I’ve managed to enjoy reasonably priced electricity at my home over the last few years but prices are now going UP, UP, UP!

I have three phases coming into the house where one phase is upstairs, one phase is downstairs and the third phase is the hot water heater. I had previsouly been with a company where the hot water (phase 3) was cheap and the other phases were the same price 24/7, but when I added 5kW of solar to the roof, I changed to Octopus Energy. At the time they had the best buy back rate for solar. Their power usage rates were based on time of day (Peak, Off-peak and Night). I worked around this by adding relays/contactors to my hot water cylinder and WiFi smart relays to freezers to limit peak usage.

My per KwH power rates are increasing between 20% and 38%, so it’s time to revisit my usage.

My Spa Pool/hot tub uses a lot of power, so it’s time to look at Solar Options to keep it hot.

I inititially considered spiralling black water pipe on some plywood, adding a pump and directly heating the water, but due to my business and my access to old used solar panels, using PV panels and a DC heating element made more sense.

I’ve ordered a 48V DC 3kW (Thats 62 Amps!) element from China. The plan is to dump (Short!) solar panels into the element – Solar panels are a current source so (within reason) shorting them into a low resistance element is possible.

Once the element arrives I’ll need to sort a relay based controller. This will be difficult as I need a way to deal with the large DC currents. Each solar panel provides around 7-8 Amps, so maybe one relay per panel is the way to go