Whither Rooftop Solar Power

The difference between hype and performance in national policy implementation is nowhere more visible than in the rooftop solar energy scenario prevailing in India and Germany. Germany decided two decades back to increase the use of renewable energy and in 2010 it legislated for a new programme called Energiewende or energy transition which aggressively promoted the switch to renewable energy with huge subsidies to wind and solar power generation and heavy investments in research to make both more technically efficient and cheaper to produce. A major thrust of this policy was to promote decentralised rooftop solar power generation with high feed in tariffs in addition to centralised solar and wind parks. As a consequence 32% of electricity production in Germany currently is from renewable energy and its cost of production has become so low that investments in coal based power has become economically unfeasible and is now having to be subsidised instead. Nuclear power generation is even more uneconomical currently and all of it is to be phased out completely by 2022. Not only centralised solar and wind generation but decentralised rooftop generation also has contributed to this huge energy transition that has become such a success that energiewende has now become a common word even in English. The price in terms of a surcharge paid by the citizens on their electricity bills which is given as a subsidy in the form of high feed in tariffs to rooftop electricity producers, is huge but has been enthusiastically cheered by the citizens because they feel that this is a transition worth making as they want to reduce Germany's green house gas emissions to zero from the 2% of world emissions that it is now. Those who first adopted roof top solar or set up solar plants on a large scale were assured returns at high rates till 2024 to promote solar power generation. Even though subsequently solar power costs have come down substantially and the rates for new generation are much less, nevertheless the German Government has kept its promise to pay the enhanced rates agreed initially to the first movers. Thus, renewable energy has become mainstream with installation and service agencies becoming common and the whole grid being optimised for the fluctuations that are a part and parcel of renewable energy due to natural fluctuations in wind flow and solar insolation over time. Despite Germany being a country with comparatively less solar insolation it took a conscious decision to promote solar energy and has now become the world leader in its technology and implementation and has brought down costs and increased efficiency of solar power tremendously.

What is the scene in India? Given that this country is much larger in area and receives much more solar insolation, we should have been the pioneers in solar electricity generation instead of the Germans or at least followed in their footsteps once they took the lead. While considerable movement is visible in centralised production of solar energy through huge solar parks, the progress in the sphere of decentralised solar energy generation is dismal. This despite the fact that supply of grid electricity to rural areas is a loss making proposition and has to be heavily subsidised. On the one hand the subsidy being offered to solar energy is not large enough and it is not being given as promised especially to the decentralised implementers and on the other there is the lack of an eco-system of service providers to make things work on the ground in remote rural areas. Thus, due to a lack of enough solar implementers the ecosystem for solar power for individual consumers is not building up and it is very difficult for such consumers to pursue solar energy deployment. I will detail below the various problems that we have faced in the implementation of decentralised solar energy that show that despite all the rhetoric we have a long way to go in India.

We began by installing 500 Watts of solar panels in our office in Indore to power the 1500 kva inverter cum battery system we already had. So instead of charging the battery from grid power we began charging it with solar power and also using the extra solar power after charging the batteries during the day directly through the inverter. We had to add a solar charge controller separately to the inverter and battery system. This charge controller had to be sourced from a supplier in Bengaluru while the panels were sourced from a manufacturer in Kolkata and the whole set up was installed by a vendor in Indore. This system worked fine except that once or twice we ran too many appliances on the inverter during the day leading to its burning out on one occasion. However, since the inverter was from a well known company that has a service centre in Indore it was repaired immediately.

After this we installed another 500 Watts of solar panels in our field centre in Pandutalav village about 50 kms from Indore. Here we installed a combined charge controller cum inverter sourced from a supplier in Chennai to save on costs. However, the solar inverter had some glitch in it and so it would not support loads of more than 10 watts or so. Since, the supplier did not have a service centre in Indore the only option was to send the inverter back to Chennai to be serviced. A detailed email was sent to the supplier giving the details of the problem. Yet the supplier sent back the inverter without solving the problem. So we had to send it back to the supplier. Yet again the inverter was sent back without the problem being solved. Eventually the supplier sent a new inverter as replacement because they were unable to diagnose what was causing the problem in the one that had been sent earlier. This meant a down time at the field centre of one month during which we had to use kerosene powered lamps!!! Solar inverter technology has become quite well developed and this particular company was using German technology and yet there were problems. Due to the fact that the market for solar inverters is not big enough, the companies selling them cannot afford to have service centres all over the country unlike say cell phone manufacturers. Neither has local expertise developed in repairing these inverters as in the case of cell phones. So if there is a breakdown then getting the inverter repaired is a pain.

In the meanwhile the solar system we had installed in the school at Kakrana last year had also stopped functioning. On investigation it was found that the special solar connectors that are used to connect the panels to the inverter had burnt out in the heat. So even though some current was coming through to the inverter it was insufficient and so neither was the system running nor were the batteries charging. Since Kakrana is situated 250 kms from Indore it was not possible to immediately go down and solve the problem. By the time the service personnel from Indore reached there, the batteries had become discharged. So the batteries had to be brought to the nearest town 25 kms away and charged from the grid, the solar connectors dispensed with and the panels connected directly to the inverter. Earlier also once the system had underperformed because the batteries had not been topped up with distilled water as is necessary from time to time. These problems that arose in Kakrana are the standard ones that have plagued decentralised solar units throughout the country for close to two decades and so currently we have thousands of panels lying idle across the country because the connectors have burnt out, the batteries have discharged and the charge controllers and inverters have malfunctioned and there are no service personnel nearby, unlike in the case of malfunctioning of the mainstream electric system. It is indeed a telling commentary on the mentality of the policy makers of this country that these basic problems have not been addressed and decentralised solar units are still being installed without providing a proper service eco-system.

