The Rooftop solar PVs need to take off right now and not late any more. Private households who can afford to have and who consumes power to a greater extent can take up the rooftop solar at their home. Government subsidy is only a ways and means through which it can be provided considering the initial cost and payback period. Meanwhile, whether it will be safe to place it on each and every household is a question which needed to be looked into. The efficiency of the solar PV arrays which is placed on roof top should provide the sufficient power only if its placed where sunlight (irradiance of sun) is available for a minimum of 4 to 5 hours (I think its true, If not kindly correct me).

For a 7 Cr/MW solar PV project, the interest subsidy of (7-2 = 5) 5% for 12 years = Rs. 182 lakhs for a debt of Rs.560 lakhs (80% of 700). Please note that the payment (Cash out to Government every year in lakhs is given below which after deflated rupee will be nothing i.e Discount factor for rupee while paying the Interest subsidy, which is a good mechanism to control the tariff too).

Energy supplied to grid can be allowed with a 3 to 5% escalation for a O & M cost recovery and sustainability as the Salaries and project overheads will be affected with Inflation.

Normal Depreciation in any way tax authorities will allow hence a good case due to negative balance sheet due to Solar PV, thus, the profit after depreciation (good tax planning for Small Entrepreneurs with new solar PV or Company ! With no loss on ROE!!)  Less transmission losses, hence, full use of Solar PV power due to point of consumption is very near by in every taluka.

Many define Solar PV Grid Parity as the "moment when solar PV LCOE becomes competitive with retail electricity prices, assuming that 100% of the electricity is self-consumed instantaneously." It points out, however, that "since 100% of instant self-consumption is not likely to happen in residential systems, net metering/net billing or equivalent mechanisms will be crucial to achieve economic feasibility for this kind of installations."

What kind of projects need to be promoted in more fertile states like Kerala, Karnataka i.e where dry lands are less on a decentralized way to increase GDP by Solar PV power projects + Agriculture + Cold & Dry storage related projects to enhance the rural GDP:

As the Operation and Maintenance agency for Solar PV power generation will have its own security agency, it may be a good scheme to protect the CANAL BREACH at distributory (few miscreants may break the wall in the nights or few may use pipes to siphon the water from canal to their fields in the night through their DG sets, therefore, we also foresee this kind of Solar PV project can bring down the costs of Canal Maintenance. If the PV Plant Security (which is a cost to Government too) is insufficient as it runs in to Kilo meters, then, breach or such mishaps may recur and it may prove additional expense to the Government.

It would be a good idea to propose these Biomass power Project Promoters to use their plant roof top (or excess land occupied during such projects) to generate Solar PV power and again take further Accelerated Depreciation or Viable Gap Funding or Capital Subsidy for these roof top solar PV systems through the good networks, which the modern day business ethics believes in at the Cost of Government Exchequer !!..... Is this Economy or Pseudo Economy... May be some banks wud be ready fund these Balance sheets too!!

Let the customers decide the viability of rooftops. Eventually it is market factors that determine the easiest path towards power fulfillment. Whether people want to pay less for grid power or for polluting DG sets (risky diesel storage) or they want to pay for something that is not reliable. Already people are invested in inverters and batteries, adding a few solar panels is the next logical step. Why would they worry about T&D losses, under recoveries, discoms not making profits and all those other things of which the lesser said the better. Agreed rooftop solutions are expensive, but people who have invested for 4 hours of battery backup per day due to unreliable grid have already, in some ways, crossed that point of no return, it is the next simple step of investing in solar PV panels and control equipment. Even that investment can be incremental. There is always a case for standalone off grid rooftop to succeed. There is enough competition in the solar PV space and day to day improvements in technology that would make subsidies irrelevant at some point in time.

In the name of OFF GRID, 400 Million population etc, we can not keep them happy with Two or Three bulb theory, instead, bring them to the mainstream, establish 5, 25 to 50 MW solar PV in such remote village area, draw mini grids and provide them more power at low cost, so that they can consume and improve their lively hood including night time usage.

Solar Peak Load, considering the barren land of Rajasthan, Gujarat and barren land in each district, with low cost debt fund (extracted from stashed black money), we can easily install 74,000 MW of Solar PV in phased manner. Scale up shall happen after a suitable storage solution or improvement in Cell or module efficiency with reduced land use.

Success of Roof top Solar system depends on 1) bringing downs the costs and 2) involvement of grid and government policies. Introducing Net Metering system where in the electricity generated during day time is drawn by grid when the home need is minimum and reverted to home during night from the grid. This will eliminate the storage and consequent cost and ensures power availability to industrial sector during day time. Net metering will facilitate the payment to others who has drawn less power at predetermined rates. For this State policies need to be tuned well.

In general, we have seen lots of very nice documentation of module/inverter suppliers complete with all certificates. But we check them at Tuv etc. and what is the surprise (even with well established names) they don't have a certificate but use a certificate of another model.
One question to all professionals: did you ever check the certificates of your suppliers at the certification institute?