TODAY’S STUDY: TO HAVE SOLAR SCHOOLS
Brighter Future: A Study on Solar in U.S. Schools
September 2014 (The Solar Foundation and the Solar Energy Industries Association)
The impressive and precipitous rise of the U.S. solar industry is well documented. As of the writing of this report, total installed solar electric capacity neared 16 gigawatts (GW), providing enough solar electricity to power over 3.2 million average U.S. households. By the end of 2014, this figure is expected to surpass 20 GW- more than four times the total amount of solar capacity that existed in the U.S. just three years ago. Of the more than 500,000 homes, businesses and public entities that have now installed a solar energy system, over 3,700 of those systems are located on public and private K-12 schools in the U.S.
While thousands of schools have already realized the cost savings and other benefits of installed solar energy capacity, this opportunity is generally underutilized. The large, flat rooftops typically found on public and private K-12 school buildings throughout the United States make many of these properties excellent candidates for rooftop solar photovoltaic (PV) or solar thermal systems. School parking lots can be put to productive use with solar PV canopies, which provide the added benefit of shading parked vehicles on sunny days, and tracts of vacant land on campus can be used to support modestly-sized solar PV farms.
Taken together, this untapped potential for solar on K-12 schools is immense. If each of the more than 72,000 schools for which solar could represent a cost-effective investment were to install an average-sized system, total PV capacity on K-12 schools would reach 5.4 GW – an amount equal to more than one-third of all the solar PV capacity currently installed in the United States.
Offsetting energy consumption with increasingly cost-competitive solar electricity, and space or water heating can deliver a significant cost savings to schools and their districts. Over time, solar can serve as a key hedge against projected increases in utility rates. As a clean energy technology, solar can provide deep reductions in greenhouse gas and criteria air pollutant emissions, helping to protect human health and the environment.
Among its environmental attributes, solar PV on schools can also help to save water, as it uses a mere fraction of the water required to produce electricity by conventional means. Perhaps most importantly, solar installations on schools can provide teachers with a unique opportunity to teach concepts in science, technology, engineering, and mathematics (STEM) and pique student interest in these critical subjects.
With these observations in mind, this report was produced to: (1) help K-12 schools understand the motivations and successes of current solar schools; (2) provide insight into the basic technical and financing aspects of these systems; (3) provide the most comprehensive baseline to date of K-12 schools with solar, providing a means for tracking future solar/school installation progress, and; (4) supply prospective solar school stakeholders with actionable information and lessons learned from previous projects so they can “go solar” with greater confidence.
• An analysis performed for this report found that 450 individual school districts could each save more than $1,000,000 over 30 years by installing a solar PV system. Of the 125,000 schools in the country, between 40,000 and 72,000 could “go solar” cost-effectively.
• There are 3,752 K-12 schools in the United States with solar installations, meaning nearly 2.7 million students attend schools with solar energy systems.
• The electricity generated in one year by all 3,727 PV systems represents a combined $77.8 million per year in utility bills ‒ an average of almost $21,000 per year per school. This combined energy value is roughly equivalent to 155,000 tablet computers or nearly 2,200 new teachers’ salaries per year.
• The 3,727 PV systems at all U.S. schools with solar installations have a combined capacity of 490 megawatts (MW), and generate roughly 642,000 megawatt-hours (MWh) of electricity each year.
• More than 3,000 of the 3,752 systems were installed in the last six years. Between 2008 and 2012, solar installations on U.S. schools experienced a compound annual growth rate of 110 percent.
• Nearly half of the systems currently installed are larger than 50 kilowatts (kW) and 55 schools have systems that are 1 megawatt (MW) or larger. About a quarter of the PV systems at schools are smaller than 5 kW.
• As schools system sizes increase, so too does the incidence of third-party ownership.
• Excluding small demonstration systems, the median system size of K-12 school PV systems was found to be 89 kW (approximately equal to 18 average residential solar PV systems).
• As with the solar industry at large, more schools are going solar as installations cost decrease.
• The likelihood of a school having a solar energy system increases with grade level due to the correlation with school size. A larger proportion of high schools have gone solar compared with elementary or middle schools.
• If the 72,000 schools for which solar could be a cost-effective investment were to deploy systems sized proportionally to their student body size, the combined electricity generation would offset greenhouse gas emissions equivalent to taking approximately 1 million passenger vehicles off the road.
The database underpinning this report was carefully built between March 2013 and July 2014 from hundreds of public and private sources. Additional database entries were found via web searches of new articles, press releases, school websites, or other sources. To complement the quantitative information derived from the database, executive interviews were conducted with representatives from 15 existing solar schools. These interviews added a qualitative perspective to the report’s findings, capturing challenges and lessons learned from practitioners with first-hand experience in bringing solar to their schools...
