Doram That price is about what I’d estimate., and much more realistic than the £20k previously stated… The prices are at least half what they were 5 years ago
Warranty periods vary from manufacturers, but Solar Edge offer 12+ (sometimes 20) years on their inverters and 25 on optimisers. A replacement will be £400-1200 depending on model at current prices.
Panels usually out preform their spec sheet out of the box, my Perlight 295s have a measured max of about 309w. It therefore takes a few years before they degrade to their official wattage, and even then they won’t degrade that much. Manufactures usually guarantee 80% after 10 or 15 years, but it’s unlikely they will fall anywhere near that. A system I fitted for someone nearly 11 years ago was attacked by squirrels (add that to the list of downsides 😁). After repairing it, it was producing 3.9kw of power at its peak. It is a 4.1kw system on a 4kw Sunnyboy inverter. And, those panels have never been cleaned.
Another site I fitted last year, 5.8kw of panels but only a 3.68kw inverter, produced 790kwh in July last year, and has produced 330kwh so far this month. Winter reduces it, but to say you won’t get much at all is a bit of a leap.
