Standard 2 kW PV System Equipment Description
The project's standard 2-kW solar electric photovoltaic system ("PV System") is directly connected to the utility grid and does not require batteries. The PV System includes only UL-listed hardware and meets all local, state, and national electric code equipment and interconnection requirements, including those established by the local electric utility.
The PV System operates in parallel with the utility grid. Should utility power be lost, the PV System will automatically shut off according to utility safety requirements. The AC power from the PV System will be tied directly into the building's main circuit panel for connection to the facility's 120/208 three-phase service.
The PV System does NOT include funding for any needed roof repair or reinforcement.
The PV System includes the following:
Each system has 2 kW photovoltaic array using modules from AstroPower (now GE Solar), BP Solar, or Sharp. The PV system requires approximately 200 - 250 sq. ft. of unobstructed roof or wall space. Twenty five of the school systems use the SMA "Sunny Boy" 2500-watt inverter, the other 25 use the Fronius "IG-2500-LV" inverter. The inverter converts DC energy to AC energy and supplies solar power to the school's electrical system. Both the SMA and Fronius inverters are UL listed and have been type tested by the State of New York.
A Heliotronics Feynman™ data collection and monitoring system allows students to monitor the daily and cumulative production of electricity from the system. For more information, view the DAS Troubleshooting Guide [PDF]. The Internet-compatible data collection monitoring system includes the following teacher- and student-friendly features:
- SunViewerTM classroom real-time display software
- SunViewer Internet-based database and plotting software
- kWh meter (electricity)
- DC power, current and voltage (electricity coming from the solar array)
- AC power, current and voltage (electricity going into the school's wires)
- Anemometer (wind speed)
- Pyranometer (solar radiation)
- Ambient temperature transducer with Gill shield (outdoor temperature)
- Module temperature sensor (temperature of solar panels)
- Avoided emissions
- Data logger with integral power supply
- Optically isolated RS 232 communications
2. Mounting Options
Sloped Roof: The PV System can be mounted flush to the south-facing side of a sloped roof, using an aluminum and stainless steel mounting system. Any penetrations to the roof are completely sealed.
Flat Roof (ballast tray): The PV System may also be mounted using a non-penetrating ballast tray system, wherein aluminum trays, measuring 4 ft. symbols x 5ft., are laid flat against the roof and weighed down with concrete blocks, rocks, or other suitable ballast. The modules are raised to a 30° angle by using aluminum legs.
Flat Roof (pressure-treated beams): Another approach is to use a series of pressure-treated wooden beams that lie flush against the roof and are bolted into supporting rafters. A series of aluminum legs are used to raise the modules upward. These legs are themselves bolted to the beams.
Wall Mount: A fourth option is to mount the modules as an awning over windows or a visible roof area. The mounting hardware used depends on several factors, including: condition of the roof, acceptability of penetrations to the roof, and ideal orientation of the modules.
3. Permitting, Installation, and System Commissioning
Solar Works has assumed responsibility for designing, installing, commissioning, and maintaining the PV System during the program. Solar Works' project managers coordinate with the local utility to ensure that the system is properly interconnected to the utility grid and that all the necessary permits are secured. Solar Works obtains all necessary building and electrical permits from the responsible political jurisdiction, and also assists school and district personnel in completing the required utility interconnection agreement from the local utility.
4. Product Warranty Information
Note: Warranty available at time of product purchase will be used. The inverters carry a standard five-year unconditional warranty, which states that the inverter will be free of defects in materials and workmanship. The warranty states that the manufacturer will, at its option, repair or replace the inverter, refund the purchase price, or provide the purchaser with a new inverter to make up for lost power, provided that the degradation is determined to be due to defects in materials and workmanship under normal installation, application, and use.
The photovoltaic modules come with a limited warranty, which states that the power rating of the individual PV modules at standard test conditions (STC) will remain at 80% or greater of the module's original power rating for either a 20-year or 25-year period, depending on manufacturer. The warranty states that the manufacturer will, at its option, repair or replace the product, refund the purchase price, or provide the purchaser with additional modules to make up for lost power.
5. Two-Year System Warranty
Solar Works warrants the school's PV System to operate as specified in the installation manual and to be free of material and labor defects for a period of two (2) years following the date of installation, with continuing manufacturer's material warranties on PV modules and inverters.