The Walkthrough Survey for an Energy Audit

Last week I toured a 6 million square-foot facility that had a $21 million annual energy bill. Nevertheless, this facility had no dedicated full-time energy manager.

Does this surprise you?

I have seen many facilities that are willing to spend millions of dollars on energy, with little or no oversight or management. Many facility managers perceive energy as a necessary evil and believe there is little to be done about it.

This is amazing when you consider that with some basic oversight, a 10% savings is highly probable for many facilities, especially if there has been no energy management practice within the last 5 years. A 10% savings on $21 million is $2.1 million, which should be enough to fund an energy department and even some capital improvements … every year.

So the potential for savings can be enormous, not only in reducing consumption but also shifting load to off-peak hours. Many facilities have a "ratchet clause," which means that they pay all year for their high demand during a few peak hours. I have discussed energy issues with people from thousands of facilities, and many have reported that demand charges are 20% to 30% of their total electric bill … sometimes higher! (See table.)  

Good energy practice calls for continual monitoring. A walkthrough survey is a key component of monitoring.

Begin by Collecting Data before the Walkthrough
If you are lucky and can get bill data for similar facilities, you can benchmark your facility against peers and see how they compare. For office or school buildings, it can be easy to get good data. For other building types, such as manufacturing facilities, it may be very is difficult or impossible to get bill data for a facility with similar processes, operation hours, and location.

Other pieces of information to collect before the walkthrough are a list of primary energy-consuming equipment and a plant layout on an 8 1/2 x 11 sheet of paper. Sometimes a fire escape plan can provide the layout and allow you to take notes on it. During the walk-through, I usually note the operation hours of each area (office, shipping, café, etc.) and where the large pieces of equipment are located.

On the day of the walkthrough, I usually spend 1 to 2 hours meeting with the plant manager. I try to discover the facility's material and personnel flows so that I don't recommend something that is infeasible or out of alignment with the long-term plans. It is also critical to understand the hurdle rate, minimum acceptable rate of return, or financial criteria that the facility manager expects for energy projects. This information helps you eliminate projects that are beyond the payback period.

Then I walk the site until lunchtime. At lunch, the survey team will formulate a list of opportunities, confirm the opportunity list with the facility manager, and then spend the rest of the day quantifying the opportunities and collecting measurements.

Understanding maintenance is key to long-term energy success. If the maintenance team doesn't understand a system, energy will be lost. An analogy is the microwave oven in my kitchen. It can do all sorts of cool functions, but I have no idea how to do those and I get by with the basics: open the door, input the time and push start. If a maintenance team is getting by without training on things like economizer controls, waste heat recovery, etc., opportunities for improvement exist. Also, if a facility does not have a maintenance policy about compressed air leaks, motors, chillers, etc., that lack of policy usually creates a lot of opportunities … and 5% to 15% savings!

Finally, safety is important if you want to survive to the next walkthrough. Safety glasses, ear protection, and hard hats in construction areas are good things to have in your toolbox. Don't touch electrical systems (high voltage buses, etc.), be aware of potentially very hot surfaces in the mechanical room, and never wear a necktie, especially around motors. If a facility staff does not supply you with adequate safety gear, it probably won't make energy management a priority either.

In next month's newsletter I will talk about advanced auditing techniques and data collection.

Eric Woodroof, Ph.D., is the Chairman of the Board for the Certified Carbon Reduction Manager (CRM) program and a board member since 1999 of the Certified Energy Manager (CEM) Program. He is a strategic advisor, corporate trainer, keynote speaker, and founder of ProfitableGreenSolutions.com.