2 Aspect PV arrays and Solar Water monitor

Finally completed my Openenergymonitor project. 

I have 2 systems in one. Two Solar PV arrays facing different directions and 3 solar water panels also facing 2 different directions. Solar water tank feeds into main water tank.  Main tank has Gas boiler back up and woodburner indirect coils as well as immersion heater.

1 emontx montioring solar PV using 3 CTs, (PV1 ,PV2 and grid). Diverting excess to main tank immersion heater.

1 emontx monitoring Solar water panel o/ps and water tanks, also greenhouse temp

1 NanodeRF to publish all data to emoncms.org

2 EmonGCLDs to display PV data and Water temp data


Main live data page http://emoncms.org/sedlescombe/gauges

Thanks to Martin R for help with power divertion PLL and others on the forum for interesting topics.

Careful use of timer on the dishwasher (with hot water feed) ensures that there is hot water and spare electricity to power it.

Cooking during the day with a slow cooker keeps bills down.


Edit - resized pics - Moderator, BT

MartinR's picture

Re: 2 Aspect PV arrays and Solar Water monitor

Looks good Paul - well done!

mad_dad's picture

Re: 2 Aspect PV arrays and Solar Water monitor

Having monitored the power divert for a few weeks now. The graphs show that even though i have used a 27 inch immersion heater, it only heats the top of the tank until its internal thermostat switches it out. The gas, woodburner and solar systems have coils at the bottom of the tank and heat the whole tank of water.

As there is still spare power to divert during the day, the next plan is to pump the water from the top to the bottom via a one way valve, using a spare pump connected to the solar divert power, so it will circulate the water whilst heating it. 

mad_dad's picture

Re: 2 Aspect PV arrays and Solar Water monitor

with regards to the pump. will the pump cope with the pulsed triac output?

Robert Wall's picture

Re: 2 Aspect PV arrays and Solar Water monitor

Almost certainly not if the duty cycle is low. It will probably sit there buzzing and just get warm, if you want to try it I'd monitor the temperature of the pump motor itself as depending on exactly how the motor is designed and without movement, it could burn out. It would be preferable to add a second triac on a second output driven by some logic that says you stir the tank when the energy bucket is above the upper threshold and stays there - the easiest is to add a second threshold. When the bucket hits the second threshold, that would imply the thermostat has cut out so you can stir the tank and make the temperature fall, which will turn the dump load on and the pump off.

Robin has gone a long way with the logic for this in one of his variants (read 'pump' instead of 2nd load).

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