In searching for potential load shedding opportunities, the Energy Manager of the Delta School District wanted to implement a program to stagger the start of the Air Sourced Heat Pumps (ASHP). Doing so would minimize the demand charges triggered by their concurrent starts.
The Delta School District has an inventory of 17 pod-type elementary schools. The schools have identical layouts and building systems and are served by air source heat pumps (ASHP) that provide heating, ventilation and air conditioning.
To prepare the rooms for school start times, all units were enabled at the same time in the morning. As a result, electrical demand was highest in the morning and led to demand charges from the utility company.
In searching for potential load shedding opportunities, the Energy Manager of the Delta School District wanted to implement a program to stagger the start of the ASHPs. Doing so would minimize the demand charges triggered by their concurrent starts.
The Energy Manager asked ESC Automation to implement a program to stagger the ASHP operation in order to reduce demand while maintaining building and occupant comfort.
ESC Automation used CopperTree Analytics to investigate the pilot building of Brooke Elementary, track historical energy consumption versus occupancy, predict demand, and track and report savings.
Once the occupancy and demand patterns were pinpointed using CopperTree Analytics, building operators programmed and executed a series of automatic modes (summer mode, winter mode, shoulder season, and after hours). They also used occupancy sensors and prioritized the start times so that preconditioning of each ASHP’s rooms began in order of priority rather than running concurrently.
The CopperTree solution for the Delta School District consisted of these products:
- CopperCube to extract and store building automation system trend logs.
- Kaizen analytics engine and logic builder to process data into meaningful, actionable information.
- Electrical demand charts to track electrical consumption across systems, rooms and time.
- Vault for demand trend logging and active kilowatt trending every five minutes.
- Golden Standard to issue insights whenever new automatic modes and set points were manually changed or degrading the impact of the costavoidance measures in place.
The results of using CopperTree to predict and manage electrical demand in Brooke Elementary saved the pilot school $609 per year in demand costs.
In addition to creating new energy efficiencies and cost reductions for the school district, the Delta School District verified the impact of a pilot program that can be implemented in the rest of the pod-type schools.
If the pilot is rolled out to the 16 other schools with the same layout and systems, the Delta School District could realize a demand cost savings of $10,353 per year.
At Brooke Elementary, the first school in which the CopperTree solution was implemented, the impact was immediate. Compared to the same month in the previous year, a demand cost savings of 46% was realized right away. A total of $609 per year is being saved in demand charges.
A drop in consumption was also recorded. Before the strategy was in place, 35,243 kWh were consumed in January 2012.
After the strategy was in place, consumption dropped dramatically to 15,597 kWh. The overall demand savings continued throughout the year and clocked in at 24% overall.
