On Sept. 24, UC Davis announced its purchase power-agreement with SunPower Corp., in which SunPower will oversee the design and construction of a 16-megawatt, ground-mounted solar power plant. The 70-acre site will be located in Davis, south of Interstate 80, and is expected to meet 14 percent of the campus’ energy needs. This project, when finished, will be the largest solar power installation in the UC system, as well as the largest solar power plant to meet the electricity demands of a U.S. university or college campus.
SunPower Corp. is a global solar company with a diversified portfolio of customers, leading residential, commercial and utility solar energy markets. UC Davis had previously collaborated with SunPower back in 2011 to create the UC Davis West Village neighborhood, the largest planned zero net energy community in the country.
“We’re really lucky with SunPower because they are… a very reputable [and well-established] firm and they’ve done large solar farms like this in the past,” said UC Davis Design and Construction Management (DCM) Assistant Director Jason Magness. “They seem to take pride in their work … We’ve had no issues or conflicts with them on meeting codes and standards and doing it as per our campus standards … We have a set of standards that our designers adhere to above and beyond the code.”
West Village Community Partners had contracted SunPower to install a 4-megawatt solar photovoltaic system to power its student housing, mixed-use buildings and recreation center. The SunPower system has helped West Village prevent more than 2,000 tons of carbon dioxide emissions per year.
For this new project, SunPower is introducing its Oasis Power Plant technology, which uses a tracking mechanism to position high-efficiency solar panels to track the sun’s location throughout the day, potentially increasing energy capture by up to 25 percent.
Currently, UC Davis already has several solar installations integrated around the main campus. These sites came online in January 2012, some of which include the solar carport installations in the parking lot servicing the Mondavi Center for the Performing Arts and the Robert Mondavi Institute of Food and Wine Science, as well as panels implemented on the roofs of the Tercero and Segundo residence areas. These sites alone generate an estimated 1,100 megawatt-hours annually. In addition to cutting costs, these systems also offset 800 metric tons of carbon emissions.
“In this case, at least we know what we’re getting and we know the source,”David Phillips, the utilities director with the university’s Administrative and Resource Management Department said. “The business-as-usual case is that we’re just buying some random electrons off the grid.”
The campus might not always have to purchase the electricity from this new solar farm, as the contract gives UC Davis the option to purchase the equipment at various periods.
“The power purchase agreement is for 20 years, and we have options to purchase the system as early as year seven,” Phillips said. “But the panels themselves these days last well in excess of 30 years — so it’s likely that if we don’t buy it before the end of year 20 that we would buy it at that point and continue to run it for another 10 or 15 years after that.”
Phillips went on to say that after 20 years the campus would be able to purchase the equipment at a relatively low price because the contract makes SunPower responsible for removing the equipment if the university chooses not to purchase it. If the equipment is purchased, Phillips and UC Davis Utilities will be responsible for maintenance of the plant.
Bringing in a third-party company for the project was a way for the university to take advantage of tax incentives that made solar power cheaper.
“We always look at the idea of just buying the system ourselves – just spending the money and buying panels and constructing it – but as a campus we don’t pay taxes and so we’re not eligible for the tax breaks that a private company would get,” Phillips said. “So every time we’ve looked at the analysis it always makes sense to bring a third party into the picture.”
Phillips estimated that approximately a third of the project’s cost will be refunded to SunPower as a result of these tax incentives, and part of those savings will be passed on to the university. Since the price of the equipment has decreased over the years, current forecasts predict that the cost of the power produced with the panels will be cheaper than the other channels.
“We set up the power purchase agreement such that the price we pay for the solar essentially matches what we expect the price for grid electricity to be,” Phillips said. “So for the first seven years it should track pretty much the same as business as usual, and then after that the price we pay each year actually drops by about 1.1 percent.”
According to Phillips, if grid electricity were to rise more than 2.6 percent over the project’s 20-year period, not impossible based on historic patterns, the project will be considered economical for the campus.
In addition to these campus sites, UC Davis had also recently purchased 26 megawatts of off-site solar panel sites that are expected to come online in 2017, according to Sid England, Assistant Vice Chancellor for the Office of Environmental Stewardship and Sustainability.
“When you take the on-site renewables and the off-site solar and you combine it with the fact that part of the electricity that we buy is large-scale hydraulics … in a typical year [after 2017] 60 percent of our electricity will be carbon-neutral,” England said.
According to England, one of the most impressive aspects about this project is the size. What started as a proposal for 7 megawatts grew over twice as large, as everyone realized more could be done without an increase in the cost of electricity … We’re trying to maximize what we can do to reduce our carbon footprint.”
Despite rapid campus growth, UC Davis greenhouse gas emissions are lower than they were five years ago due to the combined efforts of various clean energy projects. This new project will further support UC President Janet Napolitano’s goal of being carbon-neutral by 2025.
“Between 2009 and 2013, our annual energy use through one of our energy-efficiency projects has gone down by 30 million kilowatts an hour,” England said. “In the next three years, we’re looking at going down by another 25 million, [and] in between 2017 and 2025 another 36 million, for a total of about 91 million [fewer] kilowatt-hours of [electricity]. It’s a really aggressive approach; it’s not just about using renewable energy, it’s about using less.”
Samuel Moffitt, the outdoor activities coordinator of the UC Davis Environmental Club, believes that the plant not only reduces the university’s carbon footprint but also has potential to do much more than its intended purpose.
“These new campus installations should be used as hands-on teaching tools for both graduate and undergraduate students,” Moffitt said. “I studied abroad in Europe last summer, and we visited large wind and solar plants, as well as a giant biodigester, to learn how the technologies work and how they can be applied and implemented in the [United States]. The fact that these are now being installed on the UC Davis campus is exciting, but I have heard little to nothing in my classes about this. This new infrastructure can go above and beyond its direct impacts by educating students how to lobby for, install and maintain such systems.”
Unless halted by unforeseen weather conditions, construction will begin in the early months of 2015 in a field on the far southeast corner of campus which was previously used for agricultural purposes. DCM handles the proper construction of the plant to ensure its safety and efficiency, especially due to future possibilities regarding the facility.
Upon its completion in 2015, the university anticipates that one-third of the electricity demands on campus will be met by carbon-neutral energy sources, according to Phillips. He states that the solar farm has the potential to save the university about $10 million over the lifetime of the project. The power from the solar farm will be fed directly into the campus grid, ensuring that all the power produced will be used by the university.