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Solar Energy -- DIY PVac640 System

Solar Power

Photovoltaic Systems Integrated Design and Automation

The Sun is forever, don't you deserve the best in
solar panel price and efficiency?

The DIY PVac640 system is making a unique offering utilizing the knowledge for optimum power production with easy to install hardware, flush mounted (pitched roofs) or low angle profile for flat roofs with a unique AR Tempered Glass, which increases useable sunlight to the panel independent of time of day and orientation (does not apply to due North).

It increases power production over typical solar fixed installations through unique optical and electronic enhancement approaches which reduce the impact of clouds, shade, solar tilt and panel direction of solar panels used in your overall system. Each DIY PVac640 system supplies the customer with defined alternating current Voltage at 208, 230 or 240 volts fully compatible with 50 or 60 Hertz AC systems.

Panel installations involve simple screwing down of the panels, male/female safety AC connectors and easy junction boxes to typical building wiring. Note that for safety reasons, the PVac640 produces no AC voltage or current until connected by the grid or bypassed using an internet procedure to set up your system as off grid.

The protective AR Tempered Glass protects the underlying solar panel from harmful ultraviolet, hailstones, heavy rains, and debris with a tempering of the glass equivalent to that of an airplane pilot's window.

Special coatings on the AR Tempered Glass reduce cleaning schedules and maximize the amount of useful sunlight which gets to the solar panel. Our unique Dragonskinrubber-under-layer-system adds additional protection for your roof by replacing your roofing materials with a leak-proof, compressive strength, fire retardant material that not only addresses fixing leaks on existing roofs, but adds strength and insulation over wood, metal or cement structures.

The on-panel inverter electronics allow direct monitoring of each panel with the highest power factor transfer of any DC to AC conversion. Electrical storage efficiency >90% allows maximum use of sun-energy generated power every day which maximizes your return on investment, specifically designed to address your power usage throughout the year with 5.5 hours or more of non-daylight power.

Each PVac640 system provides a maximum AC power output of 2 amps and connects with other PVac640 systems through the AC harness in parallel producing up to 50 amps per circuit. Each panel is installed through simple parallel wiring.

Customers should not exceed the number of panels designed for each wiring harness and should not insert more than one circuit per junction/breaker of the junction/combiner panel. Other wiring specifications are related to the code of your area and you should refer to a licensed electrical installer or your respective utility for proper identification of code requirements.

Easy to install: Everything is provided as a dual panel system.



Initial panel install is very easy and straightforward. The panel is screwed down to the roof using the pre-drilled, countersunk holes over the Dragonskinrubber. The panels are connected with the provided wire harness to the junction box. After the junction box, THHN or Romex wiring is used to connect to the disconnect/breaker sub-panel. The flex-flat hardware chase covers the wires and supports the temperes optical enhancement glass. (Not shown in the photos.)

AC Specifications:

Optional Echelon Power line communications allows for monitoring of each panel installed. Any size system can be installed.

An up-to-500-kW-rooftop installation is already completed.

  • Certifications completed: UL 1741/IEEE 1547, CSA C22.2, CE, EN50178, VDE 0128-1-1, & TÜV Rheinland.

  • Voltage supported: 208, 230 & 240 VAC.

  • 50/60 Hertz Auto synchronization for Grid-Tie interrupted Grid-Tie and Off Grid Applications (Customer specified).

  • GFDI Protection: Remote sensing for current shorts not interrupted by breakers.

10 AWG electrical harness, for up to 25 panel installation per circuit

Easy interlock connectors.

Distinct predetermined DC to DC connectors between the two panels, with unique AC connection to harness on opposite side of Panel B, avoid possible miswiring of system. Junction box/Combiner ties circuit into standard building or house wiring.


Monitoring System

Daily Monitoring of overall system output


Individual Panel Monitoring

Individuelle Überwchung

System Specifications

  • Pmax(W) : 640, solar conversion efficiency: 16.5%+ L*W*T (Area): 3912*1068*61 mm3, 154*42*2.4 inches cubed

  • AC Output: +/- 21 VMRS (tracked to grid). Approximately 12' 10" by 3' 6"

  • Maximum Current: 2 Amps Solar Cell: Mono Silicone

  • Maximum output fault current: 3.15 Amps Glass: Tempered, antireflective coating

  • Maximum Grid Backfeed Current: 50 mA Encapsulate: EVA

  • Temperature: -40 to 65 °C operating Pmax (-0.5%/ °C)

  • Storm Resistance: IEC61215 certified. (204 mph)


Panel DC Solar Response under flash test conditions.

