20-0817 Approach to Proving Net-Positive Energy (COVID)


This clarification is in regards to ONE building in an educational campus in a suburb of Phoenix, AZ. The campus provides quality career and technical (CTE) educational programs for northern and western cities of Maricopa County, AZ.

The design for the campus began in 2014.

The campus was envisioned to be a net-zero energy campus as one of the main programs is on energy technologies and construction provided by partnering with Arizona Public Service (APS - utility company), Palo Verde Nuclear Station (the largest nuclear plant in the U.S.) and a community college. The master plan identified four phases of building development with EUI targets for these energy intensive building programs as well as associated solar production required to achieve a net-zero energy campus goal. One of the buildings (Building X) was envisioned to be an off-the-grid building providing the opportunity to educate on the future of energy in the built environment.
However, due to several constraints as well as outstanding success of the program (hence more energy usage), the entire campus is now complete and operating 75% more efficient than typical CTE campuses and includes about 500 KW of solar system installed . We have been collecting operational data since 2016 when the first phase was operational and initial assessments tell us that Building X is performing as a net-zero energy building.
This clarification is about the methodology in validating Building X's performance.
Initial design concept for validation:
1. Install building level meter in all buildings.
2. Connect all buildings through a medium voltage electrical loop to allow for energy transfer between various buildings and power generation canopies.
Final design solution:
1. Only installed building level meter for the portion that the separate community college occupies within one building.
2. Install building level meter on Building X
3. Have two service entrance sections (SES) connecting two separate clusters of buildings into their respective utility meters in lieu of a medium voltage loop.
4. Each building to have its own attached or stand alone solar canopy supporting not only the energy needs but also providing outdoor comfort.
Reality post occupancy:
1. No data logger on the building level meter on Building X is available to monitor the building's performance.
What do we have to work with:
1. We have utility bills from 2016 through 2020 showing the electricity withdrawn from the power grid (APS); solar energy credited back to the grid and the net electricity consumed by the utility meters on a monthly basis.
2. Utility meter 1 - SES1 - powers Buildings A, B, C and X.
3. Phase 1 - Building A&B was operational in 2016
4. Phase 2 - Building C was operational in 2017
5. Phase 3 - Building X was operational in 2018
6. Using the monthly utility bills and tracking the net energy consumed BEFORE Building X was operational and comparing it with AFTER Building X was operational, we noticed there was no net increase in energy consumed - leading to a conclusion that Building X is operating as a net-zero energy building. This assessment is based on a 12 month performance from Jan 2019 through December 2019.
Due to the lack of building level metering, is the approach mentioned above regarding tracking net energy consumption before and after Building X was operational, acceptable as a method to validate net-zero energy performance?
We can provide the following as part of the submission:
1. Utility bills as records.
2. A summary table of this before and after assessment.
3. An operational schedule of Building X
4. Schedule of events in Building X
5. Solar production information for the system on Building X
We would really like to get this building recognized as this has been a 6 year journey for the campus and the design team aspiring to change educational building design here in the southwest.
Please reference the attached campus map for SES (utility meter locations), Building names and phases. Also please refer to the link to the campus page showing the buildings, videos, and campus plans.
Updated proposal after additional correspondence with ILFI:
  1. 9 months of the 12 consecutive months the building was in full operation - July 2019 through March 2020.
  2. However, the first full month of production data available is from August 2019.
  3. So move the 12 consecutive month performance period to capture full annual production data: August 2019 through July 2020.
  4. Replace the last four months in 2020 - April, May, June, July with 2019 data to simulate for pre-covid consumption
  5. Compare consumption vs production for August 2019 through July 2020.


The project team may use 4 months of modeled energy consumption data, given that the actual performance data is at the front-end of the performance period and crosses the peak heating and cooling seasons. 

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