Direct PV water heater MPPT controller

[Finn DK]

Hi All
This is my first post here, after I've spent countless hours of reading.
I am the happy owner of 2 grid-tied systems, one 6.6 kWp the other 4.4 kWp.
But now I've got hand on some second hand panels I would like to use for water heating as it's not possible to add them to the existing systems.
Going through the various post here a direct connection panel/element has been excluded, so the hunt for a MPPT controller went on.
Most promising solution found so far is this one: http://www.kontiki-solar.si/en/regulatorji/1375-regulator-ktr4.html
I live in Denmark so delivery will not be a problem, but I would like to know if anyone here has some knowledge/experience regarding this product.
Thank you in advance.
Finn DK

 

[houseofancients]

here's another ( and cheaper ) one :

PWM MPPT Heater Boiler Charger Regulator Photovoltaic PV Solar Panels Hot Water | eBay

PWM regulator for heaters with an algorithm for finding the maximum MPPT power point from photovoltaic panels. The regulator enables powering standard electric DHW boilers from solar panels. It is fully automatic and starts working as soon as you plug it in.

www.ebay.com.au

and if you want to diy, take a look at loadmasterXP

LoadMaster XP - A Smart PV MPPT Solar Hot Water Controller

A solid-state, low-cost, reliable solution for solar hot water from PV. Zero maintenance & CO2, connected, smart combi pre-heat control. By stevetearle.

create.arduino.cc

 

[Finn DK]

here's another ( and cheaper ) one :

PWM MPPT Heater Boiler Charger Regulator Photovoltaic PV Solar Panels Hot Water | eBay

PWM regulator for heaters with an algorithm for finding the maximum MPPT power point from photovoltaic panels. The regulator enables powering standard electric DHW boilers from solar panels. It is fully automatic and starts working as soon as you plug it in.

www.ebay.com.au

and if you want to diy, take a look at loadmasterXP

LoadMaster XP - A Smart PV MPPT Solar Hot Water Controller

A solid-state, low-cost, reliable solution for solar hot water from PV. Zero maintenance & CO2, connected, smart combi pre-heat control. By stevetearle.

create.arduino.cc

Thank you for your reply

In fact I've been looking at the ACTii, but I need one suitable for my 230V/4kW element.
Another thing is, that I think it looks a bit flimsy, I wouldn't dare to run it at full load without strict adult supervision.
The LoadMaster looks better, but as a 70 year old electrician I doubt I have the skills to build an unit like this.

​

 

[efficientPV]

Get two, their cheap. A market still doesn't exist for water heater controllers and DIY is exceedingly rare on solar forums. These circuits are quite simple in relation to most electronics. It has surprised me just how many have succeeded building these with no background or prior experience in electronics. Just takes motivation.

Given your location, I can see you might need 4,000W of panels to get consistent hot water. But, why fo you think there is a need to put more than 2,000W into a heater element?

I do have reservations about the LoadMaster performance.

 

[Loadmaster]

Hi
Greetings all. New to the the forum and hope I can make a positive contribution.
I have personally built and tested the loadmaster and it is definitely a step ahead of other hot water controllers. It has dual outputs which means you can either power 2 x hot water cylinders or use the second output to dump excess power into a existing solar system. This ensures that no power is being wasted once the hot water cylinder has reached its set temperature.

I am currently running it on 1 x 150 and 1x 200 liter cylinders, and seeing temperatures daily of 70 deg C. It has been running for almost 6 months with no issues.

 

[houseofancients]

Hi
Greetings all. New to the the forum and hope I can make a positive contribution.
I have personally built and tested the loadmaster and it is definitely a step ahead of other hot water controllers. It has dual outputs which means you can either power 2 x hot water cylinders or use the second output to dump excess power into a existing solar system. This ensures that no power is being wasted once the hot water cylinder has reached its set temperature.

I am currently running it on 1 x 150 and 1x 200 liter cylinders, and seeing temperatures daily of 70 deg C. It has been running for almost 6 months with no issues.

wonderful to read....

 

[Digix]

Hi
Greetings all. New to the the forum and hope I can make a positive contribution.
I have personally built and tested the loadmaster and it is definitely a step ahead of other hot water controllers. It has dual outputs which means you can either power 2 x hot water cylinders or use the second output to dump excess power into a existing solar system. This ensures that no power is being wasted once the hot water cylinder has reached its set temperature.

I am currently running it on 1 x 150 and 1x 200 liter cylinders, and seeing temperatures daily of 70 deg C. It has been running for almost 6 months with no issues.

Hi ! where can I buy the pcb for loadmaster ?

 

[Steve T - IoW UK]

Hi there, thanks for your interest & Yes I still sell Loadmaster PCBs. My email address plus feedback from builders etc can be found in the 'Latest' and 'Comments' sections of the Hackster project page.

I have to say I had a good laugh at some of the "comments" I just spotted on this site regarding my Loadmaster project, eg :-

"I forgot to talk about the Loadmaster. It is a design made by a software guy and some of his claims are a little iffy. I don't think it works as well as he says because he hasn't really tested it, just made guesses."

For the record, i'm a HND Qualified electronics engineer and had 26+years in R&D Electronics design & then Technical Director for a UK company owned by Ideal Industries - I can assure you my team would have burst out laughing if someone said I was a Software guy and you don't last 26 years in the expensive world of R&D by designing and testing based on B.S ! As for testing... My LM has been heating our water 100% reliably since 2019 and I presented my downloaded 'real world' captured energy data in an XLS in the project downloads section. The design works extremely efficiently.

