Facility assessments (investigating a building’s energy, water, material usage and waste, similar to LEED O+M or other facility greening audits) can provide significant value in multiple ways. For one, when done at multiple facilities of a similar type, assessments allow us to benchmark across these similar facilities in the hopes of identifying performance standards (i.e. expectations of what resource use should be) as well as best practices.
For example, a high-end resort chain contacted us to have us look at four of their sites scattered across the U.S. and Mexico. In conducting some internal, qualitative benchmarking of practices, we found many similarities between sites across the board: heat pumps as the heating/cooling system, transferring the heat between the outside air or water; lack of food waste collection for composting; relatively light building insulation.
We also found differences:
One site had very lavish lighting. It was over-lit (which you can actually test for with illuminance meters), incandescent, and with first generation rheostat dimmers that don’t actually save energy in the dimming;
One site had inefficient water fixtures, while others had efficient fixtures serving the same purpose. The efficient fixtures clearly meet the needs of customers and still provide a rich spa experience.
At one site, when the cleaning team came in, they’d turn on all the lights, gas fireplace, in every suite even though cleaning was done room by room. We saw big opportunities to shut off appliances that weren’t required to be on, and which weren’t providing value.
And looking more broadly, and externally, at similar hotels and resorts, there were clearly best practices from other companies that could be brought to bear for this job:
Orchard Hotel’s key card system, where most of the suite, other than the entry light and the small refrigerator circuit, cannot be turned on until the room key card is placed in its holder inside the room. Occupant takes key card when they leave, ensuring unnecessary equipment isn’t inadvertently left on.
Xanterra resorts kitchen oven hood controls, which blow out only enough air to maintain air quality and temperature in the kitchen, so the fan doesn’t work more than it needs to, and energy is saved. This is a big potential asset for our resort chain, which had onsite restaurants with hoods.
And, we could even look at best practices within one site. Since each site had several units, most with their own electric and gas meters, we can quantitatively look at how much electricity and gas per square foot, or per hours of occupancy, are used.
The chart above is provided for illustration purposes only, but the data does reflect actual energy use and trends at sites. Here we have electricity and natural gas converted into BTU, because, in general, we want to control against switching around between different energies, and so look at all energy use — whether in electricity, natural gas, propane, fuel oil, etc. Then, this BTU is normalized against occupancy, and reported on a quarterly basis.
We see that we have some higher and lower performers — the best performing facility is 40% lower than the worst — and we want to figure out why that is the case. We also see that there is more seasonal variation at the NE and N sites, which could indicate poor insulation at those sites, or could indicate real differences in the temperatures to which those site are subjected (i.e. colder winter temperatures). (One can use degree days to account for weather differences, and predict actual cooling and heating for a site, but that’s a topic for another time). And the first and fourth quarters, typically colder months, exhibit higher energy use, which you might expect in areas where energy for heating drives the energy profile. In areas where cooling is the driver (e.g. southern climates with minimal heating but significant AC demand), however, the profile could be flipped.
Note that there is also value in keeping elec and natural gas separate, rather than break them down into BTU, as gas is typically driven by heating in many building types, and electricity driven by cooling, so you can see those heating/cooling trends by looking at gas and electricity individually.
So, clearly more site investigation and place-based knowledge is required to be able to start to diagnose problems and find solutions. Nevertheless, utility bill analysis is a key tool of the benchmarking trade to generate insight, turning data into useful and actionable information.
(to be continued in Part 2)