period, then the corresponding power consumption of the heat pump, which is installed to replace the electric geyser, can be estimated as Pi COP i (1) where COPi is the COP at the i -th half-hour period and it is determined by the ambient/indoor temperature/humidity and inlet/outlet water temperature. Based on the heat pump test plan of South African Bureau of Standards (SABS) and specifications of some heat pumps, the inlet hot water to the heat pump is around 30⁰C, the outlet hot water temperature is around 65⁰C, the humidity has only a little effect on the COP, therefore, the COP will be simplified as a function of ambient and indoor temperatures, which are dry bulb temperatures. The reason that the inlet hot water temperature is assumed to be 30⁰C is as follows. The incoming cold water from the water supply is usually less than 30⁰C, for example, from 15⁰C to 20⁰C. This cold water is mixed with the remaining hot water inside the geyser tank, and this mixed water has roughly a temperature of 30⁰C that will be heated by the heat pump. This hypothesis does not lose generality as this temperature has very little impact to the COP. Note further that indoor temperature changes slowly compared to the ambient temperature, the COP can be further expressed as a function of the ambient temperature. This COP function will be updated according to the test results from SABS. Any variable which has been tested by SABS having a big influence on COP will be included in the COP function to improve the accuracy of energy consumption calculation. Besides COP, another important factor determining the energy consumption of the heat pump is the electric geyser load P i. This P i can be obtained from the RLM study for coastal and inland cities. In the Appendix C of [8], the daily half hour average power consumption of coastal and inland cities in each of the 12 month period before the RLM implementation is given. This data will be applied to calculate the heat pump energy consumption, and thus the energy saving. Note that the Solar Water Heating (SWH) Programme is developing a different water usage load profile in terms of the number of persons in a house and the day time occupancy. However, the corresponding load profiles are still not available. This RHPR M&V project will ask the customer to provide also the same information on the number of persons in a house and the day time occupancy so that the obtained water usage profiles can be incorporated with those obtained by the Solar Water Heating Programme. PAGE 8
Temperature data for a list of 34 cities will be obtained from the South Africa Weather Service, and these data will be applied in the COP calculation. Energy meters will also be installed at selected houses to monitor the actual energy consumption of heat pumps in real time. The metered data will be used at the performance tracking stage to update the baselines, heat pump energy consumptions, and the corresponding energy savings. All these calculations and baseline and saving updates will be done by an RHPR Excel Application developed by the UP M&V Team. Detailed user manual for this RHPR Application will be handed out to each M&V Team. 3 M&V STRATEGY The M&V process is designed to provide an impartial quantification and assessment of project impacts and savings that result from DSM activities. M&V also provide continuous feedback to the various stakeholders (Eskom and Supplier/Esco) regarding the impacts achieved. M&V consequently make a substantial contribution towards the sustainable implementation of DSM and energy efficiency in South Africa [1]. The following sections describe the process on how to perform M&V on the RHPR project. A number of standardised deliverables have been designed by the M&V teams to achieve the objectives of this type of M&V project: Scoping report; M&V plan Baseline report (Buy-in from the Esco/supplier should be obtained); Post implementation report Performance assessment reports; Performance tracking reports. 3.1 THE SCOPING STUDY The scoping study is the first stage in the M&V process after receiving the request to perform M&V on a RHPR project. The purpose of the scoping study is to enable the M&V team to gather all relevant and available information on the project. PAGE 9
3.2 THE M&V PLAN AND BASELINE The M&V plan is developed for each region by taking into consideration of the specifics of the respective region, but it can be developed in a simplified way, since the prescribed methodology is given in this guideline. Step 1: The required data can be collected via the standard questionnaire in Appendix A ESKOM Residential Heat Pump Rebate Programme Bulk Claim Form. This filled form will be provided to the M&V Teams by Deloitte. The following key information should be filled in on the questionnaire: I. Name and address of homeowner; II. III. House occupancy information (occupancy in the day time, number of persons in house); Heat pump information (model, tank size, power rating, auxiliary electric heating element power, energy meter installation); and IV. Existing electric geyser information (power and tank size for each of the electric geyser to be replaced by the heat pump listed in III). The information gathered will determine the type of hot water usage profile and the corresponding post-implementation energy consumption and energy saving. Please note that a user of the RHPR Excel Application must input the heat pump installation date, a unique series number for each installed heat pump, and also choose the nearest big city to the installation site from a list of 34 