I receive a large number of enquiries on solar electrical power plants for domestic and industrial use. First of all, it is a myth that solar energy is free to use. There is no free lunch in this world. So for this case lots of facts are not disclosed by so called solar sellers and companies. Basically every solar company mentions about off grid (OG) and grid connected (GC) (some call it grid tie)solar system which many non-technical people fail to understand. Let me make it simple:-
- OG requires costly batteries while GC does not need it at all.
- Therefore OG is just like a house inverter using a battery but instead of charging it from mains supply it charges from very costly solar photovoltaic cells and one needs no permission from any one to install it. One can use the electricity so made from the solar system but to dedicated loads only or with some switching arrangement.
- Contrary to the above GC uses no batteries and there are large regulatory controls , as the electricity so generated has to be fed to the power generating company. One has to replace the conventional energy meter to another one that subtracts the units so generated from the solar system so your electricity bill is reduced to that extent.
- As such both the cases they are at the moment very costly beyond the reach of common people. That is the reason why in most affluent countries like the USA it uses 5% solar electricity only even after very large subsidy ( this subsidy is already gone in all most all countries and the 2016 is also the final year for USA.) In India too it is getting slowly getting abolished.
- As OG uses batteries but then, one has to replace them every few years, ie 40% of the total OG system
- Both of them (OG & GC ) use lot of electronics which are prone to getting damaged on misuse or mains disturbance, in particular the cheap ones which constitute to about 25% of the system
- Thus recurring expenses are hidden facts that no one spells out.
- They speak some hyped payback period which are possible on ideal situation only but that never exists in real terms.
- Both of them require lot of open and un-shaded space for solar panels. So people staying in flats have no chance.
- If I list out all the disadvantages it will run to few pages with 30 more negative points.
- So in a nutshell stay away from solar if you are already in a place with mains availability.
My next topic will be on LED lights ,which is again a much hyped about hot topic around the world.