Hybridsolaroof Combined PV solar thermal system with 4 year payback

OPTICAL ENERGY TECHNOLOGIES INC. www.opticalenergy.com 472 WESTOVER ROAD, STAMFORD CT. 06902 TEL: 203-357-0626 FAX: 203-348-8761 email: [email protected]

PROPRIETARY DESIGN INFORMATION

HYBRID-PHOTOVOLTAIC/THERMAL SOLAROOF™

Photovoltaic electric solar panels can also be built into the roof in the SOLAROOF configuration to provide an aesthetic appearance, save roofing costs, and provide a 50 year roof while eliminating the possibility of leaks at the mounting points applicable to standard, rack-mounted panel installations. The construction of PHOTOVOLTAIC SOLAROOF™ is shown in Figure 1, and is lower cost than conventional solar panel installations, since mounting brackets for these panels are eliminated.

This hybrid photovoltaic + solar thermal configuration is shown in Figure 1, in which an EPDM rubber tubing mat (Figure 2) is pressed to the rear surface of the photovoltaic panel glass. The measured typical increase in the temperature of this rear surface is more than 50°F above the outsi de ambient temperature for summer solar insolation. When the rear surface of the solar panel exceeds 80°F, tank water temperature, anti-freeze is pumped through this mat, transferring its collected thermal energy to the domestic hot water in the storage tank to provide solar thermal domestic hot water pre-heating, thus providing additional solar energy harvesting, which further reduces the payback period. For typical water heaters, the water temperature starts at the 54°F o f incoming cold water at sunrise. Therefore, the anti-freeze in the heat exchanger cools the photovoltaic panel to near its rated electrical output at 25°C ( 77°F) thus improving the electrical output efficiency relative to that of convention rack mounted PV panel installations. This heat collection also cools the temperature of the photovoltaic solar panel during the warm months, (which are also the months in which the maximum photovoltaic energy is generated). Depending upon the size of the domestic hot water tank and the number of PV panels, the temperature of the panel will never reach the 120°F typical panel temp erature with only rear surface air cooling, when mounted in conventional racks. In our system the panels will have an average temperature during the solar day less than 100°F. For solar swimming pool heating, the pool water is circulated directly through the rubber tube mats, and the panel temperatures are maintained throughout the day at less than 85 °F.

Since photovoltaic panel electrical output efficiency degrades by approximately 0.4% per degree Celsius above 25°C, (*77°F) the sol ar electrical energy generated during the warm months is improved by up to 15% over conventionally mounted PV panels, while also pre-heating the domestic hot water, (or the



swimming pool) which provides further savings of fuel or electricity costs during this period.

In the winter, during a snow storm, by manually turning on the solar heating pump, this system can also melt off the snow cover of the panels to restore full photovoltaic output.

The material cost of installing these EPDM rubber mats is less than $2.00 per square foot, or approximately $30 per 300 watt PV panel, which is paid for by the savings generated by the elimination of the conventional PV panel mounting racks.

In view of the above discussion, it can be concluded that the incorporation of this hybrid solar system generates a significant improvement in the total energy output of a conventional PV panel system, and significantly reduces its payback period.

EPDM RUBBER TUBING MAT STRIPS PRESSED AGAINST

REAR SOLAR PANEL GLASS CONDUCTS HEAT ENERGY

TO DOMESTIC HOT WATER TANK, AND IMPROVES

PHOTOELECTRIC OUTPUT EFFICIENCY

SOLAR PANEL REAR GLASS

SOLAR CELL

ROOF SHEATHINGROOF

SHINGLES

PVC MANIFOLD

A

A

PROPRIETARY DESIGN

SEALING SCREWS TEN, 380 WATT SUNPREME

FRAMELESS SOLAR PANELS

FIGURE 1 LAYOUT OF HYBRID PV/THERMAL SOLAROOF INSTALLATION



FIGURE 2 TYPICAL EPDM RUBBER 5” WIDE TUBE MAT CURRENTLY USED IN OVER TEN OF OUR SOLAR SWIMMING

POOL HEATERS



AUTO . A IR

VENT

TO HOUSE

FAUCETS

EXTROL

EXPANSION

TANK 1/25 HP . PUMP

PRESURE

RELIEF VALVE

(MOVED)

PRESSURE

GAUGE

COLD WATER

SUPPLY

EXTERNAL

STA INLESS

STEELHEAT

EXCHANGER

FOUR

FRAMELESS

SUNPREME

PHOTOVOLTAIC

PANELS

THERMAL

PUMP

CONTROLLER

ANTI-FREEZE

FLOW

RUBBER TUBE

MATS ON

BACK

OF PANELS

120 GALLON

ELECTRIC

WATER

HEATER TANK

FIGURE 3 HYBRID PV/THERMAL BLOCK DIAGRAM



FIGURE 4 SUNPREME FRAMELESS PANEL DESCRIPTION



TYPICAL HYBRID SYSTEM PRICE QUOTATION

DESCRIPTION

TEN, 330 WATT SUNPREME PHOTOVOLTAIC PANELS, WITH EPDM RUBBER TUBE MATS PRESSED AGAINST THE REAR OF PANELS, FLUSH MOUNTED TO SOUTH ROOF, AS IS SHOWN IN THE ATTACHED DRAWING. A REFLECTIVE FOIL IS MOUNTED BETWEEN THE RUBBER TUBE MATS AND THE REAR GLASS OF THE PV PANEL. THIS INCREASES THE OUTPUT OF THE PANEL TO 380 WATTS.