cities with weather data available. If any of the information is missing, then the Application cannot generate the accurate baselines and savings for such kind of heat pumps with incomplete information. Estimation on the corresponding baseline and savings will be performed for heat pumps with incomplete information. Step 2: In this step the project classification is made in terms of the information collected above. According to the geographic locations and the heat pump tank sizes, customers will be classified into the classes of Coastal Category 1, Coastal Category 2, Inland Category 1, Inland Category 2; where Category 1 is for low priced heat pump systems with tank size from 100 to 300 Litres; while Category 2 is for high priced systems with tank size between 301~500 Litres. It is generally assumed that a smaller wattage (0.8kW) heat pump is to replace an electric heater with tank size between 100 to 300 Litres, whereas a bigger wattage (1.2kW) heat pump is to replace an electric heater with tank size between 301 to 500 Litres. These classifications will be automatically done in the RHPR Excel Application for the baselines and savings calculation by using the information input in Step 1. PAGE 10
The baseline for a total region reported in the regional baseline report will be determined from the total number of heat pumps allocated to this region listed in Table 1 and an estimated portion of inland and coastal customers within the region. The way of estimation does not affect the actual baseline and savings at the end of the project because each installation will be recorded in the Excel Application, the installed heat pumps at different stages will be used to generate the corresponding stage baseline and saving in the performance assessment or tracking reports; and by the end of the rebate programme, all the installation location will become accurate, thus the regional baseline and the savings will be correctly reported in the performance assessment/tracking reports after the completion of the project. Important to note that the locations of installed heat pumps can only be determined after the Suppliers have sold the heat pump systems to the clients, therefore the baselines and savings in the performance assessment/tracking reports will be dynamically increasing as more heat pump systems are sold; while the baseline for the whole region in the regional baseline report is only an estimated one. Step 3: Hot water usage profile classification With the installation of every heat pump system, the installer and the customer must fill in the questionnaire in Appendix A, and the supplier will claim the incentives for installed heat pumps by filling the bulk claim form which covers not only the questionnaire in Appendix A, but also some other information which is not directly used in this M&V project. As mentioned in Step 1, the M&V team will input the collected information to the RHPR Excel Application, and typical hot water usage load profile for each heat pump system will be automatically classified by this Excel Application if the customer s heat pump system is not remotely controlled by the RLM project. In the case that a customer s electric geyser is controlled by the RLM project, and this customer participates also this RHPR programme to replace the electric geyser into heat pump, then the baseline load profile cannot be automatically generated by the Excel Application, and needs to be manually input by the M&V Team. The corresponding post-implementation RLM geyser load profile can be found from the RLM project. It is important to note that the load profile for one single geyser in Coastal Category 1 is the same as that of Coastal Category 2, and similarly the load profile of one single geyser in Inland Category 1 is the same as that in Inland Category 2. This is because that the RLM project does not discriminate tank sizes. For an M&V team, the heat pumps which need to be measured and verified may include only two classes. For instance, the team working on the North Western region has only the two classes of Inland Category 1 and Inland Category 2. The UP M&V team will work on the national region which will include all the four classes. Baselines for each class of heat pumps need to be given. Step 4: Baseline calculation method PAGE 11
Step 4.1 Regional baseline in the Baseline Report The regional baseline for a particular region is estimated as commented in the end of Step 2. For instance, a region allocated with 5000 category 1 heat pumps and 2000 category 2 heat pumps estimates that the portion of inland customers is 80%, then the regional baseline will consists of the corresponding baselines for 1000 coastal category 1 heat pumps, 400 coastal category 2 heat pumps, 4000 inland category 1 heat pumps, and 1600 inland category 2 heat pumps. With the aid of the coastal and inland baseline load profiles generated in the RLM project, estimated load profile for all the heat pumps to be installed in the region can be found. For example, if 100 out of the 1000 coastal category 1 heat pumps are controlled by RLM, while the rest 900 are not, then one should apply the post-implementation RLM coastal load profile to the 100 heat pumps, while apply the pre-implementation RLM coastal load profile to the 900 heat pumps. That is, Baseline of the 1000 Coastal Category 1 heat pumps = 100 * Post-implementation RLM coastal load profile + 900 * Pre-implementation RLM coastal load profile. Similarly, one can find the baselines for other classes. The regional baseline will be reported in the baseline report