In a solar rooftop system, the solar panels are installed in the roof of any residential,
institutional, social, Government, commercial, industrial buildings etc.. This can be of two
- Solar Rooftop System with storage facility using battery
- Grid Connected Solar Rooftop System.
In grid connected rooftop or small SPV system, the DC power generated from SPV panel is
converted to AC power using power conditioning unit/Inverter and is fed to the grid either of
440/220 Volt three/single phase line or of 33 kV/11 kV three phase lines depending on the
capacity of the system installed at residential, institution/commercial establishment and the
regulatory framework specified for respective States. These systems generate power during
the day time which is utilized by powering captive loads and feed excess power to the grid as
long as grid is available. In case, where solar power is not sufficient due to cloud cover etc.,
the captive loads are served by drawing balance power from the grid.
Solar PV Modules/Solar Panels – The Solar PV modules/Solar Panels convert solar
energy to electrical energy. They are available in different technologies such as
crystalline, thin film, CIGS, CdTe, HIT, etc. Crystalline Solar PV panels are most
common in use on roof tops.
- Inverter : Inverter converts DC output of Solar PV panels into AC power.
- Mounting structure : The mounting structure, is the support structure that holds the
Solar PV panels.
- Balance of System : These consist of cables, switchboards, junction boxes, meters,
structures, tracking system (if required), earthing system ,circuit breaker,fuses etc.
- CAPEX Model : Here, the entire system is owned by the rooftop owners and he bears the cost of the Soalr system. Responsibility of O&M for the system lifetime (25 years) is also with the rooftop owner. Developer is responsible for installing the system and initial 2 years O&M and five years warranty.
- RESCO Model : Here, the entire system is owned by the developer. Responsibility of O&M for the system lifetime (say about 25 years) is also with the developer. Rooftop owners may consume the electricity generated, for which they have to pay a pre-decided tariff on a monthly basis. Excess generation may be exported to the grid, subject to availability of requisite state regulations.