Evaluation of SV benefits

[Telegram Sam]

Am I right in concluding that, contrary to my original assumptions, it is not possible to calculate the energy consumption "savings" you achieve by installing solar panels (apart from the FIT credits)? I can't just take the total kWh generated as per my meter readings, multiply this by the unit cost charged by my electricity supplier, and come up with a "savings figure"??
I suspect that this might be doable if I invested in a storage battery but I am far from convinced that the costs of doing this make economic sense (at least in my situation)

 

[Zerax]

Undertaking a cost/benefit analysis for PV panels with/without battery storage is a very complex task. There are all sorts of variables that would need to be factored in... with sensible 'guesses' needed for many of them. Whilst you could probably find some fairly accurate numbers for how much sunshine we typically get in any given year... you'd struggle to predict the future price of grid supplied power. This is hard enough to do for next year.... but in 20 years time, almost impossible.

My own analysis showed that without FITs, it was highly unlikely that the capital cost would ever be recovered from any savings made.

However, I've recently come across the Octopus Agile Outgoing tariff that might actually change that... as soon as I get a spare couple of days to plug some numbers into a spreadsheet... I'll have a good idea if it makes any sense. In fact, this may make more sense with just batteries and no PV. The idea being to charge the batteries from the grid during 'cheap' time slots, then sell it back during 'expensive' time slots.