Page 108 - Zero Net Energy Case Study Buildings-Volume 3

CASE STUDY NO. 15
BUTTE COLLEGE CHICO CENTER
Renewable On-Site Energy Supply
The initial installation of Phase 3 of the solar PV system project was at the Chico Center in 2011. By then, there was good data on the electrical energy use of the building over several years. The District wanted to include a number of electric vehicle charging stations in that canopied parking area as well.
As designed, the solar PV installation supplies energy directly to the building as required. Other- wise, the electric energy produced is fed to the electric grid. A utility net meter records the data as is conventionally done. Therefore, there is good data for solar energy production and total build- ing use of electric energy. The electric vehicle charging stations are recorded as a building load, since they are connected back to the electrical distribution system of the building, and should be deducted from the building energy use in the ZNE calculation.
PHOTO: PETERSON PROVIDEO
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Zero Net Energy Case Study Buildings: Volume 3
Energy Design Analysis and Energy Performance
Modeling versus Post-Occupancy Measurement
Energy Modeling
Energy Pro, the certified whole building energy analysis software for use in Savings By Design, was used (2005 version) to verify energy use performance of at least 10% better than that re- quired by Title-24 standards. (Results are not available.)
Energy Use—Actual Measurement and Comparison to Modeling Results
Using the building’s net energy meter and the total solar electric energy production as mea- sured by meters on the PV system, it is possible to determine the total electric energy use of the building. In addition, the utility’s gas meter reading provides the other energy-use component of the building, the gas used for space heating and domestic hot water. The chart shows these performance results for the sample year 2016. The building’s EUI is 44.1, rather high for a ZNE design, but good for an energy-efficient design intended to be slightly better than the California energy standards.