Harnessing Solar energy, Options for India

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. The fact remains, as our analysis will
demonstrate, that solar PV systems with battery storage are too expensive, and systems without
battery cannot serve to completely replace diesel-generated power. With respect to the grid
integration, the current urban grid infrastructure does not have the capacity at low tension level to
accommodate distributed generation. The other constraint could be finding adequate and
appropriate space (not covered by shade) on the roof to mount solar modules.
This report details the policy frameworks and economic feasibility of rooftop projects based on
current MNRE guidelines. While the techno-economics are discussed, the technical challenges and
establishments of standards for grid integration in urban rooftops are given in Appendix 2: Grid
Integration in Urban India.
3.1. Current Policy
As we are aware, the JNNSM’s target for all off-grid solar applications is 200 MW for the first phase,
and 2,000 MW by 2022. Furthermore, another 100 MW is targeted for small ground-mounted solar
plants as well as rooftop PV systems. In June 2010, the MNRE came out with guidelines that specify
the financial support available, and standards and technical requirements for the equipment to be
used in these systems. 36
Small-scale solar PV systems can be classified into two categories:
1. Off-grid systems: Where the electricity generated is consumed locally and not fed back to the
grid. In some cases a battery may be provided for storage of electricity. This application
includes rooftop PV as well as decentralised distributed generation.
2. Grid-connected systems: Where the electricity generated is either fed into the grid or
consumed when the grid is not live (therefore reducing diesel consumption). The inverter
needs to synchronise with the grid and additional protection features should be included in
the inverter to prevent islanding.
3.1.1. Off-grid Solar PV Systems
The JNNSM specifications for off-grid solar systems are as follows:
Installation up to a maximum capacity of 100 kW p for urban areas.
One of the motivating factors being to encourage replacement of diesel.
MNRE financial support: combination of 30% subsidy and /or 5% interest loans.
o Non-commercial entities: capital subsidy and interest subsidy.
o Industrial/commercial entities: capital subsidy or interest subsidy.
Solar Photovoltaic Applications CSTEP | Page 79