Here is an ‘open ended’ opinion from The Guardian where Dr Alona Armstrong, faculty fellow in energy at Lancaster Environment Centre explores what possible issues we might face with solar parks in the near future. It is observed that in environmental terms, building-mounted rooftop PV is the greenest approach, but more complex and costly than ground-mounted systems. Solar PV parks are mostly built on brownfield sites or low grade agricultural land with the split between building- and ground-mounted systems reported to vary between, for example 82% ground-mounted systems in China and around 45% across Europe in 2011. I am not sure if any data would be available for India during this period, though currently almost all of the 2.5 GW capacity (May 2013) would consist of ground mounted systems.
CFD based simulations show that Large solar farms can lead to changes in micro climate of the location. While the preliminary results are not outright threatening, that is something which could (or maybe should) be explored. Work on wind farm sites for example has highlighted local effects on temperatures, changed humidity levels, higher concentrations of CO2, methane and nitrous oxide, and changes in patterns of cloud cover and rainfall. It’s clear that PV panels will cause shading and changes to wind flow, and in principle is likely to alter temperature, change the rainfall distribution (which impacts on soil moisture) and the wind flow over the land. But currently enough information is not available about what happens to the soil, plants and wildlife in areas where ground mounted PV parks are constructed.