AS IS SHOWN IN FIGURE 3, THE RUBBER TUBE MAT MANIFOLDS ARE CONNECTED TO A STAINLESS STEEL HEAT EXCHANGER, ATTACHED TO THE EXISTING SOLAR TANK IN THE BASEMENT, A 60°F THE RMAL SWITCH ENERGIZES THE PUMPS TO RUN ANTI-FREEZE THROUGH THE RUBBER TUBE MATS THUS COOLING PANELS, AND PRE-HEATING DOMESTIC HOT WATER IN THE EXISTING HOT WATER HEATER TANK.

THE SYSTEM IS WARRANTED TO PREVENT SOLAR PANEL TEMPERATURES FROM EXCEEDING 120°F.

NO CASH DOWN FINANCING FOR SOLAROOF TM

The following summarizes the no cash down financing of our SOLAROOFTM Hybrid PV/solar thermal systems for either PV + domestic hot water heating or PV + solar swimming pool heating.

In both cases, the 30% Federal income tax rebate applies.

Note: For solar swimming pool heating alone, the 30 % federal tax rebate does not apply, but with the inclusion of PV panels , the tax rebate is applicable.

Please also note that for a $10,000 loan for which your net cost after rebate is only $7,000, you will be paying down the loan for the remainder of 2014 at an interest rate applicable to a principal of $7,000, but when you get your $3,000 rebate in April 2015, you can use it to pay down the principal to $7,000.

With the 3.5 year payback shown in the following calculation, you should have positive cash flow for a 120 month loan immediately after the installation!



TOTAL INSTALLED PRICE: $10,000-

NET COST AFTER 30% FED INCOME TAX SOLAR REBATE (CONNECTICUT) $7,000.00

NET COST IN NY STATE, AFTER 30% FED INCOME TAX SOLA R REBATE AND NY STATE 25% REBATE $5,250.00

NET COST IN CONNECTICUT, AFTER 30% FED INCOME TAX SOLAR REBATE AND CONNECTICUT $1,520- REBATE $5,480. 00

ELECTRICAL ENERGY COST SAVINGS FOR AN INSTALLATION USING TEN, 380 WATT SOLAR PANELS

(3.8 KWATTS):

1. ELECTRICAL POWER COLLECTION AT NOON WITH 1,000 WATT/m2 SOLAR IRRADIANCE = 10 X 380 WATTS/PANEL

= 3.8 KWATT-HR X 6 EFFECTIVE HOURS/DAY

= 22.8 KWATT-HRS/SUNNY DAY X $0.25/KWATT-HR. = $5.70 PER SUNNY DAY X 200 SUNNY DAYS PER YEAR IN CT. = $1,140/YEAR ELECTRICITY COST SAVINGS

2. THERMAL ENERGY COST SAVINGS (NOT APPLICABLE IN CONVENTIONAL PHOTOVOLTAIC-ONLY INSTALLATION)

50°F TEMPERATURE RISE IN 120 GALLON STORAGE TANK PE R SUNNY DAY IN THE SUMMER

= 120 GAL. X 8.34 LBS./GALLON X 50°F X 1 BTU/LB./DE G.F

= 50,040 BTU/SUNNY DAY = 0.50 GALLON OF OIL

= $2.00 SAVINGS PER DAY AT $4.00/GALLON OIL COST

= $2.00 X 200 SUNNY DAYS/YEAR = $400/YEAR THERMAL SAVINGS



PAYBACK PERIOD ASSUMING NO OIL OR ELECTRIC RATE PRI CE INCREASES FOR CONNECTICUT

$1,140 + $400 = $1,540/YEAR

$5,480-/$1,540 = 3.56 YEARS = 43 MONTHS

= 28% RETURN ON YOUR INVESTMENT, TAX FREE!!

PAYBACK PERIOD ASSUMING NO OIL OR ELECTRIC RATE CO ST INCREASES FOR NY STATE

$5,250/$1,540 = 2.9 YEARS

=34% RETURN ON YOUR INVESTMENT TAX FREE!!

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Hybridsolaroof Combined PV solar thermal system with 4 year payback