and will be accurately corrected in the last performance assessment report after the project is completed. Since performance assessment needs to be done quarterly within the 3-year period of the project, real savings upon installed heat pumps at different stages must be reported, and this needs a dynamically updated baseline for installed heat pumps. Therefore, Step 4.2 discusses how to generate this dynamic baseline for installed heat pumps. Step 4.2 Baseline for installed heat pumps in the Performance Assessment/Tracking Reports The baselines for the actually installed heat pumps need to be calculated differently in the performance assessment and tracking reports. The calculation method is based on the assumption that the customer would have had an electric geyser installed prior to the heat pump installation. This assumption is reasonable since this is in fact a requirement of this heat pump rebate programme. Thus, the baseline for a certain heat pump system will be the electrical energy use due to the hot water usage profile prior to the installation of the heat pump system. The data required for the baseline development for installed heat pumps are the following: Hot water usage profile associated with each heat pump: In case that there are more than one electric geyser, say, two electric geysers, are replaced by one heat pump system, then the hot water usage profile for the heat pump is the sum of the water usage profiles of the two electric geysers. PAGE 12
Baseline of installed heat pumps in a specific class of hot water usage profile: Note that the hot water usage profiles for each heat pump within a class of water usage profile (e.g. Coastal Category 1) will be summated to find the baseline for this class of water usage profile. In case a house (e.g. a B&B guest house) have installed two or more heat pump systems, then the water usage profile for each of the heat pumps must be calculated independently. In the end, an M&V team might generate 2 or 4 baselines provided there are 2 or 4 classes of water usage profiles in the corresponding region. A collective baseline can also be delivered, and will be reported, for the whole region when the baselines of different class of hot water usage profiles are added together. To summarise, the following 4 classes of baselines can be generated, and each class of baseline consists of 12 baselines for the months from January to December: I. Coastal Category 1 baseline: 12 months baselines for geyser tank size being greater than or equal to 100 Litres but less than 300 Litres; II. Coastal Category 2 baseline: 12 months baselines for geyser tank size being greater than or equal to 301 Litres and less than or equal to 500 Litres; III. Inland Category 1 baseline: 12 months baselines for geyser tank size being greater than or equal to 100 Litres but less than 300 Litres; IV. Inland Category 2 baseline: 12 months baselines for geyser tank size being greater than or equal to 301 Litres and less than or equal to 500 Litres. The baseline for a single heat pump can be developed as follows. Each geyser will be put into one of the above four classes. The energy consumption baseline of a single geyser in a specific month is a 24-hour electric load profile for that month, therefore the following time function for j =1,2,,24 at the r -th month is defined: Di ( j, r, l ) where D ( j, r, l ) is the baseline of the i -th heat pump from the l -th class of hot water i usage profile at the j -th hour in the r -th month, and l =1, 2, 3, and 4 correspond to the Class I, II, III and IV hot water usage profiles respectively. When the baseline for a single heat pump is determined, the accumulated heat pump,,, baselines are determined easily. Assume that there are a1 a2 a3 a4 heat pumps installed, respectively, for the above four classes. Then the accumulated baselines, denoted by the notation Baseline( j, r, l ) for the power consumption at the j -th hour in the r -th month, for the above 4 classes will be: PAGE 13
Class I: Baseline( j, r,1) = Class II: Baseline( j, r, 2) = a 1 i= 1 Class III: Baseline( j, r,3) = a 2 i= 1 a 3 i D ( j, r,1) i D ( j, r,2) i D ( j, r,3) i Class IV: Baseline( j, r, 4) = a 4 i= 1 D ( j, r,4) i The baseline will be dynamically updated and simulated on a periodic basis as more heat pumps are installed. That is, the baseline will be updated during every performance assessment (PA) and performance tracking (PT). PA and PT will be performed every 3 months for a 3-year period as illustrated in Fig.2. In Fig. 2, with the installation of some heat pumps, PA is performed to find a baseline, then more heat pumps are installed, and the baselines must be updated to cater for the newly installed heat pumps. Metered data might also be possible. However, metered data will not be used in PA, but only used in PT. Metered data can be used to update the baselines and the savings. Here only metered data with at least 7 days in a calendar month will be processed to improve the reliability of updated baselines and savings. Details for this updating process will be discussed in Section 3.5 of this Guideline. The baseline calculations are automatically finished by the RHPR Excel Application. Fig. 3 is an example calculated by this RHPR Excel Application. This Excel Application will generate a table to give detailed data for the 12 months baselines as well. PAGE 14
Fig. 2. RHPR M&V Project Process Fig. 3. A baseline example generated by the RHPR Excel Application PAGE 15
