The last time I looked, it looked like by the time you paid for your system (cells and batteries) with the energy savings, you would be about ready to start replacing the system. Has it gotten any better?
There’s not much cost or energy savings that I can see happening soon, unless they pass some sort of cap and trade that would make electricity generated from fossil fuels a lot more expensive (which is naturally what they want to do). I could probably spend about 30K to 40K $$ and cut my electric bill in half (all electric house) but the payback would probably take around 15 years.