Page 105 - Designing for Zero Carbon - Case Studies of All-Electric Buildings

REDFORD CONSERVANCY AT PITZER COLLEGE
CASE STUDY NO. 4
Energy Production versus Energy Use: Zero Net Energy
The monthly solar PV production is separately metered. For the initial twelve months beginning in February, 2018, the total energy produced was 83,000 kWh, or 26.6 kBtu/sq.ft. per year, mak- ing the performance easily zero-net-energy for that year. The chart on the oppposite page (top) shows the monthly energy production of the solar PV system versus energy use over those twelve months.
The second chart on the opposite page (bottom), Cumulative Net Energy Performance, sums the net energy production each month to that of the month prior, so that the annual total would be exactly zero if the performance is zero-net-energy (ZNE). The chart confirms that this building is in fact net positive by a large margin.
Post Occupancy: Observations and Conclusions
Post Occupancy: Controls and Monitoring
The systems are quite simple and therefore easy to maintain. The absence of metering the vari- ous energy uses and the possibility of reporting the data to the various users, does not allow behavioral responses to changes in usage. As an educational facility specifically concerning the subjects of conservancy and the natural environment, such data reporting displays or other methodologies would provide both awareness and udnerstanding.
Post Occupancy: Natural Ventilation
The natural ventilation system as part of the mixed-mode environmental management approach to heating, cooling and fresh air supply requires the direct involvement of the user. Each building user must understand how the system works to ensure comfortable conditions at all times. The building has only recently been re-occupied, so this aspect will be assessed in the near future for impact on overall energy use and efficient operation.
Post Occupancy: Solar PV System
The solar PV system was donated to the Conservancy and installed on the canopies above the outdoor classrooms. The Pitzer College facilities department is therefore responsible for clean- ing and maintaining the system to ensure maximum production by the system. This is a new responsibility for the department and there will be an inevitable learning curve. (This is in contrast to the PPA arrangement of Case Study No. 3, Kaiser Medical Office Building, where a third party is responsible for the maintenance and operation of the system.)
Designing for Zero Carbon: Volume 1
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