The Thanksgiving holiday is a special time of year where we spend time with our family and friends celebrating all that we have to be thankful for. Thanksgiving is also a special time of year for energy management. Over the extended holiday the buildings will be vacant of people and we see this as an energy savings opportunity.
Leading up to the break, Navitas energy managers engaged building leaders, custodians, and maintenance departments reminding them to turn off plug loads and lights in their building. Plug loads are defined as electronic devises that need to be plugged in. This includes TVs, radios, computers, anything that requires electricity to operate. By turning off lights and these devices, we capture energy savings as a result.
In addition to plug loads, we also capture energy savings by implementing a heating and cooling set point setback. A set point setback expands the heating and cooling set points allowing the space temperature to float while the HVAC equipment sits idle saving energy. Because of the sophisticated building automation system or BAS implemented during the energy performance contract, we are able to do this without compromising the end users’ comfort. The BAS starts the equipment earlier than normal on Monday morning, so the space temperature is back to normal when the building occupants return.
Figure 1: Total Electric Demand Over Thanksgiving Week
The example depicted in Figure 1 shows the total electric demand of Platte County R-3 School District’s buildings over the week of Thanksgiving and the following Monday. From the demand profile you are able to see when the building operates under normal conditions such as Monday, Tuesday and then again Monday. During this operation, the average electric demand per square foot is around 1 Watt. Since Tuesday’s weather closely matches the weather during the break, we will use its consumption of 21,670 kWh as our baseline. Now taking a look at the five days of operation with reduced plug loads and HVAC setbacks, (Wednesday – Sunday), we can see the electric demand has drastically been reduced down to an average of 0.2 Watts per square foot. This equates to an average of 7,075 kWh per day. If you take the kWh difference of the baseline (21,670) and the average daily holiday usage (7,075) and multiply by the five days of the holiday, we get a total kilowatt hour savings of 72,975 kWh. Multiplying this by $0.10 per kWh gives us a total cost avoidance savings of $7,298. This reduction in electric demand also equates to approximately 51.6 metric tons of greenhouse gas emission from being released. That amount is the same as a car driving from New York to Los Angeles and back 23 times! This is something definitely to be thankful for.
It is pretty easy to see how turning off electric devices and using heating cooling setbacks, Platte County School District was able to capture cost avoidance savings reducing their utility bills.
About the author – Devin Klish is an Energy Manager with Navitas. Through the use of Data Analytics and other proprietary tools, he works to educate owners, occupants, and operators to further optimize facility operation and ongoing initiatives.