I have a similar, but much simpler setup. I used a PWM motor controller and control the power according to PV voltage using custom Arduino code. On cloudy days it can really produce two times or more energy than connecting the panels directly. My total cost for 80A PWM controller and Arduino was 30 EUR. I plan to make a video about that at some point.
@@evsolar I've been developing and evaluating efficient PV hot water designs for years. The solar panel side must have a capacitor bank suitable to supplying current and keeping the charging adiabatic in order to be efficient. Speed controls depend on a low impedance source like a battery to operate. The capacitor in these modules is only sufficient to stabilize the circuit and not supply the needed energy. Solar panels are current sources and not low impedance. Cheap modules from China are appealing but have no advantage over just a FET/capacitor bank and the next time a speed control is ordered they have changed the circuit or it is no longer available. The techluck guy tried to cheat on capacitors and now his units are failing. What voltage is your array? Lower voltages and higher currents just increase the issues.
it would be nice to see an installation video. I know there are installation instructions in the manual but a video of how everything has to be connected would be very helpful.
How do you set the temp, i have 5 x 350w panels at 40vdc each in series powering a 230v 2000w element for my aquaponics, what button do i press to set max temp at 28 celcius? The booklet that comes with this exact same unit is crap english and doesnt mention what button actually sets the temp
Update June 14, 2020: The unit has been functioning normally. I mistakenly was reading the output voltage with a digital multimeter, not realizing that typically these meters will give an erroneously low reading due to the PWM of the output current. Monitoring the "input" voltage and amps (watts) gives good correlation with the unit's display. The unit itself seems to draw very little power. I am heating at 800 - 830 watts in sunny weather, which is close to my array's rating. I get a good temperature rise in a 50-gallon water heater each day. With overcast skies, I still get 150-200 watts of heating. -------------------- Hello! I installed the controller and it appeared to work well in the sun and under clouds. The displayed watts showed a good output even in overcast skies. However, I checked the output voltage and amperage with a meter, and found that the controller appears to use the input PV volts and amps to calculate output watts. In my setup, the actual output watts to the heater is much lower than the display shows, because in cloudy weather the output voltage is much lower than the PV voltage. Because I had used your spreadsheet to make sure my panel setup (900w and 100v) would work for my 4500w, 240v heater element, I was puzzled. So, with cloudy weather, I checked the power output after adding a second heater element in series (so - a load of 26 ohms instead of 13 ohms), and the overall power output increased. I then added 50 additional ohms resistance with a power resistor, and the power increased further. (But, adding more resistance than this total of 76 ohms did not further improve power.) When the sun returned after the testing, the optimum load (the highest watts I could get out of the three choices of resistance) went back to the original 13 ohms (the single 4500w element). My concern is that I’ve done something wrong with the panel configuration, or that the controller’s MPPT function is defective. Currently, I am getting no benefit from the controller in cloudy conditions. I could simply wire the panels directly to the heater spiral. I also don't understand why the display will show several hundred watts in cloudy weather, but the actual watts to the heater is only tens of watts. In sunny conditions, the output voltage approaches the PV voltage, and so the display reads closer to the actual watts, but still too high. Hopefully you can point out what my error is, and thank you! Is the issue that the volt meter does not read the output (pulsed) current correctly?
25.09.20 at 12h show me 175V, 1.57kw :) ....now im worry for the controller how many time will be fine.... before need new one today is my day one for free hot water...5 panels x 400W and 2500W heating element ..its show me 1.4kW to heating element and is just 8:51 morning :)
I have 4x 300w panels V voc. 40.1v V mpp 32.8 A 9.05 I have used your calculator and I get 240v. 2700w heater element,is this right? Can't find 2700w element,can I use 2500w or 3000w element? Could I use a dc element? Thank you
just look at ur PV resistence to be little bit less than Heating element resistence...if ur pv system is with 20ohm then ur heating element shoud be 21-23 ohm...etc.
Hi, I am a bit confused. You say the panels and the heater must be matched, but your installation has 4x30V DC panels at 700W and a 220V AC element at 2kW? I have 12x100W 17V DC panels and a 2kW 220V AC element, can this work? I was thinking to use 2p5s to give me 85V but it seems like I would need a different arrangement for your system?
