Practical Exercise: Non-Routine Adjustments

In This Issue

March 2018 - M&V Focus Issue #1

With the fast development of new and relatively cheap data collection and analysis tools, we hear a lot about what is called M&V 2.0 or advanced M&V. This topic motivated our search for articles for this first issue of M&V Focus. We invited Colm Gallagher to tell us more about his research on the difficulties of M&V in industrial applications and how machine learning techniques could help extract valuable knowledge contained within complex data sets collected in industrial facilities. Paul Calberg-Ellen and Eric Vorger volunteered an article which deals with recent breakthroughs in the world of energy simulation and the corresponding questions about the application of the IPMVP to the new capabilities offered by energy building simulation programs. David Jump accepted to re-post an article previously shared on his company’s blog on the concept of M&V 2.0 and normalized metered energy consumption. Many months ago, Greg Kats suggested it would be nice to tell the story of the early days of the IPMVP. The opportunity became obvious with the launch of this first issue of M&V Focus. Greg searched his notes and recollected his memory to tell us more about the early days of the IPMVP. To complement this set of core articles, we feature a practical exercise on non-routine adjustments for a real Option C case. This idea comes from Colin Grenville who originally proposed this exercise during an interactive workshop session at a conference in the U.K.

By Colin Grenville*

The following is an exercise originally discussed in an interactive workshop session at the MAVCON’17 M&V conference in the U.K. in November 2017.

An Option C (whole facility) measurement approach is often proposed where numerous ECMs are installed at once and may have interactive effects which cannot be successfully isolated by local measurement. However, as M&V experience grows in U.K. energy services market we are increasingly discovering examples where using Option C is far from ideal. Using Option C introduces the real risk that changes in static factors (which could not reasonably be foreseen and considered when the M&V plan is written) could dwarf actual savings achieved by the installed ECMs. This risk increases where baseline data is not comprehensive and lacks proper schedules of installed energy consuming equipment. By the time a performance gap is identified, the chance of gathering baseline data may have passed, and calculating accurate non-routine adjustment becomes difficult or impossible.

The following is example is a modified version of a real project where Option C was used.

Project background

Facility electricity baseline annual demand is 200 MWh, at say £0.10/kWh = £20,000/annum.
4 variable frequency drives were installed to save 18 MWh/year = £1,800, i.e. savings represent 9% of baseline.
VFDs were commissioned with fixed reduced output which meets requirements for air flow and reduces excessive ventilation, i.e. no modulation of fan speed. Time clock control was added to match fan operation to occupancy hours. Each fan motor has a different kW rating.
Anticipated savings were derived from reduced fan power and reduced operating hours.
In order to avoid local metering at each ECM location, Option C was selected in the interests of minimising M&V cost, but unfortunately the following savings are observed using data from the main utility meter:

Colin Chart

Investigations revealed the facility had introduced a significant new seasonal (space heating) electricity load at some time after the agreed baseline period and before start of measurement. The graph shows the impact of this change. Not only did the VFDs not apparently deliver their savings but it appears they caused an increase in the total site electricity use.

Questions for consideration:

1) What was wrong/went wrong with the measurement plan?
2) Is a non-routine adjustment appropriate in this situation? If so, how can you adjust?
3) How else could savings performance now be accurately calculated?
4) Should negative savings ever be reported if the ECM could not have caused the observed increase in electricity demand and no other explanation can be easily identified or should there be a floor on underperformance (e.g. zero savings)?

Please take the time to go through this exercice alone or in group within your company. Come back on March 21 for the solution.

NOTE: To see the solution, you must have an EVO website subscription. Please login into your account to see the solution and access M&V Focus additional interactive features. Follow this link to know more about EVO web subscriptions.

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(*) Colin Grenville is the President of Erebus Environmental.

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In This Issue

March 2018 - M&V Focus Issue #1