Many people, for some reason want to add a battery backup to their grid tie solar power systems in the USA even though in most areas we have a very reliable gird. The security of having a little power for critical loads during a black out comes with significant disadvantages which include:

• you will have to install more components compared to simple grid tie system
• Batteries will require maintenance and will add significantly to the final cost of the system.
• efficiency loss will occur due to charging batteries. up to 15% loss in performance.
• your not going to be able to power your entire home or business off a solar power grid tie backup system.

I live in Los Angeles, we don't have many power outages here, so its really not worth a battery backup unless I am worried about the next big earthquake in our area. For disaster purposes it maybe better to have a separate backup generator that is not connected to the solar power system but only used when the power goes out for a long period of time. What do you think? Are batteries worth the disadvantages?

 

Deep Patel