IPMVP—from a DOE-Funded Initiative to a Not-for-Profit Organization
Seven years ago, the U.S. Department of Energy (DOE) started a market transformation initiative to help secure low-interest loans from financial institutions for energy efficiency investments. DOE envisioned achieving this by developing industry consensus and standard methods to measure and verify energy savings resulting from the implementation of energy-conservation measures (ECMs). The product, International Performance Measurement & Verification Protocol (IPMVP), provides standard measurement and verification (M&V) terminology and defines four M&V options to quantify energy and water savings. It is a savings-verification tool with principles that are applicable to commercial and industrial energy efficiency projects.
Seven years and three editions later, use of IPMVP has become standard in almost all energy efficiency projects where payments to the contractors is based on the energy savings that will result from the implementation of a variety of ECMs. IPMVP has been translated into ten languages. More than 300 professionals from 100 U.S. and international organizations have contributed thousands of hours on a completely voluntary basis to update and revise IPMVP.
Satish Kumar of EETD's Energy Analysis Department in the Washington, D.C., office has provided the technical leadership and has helped refine the M&V methods for different types of energy-conservation measures. He has also managed a coalition of energy professionals representing industry (ESCOs, utilities, consulting companies, standards- setting organizations like ASHRAE, etc.); researchers from research centers, universities, and national research labs; policy makers and program managers from federal and state agencies; as well as a significant number of international energy and indoor environmental quality (IEQ) professionals.
A variety of mechanisms such as shared-savings contracts and energy-savings performance contracts (ESPCs) are presently used to attract third-party financing for energy efficiency projects. The foundation of these contractual vehicles is the assumption that the ECMs would result in reduced energy use, allowing the resulting cost savings to be used to pay for energy services and loan servicing for the duration of the contract. In these projects, it is essential not only to measure the energy savings but also to verify those savings and associate them with specific ECMs.
Figure 1 depicts the conceptual framework for the ESPCs used by the U.S. DOE and U.S. Department of Defense (DOD) to help federal agencies reduce energy use and greenhouse gas emissions using funds from the private sector. The use of IPMVP, or the Federal Energy Management Program M&V Guidelines (an application of IPMVP), or both is mandatory for verifying such savings in most federal ESPC projects. Also, the use of IPMVP is required for energy efficiency projects funded under state performance contracting programs in California, New York, Texas, and Wisconsin.
Measurement & Verification Plan
The latest version of IPMVP, published in January 2001, offers four M&V options to determine energy savings resulting from the implementation of an ECM at the individual project level. The preparation of an M&V plan is central to the proper determination of savings and forms the basis for verification. A good M&V plan should:
- Identify appropriate M&V options for different ECMs.
- Define the boundaries (individual energy systems or whole building) of the ECMs for savings determination, and rigorously document the facility's baseline conditions and the resultant baseline energy data.
- Specify quality control and quality assurance procedures for data collection as well as the format in which the annual M&V reports will be submitted.
- Include cost estimates for both the initial instrumentation and recurring M&V tasks.
Measurement Versus Stipulation
One of the most contentious issues with respect to M&V has been the use of stipulations in determining energy savings. (According to IPMVP, whenever a parameter is not measured, it should be treated as a stipulated value.) At the heart of the debate is the perception that M&V strategies heavy on metering can be very expensive and do not provide as much value. Indeed, there are situations where stipulations based on reasonable assumptions or historical data can substitute for expensive instrumentation, keeping the cost of the project down. However, past experience has shown that ESPC customers, without fully realizing the risks and the associated uncertainty implications that comes with unreasonable stipulations, have often opted for the lowest cost M&V option.The latest version of IPMVP, after much deliberation within the Protocol's Technical Committee, has put in additional requirements to promote best M&V practices that conform to best engineering practices.
The four M&V options titled A, B, C, and D are the cornerstones of the standardized set of procedures contained in the IPMVP. Options A and B focus on the performance of specific ECMs. Option C assesses the energy savings at the whole-facility level by analyzing utility bills before and after the implementation of ECMs. Option D is based on simulations of the energy performance of equipment or the whole facility, permitting the determination of savings when base year retrofit data are unreliable or unavailable. Each M&V Option is explained in detail in Table 1.
|A. Partially Measured Retrofit Isolation||Savings are determined by partial field measurements of the energy use of the system(s) to which an ECM was applied, separate from the energy use of the rest of the facility. Measurements may be either short-term or continuous. Some but not all parameters may be stipulated.||Lighting retrofit where power draw is measured periodically. Operating hours of the lights are assumed to be one-half hour per day longer than facility occupancy hours.|
|B. Retrofit Isolation||Savings are determined by field measurement of the energy use of the systems to which the ECM was applied, separate from the energy use of the rest of the facility. Short-term or continuous measurements are taken throughout the post-retrofit period.||Application of controls to vary the load on a constant speed pump using variable-speed drive. Electricity use is measured by a kWh meter installed on the electrical supply to the pump motor.|
|C. Whole Facility||Savings are determined by measuring energy use at the whole facility level. Short-term or continuous measurements are taken throughout the post-retrofit period.||Multifacted energy management program affecting many systems in a building. Energy use is measured by the gas and electric utility meters for a twelve-month base-year period and throughout the post-retrofit period.|
|D. Calibrated Simulation||Savings are determined through simulation of the energy use of components or the whole facility. Simulation routines must be demonstrated to adequately model actual energy performance measured in the facility. This option usually requires considerable skill in calibrated simulation.||Multifaceted energy management program affecting many systems in a building but where no base-year data are available. Base-year energy use is determined by simulation using a model calibrated by the post-retrofit period data.|
Every year about 3000 copies of IPMVP Vol.I—Concepts and Options for Determining Energy Savings and 1500 copies of IPMVP Vol. II—Concepts and Practices for Improved IEQ are either downloaded electronically or ordered through the Energy Efficiency and Renewable Energy Clearinghouse (1-800-DOE-EREC).
DOE's Office of Building Technology, State and Community Programs (OBTS) has funded the IPMVP project for the last seven years. Recently, IPMVP, Inc. was incorporated as a not-for-profit organization to broaden its support and provide technical and educational services to professionals and organizations interested in the measurement and verification of energy savings. IPMVP, Inc. together with the Association of Energy Engineers launched a new certification program for M&V professionals in April 2002 to raise the professional standards and improve M&V practice. EETD continues to play a central role as IPMVP, Inc. tries transitions from a government-funded to a not-for-profit model and at the same time maintains its objectivity as it helps improve and refine the art and science of M&V. If it manages to successfully make the transition, it will be a victory for the collaborative model that brought about such a successful government industry partnership.
For more information, contact:
- Satish Kumar
- (202) 646-7953
This project is funded in part by the U.S. Department of Energy, Office of Building Technology, State and Community Programs.