Solar panels -> Charge controllers -> inverters -> power

My suggestion for using solar panels -> Charge controllers -> inverters -> power as usual to the traffic lights is keeping in mind the time it takes for govt. depts. to first accept new technology, then incorporate it as part of daily life and then ensure that they do not get caught in any blame game for failure.

The addition of solar panels and a suitably sized inverter is a day's work as compared to understanding each and every traffic light's power supply requirements and then designing and catering to this custom requirement. The inverter manufacturing is a mature activity and every district in the country has at least one dealer who can handle this addition to the traffic signals.

Indians would love to see this change take place in about an year's time all over the country rather than wait another 60 years! Any inverter manufacturer with a national footprint reading this?

Personally I am of the opinion of not using AC at all in homes if solar power is the primary source of energy. LCD monitors, LCD TVs, Laptops, DC Fans, Peltier effect refrigerators, LED lights, LED tube lights all work on DC - why use solar to convert DC to DC to AC and then DC again. Most of the Lighting products designed by us work on direct batteries from full charge to the set DOD.

Why do you need an inverter. Led are DC lights and DC charge controllers should do the job. You will need battery + DC Charge controller. The DC charge controller will have system interconnection so that your battery is charged by Grid in case of cloudy days or no PV production due to whatever reasons. This keeps your battery from failing early due to frequent deep discharges and also eliminates AC> DC LED driver which have shorter life. Overall keeps system alive longer and payback certainty. In fact one can use this for highway lighting (with or without grid connection) where the NHAI is said to be using DG sets.
Inverters in small systems eat into output and also make system costly.
They are required some places where you need to run fan and TV in existing AC circuit in a house but....maybe we require new ideas for those.

- - - -> by: Mehta

About the solar panel -> charge controllers -> inverters route you mentioned, have you missed out on batteries or are you eliminating the batteries to keep system costs low.
If so then it means immediate consumption of what your PV panels are producing and reliance on the grid after sun hours or cloudy days.
I request you to do the calculations both ways. PV + DC charge controllers + Inverters Vs PV + DC charge controllers with battery charging from grid (optional) + pure DC power for LED signals or other applications. If you compare battery costs per KWP with inverter costs, battery tends to be costlier ( 2.5 days backup). But you are eliminating the inverter which costs something and has system loses. With best in class inverter the DC output from panels to AC output ratio from inverter is 85% due to losses in DC charge controller, battery and inverter.
If you are including battery in your system then it becomes costlier anyways.
About inverter manufacturers I think most are sourcing from china. I think we need a simple DC-AC convertor if the DC power is drawn thru a good charge controller which takes care of all the other problems. This convertor BTW can be manufactured in India at a low cost without much sacrifice in quality.
Such a convertor can be useful for eg for installation in rural areas where any tinkering with wiring may mean budget going thru the window and the customer getting suspicious (eg buying a DC fan etc or putting separate DC circuit).
Hope we can work on these things and not import everything.

- - - -> by: Terry