3.3 IMPACT CALCULATION The Impact calculation of any DSM project is done by subtracting the actual electrical demand profile from the baseline electrical demand profile, and so is the RHPR project. The RHPR Excel Application is used to simulate the heat pump system and to calculate the actual electrical profile. The inputs to the RHPR Excel Application include the heat pump specification, geographical location, and electric geyser information amongst others. 24-hour averaged weather data for each of the 12 months for 34 cities in 2009 were obtained from the Weather Service, and were built in the Excel Application. The M&V team is requested to choose a nearest city from the 34 city list to the heat pump installation site. If the heat pump is controlled by RLM project, then the user needs to input the corresponding postimplementation RLM load profile. Now the Excel Application will automatically calculate the actual electrical profile for heat pumps and the corresponding 24-hour power/energy saving for each of the 12 months. Note that the actual energy consumption of heat pump is calculated by the fraction in (1) in Section 2.4 of this Guideline. Therefore, the savings calculation relies on the COPs of heat pumps. SABS will issue their test results on the performance of specific heat pumps. The test will focus on the COP under different ambient temperatures. These tested COP values will be combined with the weather data of the 34 cities so that a linear interpolation technique can be applied to find the corresponding COP at any time in a day in any place of the country. For conservatism of M&V savings and to cater for foreseeable delays in COP tests for a specific type of heat pumps already installed and claimed to DeLoitte, a COP of 2.8 will be used in baseline and impact calculations of this type of heat pumps, because an averaged COP of 2.8 is the minimal entering requirement for RHPR programme. Note that a residential home may have both RLM and the RHPR projects implemented. The savings calculated in the RHPR project will not be affected by the savings in the RLM project. This is because that the RLM project is mainly a load shifting DSM project, while the RHPR is essentially an energy efficiency improvement project. PAGE 16
3.4 PERFORMANCE ASSESSMENT Due to the heat pumps will be installed from time to time during the whole period of November 2010 to March 2013, and the energy efficiency performance of heat pumps is closely related to weather changes, the performance assessment will be done every 3 months as illustrated in Fig. 2. In a performance report, the system performance over each month of the reporting period will be given. The purpose of the performance assessment is to provide information to relevant stakeholders the actual savings impact of the heat pumps so that intervention can be taken in case of a problem detected. Note that this performance assessment for the RHPR project is very different to any usual performance assessment. A usual performance assessment takes place only after the completion of an energy project, while this heat pump projects lasts for more than three years, and the stakeholders expect to know the impact of installed heat pumps within the three-year installation period though not all the 65,586 heat pumps are finished installation. Therefore, the performance assessment report will be issued every three months to dynamically include newly installed heat pumps in the assessment, and the last performance assessment will be the one to be issued immediately after the installation of all the 65,586 heat pumps. In other words, the performance assessment for the RHPR project provides a kind of dynamically updated post-implementation load profile. Since new heat pumps will be continuously installed after the issuing of a performance assessment report, it is recommended that M&V teams conduct site visits on a regular basis to check and confirm if the installation has been finished as claimed. For instance, to confirm the actual installation of 10% of the total number of claimed installations will be helpful to increase the accuracy of the reported impact from the RHPR project. The inputs needed for the Performance Assessment of the RHPR programme are the following: Begin and end date of performance assessment period; Applicable energy tariff structure; Baseline profile for each of the 3 months; Actual electrical profile for each of the 3 months; Conversion factors to determine the following emissions: CO 2, H 2 O, NOx, SOx; The output is a Performance Assessment report, containing the following: Summary of the total and monthly energy savings within the 3-month reporting period for each class of hot water usage profiles; PAGE 17
Summary of the total and monthly energy savings within the 3-month reporting period for the whole region; Summary of the total and monthly energy savings of each type of heat pump systems for each class of hot water usage profiles; Monthly average impacts on energy, cost, CO 2, H 2 O, NOx, SOx. The reason to include the savings report for each type of heat pump is to find out the performance of different type of heat pumps. This part will be included in the report provided that the sign off from all the M&V teams is obtained. The performance assessment reports will be sent to all project stakeholders. 3.5 SUSTAINABILITY CHECKUPS AND PERFORMANCE TRACKING 3.5.1 Sustainability checkups Sustainability checkups are done by spot-checking the heat pump systems after a period of six and twelve months to determine the sustainability of the RHPR project. An M&V fieldworker will need to verify if the information on the Bulk Claim Form (see Appendix A) is correct, and if the heat pump system is working properly as expected. The purpose of the sustainability checkups is to determine if a heat pump system is working satisfactorily or has it been bypassed. 