Wrong Focus on Solar Projects

In the recent times it has become a fad to associate every single product as eco-friendly and green. In this process we also see a lot of products being launched with a “solar” tag – Television, … (some sample). A recent post by Sri. Piyush Goyal on installation of solar panels on trains triggered my urge to write this blog.

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On moving body (vehicles, train, boat, plane), it makes sense to install solar panels only if the following condition are met:

  1. Source of energy cannot be from grid when the body is in motion
  2. The total cost of Solar energy is less than that of the alternate energy source
  3. The solar energy can provide a reasonable share of energy

Let us take the case of first rule. The logic of this rule is that cost of power from grid would be the lowest possible cost of power. So, if there is access to grid power when the body is in motion, then that power would be the cheapest. Trains are a means of transport that can avail this advantage; so do trams. Vehicles on road (until the proposed technology to charge from the roads while running come up), boats and airplanes do not have this benefit.

So, when someone talks of installing solar panels on train, and if the person is Minister of Power, then it has to be pointed out that it is a wrong approach. It makes immense sense to focus on making trains electric and then create large solar power plants to feed the power to the grid. Rest is just for marketing and not with any substance. So the two Ministers (Railways and Power) must focus on installing large roof top solar grid-tie installation on railways stations, their properties; convert all railway coaches and lines to electric; encourage/invest in large solar power plants (100s of Mega watts) to increase the share of green power in our energy mix.

Of course on a very tactical approach, Sri Piyush Goyal is right given that we are stuck with diesel locomotives which will not become electric in the near term. Even for these trains the Rule 2 is doubtful since cost of power from large generators (train electric power source) might be cheaper than small solar installations (on train roof). But again Rule 3 fails here for sure.

For academic interest, the Rule 3 fails in case of vehicles on road, where the energy from sun can be barely 10-15% and hence not very attractive. However in case of boats, and specifically slow moving, public transport, all the 3 rules are met. The sun can provide 80% of energy and hence super-attractive, as was demonstrated by ADITYA, India’s first solar ferry.

In the same media one also hears many solar hyphened electrical devices, especially home equipments. Again, it makes sense for some one to create an off-grid power plant and then use a normal electric device rather than separate solar devices. So no more solar-fridge, solar-TV, solar-incubators,…The only exception are when there are situation when such a device operate in isolation and in location without grid, for example, solar water pumps for irrigation where there is no electric power.

So, enough of marketing hype on green and eco-friendly, lets separate real stuff from marketing gimmicks.

Comments are welcome.





  1. Totally agree… Very Few attempt to criticize the Marketing Gimmicks of BJP with factual and real information. Not that I do not support them but they have got into the habit of singing a lot more than the actual job done.

  2. Disagree. The amount of electricity lost in transmission is over 25%. It is always better to avoid the grid wherever and to whatever extent possible. Also, the conversion of diesel to electricity leads to further losses in case of diesel engine trains. At this stage, where adoption is minimal, it is important to make solar as visible and demonstrable as possible to masses as possible. It is as much about making a statement as about being a viable project. Like streetlamps.

    1. Mixing issues. Street lamp is not viable if it is purely solar versus grid. Since back up is needed when power fails it becomes. Also please check the transmission losses. I understand that it is much lower than you quote.

  3. Did u brought to the ministers attention ? Probably experts may have mislead him. Minister is a person with good intentions

  4. Because of this approach technocrats are not final authority. They look at everything with very technical benefits. Pros and cons and so on. That’s why nations are run by political class since theoretically they are connected with masses. They understand sentiments, they know how to keep these sentiments upbeat and only then they remain at the helm. So every decision by them can’t be expected to be technically best. Its also important to generate a momentum and promote important objectives. In which I think they have succecced well and have increased the visibility of solar power in a big way.

    1. It is not technical, it is commercial. With limited capital, opportunity cost is a crucial aspect. However your point is valid if putting solar on train has changed the image of solar technology so much so that this cost is offset by the benefit.

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