Recommendations for Solar Technologies

Carolyn Luce, Redwood City, CA

5.2 kW Solar Photovoltaic System: The recommended system would be a 5.2 kW AC system ($40,285) built with (52) Kyocera KC-120 modules, (1) SMA “Sunny Boy” SWR2500U Inverter for those panels on the western roof, (2) SMA “Sunny Boy” SWR1800U Inverters for those panels on the southern roof and all connections and mounting hardware. The Kyocera modules carry a (25) year warranty. This system has a CEC rating of 5,189 watts and will produce 9,129 kWh per year in Redwood City, CA. Sun Power will charge ($9,516) to install the system and carry a (5) year, all-inclusive parts and labor warranty. The state of California will give you a cash rebate of ($20,446.61) approximately 4-6 weeks after the system is installed. After rebates and tax credits, your system will cost ($28,074). This system will save you approximately ($2,100) per year. You can see on the attachment, “Luce-PV effect on PG&E Bills,” that you will save an additional ($100) per year by switching to an E7 rate schedule. Please see the attached “Luce-System Proposals” for detailed price breakdown.

6.8 kW Solar Photovoltaic System: Should you decide to include the additional 1.6 kW of solar on the front of the home, you will receive a higher return on your investment. This system has a CEC rating of 6,785 watts and will produce 11,734 kWh per year in Redwood City, CA. The additional 16 panels will require a fourth inverter (SWR1800U). After rebates and tax credits, this system will cost ($35,062). This system will save you approximately ($2,700) per year. You will save an additional ($150) per year by switching to an E7 rate schedule. Please see the excel attachments for details on the larger system.

Sunny Boy Data Analysis Equipment: In order to analyze the output of your solar system, you will need to install a RS 485 Module into each inverter. These modules will give you daily kWh output, and real time voltage, amperage, and wattage information. These cost ($140) each and replace the digital display on the inverter. You will also need a cable running from your computer that will daisy chain at the inverters. At your PC, you will need an RS 485 to RS 232 converter. The SMA website has free software downloads that will allow you to analyze the data (www.sma-america.com). John Berdner at SMA is available to help you should you need guidance on how to best configure your system and analyze the data. jberndner@sma-america.

Spa Hot Water System: The recommended system would be an HT 410 G Drainback Spa System Kit ($1,659), which includes (1) Gobi 410 collector, (1) flush mount kit, (1) LX220/B differential thermostat, sensors, 1/6^th hp pump, air vent and bushing. Please see the attached “Spa Proposal” for detailed price breakdown. This system will handle 90-95% (90-95°F) of the hot water needs of a 200-250 gallon capacity hot tub for 6-8 months of the year. The output in winter will vary depending on the amount of sunlight and ambient temperature. The pump will turnover 3 gallons per minute at maximum.

The weight of the Gobi 410 is 153 lbs, plus its capacity of 1.34 gallons of water, for a total of 165 lbs.

Sun Power will assume the responsibility for installing all collectors and associated plumbing above the roof of the Gazebo. Our understanding is that your plumber will take care of all plumbing associated with the installation of the Hot Tub. Sun Power will charge ($400) for installation of the Gobi collector as shown on the attached proposal. Should you want Sun Power to work with the plumber to handle more aspects of the installation, we will need to negotiate the responsibility of each party.

Please see: http://www.heliodyne.com/gobi_solar_collectors/gobi_solar_collectors_right.htm for details on the Gobi Collectors.

Roof Layout: Attached to the email is a roof layout detailing the placement of the 52 panels for the 5.2 kW system. Should you not have an AutoCAD program to view this document, you may download a free CAD viewer at http://usa.autodesk.com/adsk/index/0,,837403-123112,00.html. This layout represents our first cut at a design, should you have input we will accommodate you to the best of our ability.