3.5.2 Performance tracking The performance tracking reports provide a tracking of the savings that has been achieved after the performance assessment stage. These reports are submitted every 3 months to all the DSM stakeholders. The purpose of this report is to provide verified savings to the stakeholders. This report has the same basic structure and sections as the performance assessment report. The tracking report does have some places different from the assessment report. For instance, the first part of the performance tracking report provides the project impacts for each of the 3 months in the reporting period; the section on accumulated savings provides the impacts obtained over the total period to the date of the report for which the project delivered were active. In other words, each consecutive month will contain the impact of previously installed heat pump systems as well as the impact from newly installed heat pumps. PAGE 18
Again the performance tracking for the RHPR project is different from usual performance tracking in the sense that usual performance tracking has a fixed target for completed energy efficiency measures, while the heat pump installation in the RHPR project can only be completed by March 2013 and the performance tracking reports issued before March 2013 will give a view on the impact of those already installed heat pumps. These performance tracking reports will be updated every three months to include newly installed heat pumps assessed in the performance assessment reports. After March 2013, all the 65,586 heat pumps will be installed, and the performance tracking reports after that will be the same as a usual performance tracking report since these 65,586 heat pumps are the fixed targets of the tracking reports. An important difference between the performance tracking and performance assessment report for this RHPR project is that metered data will not be processed in the performance assessment report, but be processed in the performance tracking report. The following is the detailed metering plan. 3.5.2.1 Metering plan Since it is too expensive to install an energy meter for each heat pump, it is expected that about 0.4% of the total number of heat pumps in each region will be installed energy meters. The reason for the 0.4% of meters is due to the consideration of a total of 65,586 heat pumps, and the fact that 29 meters out of 4003 GHPs were installed in the GHP project in Louisiana [5]. The M&V teams will determine which heat pump should install a meter so that the metered data will be representative. Following a similar idea in the Solar Water Heating Programme [8], it is advised that two types of meters are installed: long term and short term meters. A long term meter will be intalled at a heat pump for at least one year to observe seasonal energy consumption changes, a short term meter will be installed at a heat pump for 1~3 months to monitor the corresponding energy consumption and will then removed and reinstalled at other heat pumps. Each hot water usage class should install both long and short term meters, and the short term meters will be roll out for all the possible classes in an M&V region. It is the best that these meters are evenly distributed in terms of the hot water usage classes and the geographical locations. Considering the meter cost and the convenience of data collection, it is advised to install single phase 230V energy usage meters which are integrated with GSM Modem and SIM card. The company Measurements Group (Pty) Ltd from Johannesburg has this kind of meters which do not need installation as the heat pump geyser can be directly powered from the 3 pin plug socket of the meter. For instance, both of its MG ENU meter and MG TOU meter have all the features needed, and the only difference between the two products is that MG TOU meter has finer metering integration period for time-of-use tariffs. Estimated cost is R1350 for an MG ENU meter, and R1925 for an MG TOU meter. PAGE 19
Metered data will be collected by the heat pump suppliers or an independent ESCo and then sent to the M&V teams. The above Measurements Group can also provide this data collection service at extra cost. The M&V team will further process and input the metered data into the RHPR Excel Application to generate the adjusted energy consumption baseline and savings for the performance tracking report. 3.5.2.2 Baseline adjustment based on metered data Without loss of generality, the baseline adjustment method is discussed only for Class I hot water usage profile, i.e., coastal category 1. Assume that a heat pump has been metered at the r -th month so that an averaged hourly energy consumption profile for a 24-hour period is obtained. Let P( j, r ) (kwh) be the energy consumed by this heat pump at the j -hour in the r -th month, COP( j, r) the corresponding COP at the j -th hour in the r -th month, and Q( j, r ) the corresponding electric geyser hot water usage. Then Q( j, r) = P( j, r)* COP( j, r) This Q( j, r) is in fact the adjusted baseline for this heat pump. The savings of this heat pump can be calculated as Q( j, r) P( j, r ). The above baseline adjustment method for a single heat pump is easily generalised to all the installed heat pumps, and the corresponding energy savings can be updated in a similar manner. 3.5.2.3 Hot water usage profile update with solar water heating M&V project data PAGE 20
