Trust. But Verify: The Importance of Measurement & Verification
If it can’t be expressed in figures, it is not science; it is opinion.
— Robert Heinlein.
Increasing energy efficiency offers the most cost-effective opportunity for both private and public sector organizations to combat rising energy prices and achieve sustainability goals. But providing evidence of achieved savings is essential to securing funding and support. Measurement and Verification (M&V) delivers that evidence by quantifying the precise impact of implemented energy conservation measures (ECMs). Data gathered through M&V allows organizations to assess the performance of each ECM, and determine if the program is generating the expected/promised savings.
M&V is even more essential for Efficiency-as-a-Service (EaaS) endeavors as it is the mechanism that verifies whether the project is meeting the guaranteed energy savings or not.
Why Invest in Measurement and Verification?
A recent review of efficiency investments in buildings in the U.S. suggests that projects with strong M&V protocols result in a substantially higher level of savings (typically 20% to 30%) than projects that have little or no M&V.
M&V gives organizations the ability to:
- Prove the economic impact of an energy efficiency investment
- Identify the specific efficiency upgrades that are delivering the highest return on investment
- Identify the upgrades producing the highest realized energy savings
- Monitor and adjust energy systems to maintain and increase savings
- Establish a benchmark for future energy savings. (For example, companies with multiple locations can use M&V to calculate the savings of a measure in one building before rolling out similar projects to their entire portfolio of buildings)
Naturally, one of the first steps in the M&V process is to identify and define the desired data measures. Once that is established, the next step is to establish an accurate energy baseline. An energy baseline allows organizations to compare energy consumption and performance before and after efficiency upgrades are implemented.
Baseline physical conditions such as equipment inventory, occupancy, energy consumption rate, and control strategies are normally evaluated during an Investment Grade Audit (IGA). The baseline should also include data on ‘independent variables’ – factors (such as production volume and weather) that may have a direct effect on baseline energy usage patterns.
Preparing the M&V Plan:
Having a clear understanding and definition of how the ECM is expected to perform is critical to program success. The M&V plan defines exactly how the savings analysis will be conducted before the ECM is implemented. This provides greater objectivity than simply evaluating savings after implementation. An effective M&V plan allows for on-going adjustments to increase program performance as issues develop. Typically, M&V plans include:
- Details of baseline conditions and data collected
- Documentation of all assumptions and sources of data
- What will be measured and verified
- What will be stipulated
- Who will conduct the M&V activities
- Schedule for all M&V activities
- Details of engineering analysis performed
- How energy savings will be calculated
- Utility rates and how they will be used to calculate cost savings
- Defined content and format of all M&V reports
- How and why the baseline may be adjusted.
- Responsibilities of customer
Having a Certified Measurement & Verification Professional (CMVP) who is familiar with the project’s EMCs provides greater the certainty that the project will meet the savings expectations.
Data Measurement Options:
- Measurements are simply taken when and where appropriate.
- Operational factors such as lighting operating or cooling hours should be stipulated to reach accurate results.
- This approach is best suited to efficiency projects where the main goal is simply to verify the installation.
- Measurements are taken continuously throughout the term of the contract.
- Best suited for larger projects where the organization doesn’t want to assume performance risk.
Utility Bill Comparisons
- A high-level approach where all efficiency upgrades within a metered building or group can be measured and analyzed by using current and historical utility meter/sub-meter data.
- Best suited for projects where energy performance is projected to be greater than 10% – 20% of baseline energy use.
- Performance is determined through simulation of facility components and/or the whole facility where all efficiency upgrades can be applied.
- The actual measurement from before or after the upgrades is used to calibrate the simulation model.
- Best suited for projects without any meter data.
Periodic audits and data reconciliation should be performed to validate the measurements.
Calculating the Savings:
Energy use is often dictated by a large number of dynamic, interrelated factors. Energy savings cannot be directly measured since savings represent the absence of energy used. It is, accordingly, more complex than other kinds of energy measurement.
For example, while the output of a solar photovoltaic array can be directly metered to obtain an indisputable report of total kilowatt-hours generated and average kilowatts delivered, an energy efficiency project depends on measuring both the metered usage and the energy that would have been used in the absence of the project. This can be accomplished partly through metering and sub-metering of facilities and equipment. As mentioned, the correct interpretation of the data is essential and involves adjusting the data for such things as temperature variations, changes in building occupancy and use. The final energy consumption figures are compared to an accurately determined baseline of energy use to come up with the energy savings figures.
The International Performance Measurement and Verification Protocol (IPMVP ) provides an overview of recommended approaches for verifying results of energy efficiency, water efficiency, and renewable energy projects. IPMVP categorizes the four main M&V approach options as:
Option A – Retrofit-isolation: Key Parameter Measurement
Option B – Retrofit-Isolation: All Parameter Measurement
Option C – Whole Facility
Option D – Calibrated Simulation
Each of these M&V approaches will require different data measurement requirements. The level of required M&V, along with the associated costs, should determine the optimum M&V approach.
M&V 2.0 is the term typically used to describe new M&V practices that take advantage of enhanced data analytics and increased data availability. The rise of smart meters, smart devices, and innovations in energy data and analytics present significant opportunities for organizations. The shift towards using more meter-based approaches and advanced analytic tools can save both time and resources. It can also help enhance customer engagement and increase the accuracy of savings calculations. It’s all about using data in smarter ways – applying big data to savings calculations. M&V 2.0 is generally conducted remotely and does not require on-site installation or inspection. As such it has the potential to provide results quicker, and at a lower cost than traditional M&V.
Regardless of the specific approach, integrating measurement & verification into an energy efficiency project is the best way to determine the true impact of the investment. Organizations that apply M&V correctly achieve a more accurate understanding of how their building works, where and when it is using energy, and what is needed to ensure ongoing savings.