In this manner (so goes the theory!!) if I get 4kw/hrs of power in a day then my pump will run for about 4 hours, spread throughout the day as the battery bank gets sufficient charge. This is certainly enough to keep the water clear.

The beauty of the system is that the timing is not critical at all - in fact if I go for a couple of days of no wind, so I get no filtering of the pool water, then it's no big deal.

I'm making 2 overrides in the pump controller - one is if the solar controller (which looks for the solar panel to be 4c higher in temperature than the pool) wants to run its pump then it will use the inverter power if its available. If I have no wind then I could end up with a pretty cold pool so I'll have a manual override that will use mains power if necessary and just use the filter pump as the dump load.

The second override is the dosing of chlorine etc which is handled by another controller (which has various solenoid operated valves). This will be set up to run for one hour each night. If there is battery power then the pump will already be running, doing its job as a dump load. If not then mains power will run the pump.

This area is where a more intelligent controller will be useful - to predict that the chemical cycle is due in half an hour so allow the battery bank to charge for those few extra minutes or if the pool is getting cold then automatically use mains for the solar pump to push the 45kw of heat into the pool (its amazing how quickly 50sq.m of bespoke neoprene solar collector warms things up!)