Joy of solar panels for full time boaters

With today's sunshine our solar panels have been producing more than our 6 110amphour batteries can store.
Our system is very basic - cheapest reasonable wattage panels on ebay. Two 80watt for £380 two years ago, so we bought 4 panels. These days they are cheaper still. Buy a bigger regulator than you need, ours cost £30 or so. They are all wired into the regulator with two cables from there to battery bank. Our 4 panels are bolted flat on the boat's roof for simplicity but other tilt and turn mountings are available if you have the patience to fiddle with them.
Our 320 watts will produce 18+amps per hour throughout a day like today and 4-6 amps even on a dull day. Length of the day is the real key and from now until October we can moor for days without charging with the engine. We have the usual fridge, watch a bit of telly and run the laptop a lot. In addition I run my CPAP breathing machine on our mains, supplied by an inverter, for 8 hours every night ( I suffer from sleep apnoea ) and the panels keep up with all those demands. We don't use electric kettles, microwave, dishwasher or other power hungry items.
Without the panels I would need to run the engine 2 hours most days so that's a couple of litres of diesel or £1.60 a day even Norbury's 79.9 price.
Work out the figures yourself - £11.20 a week or £290 or so over 6 months plus the winter contribution when it can cut your running time by an hour a day. Say its saving you £350 a year in diesel - and that's at the lowest price. Add in the saving on engine wear and servicing costs and you can see how my £800 has come back to me. The panels are guaranteed for 25 years so they will continue to contribute to the beer fund.