Peter and Tim, I am curious as to what is the payback period for your installations and are there maintenance costs that have to be included in that costing e.g. new batteries, panels, etc? I realise the costs can be somewhat subjective dependent on the system/consumption, we have over 300 days of sun a year and are South facing so an ideal candidate but would have to convert the house from gas to electricity which is quite a cost to add.
Bruce,
when we bought the system in 2011 we opted got the more expensive "high efficiency" panels from Sanyo. They, the inverter and installation were £15,234. They reached payback in September 2019. The later battery pack and inverter was £4,500 and comparing 2018 with 2020 consumption of electricity I'm not convinced it was a good investment, the payback seems to be about 10 years, although if as Tim predicts electricity costs go up the payback may be shorter. I will not be adding any additional batteries, at the moment!
The panels are still generating at more than 90% of their specified output, despite not having been washed.
The Inverter was estimated to have a life of 10 to 15 years, but it is mounted on a NE facing wall that gets no sunlight, so it will not be heat stressed. So far, so good...