Nominal operating cell temperature of 47 degrees Celsius, 117 degrees Fahrenheit when back side cooling is not applied



Optional Electrical Storage


2400 Watt DC or approximately 5.5 hours of storage at 2 amps and 220 Volt output; longer storage times can be obtained with lower amperage output.

Composition - A special Lithium Lead Oxide battery cell. 2x duty cycle of typical lead acid batteries. Special battery management system prevents full discharge increasing duty cycle to extend battery life to 20 years.

DragonskinRubber Fire Retardant and Leak Proof Underlayer


Upper left corner: Sample with Rubber Kevlar® plus topcoat. Upper right corner: flame test. Bottom left corner: topcoat starts to burn off at 60 seconds. Underlayer not affected. Bottom right corner: after 10 minutes the underlayer still does not catch on fire. No fire has penetrated the Rubber Kevlar® underlayer.

In addition to the Dragonskinrubber, rubber feet on the system hardware assure no leaks from penetration of screws into roof area. In initial test using plywood underneath only minor darkening of the plywood occurs after the 10 minute open flame burn test. Further work to improve the layout of material when covering corners, ridge lines or other contours, is in progress.

The Dragonskinrubber is highly recommended as part of the overall system, either underneath the solar panels or as a direct replacement of roofing material. The Dragonskinrubber resists fires due to embers, open flames and electrical shorts.

Application requirements

Application of the Dragonskinrubber requires no special equipment and is easy to put down using normal paint applications.

10.24 kW Return on Investment analysis for New York City and surrounding area using PVac640 rooftop mounted systems, pitched or flat roof.

Used the 22 year NASA data averaged over the area of NYC , southern boundary - 40 degrees North Latitude, Northern Boundary - 41 N, Eastern Boundary of 74W and Western Boundary of 75West. This essentially covers NYC and some of Northern New Jersey.

The data report of June 19th, 2013 was used from the New York - New Jersey Information office to obtain an average cost per kWh of 19.3 cents. I assumed that all power generated is actually used. The kWh per month projected production of a 16 unit, PVac640 system at $1.81 CAPEX and $0.25 per watt install cost was used for the analysis. Loan costs not included.


Figure 1. 10.24 kW total installed system. Lowest production in January of 599 kWh and highest production in July of 1726 kWh. Variations per year predicted to be +/- 10%.

New York ROI

Figure 2. Income saved per month based on the present $0.193 per kWh rate presently in place.


Figure 3. Return on Investment with the assumption that the business making the install can use all power generated and can use the different USA tax credits available.

The return on investment is based on the 20 year warranty of the Solar PVac-systems, no storage system utilization, grid tied systems. Note that even without tax credits, the system is paid off by year 8 and profit occurs after year 8. Also note that in general the systems are good for 30 to 50 years of production and, it is assumed that the retail rate stays constant at $0.193 per kWh.

In summary, the investments pay off with reasonable return for the 10.24 kW installations even in New York with reduced output in the winter. All data is based on actual measured 22 year NASA data and not projected of the actual weather or sunlight availability.

Non-imaging Optics Antireflective Glass Characteristics and contribution to Design

Durability Testing

  • Meets IEC 61215 protocol for 1000 hours of damp heat exposure (85°C/85%RH) and 10 cycles of humidity freeze testing.

  • Over 1 year of damp heat exposure, 60 cycles of humidity-freeze testing.

  • 17 weeks in ASTM B-117 salt fog testing.

  • Overall decrease in transmittance (ISO 9050, 400-1100nm) for each test was less than 0.5 percent.

  • Transmittance done at 90 degree incident using a Gaertner Spectrometer.



Tempered Glass, equivalent to auto or airplane windshield, protects solar panels. UV and IR transmittance reduced. Lower rate of heat buildup in solar cell which improves power production. High Match to Silicon absorption of solar spectra. Applicable to single and multi- junction solar cells.

2XAR Variable Angle Transmittance


Combined with non-imaging reflective optics, the total insulation to panels increased due to additional transmittance of useable solar spectra.

MSVD (magnetic sputtered vacuum deposited) AR coating on Front and back of glass.
Knoop Hardness factor

  • Indent load – 500 gm
  • 470 kgf/mm²

Poisson's ratio – 0.22
Modulus of Elasticity – 73.1GPa

  • 10,600,000 psi

Tensile rupture strength

  • 2.51 g/cm³
  • 157 lb/ft³

Double-sided tempered AR glass used over the solar panels to add physical protection and increase power output. The protective glass reduces damage to the solar panels due to sand, hail, rocks, vandalism and devitrification or fogging. The double sided AR coating is part of the non-imaging optical design to increase useable solar irradiance to the solar cell junction thus increasing power output.



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