In the commentary below I described how it is connected and there is a way to calculate what heater will match the PW panels. Here is the Simple Calculator I wrote to calculate the heater power: docs.google.com/spreadsheets/d/1FjDoYirKaPE2ySRWk692UgPUEOe60DQdEj-M76z49-0/edit?usp=sharing For 12 x PW Panels (100W 17V DC each) = 1200W, 204V (Series Circuit) You can use 1500W 230V Heater. ---- I(A) = P(W) / V(V) R=U / I P = I2 · R ---- WP Panels I(A) 5,88A PW Panels R(Ω): 34,68Ω Optimal Heater Power P(W): 1525W ,230V Remember that if you use a stronger heater or a weaker one, it will not be correct and may overload the PWM controller, and after it lead to its damage after several months of such work.
@@actionpol Im a little confused by your video aswell. According to what ive calculated, your 4x 230w solar panels, connected in series @ 29.9VDC will give a total array voltage of 119.6v, with a total current of 7.68A. A 230v, 2KW immersion heater has a resistance of 26.45 Ohms. A 119.6v supply, with a load resistance of 26.45 Ohms will give you a max output of 540.8 watts to your immersion heater. Unless ive calculated this wrong? To match your 4 x 230 watt panels (total 920 watts), with a total Vm of 119.6v & an Im of 7.68a, I think you should be using an immersion heater with a resistance of 15.57 Ohms (ish)? Doesnt this then enable you (in ideal conditions), put 920 watts from the solar array into 920 watts heat power in the immersion?
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@@n.e.d I was testing similar circuitry (I had 120V/6A in panels) and the voltage did rise up to 140V when there was enough sun (and the PWM constantly ON), so in fact here the heater is not that underpowered, you may realistically have 920 Wpp to 750W heat.
If you are owner of this device and look at the connectors of the Foto Booster, one side has a diode and one is without. Which side is in and which is out?
Do you use the Voc for the calculator ?
I have a similar, but much simpler setup. I used a PWM motor controller and control the power according to PV voltage using custom Arduino code. On cloudy days it can really produce two times or more energy than connecting the panels directly. My total cost for 80A PWM controller and Arduino was 30 EUR. I plan to make a video about that at some point.
You should be able to produce way more than 2X on cloudy days. I can get 10X more. Obviously, you are not storing much power in the off times.
@@opera5714 I don't use any battery. This is setup directly with resistive heater. So all that is stored is heat ;)
@@evsolar I've been developing and evaluating efficient PV hot water designs for years. The solar panel side must have a capacitor bank suitable to supplying current and keeping the charging adiabatic in order to be efficient. Speed controls depend on a low impedance source like a battery to operate. The capacitor in these modules is only sufficient to stabilize the circuit and not supply the needed energy. Solar panels are current sources and not low impedance. Cheap modules from China are appealing but have no advantage over just a FET/capacitor bank and the next time a speed control is ordered they have changed the circuit or it is no longer available. The techluck guy tried to cheat on capacitors and now his units are failing. What voltage is your array? Lower voltages and higher currents just increase the issues.
Hope you do your vid soon
@@opera5714 I was unable to find any product with capacitor bank and FET so I ended up doing it myself. Works great for the simplicity!
it would be nice to see an installation video. I know there are installation instructions in the manual but a video of how everything has to be connected would be very helpful.
How do you set the temp, i have 5 x 350w panels at 40vdc each in series powering a 230v 2000w element for my aquaponics, what button do i press to set max temp at 28 celcius? The booklet that comes with this exact same unit is crap english and doesnt mention what button actually sets the temp
Update June 14, 2020: The unit has been functioning normally. I mistakenly was reading the output voltage with a digital multimeter, not realizing that typically these meters will give an erroneously low reading due to the PWM of the output current. Monitoring the "input" voltage and amps (watts) gives good correlation with the unit's display. The unit itself seems to draw very little power.
I am heating at 800 - 830 watts in sunny weather, which is close to my array's rating. I get a good temperature rise in a 50-gallon water heater each day. With overcast skies, I still get 150-200 watts of heating.
--------------------
Hello! I installed the controller and it appeared to work well in the sun and under clouds. The displayed watts showed a good output even in overcast skies. However, I checked the output voltage and amperage with a meter, and found that the controller appears to use the input PV volts and amps to calculate output watts. In my setup, the actual output watts to the heater is much lower than the display shows, because in cloudy weather the output voltage is much lower than the PV voltage.