Why Are Schools Going Solar?
Investments in solar energy provide schools with a number of benefits that appeal to a broad set of stakeholders. Facilities managers recognize the value of solar energy in providing a long-term hedge against increases in utility rates while school boards and administrators are attracted to the technology’s ability to deliver cost savings. Solar also presents teachers with a number of educational opportunities in science, technology, engineering, and mathematics (STEM) subjects. Finally, the increased use of clean energy technologies like solar can help significantly reduce emissions of pollutants that can harm human health and the environment. This section discusses schools’ motivations for going solar in greater detail and provides examples of schools that have successfully unlocked these benefits.
One of the most frequently cited reasons schools give for going solar is the opportunity to save money. This has been largely driven by the rapid decline in system pricing over the last several years. From 2010 to the second quarter of 2014, average installed costs for commercial solar photovoltaic (PV) systems have fallen by over 50 percent, from $6.00 to $2.97 per watt-DC (WDC)3, and it is not uncommon for PV systems to be installed in many markets for less than $2.00/WDC. In addition to this price drop, systems have become more accessible and affordable for more customers due to the increased availability of financing options, including third-party system ownership, improved availability of debt financing, and other traditional school financing vehicles such as bonds and tax-exempt lease purchases (for more on financing, see “Understand Solar Financing Options” on page 34).
Interviews with facilities managers and school administrators across the country show that solar is providing schools with significant cost savings, which has been used to reduce electricity bills, improve education, and retain existing staff and resources in the face of budget cuts. For example, Clovis Unified School District, located just northeast of Fresno, California, funded the installation of 5.9 megawatts (MW) across 19 individual PV systems through a bond measure in 2012. Together, these systems are expected to save the district approximately $2.7 million each year, freeing up space in the district’s general fund that can be used for teacher training, new teaching materials, and facilities maintenance. At Rio Rancho High School and Cleveland High School in New Mexico, district decision makers evaluated several options for reducing utility costs (the district’s second-largest expenditure after personnel), and identified solar as offering the greatest potential for cost savings. The $200,000 in expected annual energy cost savings was originally earmarked for making improvements to existing building systems (e.g., HVAC systems, boilers, etc.), but unexpected budget cuts made it necessary to put this money toward teacher and staff salaries. In rural Utah, a small 10-kW solar energy system at Milford High School is saving this small district approximately $1,500 per year (see the case study on page 11).
These opportunities are not just in the Southwest – schools across the country have gone solar to save money. A 39.5-kW system at Drury High School in North Adams, Massachusetts has saved the school over $16,500 since it was placed in service in the summer of 2011. While these savings may not appear significant when compared with other examples, they were enough to help the school avoid cuts to programs and teachers in the face of low tax revenues. In the Midwest, Parkway School District in St. Louis County, Missouri expects to save $1 million in avoided energy costs over the next 20 years, reducing the need to reallocate funds from other budget areas (especially those impacting educational quality) to pay utility bills as rates continue to rise over time (see case study below). The Medford Board of Education in southern New Jersey saw a similar opportunity for solar. The district’s combined 2.7 MW of solar PV systems are saving Medford $300,000 a year in utility costs, freeing up funds to help further improve the education students receive.
As prices continue to fall toward the Department of Energy’s SunShot Initiative goal of $1.25/W for commercial rooftop PV systems by 2020,4 more schools will be able to leverage solar to their financial benefit. According to an original analysis produced for this report, by the end of 2015, up to 60 percent of all K-12 schools in the U.S. could be able to save money by going solar. More information about this analysis can be found in the “Massive Untapped Potential” section starting on page 25.
Solar also provides schools with a much-needed means of expanding educational opportunities for STEM subjects. According to the latest results for the Programme for International Student Assessment (PISA 2012), which tests 15-year-old students in 65 countries and economies worldwide (including all 34 member countries of the Organization for Economic Cooperation and Development, or OECD) on proficiency in math, reading, and science, students in the U.S. performed “below average” in math and only close to the OECD average in science.5 Students in Massachusetts – one of the strongest performing states in the nation – were found to be over two years behind those in Shanghai, the top-performers in the math portion of the assessment. Looking at the math results more closely reveals that U.S. students have “particular weaknesses” in “taking real-world situations, translating them into mathematical terms, and interpreting mathematical aspects in real-world problems.”
