CenterPoint EnergyElectric Transmission and Distribution
Measurement & Verification
Commercial & Industrial Standard Offer Program

The purpose of measurement and verification (M&V) is to establish the potential of a project's measures to save demand and energy and to determine the actual savings produced by those measures.

In the C&I Standard Offer Program, Project Sponsors are responsible for planning and conducting all the M&V activities associated with their projects. They are required to submit, as part of the Project Application, an M&V plan that describes the specific activities, tools, and calculations the Sponsor intends to use to determine the projects' actual savings.

Table below highlights the basic steps required during the M&V process for most retrofit projects under this program.

Step  M&V Activity  Performed by: 
1 Develop a site-specific M&V plan  Sponsor
2 Ensure that the M&V plans adhere to the IPMVP guidelines  CenterPoint Energy
3 Conduct a pre-installation equipment survey  Sponsor
4 Conduct a pre-installation inspection  CenterPoint Energy
5 Install retrofit equipment  Sponsor
6 Conduct a post-installation equipment survey  Sponsor
7 Conduct a post-installation inspection  CenterPoint Energy
8 Execute the M&V plan (conduct M&V activities if necessary)  Sponsor
9 True-up savings, based on M&V results  Sponsor


This section of the site provides guidelines and instructions to help Project Sponsors develop their M&V plans. Also discussed are the site inspections that CenterPoint Energy Houston Electric conducts during the program process to verify project site conditions.


Measure-specific M&V approaches

M&V procedures will vary in detail and rigor depending on the measures installed. For each installed measure, the chosen procedures will depend upon the predictability of equipment operation, the availability of evaluation data from previous programs, and the benefits of the chosen M&V approach relative to its cost.

Project specific M&V procedures may be classified according to three distinct approaches that represent increasing levels of detail and rigor:

  • Deemed savings: Deemed approach refer to a savings estimation approach that does not require short-term testing or long-term metering. Instead, demand and energy savings are stipulated based on evaluation data from past DSM programs or other publicly available industry data. The data are used to make assumptions about typical operating characteristics, manufacturer’s nameplate efficiency data, and types of equipment likely to be installed. The deemed savings M&V approach is appropriate for energy efficiency measures for which savings are relatively certain, such as lighting efficiency.
  • Simple M&V: A simplified measurement approach may involve short-term testing, but relies primarily on manufacturer’s efficiency data and pre-set savings calculation formulas. Simplified methods can reduce the need for extensive field monitoring or performance testing. For example, pre-retrofit chiller demand and energy may be extrapolated for one-to-one chiller replacements by measuring energy, flow, chill water supply and return temperatures of the new chiller.  Manufacturer curves for kW and tonnage of the old chiller are then compared to the metered data (tonnage) to extrapolate the consumption of the old chiller.
  • Full M&V: The full measurement approach estimates demand and energy savings using a higher level of rigor than the deemed or metered measurement approaches through the application of computer simulation. Any full measurement methods other than computer simulation should be developed in accordance with the 2007 International Performance Measurement and Inspection Protocol (IPMVP) and be approved by CenterPoint Energy Houston Electric.  

M&V guidelines have been developed for use in this program. To download a guideline, simply click on a filename in the following table. Note that these files are in PDF format, available for viewing and printing only with Adobe Acrobat Reader®.

Measure/approach type M&V guideline
(click to download)
Retrofit Lighting and Controls Retrofit Lighting M&V.pdf
Retrofit Cooling Retrofit Cooling M&V.pdf 
Retrofit Constant Load Motor Retrofit Constant Load Motor M&V.pdf
Retrofit Premium Motor

Retrofit Premium Motor M&V.pdf

Retrofit VSD Retrofit VSD M&V.pdf
Retrofit Generic Variable Load Retrofit Generic Variable Load M&V.pdf
Retrofit Window Film Retrofit Window Film M&V.pdf 
Retrofit using Billing Analysis and Regression Models Retrofit using Billing Analysis and Regression Models M&V.pdf 
Retrofit Using Calibrated Simulation Analysis Retrofit Using Calibrated Simulation Analysis M&V.pdf 
New Construction Lighting and Controls New Construction Lighting M&V.pdf 
New Construction Cooling New Construction Cooling M&V.pdf 
New Construction Constant Load Motor New Construction Constant Load Motor M&V.pdf 
New Construction Generic Variable Load New Construction Generic Variable Load M&V.pdf 
New Construction using Billing Analysis and Regression Models New Construction using Billing Analysis and Regression Models M&V.pdf 
New Construction Using Calibrated Simulation Analysis New Construction Using Calibrated Simulation Analysis M&V.pdf 


Project Sponsors will need to adapt these guidelines to their specific projects when developing the M&V plan required for program participation. Project Sponsors may recommend an M&V approach not covered in these guidelines; however, any alternate approach must be approved by CenterPoint Energy and adhere to IPMVP standards.