The M&V for the SWH programme will classify the hot water usage profile into 10 classes in terms of the day time occupancy and number of persons/household appliances that draw high quantities of water, and metered data will also generate reliable hot water usage profiles. The hot water usage profile generated from SWH project is different from the RLM project where the latter classifies the water usage in terms of coastal and inland locations. For the moment, the SWH hot water usage profile is still not available. Whenever it is available, the SWH hot water usage profile can be combined with the RLM and RHPR water profiles since the RHPR project also has statistics on the day time occupancy and number of persons in each house with heat pump installed. Note that the questionnaire for each installed solar water heaters in the SWH project will have the information on the geographical location of the installation, this enables the possibility of further classifying each of the 10 classes of hot water usage profiles in SWH project into coastal and inland, and in then end 20 classes of hot water usage profiles can be obtained. That is, for coastal cities, there will be the 10 classes of hot water usage profiles like the SWH project; and for inland cities, similar 10 classes of hot water usage profiles will also be developed. These 20 classes of hot water usage profiles can also be emerged into only 2 classes, the coastal and the inland, to match the RLM result. Note also that geyser tank sizes are obtained in the SWH project; it is easy to classify the SWH hot water usage profiles into the 4 classes in this RHPR project. That is, Coastal category 1, Coastal category 2, Inland category 1, and Inland category 2 baselines in the RHPR project can be updated by metered data from SWH project, and the updating method is exactly the same as what is done in the performance tracking stage. The above method proposed for the combination of SWH, RLM and RHPR hot water usage profiles relies on the geographic location and geyser tank size information in the SWH project. In case that the SWH project provides only the 10 classes of hot water usage profiles without any geographic location or geyser tank size information, then the combination of the SWH results with the RHPR project will be impossible. 4 DISCUSSIONS The RHPR Excel Application will be very helpful for each regional M&V team for the calculations of baselines and the performance assessment and tracking. However, each M&V team still needs to spend much time on the analysis of heat pump installation information, Excel Application input data preparation, meter data pre-processing, report preparation, site visit, and communication with stakeholders and customers amongst others. The determination of meter allocation will be a challenge in the project though the general principle has been discussed in section 3.5.2.1 of this guideline. The number of performance assessment site visits needs also be determined by each M&V team according to the distribution and complexity of different classes of installed heat pumps. There might be other unforeseen reasons which need more input from each of the M&V teams. PAGE 21
The baseline, performance assessment and performance tracking methods for this RHPR M&V project have been discussed in the previous section, and it is obvious that the accuracy of the reported savings depends on the completeness and accuracy of collected data. In practice, it is usually difficult to ensure that the collected data are 100% accurate and complete. Site visit and metered data will usually be able to identify possible problems in the inaccurate and/or incomplete data. For the case of incomplete data, it may happen that some of the installed heat pumps have no the required information in the RHPR Excel Application, for instance, the geographic location information and heat pump types are not available. In this case of incomplete information, the Excel Application cannot generate the corresponding savings impact of these heat pumps. However, if there is any evidence to show that these heat pumps are really installed, then there is no need to perform site visit in order to minimise M&V cost, and this Excel Application will include the savings impact from these heat pumps by multiplying the existing baselines and savings a suitable weighting factor. 5 REFERENCES [1] WLR Den Heijer and LJ Grobler, The Measurement and Verification Guideline for Demand-Side Management Projects, February 2006. [2] FEMP, M&V Guidelines: Measurement and Verification for Federal Energy Projects, Version 3.0, US Department of Energy, April 2008. [3] PJ Hughes, Geothermal (Ground-source) heat pumps: market status, barriers to adoption and actions to overcome barriers, ORNL/TM-2008/232, Oak Ridge National Laboratory, Dec 2008. [4] PJ Hughes and JA Shonder, An evaluation of the Fort Polk energy savings performance contract, ORNL/CP-99304, Oak Ridge National Laboratory, 1998. [5] PJ Hughes, JA Shonder, DL White and HL Huang, Methodology for the evaluation of a 4000-home geothermal heat pump retrofit at Fort Polk, Louisiana, ORNL/CON-462, Oak Ridge National laboratory, March 1998. [6] M Ndlovu, Heat Pump Rebate Programme Residential Sector, ESKOM DSM, 2010. [7] North-West University M&V Team, RLM Research, July 2008. [8] North-West University M&V Team, Measurement and Verification-- SWH and RLM Study, Dec 2009. [9] JA Shonder, Measurement and Verification of Geothermal Heat Pumps, Slides, FEMP M&V Summit, New Orleans, LA, May 2003. PAGE 22