By 10 am in early April, usually, my SOC is 100% and batteries on float, with the sun on th pv's for another good 6-7 hours. At end of day the lowest yield readings are 3 kw, usually 4.5 kw.
Can I use this information to assess if I would have enough extra power, currently unused, to run a 1 kw pool pump and 2 kw inverter pool heater (the size I'd need) on such days while the sun is on the pv's?
Yes you can, but I would use the relays output of the MPPT an set it up for "High Voltage" which I have done too (my system is 24V),
e.G.
Switching on at 28,8V
Switching off at 26,4V
Minimum time 2 hours
However, with the Relays output you have to drive a High Power Relays to switch the Pump and Heating Element.
Question: How big is your pool?
Remember, Water can store 1,15W/kg/K
Hence if your pool has e.G. 10m3 you need at least 15kW to increase the temperature by 1K.
Iheat with this settings my 200l Boiler using a 2x500W/24V Heating elementand if the Boiler is cold from the well Water, e.G. 10C and I want to get 70C hot water, then I need already 15kWh of energy, Hence I heat it up over 4-7 days which is completely enough for a single person since I can not use up this amount of water.
To be more precise. I use only 500W for heating the boiler, set it up to 70C and it is more or less permanently at 60C by only heating at daytime, when the Battery voltage is above 27,6V, which mean, even with heating with 500W, the Batteries can go into float and also equalize since I have not over 6kWp installed (I do not use the Relays option "float").
However, maybe you should think about a DIY Solarcollector by using 2x100m HDPE pipe 25mm in parallel or if your pump can not handle the pressure, 4x50m.
Ihave a Hottube build myself in Estonia and use 50m HDPE pipe with 20mm and I get my 300l nicely warm, sometimes even too hot.
Could send tomorrow a photo from it (the collector has to be repaired, because after 4 years of use, the transparent membrane is broken.
