Page 94 - Zero Net Energy Case Study Buildings-Volume 3

PREFACE TO CASE STUDY NO. 15 BUTTE COLLEGE
Butte College
Preface to Case Study No. 15
(Opposite page) Location of Butte College in northern Cali- fornia. (Satellite map courtesy of Planet Labs Inc., San Fran- cisco.)
(Below) Some of the solar PV arrays on the Butte College campus.
(Photos: Peterson ProVideo)
(Overleaf, next page) Aerial photograph of the Oroville campus, in which the many solar PV arrays are visible across the site.
The California community college system is the largest post-secondary education system in the United States, with an enrollment of 2.1 million students and a total of 72 community college districts distributed throughout the state. Of these, the Butte-Glenn Community College District located near Oroville in the northern part of the Central Valley of California, serves over 14,000 students.
Typical in many respects, Butte College is, however, a noteworthy case study because of its extraordinary commitment and successful efforts at overall sustainability and renewable energy supply for all of its campus facilities. This investment in renewable energy in the form of electric power from solar photovoltaic systems is, in fact, the unique story of Butte College. In the case of one its satellite buildings, the Chico Center (Case Study No. 15), total zero-net-energy perfor- mance has essentially been achieved.
Zero Net Electric Energy: Bold Initiative for a Community College
In 2004, college administrative leaders embarked on a bold sustainability program to transform existing campus facilities and to require new facilities to meet aggressive design standards that would enable the campus to reach the design goal of grid-positive performance. The challenge was not only technical but also very much one of funding such an investment in solar power for a public community college.
A comprehensive initial study examined the feasibility of facility retrofits for energy efficiency as well as design requirements for the first wave of new buildings, both of which would be funded through a local bond measure and state capital funds. With the passage of the bond measure, one side of the equation was able to be estimated, namely the total electric power demand of the campus over the course of a typical year. The corresponding annual solar PV production and overall size of the system required was then estimated. The practical issues could then be addressed: where to locate the PV panels, how to phase the installation of the total system and how to finance the entire collection of system components.
The estimated total size of the solar PV system required was approximately 4.5 MW (DC). This entire campus solar PV system was built in three separate phases from 2005 until 2011; the total rating of the final installed system is 4.55 MW (DC). The first two phases consisted of 10,000 so- lar PV panels, meeting less than 40% of the campus electric demand. The third phase then was the largest installation, consisting of 15,000 panels that generates the remainder of the power necessary to offset the majority of the District’s electric demand.
Financing such a large and extensive solar PV system came from existing campus construction funds,specialbonds,commercialloansandutilityrebates.Thecampusbenefitedfromdeclining prices for PV panels and the weakened economy from the Great Recession, which resulted in more competitive bids for the work. The federal economic stimulus package, passed by Con- gress in response to that recession, featured a bond program, the “Clean Renewable Energy
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Zero Net Energy Case Study Buildings: Volume 3