Solar + Inverter battery payback

If we can prove that by using full energy generated by Solar panel every day (as compared to using Inverter only in case of Power outages) it makes economic sense, the Solar system will get a boost. 99% of the domestic Inverters are for Fans and Tube lights and may be TV and not for AC or Fridge. So if we start using Fans, lighting almost solely on Solar and if that makes economic sense ( 2-3 years payback should be good) , we can propagate Solar Power for domestic use.

The broad assumptions based on which that assertion was made is mentioned above in this article. If all electricity from panels is consumed on-site and grid electricity is abated, it'll give you a payback of about 8-10 years. This high payback is because generated and excess electricity cannot be exported to the grid at a higher export tariff which is the case in Germany/UK/Spain/US (Cal). Residential feed-in tariffs bring down payback to 3-5 years.

Despite that it is a good investment considering very low O&M compared to the hassles of replacing inverter batteries every now and then. Also, power outages mostly occur during day time and hence, solar PV can provide continuous supply unlike batteries that have to run out. So effectively you can get Battery supply + PV supply during day which could last all day + 4 hours in the night.

I think it's fair to say that the average income household who can already afford inverter battery backup, can also afford solar PV if it offers some sort of significant benefit over business as usual. The challenge for service providers is to communicate this benefit. This could be through economic benefits (Annual savings of $. ___) or improvement in lifestyle (Powering homes longer than what your battery can offer) or zero-maintenance, no-fuel expense etc. What clicks with these households will be an interesting observation.