Then we installed a net metering system in our office in Indore adding another 500 Watts of panels to make it a 1 KW system once net metering was made functional in Indore. In net metering during the day the consumer feeds the extra solar electricity produced into the grid while during the night she imports electricity from the grid. In this way there is no need to invest in expensive storage batteries. The consumer thus becomes a prosumer, producing and exporting electricity to the grid during the day and importing it during the night. If the prosumer is a net exporter then she gets paid for the electricity that she has supplied to the grid at a tariff rate decided by the Electricity Regulatory Commission. Unlike in the case of Germany this tariff rate is very small and equivalent to the prevailing wholesale rate for mainstream electricity.  Theoretically this is all very nice but in reality there are a lot of problems. The general employees of the electricity distribution company are not aware about this policy but the ground approvals have to come from them. Being used to bribes for any approval these employees stall the process expecting bribes despite the top level policy push for roof top solar net metering. Thus, the whole process of getting the approvals turned out to be a tortuous one since we were not prepared to pay bribes and took a few months to get through. Eventually, once the system was installed and operational the problem of billing arose. The meter reader was neither acquainted with the new metering system and nor was he ready to learn it when we tried to explain it to him. Despite our system having been a net exporter for the month for which the reading had to be taken, he arbitrarily reported that we had imported electricity as we used to earlier. So we got an inflated bill that we had to complain against. After this another person came to check the meter and we explained to him the whole system as he was also not aware of the net metering system. Anyway our bill got rectified for that month. Next month, however, the same problem occurred again and once again we had to file a complaint. This went on for a few months and now things have become better with zero meter readings being recorded. The cumulative export into the grid is to be paid for by the electricity company only at the end of the annual billing cycle and not monthly. Even though one such annual billing cycle is over, there is no sign of the electricity company paying us for the electricity we have exported to it. Knowing that the electricity company is not likely to pay for the exported electricity easily, given the huge losses under which it is running, I had sized our system in such a way that we would export during the winters and import during the summers and overall be only marginal exporters. We have fought with the electricity company and succeeded in getting the bills rectified but in many cases the prosumers have not been able to do so and are being slapped with the old bills in an ad hoc manner and so are complaining that they are not receiving the benefits that were promised. The capital subsidy that was promised on the installation cost has also not materialised. Thus, the net metering solar roof top programme is not likely to become a great hit in Madhya Pradesh if it is administered in such a slipshod manner. The situation elsewhere in India too is not very encouraging.

Finally, we got round to installing a bigger solar system in the field centre in Pandutalav village. The plan was to install a 1 horsepower submersible pump in the borewell cum hand pump that was installed there. However, sizing the solar system for this turned out to be a tricky proposition. Even though the power demand was only 0.75 KW what was crucial for designing the system was the electric current drawal by the motor. The pump runs at a current of about 8 amperes but the initial starting torque is almost double that at 15 amperes. Therefore, an inverter would have to be installed that could deliver 15 amperes to start the pump even if the running requirement was only 8 amperes. Given the way solar inverters work this would require a 3.5 KW inverter instead of the 0.75 KW of power required by the pump. So not only would the cost of the inverter go up but also that of the panels as a minimum of 2 KW of panels would have to be installed to be able to supply 15 amperes of current. Similarly the battery storage required would also go up from just two batteries to four. Since it was a waste of resources to install such a system just to run the pump it was decided to use it for other heavy duty uses also like running mechanical grinders, drills and welding machines. This is the big problem with solar powered pumps as it is a huge investment that does not make economic sense without a subsidy. In our case since the system was being installed with grant funding there was a hundred percent subsidy. However, it is unlikely that decentralised solar irrigation will take off in a major way in this country without subsidy from the government. There is a scheme for providing 90 percent subsidy to farmers for installing solar pumps but it is being provided to only a very few farmers in a district every year.

Once again in this system also there was a malfunction problem. I was away from Indore on an assignment when our centre manager, who is only functionally literate, phoned to say that the inverter had stopped working. By the time I came back ten days later and checked I found that the charge controller of the solar power unit was not working. The batteries had discharged completely. So I had to take the batteries in my car to the town nearby and get them charged from the grid. After that the vendor in Indore and I took videos of the various control panel indicators showing that the charge controller was not working and sent them to the supplier in Mumbai. In the meanwhile I used the original charge controller that we had installed in our office in Indore and which had now become redundant after the installation of the net metering system to charge the batteries and run the inverter and the pump. The service person from the supplier arrived in Indore after a couple of days with the replacement card for the inverter and not that for the charge controller. After testing of the system it became clear that it was the charge controller that was malfunctioning as we had informed them. Yet they had sent the service personnel with the card for the inverter and not for the charge controller. Eventually, another service person came with the proper card and the inverter was repaired after a week of down time. If we hadn't had a spare charge controller, then in the height of summer there would have been a serious water shortage and we would have to draw water manually from the hand pump to irrigate our plants as we had to do for a few days when I was away from Indore.

Given this kind of a discouraging scenario, the huge potential of decentralised rooftop solar energy is not being harnessed in any systematic manner in this country despite a lot of propaganda. It is both economically and practically difficult to implement decentralised rooftop solar given the lack of subsidies and a functioning ecosystem in remote areas for maintenance and repairs. Consequently it is only the committed people who have some kind of grant funding who are pursuing solar energy and it is unlikely to become a revolution like it has in Germany despite our country being much richer in solar insolation and much in need of moving away from coal based thermal power given its adverse climate impacts and the negative social and environmental impacts of coal mining.