"I do have reservations about the LoadMaster performance." - Unfortunately there was no explanation for that comment - Why? What?. Its a real shame as I would have been happy to address any questions or doubts (usually via the Hackster or Arduino comments). I come from a view that our Planet, current energy economics and insane geopolitics could seriously benefit from encouraging and motivating more people to get hold of some cheap or 2nd hand PV panels and put them to good use in any project.. whether is Loadmaster or any another PV application.

"The Loadmaster is really overly complicated and expensive to make with no real advantage" . Blimey!... its an Arduino Nano, Power MOSFET, a handful of components -it has a display, shows temperature & energy readings, it has connectivity, basic data logging and some safety features included in the design. The capacitor is potentially the most expensive part but search around ebay etc and you can usually find bargains. It seems that a key 'advantage' & attraction to many builders is the potential for customisation & hackability offered by being Arduino based.

The operating principle and circuit design is very simple, certainly no smoke and mirrors, the heating performance is all just maths! It's certainly not a project for everyone and I usually suggest If you don't understand how it works or what you are doing, then it's perhaps time to find a different project! Cheers Steve

 

[houseofancients]

Hi there, thanks for your interest & Yes I still sell Loadmaster PCBs. My email address plus feedback from builders etc can be found in the 'Latest' and 'Comments' sections of the Hackster project page.

I have to say I had a good laugh at some of the "comments" I just spotted on this site regarding my Loadmaster project, eg :-

"I forgot to talk about the Loadmaster. It is a design made by a software guy and some of his claims are a little iffy. I don't think it works as well as he says because he hasn't really tested it, just made guesses."

For the record, i'm a HND Qualified electronics engineer and had 26+years in R&D Electronics design & then Technical Director for a UK company owned by Ideal Industries - I can assure you my team would have burst out laughing if someone said I was a Software guy and you don't last 26 years in the expensive world of R&D by designing and testing based on B.S ! As for testing... My LM has been heating our water 100% reliably since 2019 and I presented my downloaded 'real world' captured energy data in an XLS in the project downloads section. The design works extremely efficiently.

"I do have reservations about the LoadMaster performance." - Unfortunately there was no explanation for that comment - Why? What?. Its a real shame as I would have been happy to address any questions or doubts (usually via the Hackster or Arduino comments). I come from a view that our Planet, current energy economics and insane geopolitics could seriously benefit from encouraging and motivating more people to get hold of some cheap or 2nd hand PV panels and put them to good use in any project.. whether is Loadmaster or any another PV application.

"The Loadmaster is really overly complicated and expensive to make with no real advantage" . Blimey!... its an Arduino Nano, Power MOSFET, a handful of components -it has a display, shows temperature & energy readings, it has connectivity, basic data logging and some safety features included in the design. The capacitor is potentially the most expensive part but search around ebay etc and you can usually find bargains. It seems that a key 'advantage' & attraction to many builders is the potential for customisation & hackability offered by being Arduino based.

The operating principle and circuit design is very simple, certainly no smoke and mirrors, the heating performance is all just maths! It's certainly not a project for everyone and I usually suggest If you don't understand how it works or what you are doing, then it's perhaps time to find a different project! Cheers Steve

like i once already mentioned..
wish i had the soldering skills

 

[solarsimon]

Hi there, thanks for your interest & Yes I still sell Loadmaster PCBs. My email address plus feedback from builders etc can be found in the 'Latest' and 'Comments' sections of the Hackster project page.

I have to say I had a good laugh at some of the "comments" I just spotted on this site regarding my Loadmaster project, eg :-

"I forgot to talk about the Loadmaster. It is a design made by a software guy and some of his claims are a little iffy. I don't think it works as well as he says because he hasn't really tested it, just made guesses."

For the record, i'm a HND Qualified electronics engineer and had 26+years in R&D Electronics design & then Technical Director for a UK company owned by Ideal Industries - I can assure you my team would have burst out laughing if someone said I was a Software guy and you don't last 26 years in the expensive world of R&D by designing and testing based on B.S ! As for testing... My LM has been heating our water 100% reliably since 2019 and I presented my downloaded 'real world' captured energy data in an XLS in the project downloads section. The design works extremely efficiently.

"I do have reservations about the LoadMaster performance." - Unfortunately there was no explanation for that comment - Why? What?. Its a real shame as I would have been happy to address any questions or doubts (usually via the Hackster or Arduino comments). I come from a view that our Planet, current energy economics and insane geopolitics could seriously benefit from encouraging and motivating more people to get hold of some cheap or 2nd hand PV panels and put them to good use in any project.. whether is Loadmaster or any another PV application.

"The Loadmaster is really overly complicated and expensive to make with no real advantage" . Blimey!... its an Arduino Nano, Power MOSFET, a handful of components -it has a display, shows temperature & energy readings, it has connectivity, basic data logging and some safety features included in the design. The capacitor is potentially the most expensive part but search around ebay etc and you can usually find bargains. It seems that a key 'advantage' & attraction to many builders is the potential for customisation & hackability offered by being Arduino based.

The operating principle and circuit design is very simple, certainly no smoke and mirrors, the heating performance is all just maths! It's certainly not a project for everyone and I usually suggest If you don't understand how it works or what you are doing, then it's perhaps time to find a different project! Cheers Steve

I'm glad you can laugh at the comments, rather than get rattled by them. It's clear that you've put a great deal of time, effort & thought into Loadmaster & arrived at a very good design. Congratulations.

 

[upnorthandpersonal]

@Steve T - IoW UK - just dropped you an email; wonder if you still have some PCB's laying around