Sunpower for School Kids

A PV system can supply some of the energy your school needs, but may be even better as a teacher of physics, energy, and sustainability concepts.
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From Architectural Record
Deane Evans, FAIA

The Upsides of PV in Schools

There are three types of benefits to incorporating some form of PV into a school facility: environmental, educational, and economic.

By using the sun's energy to create electricity, PV systems offset the need for-and the pollution and CO2 created by the burning of fossil fuels to create electricity. As one of the most benign forms of energy production available, PV provides clear and compelling environmental benefits. From an educational perspective, the photoelectric effect is an elegant and scientifically compelling phenomenon. It is intriguing to children and adults alike and lends itself easily to being used as a teaching tool. It is for this reason that several states and/or local utilities have initiated demonstration programs to install small PV arrays on schools, primarily for educational purposes.

PV and LEED
The recently released LEED for Schools "On-Site Renewable Energy" credit awards up to three points for incorporating renewable energy technologies, including PV, into a school. One point is awarded for supplying 2.5 percent of the building's annual energy cost through renewables, two points for 7.5 percent, and three points for 12.5 percent.

Good buildings first, PV Second
PV should not be considered the only or even the first step a school takes to reduce its energy usage. Improving the building envelope, taking maximum advantage of daylighting, incorporating high performance (and "right-sized") HVAC systems will all have a far greater impact on reducing a school's energy costs than adding PV. The best approach is to drive the building's energy use down as far as possible first, then try to meet the energy "load" that remains with photovoltaics.

Madison Gas and Electric in Madison, Wisconsin, for example, has funded PV arrays on 10 high schools as part of its "Solar in Schools" program. The arrays are modestly sized-roughly eight modules each, producing 2400 watts of peak power, and are designed primarily as teaching tools. The utility installed monitoring equipment in each school so that students can keep track of the output, and it developed a comprehensive "solar curriculum" that students and teachers can use to optimize the learning experience offered by the system. Similar programs, such as New York State's "School Power Naturally" and Pacific Gas and Electric's "Solar Schools" program, have been or are being implemented across the country. Clearly, the educational benefits-scientific, environmental, and social-of PV systems are a compelling justification for incorporating them into schools.

Economic Benefits

The economics of PV are a little more complex. PV power is still not cheap, especially relative to other sources of electricity in the U.S. Even though costs have come way down-from $80 per watt in 1973 to as low as $3 per watt today-amortized over a 20 year period, the cost of generating one kilowatt hour of power from photovoltaics is still as much as four times greater in some parts of the country than the cost of buying that kilowatt hour from the local utility. And while the price per watt for PV is expected to continue its downward trend, the fact remains that it is difficult to justify the cost of PV in schools based on energy economics alone. However, there are a variety of federal, state, and local incentive/rebate programs across the country that are helping to "buy down" the costs of PV installations for schools. Some of these are demonstration programs, such as the Wisconsin "Solar in Schools" initiative, that fund very modest PV arrays primarily for educational purposes. Others, like New York's Energy $mart program or the California Solar Initiative, are more substantial and can help defray the costs of installing much larger systems. While the school district still needs to provide some of the funding through combinations of rebates and other incentives, they can often cover substantial portions of the upfront investment-as much as 70 percent in New York's case.

All the energy savings go to the school, and it can really add up over the minimum 25-year life of a PV system. As a consequence, it definitely pays to check out any and all locally available incentive programs that could help defray the cost of a PV installation. In addition to rebates, some states are exploring innovative ways of financing PV installations. New Jersey, for example, is looking at Solar Renewable Energy Certificates (SRECs) as an alternative to rebates. SRECs would be issued to PV system owners, such as school districts, for every kilowatt hour produced by one of their PV systems. The SRECs that a district or individual school receives can be sold to utilities, who are required by state regulations to either produce or purchase a specified amount of electricity from renewable sources each year. Usually a utility commission or similar body sets the prices and maintains the stability of the market. The revenue generated by the SREC sales can then be used to pay off the cost of the installation.

While new and still evolving, the SREC approach allows a school district to finance the entire cost of a PV system out of projected savings, rather than receive a rebate for only a portion of the system. This can be the difference between a go and a no-go decision on PV and is definitely worth investigating in jurisdictions that support SRECs. Third party financing may also be available.

 

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Originally published in Schools of the 21st Century, a supplement of Architectural Record.
Originally published in January 2008

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