Solar arrays sited on K-12 schools and designed with education in mind can help students overcome these shortcomings, providing a “real-world situation” for students to sharpen their math and science skills. At Woodstock Union High School in central Vermont, Jen Stainton, a science teacher, led the effort to install a 10 kW solar PV array and has helped incorporate the system into science and math lesson plans. Students have access to system performance data in order to understand how much electricity is being produced, the amount of carbon emissions offset by the system, and how much money has been saved. The school has also incorporated a unit into its science classes designed to teach students about the physics of solar energy and how the technology compares with conventional sources of electricity. This unit incorporates lessons on system tilt angles and orientation and how changes in these variables affect system production, providing students with a real-world situation to further develop their math and science skills. Milford High School seized a unique educational opportunity that arose from complications with the tracking system installed at the school (see case study below). As part of an effort to overcome this technical issue, students devised and proposed their own engineering solutions. Though none of these solutions were ultimately implemented, this unanticipated problem provided students with a unique and valuable STEM educational experience. Finally, teachers at Drury High School plan to build on what students have learned about solar and other clean energy options in the classroom through a summer program in which students will conduct an energy audit of a local homeless shelter and make recommendations to reduce its energy consumption (see the case study on page 13).
While solar energy has proven cross-cutting educational value that merits much more than a brief mention, there is limited discussion on the technology in the Common Core State Standards6 or the Next Generation Science Standards7 – the most widely referenced and adopted state standards. This limited acknowledgement forces educators to determine for themselves how and when to incorporate solar into their classrooms, as well as how to measure progress against a non-existent standard/benchmark.
Additionally, any significant inclusions are likely to require exclusions – potentially creating controversy. However, for the motivated solar educator, there are many free, high-quality resources to choose from (see Appendix A for a list of resources). Some teachers have chosen to supplement their lesson plans with energy science education kits and system monitoring software. As part of the agreement with their solar PV installer, Jurupa Unified School District (CA) received a number of high-quality science kits containing PV system components, meters to measure system output, interconnection devices, and water pumps to provide students with a hands-on learning experience and use solar energy as a means of teaching key science and math topics. Still other schools arranged for installation contractors to provide solar monitoring software that students can use to learn about system production and the factors affecting performance, as well as the environmental and economic benefits of solar. Though the capabilities of these monitoring programs can vary widely, all of them provide important basic system information. Examples of monitoring platforms can be found at Drury High School,8 Carlisle High School (PA),9 and Rapoport Academy (TX).10 Environmental Protection
In addition to economic and educational benefits, using solar energy conserves natural resources and significantly reduces emissions of pollutants that threaten human health and the environment. A 89 kW solar PV system (the median system size from The Solar Foundation’s National Solar Schools Census Database) that receives an average of 5.0 kWh/m2/day of solar radiation will produce approximately 117,000 kWh of electricity in its first year of operation. This translates into more than 80 tons of annual avoided carbon dioxide (CO2) emissions, the equivalent of avoiding more than 9,000 gallons of gasoline and of the amount of carbon sequestered by 66 acres of U.S. forests.11
This amount of solar electricity will also reduce nitrogen oxide (NOx) emissions – which contribute to ground-level ozone formation and can adversely affect the human respiratory system – by 11 pounds annually. Beyond these avoided air pollution benefits, solar PV systems also use much less water per unit of electricity generated compared with conventional energy sources. Offsetting this amount of electricity with solar PV results in an annual savings of nearly 24,000 gallons of water over the same amount of production from a natural gas combined-cycle plant.
Resiliency and Emergency Response
An emerging trend in the use of solar energy at K-12 schools is to provide power during times of emergency or when electricity from the grid is otherwise unavailable. One notable example is the Florida Solar Energy Center’s “Sun Smart E-Shelter” program, a partnership with multiple state agencies, emergency managers, utilities and 42 school districts to install 100 emergency center systems across the state. At 10 kW each, these systems provide 1 MW worth of solar capacity combined with battery backup. Under normal conditions, these systems provide electricity directly to the schools at which they are sited. When the grid goes down, the batteries attached to these systems provide a basic level of power service to the centers.13 Solar energy in an emergency response context took the spotlight during Superstorm Sandy in late 2012.
Midtown Community School serves the community of Bayonne, New Jersey not only as a combined elementary and middle school, but also as a community emergency evacuation center. With these dual roles in mind, the school facilities manager looked to solar not only to offset utility bills through its daily operation, but also to provide a source of backup power in the event of a loss of power from the grid. Rather than connecting the solar array to a bank of batteries to store energy until it is needed, the Midtown system was specially designed to work in tandem with the school’s diesel generator. When the grid goes down, the solar energy system automatically begins providing power to the school’s emergency systems, reducing the workload of the diesel generator and helping stretch the available supply of fuel which can be in short supply during emergencies…
More information on these topics is available atwww.solaroutreach.org/resources or by contacting The Solar Foundation at firstname.lastname@example.org