The time required to complete M&V activities will range from less than one month to up to 12 months, depending on the approach chosen.


Sampling guidelines

When preparing the Project Application, a Project Sponsor is required to document each fixture or piece of equipment that is part of a project. Equipment with similar functional uses may be grouped together for M&V purposes. Once the equipment has been grouped, a sample of each grouping's equipment may be monitored and the results used to estimate the operating hours for all of the fixtures or equipment within that group. (For more information on specific equipment groupings, see the measure-specific M&V approaches for that equipment type.)

The table below shows how large the sample size must be to provide a reliable estimate for varying sizes of groups. The initial sample sizes represent 80% confidence/20% precision and have a coefficient of variation of 0.5; the suggested sample sizes have been increased by 10% to compensate for equipment failure or loss.

Group
population
Initial
sample size
(80/20)
Suggested
sample size
(80/20 plus 10%)
4
3
4
5
4
5
12
6
7
16
7
8
20
7
8
25
8
9
30
8
9
35
8
9
40
9
10
45
9
10
60
9
10
65
9
10
70
9
10
80
10
11
90
10
11
100
10
11
125
10
11
150
10
11
175
10
11
200
10
11
300
10
11
400
11
13
500
11
13


The Project Sponsor may propose an alternative approach to determining sampling sizes, but it must be approved by CenterPoint Energy and be based on sound statistical principles.


M&V plan requirements

Projects involving full measurement must submit a project-specific measurement plan. At a minimum, the plan should address the following (from the 2007 IPMVP):

  1. Describe the project site and the project; include information on how the project saves energy and which key variables affect the realization of savings.
  2. Describe the Measurement method to be used.
  3. Indicate who will conduct the Measurement activities and prepare the Measurement analyses and documentation.
  4. Define the details of how calculations will be made. For instance: “List analysis tools, such as DOE-2 computer simulations, and/or show the equations to be used.” A complete “path” should be defined indicating how collected survey and metering/monitoring data will be used to calculate savings. All equations should be shown.
  5. Specify what metering equipment will be used, who will provide the equipment, its accuracy and calibration procedures. Include a metering schedule describing metering duration and when it will occur, and how data from the metering will be validated and reported. Include data formats. Electronic, formatted data read directly from a meter or data logger are recommended for any short-or long-term metering.
  6. Define what key assumptions will be made about significant variables or unknowns. For instance: “actual weather data will be used, rather than typical-year data,” or “fan power will be metered for one full year for two of the six supply air systems.” Describe any stipulations that will be made and the source of data for the stipulations.
  7. Define how any baseline adjustments will be made.
  8. Describe any sampling method that will be used, what is included, sample sizes, documentation on how sample sizes were selected, and information on how random sample points will be selected.
  9. Indicate how quality assurance will be maintained and replication confirmed.

Site inspections

Over the course of a project, CenterPoint Energy conducts two site inspections. A pre-installation inspection is performed as part of the Final Application review; a post-installation inspection is performed following the Project Sponsor's submission of the Installation Report.

Pre-installation inspection

As part of the Project Application review process, CenterPoint Energy will conduct a pre-installation inspection of the project site at its discretion to verify the baseline conditions documented in the Project Application (PA). The inspection will verify the following information:

  • The accuracy of the equipment survey. For most measures the accuracy of the equipment quantity and nameplate information is verified. For lighting measures, the requirement for acceptance is that the installed demand of the sample must be within +/- 5 % of the total demand submitted on the survey form.
  • The M&V plan is appropriate for the measure, and the necessary M&V activities are being performed.
  • All existing equipment listed in the Final Application is still in place and operational.
  • New equipment installation, or preparation for installation, has not begun.

Post-installation inspection

CenterPoint Energy will conduct a post-installation inspection of the project site within 30 days of the receipt of a complete IR. The post-installation inspection requires the presence of at least one representative of the Project Sponsor who is familiar with the project and the facility. The inspection shall verify that:

  • The installation of the equipment specified in the approved Final Application. For most measures the accuracy of the equipment quantity and nameplate information is verified. For lighting measures, the requirement for acceptance is that the installed demand of the sample must be within +/- 5 % of the total demand submitted on the survey form.
  • The M&V plan is being followed in accordance with the approved Final Application.

For both inspections, the presence of at least one representative of the Project Sponsor familiar with the project and with the facility is required. When electrical measurements are necessary, the representative is required to perform any necessary disruptions in equipment operation, the opening of any electrical connection boxes, or the connection of current and power transducers.

If an inspection cannot be completed in a timely manner because the representative is unfamiliar with the facility or project, the project will fail the inspection. A project has two chances to pass each type of inspection (pre or post); after failing two inspections, the Project Sponsor must pay the cost incurred by CenterPoint Energy Houston Electric for performing additional inspections of that type.