Roof top solar systems
Government of India launched its National Solar Mission in January 2010 with a targeted installation of about 20 GW of solar electricity by 2022 under the Jawaharlal Nehru National Solar Mission (JNNSM). The first phase targets were of the order of 1000 MW by 2013, the second phase targets were set to be about 4000 MW by 2017, and in the third phase the targets were set to be of the order of 20000 MW. The first phase has observed a remarkable attention of and achieved installations of the order of 950 MW of solar electricity in the country. While there is a considerable interest in the utility scale grid connected solar power plants, roof top systems are equally getting attention and the country has about 43 MW of roof top systems connected to the grid. Rooftop PV systems find much more attractive due to the fact that these systems have potential to reduce transmission and distribution losses reduce additional burden of laying the T&D infrastructure. Connecting roof top solar PV systems to the grid is a great challenge, specially the rooftop systems which are in kW capacity, the utilities face tremendous challenge in terms handling the unstable sources of electricity at distributed level. While the PV system cost have come down considerably, roof top systems provide altogether a new market to the urban households who already has an inverter and battery storage systems as back up source in the event of grid unavailability.
In India, the application of solar PV has particular significance given the condition of its transmission and distribution infrastructure – high losses, poor power quality and frequent load shedding. Most buildings, public, private and commercial (for example, malls, hotels, hospitals and nursing homes), have diesel generators for back-up in case of load shedding by the utility. Given environmental considerations, the use of diesel should be minimised. There is abundant opportunity to use rooftop
or building-mounted solar PV systems to generate electricity and thereby reduce the consumption of diesel. However, due to the intermittent supply of solar power and grid outages, diesel–solar PV hybrid models could be potential solutions.
Generous subsidies have been offered by the government (both central and state). Despite this,widespread installation of solar PV systems to generate electricity on urban rooftops does not seem like a reality that will take shape in the near future.