Because I had used your spreadsheet to make sure my panel setup (900w and 100v) would work for my 4500w, 240v heater element, I was puzzled. So, with cloudy weather, I checked the power output after adding a second heater element in series (so - a load of 26 ohms instead of 13 ohms), and the overall power output increased. I then added 50 additional ohms resistance with a power resistor, and the power increased further. (But, adding more resistance than this total of 76 ohms did not further improve power.) When the sun returned after the testing, the optimum load (the highest watts I could get out of the three choices of resistance) went back to the original 13 ohms (the single 4500w element).
My concern is that I’ve done something wrong with the panel configuration, or that the controller’s MPPT function is defective. Currently, I am getting no benefit from the controller in cloudy conditions. I could simply wire the panels directly to the heater spiral. I also don't understand why the display will show several hundred watts in cloudy weather, but the actual watts to the heater is only tens of watts.
In sunny conditions, the output voltage approaches the PV voltage, and so the display reads closer to the actual watts, but still too high. Hopefully you can point out what my error is, and thank you!
Is the issue that the volt meter does not read the output (pulsed) current correctly?
Hope you get an answer. I'm poised to buy one, but perhaps not.
@@bokchoy335 I updated the post above. I wish there was better support for the product - however it is well-made and I'd recommend buying it.
Is it still working ?
25.09.20 at 12h show me 175V, 1.57kw :) ....now im worry for the controller how many time will be fine.... before need new one
today is my day one for free hot water...5 panels x 400W and 2500W heating element ..its show me 1.4kW to heating element and is just 8:51 morning :)
I have 4x 300w panels
V voc. 40.1v
V mpp 32.8
A 9.05
I have used your calculator and I get 240v. 2700w heater element,is this right?
Can't find 2700w element,can I use 2500w or 3000w element?
Could I use a dc element?
Thank you
just look at ur PV resistence to be little bit less than Heating element resistence...if ur pv system is with 20ohm then ur heating element shoud be 21-23 ohm...etc.
Yes it will work. So annoying that nobody answer you simply
so it s only for 10 pannels of 200kwc and no more,does it exact?
Hi, I am a bit confused.
You say the panels and the heater must be matched, but your installation has 4x30V DC panels at 700W and a 220V AC element at 2kW?
I have 12x100W 17V DC panels and a 2kW 220V AC element, can this work? I was thinking to use 2p5s to give me 85V but it seems like I would need a different arrangement for your system?
In the commentary below I described how it is connected and there is a way to calculate what heater will match the PW panels.
Here is the Simple Calculator I wrote to calculate the heater power:
docs.google.com/spreadsheets/d/1FjDoYirKaPE2ySRWk692UgPUEOe60DQdEj-M76z49-0/edit?usp=sharing
For 12 x PW Panels (100W 17V DC each) = 1200W, 204V (Series Circuit)
You can use 1500W 230V Heater.
----
I(A) = P(W) / V(V)
R=U / I
P = I2 · R
----
WP Panels I(A) 5,88A
PW Panels R(Ω): 34,68Ω
Optimal Heater Power P(W): 1525W ,230V
Remember that if you use a stronger heater or a weaker one, it will not be correct and may overload the PWM controller, and after it lead to its damage after several months of such work.
@@actionpol Im a little confused by your video aswell. According to what ive calculated, your 4x 230w solar panels, connected in series @ 29.9VDC will give a total array voltage of 119.6v, with a total current of 7.68A. A 230v, 2KW immersion heater has a resistance of 26.45 Ohms. A 119.6v supply, with a load resistance of 26.45 Ohms will give you a max output of 540.8 watts to your immersion heater. Unless ive calculated this wrong? To match your 4 x 230 watt panels (total 920 watts), with a total Vm of 119.6v & an Im of 7.68a, I think you should be using an immersion heater with a resistance of 15.57 Ohms (ish)? Doesnt this then enable you (in ideal conditions), put 920 watts from the solar array into 920 watts heat power in the immersion?
@@n.e.d I was testing similar circuitry (I had 120V/6A in panels) and the voltage did rise up to 140V when there was enough sun (and the PWM constantly ON), so in fact here the heater is not that underpowered, you may realistically have 920 Wpp to 750W heat.
If you are owner of this device and look at the connectors of the Foto Booster, one side has a diode and one is without. Which side is in and which is out?
In the bottom, out the top.
For 200 lt .what i need ?.
In the manual it say water heater max 2kw why?
2kW is maximum Solar Input
?