Sedona School District Goes Solar
Sedona-Oak Creek Unified School District #9 (Sedona), a district of 1,500 students located in Northern Arizona, consists of two K-8 and one 9-12 school. While the district may be small in terms of student population and number of facilities, administrators are proving large in terms of planning for the future. Specifically, the district is in the process of installing solar energy projects to reduce energy costs.
As is common in other states, Arizona school districts received a certain amount of money from the state every year that was earmarked to pay for utilities in excess of a baseline. In Arizona, that amount was based on a figure that was developed several years ago and was intended to help school districts offset fluctuations in utility rates. Since 2009, that help from the state has disappeared, and school districts now must pay for all utility costs from the same budget that funds the classroom teachers and supplies.
Unfortunately, such a situation forces school districts to cut programs and teachers in order to pay their utility bills. “Energy consumption is one thing you can’t cut from the budget,” says Michael Thomas, LEED-AP, project manager with Flagstaff, Ariz.-based Kinney Construction Services, Inc., which designed some of the solar systems with engineers and architects in a design-build process and is now constructing them. “You have to have the buildings up and running.”
When a $73-million bond passed in November 2007, savvy Sedona administrators decided to invest the money in solar energy in order to reduce energy consumption. This would allow them to pay their utility bills without having to dip into other line item costs and thus still have sufficient funds available for programs and salaries. “It was forward thinking,” says Thomas. “It was a good investment on the part of the district.”
The first project, completed in spring of 2009, was a 100-kW, roof-mounted, thin film system located at Big Park Community School, offsetting approximately 35 percent of the school’s electricity cost.
The largest project includes an 806-kW, ground-mounted, solar photovoltaic array at Sedona Red Rock High School, which was completed last fall. The system is not only an energy saver, but also a teaching tool for the science program at the high school.
The next project to come online will be a roof-mounted, crystalline panel system at the new district office, including a geothermal HVAC system and 48 kW of solar photovoltaics, which will offset a portion of the office’s electricity.
The fourth project, at West Sedona School, is a rebuilt pool that will have a solar thermal system to heat the water in the pool, as opposed to using a gas boiler, the panels of which will double as shade structures for the swimmers. “So, there’s a dual benefit to putting in the solar thermal system at the pool,” says Dave Young, LEED-AP, Sedona’s project manager via Arcadis, an international firm that manages the bond. The school will also boast a 58-kW, ground-mounted, solar photovoltaic system to help offset electricity costs.
Because it’s a school district, Sedona didn’t receive any federal incentives or tax breaks to reduce the cost of the projects. However, a $1.8-million rebate for the high school from local power provider APS reduced the cost of that project from $4.8 million to $3 million, Young notes. From this investment, the district will save 1.2 million kW hours per year at the high school, between 50 percent and 60 percent of its electricity consumption. Specifically, administrators anticipate saving more than $100,000 in the first year from the high school’s system.
“The obvious benefit of solar,” says Young, “is it reduces the amount of power the high school consumes. It also means that there is additional savings in the maintenance and operations budget, which provides teachers’ salaries and school supplies.” Plus, as utilities increase, the cost of the system won’t go up — it’s paid for and will keep on generating electricity.
As indicated, two of Sedona’s solar systems are ground mounted. Thomas cites two reasons that a building owner might choose to mount a system on the ground as opposed to the roofs — there are doubtless even more. The first is safety. “Someone has to maintain the systems, including looking at them a few times every year,” says Thomas, “and it just isn’t safe to be climbing around on roofs.”
The second is that existing facilities typically aren’t designed with the intent of someday accommodating solar systems on the roofs. “To be efficient with the funds that were available — to get the most bang for the buck — we were able to maximize construction costs and install much more on the ground,” Thomas says. “You can easily replicate your systems in this manner and thus not have to invest in renovating rooftops, all of which have different slopes.”
The average payback for one photovoltaic system is about 12 years. And, because the four projects are different, each has its own payback period.
Each solar photovoltaic panel has a 20-year lifetime. The panels’ degradation rate is less than one percent per year guaranteed and, even though they naturally degrade through time, they still work. “We feel, and it’s been proven, that the panels last much longer than 20 years,” Thomas says. “In fact, the panels still work on systems that were installed 50 years ago.”
Panel installation is easy — they simply plug together. If one panel stops working, the string (usually 12 to 15 individual panels) that it is attached to stops working, but all the other strings in the array continue to operate. To put that in perspective, the Sedona High School project includes 3,838 panels. If one panel stops working, an entire string of 14 stops working, but the remaining 3,824 panels remain in operation.
Thomas is seeing a trend toward the installation of solar power in schools, both in new construction and in retrofits. “It’s about saving the district money,” he says. It’s about the bottom line in the budget. And they get the environmental benefit as a bonus.”
Sedona administrators have recognized several other bonuses of using solar energy. One is what Thomas calls the “touchy feely” aspect — it’s good public relations to say that you’re using less electricity produced from coal-burning plants.
Another is educational. Science curriculum is being assembled that includes the district’s use of solar energy. “It’s like an exterior lab,” Thomas says. “The students can see the panels. They can study the data being collected through the inverters (the smart part of the system), such as how many watts are being produced, the irradiance of the sun and more. So, it is more than a static system producing electricity; it is also an educational element.”
A final bonus for this specific project was keeping the bond money in the community. “In this tough economic climate,” Thomas observes, “it was important. The project was paid for with tax money from the community, and that money went back to the community through salaries paid to local contractors and subcontractors. If they needed a little training, we provided it to them.”
In planning for their future, Sedona administrators are getting more bang for their buck than they probably anticipated. Of course they knew they would realize huge savings from generating electricity via solar power, but did they anticipate the benefits of good public relations, keeping the investment local and a stronger science program? Regardless, they’re clearly taking advantage of all that solar power offers.