ROOFTOP PHOTOVOLTAIC SYSTEMS

1 . A rooftop photovoltaic system, comprising:

one or more strings, each comprising a roofing material piece and one or more units that each comprises a photovoltaic module disposed on the roofing material piece and an inverter configured to convert DC from the photovoltaic module into AC.

2 . The rooftop photovoltaic system of claim 1 , wherein the roofing material piece has a shape of a roll or a ribbon and wherein the photovoltaic module of each of the one or more units is a flexible photovoltaic module comprising thin film photovoltaic cells.

3 . The rooftop photovoltaic system of claim 2 , wherein the photovoltaic module of each of the one or more units is a photovoltaic module comprising a first photovoltaic cell and a second photovoltaic cell and a collector-connector configured to collect current from the first photovoltaic cell and to electrically connect the first photovoltaic cell with the second photovoltaic cell.

4 . The rooftop photovoltaic system of claim 2 , wherein the photovoltaic module of each of the one or more units is laminated to the roofing material piece.

5 . The rooftop photovoltaic system of claim 2 , wherein the inverter is disposed on the roofing material piece adjacent to the photovoltaic module.

6 . The rooftop photovoltaic system of claim 2 , wherein each of the one or more units further comprises one or more AC bus bars integrated with the roofing material piece.

7 . The rooftop photovoltaic system of claim 2 , wherein the inverter comprises an inverter housing and a detachable inverter piece.

8 . The rooftop photovoltaic system of claim 1 , wherein each of the one or more strings comprise a first unit and a second unit that is adjacent to the first unit and that is factory interconnected to the first unit.

9 . The rooftop photovoltaic system of claim 1 , further comprising:

a monitoring station connected to each of the one or more units of each of the one or more strings via wireless, wired or optical network, wherein the monitoring station is connected to the inverter of to each of the one or more units of each of the one or more strings via wireless, wired or optical network; and

an AC disconnect electrically connected to each of the one or more strings.

10 . A rooftop photovoltaic system, comprising:

at least one active unit comprising one or more photovoltaic modules each comprising photovoltaic cells shaped as shingles to provide a roofing material appearance; and

one or more inactive units having the roofing material appearance.

11 . The rooftop photovoltaic system of claim 10 , wherein:

each of the one or more photovoltaic modules comprises thin film photovoltaic cells; and

each of the one or more photovoltaic modules is a photovoltaic module comprising a first photovoltaic cell and a second photovoltaic cell and a collector-connector configured to collect current from the first photovoltaic cell and to electrically connect the first photovoltaic cell with the second photovoltaic cell.

12 . The rooftop photovoltaic system of claim 10 , wherein the one or more of photovoltaic modules are laminated to a membrane back sheet.

13 . The rooftop photovoltaic system of claim 10 , wherein each of the one or more photovoltaic modules comprises an integrated inverter.

14 . The rooftop photovoltaic system of claim 10 , further comprising a central inverter and an integrated voltage regulator configured to regulate voltage output of each of the one or more modules, wherein the voltage regulator is electrically connected to the central inverter.

15 . The rooftop photovoltaic system of claim 10 , wherein the at least one unit comprises a first unit and a second unit factory interconnected to the first unit.

16 . The rooftop photovoltaic system of claim 10 , further comprising:

a monitoring station connected to each of the one or more photovoltaic modules via wireless, wired or optical network; and

an AC disconnect.

17 . The rooftop photovoltaic system of claim 10 , wherein the one or more inactive units are configured to facilitate attachment of the at least one active unit to a roof.

18 . The rooftop photovoltaic system of claim 10 , wherein when the at least one active unit is installed on a roof, the one or more inactive units are configured to match a shape of the roof together with the at least one active unit.

19 . A rooftop photovoltaic system, comprising:

at least one photovoltaic module each comprising photovoltaic cells;

at least one inverter housing which is electrically connected to the at least one photovoltaic module; and

a detachable inverter element which is detachably located in the inverter housing.

20 . A method of installing a rooftop photovoltaic system, comprising:

providing a sheet comprising a plurality of photovoltaic modules each module comprising photovoltaic cells, and a plurality of inverter housings which contain prefabricated DC electrical connections to the plurality of photovoltaic modules;

installing the sheet on a roof of a structure; and

connecting the plurality of inverter housings to an AC electrical system of the structure.

21 . The method of claim 20 , further comprising inserting a detachable inverter element into a respective inverter housing.

22 . The method of claim 20 , wherein the step of providing comprises unrolling the sheet prior to the step of inserting a detachable inverter element into a respective inverter housing.