DIY 1.3kw Solar Panels PV to heat water directly, solar pv electric water heater 

Great information thank you so much for sharing

Great idea

Good to hear. Do a overview video so people can have a better idea how your work. Thanks.

@@devildestiny555 here is his video on his pv water heater controller ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-Iw2ZgvgHr9k.html

Thank for your comment... Yes if you have a grid tie system, then you wouldn't want this. I wouldn't do any of this if I had a grid tie system, but you know how that goes with the current Power Company only want to take advantage of the consumer and always claim otherwise. Tankless would work good during day though because you would be using your solar power... but wouldn't most shower occur in the morning and afternoon? :) Do you have video of your off grid li-ion set up? I am interested in switching to li-ion, my AGM is ok, but not that great...

I have net metering with aps, so it's using the grid when it heats water, but the grid ties offset some of that over time. Winter though right now so my power generation is terrible. Panels are all on the roof so no adjusting to the proper angle. My offgrid though is on a rack that i can adjust. I haven't done a video yet on it. I really should get one out. There's a lot of guys doing the li-ion right now. facebook.com/groups/diypowerwalls/ or www.diypowerwalls.com

Thanks. Have you heard anyone using salvage battery from the Tesla model X car as off grid battery storage? I have scan the DIYpowerwall forum but couldn't find anything. I saw on Ebay some guy in Surprise is selling them module at a good price. But I would like to find out if we can use the onboard battery management and the cooling system.

All these power companies are greedy, they are paying less and less for exported power so don't trust them if you are just getting started with your solar hot water system. Use the advanced technology available today and forget the power company, I did! See my channel.

How do you like the lithium ion set up? Can I tease some answers? How large is your bank and what is your state of charge the next morning...?

Hi Don, Glad to hear. Can you share more on how it's being wired and what cap. did you use? Maybe a video of your system?

I'd think a good old automotive points condenser would work. they're good for about 400v. I don't know the uf of them

hi, im using half of Your wattage, just started 4days ago. i have 2000w 220v heating element. it doesnt perform well on solar 100dc 500wats total. what if i replace heating element to 1000 wats?

Martynas Luote ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-kVaxAfXQPDU.html

Electric water heaters are rated 1,500 watts or more. Losses in a 3,000 watts inverter are of the order of 50 watts. I would use a square wave inverter to energize the water heaters, it’s a pure resistive load.

Use the thermal to control the relay run 12 volts through it

Thanks for watching.

Glad you liked it!

You're welcome, there's a lot more I want to say, but didn't want to drag on the video too long and bore everyone... haha.

Yes, I am in the process of testing solid state relay. Adruino or not is not important... I was thinking to use a power supply and feed it through the stock thermostat and powering the relay. If the thermostat shut off, it will cut power to the relay and it will turn off. However, like I mention in the video, it's hard to find a good quality high voltage DC relay at a good price... most I have seen are 150bucks or more for a good one.

Do a spell check man ffs

Thanks for stopping by. :)

Too much distance for DC.

Yes, i have since installed a digital temp controller and a relay. Here's the update video. ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-2nEfElD7B5s.html

thanks

any info on the power meter or disconnect? I'm running 148 VDC it would be great to get a meter that can handle this. Thanks

If you talk to the supply co. , They will explain the thermostat. You can't change it by using a blow-dryer. It functions by sensing the change in resistance. As temperature rises in the tank the element resistance drops. Then it shuts off. 160 degree unit works fine. Use the pressure relief valve to release a small cup of water, then measure temp. You will be pleasantly surprised.

Thanks Mr. KWH police.

Yes, you can. Remember that you are going to have too much heat in Summer and almost nothing in winter time.

40gals.

There's no need to calculate, it's so obvious. Some people's is just to stubborn to realize it. But a lot of company is installing this system.

This is the one I got. www.ebay.com/itm/LCD-Digital-Ammeter-Voltmeter-Volt-Watt-Current-Power-Meter-Coulomb-Counter-V5Q2-/322335599012?var=&hash=item77086a1549&tstore=1&tfrom=30637516 They are showing as 400V now.

That link is no good can you provide a good brand and model. Please

I am struggling with my meter. I do not get any voltage and wattage readings with my PZEM-15, so I am still looking for a meter that is not based on a battery bank.

E K Google Lens says it KKmoon brand, but try DROK on Amazon

If you're going to run 120v on the top element, yes you can swap it out to get the full 1500watts rating and it can heat up the water a bit faster when needed it most. I didn't do it because I already pump the tank full and didn't feel like drain it and change it out. As for the wire size, I didn't have to parallels my 12awg, one should have been enough and the voltage drop was 1-2volts, not much. But I parallels because I had the extra wired and it was already ran through as a spare so I use it anyway. It's true that stranded wire would work a bit better, but the current which I am running it at and the high voltage, it doesn't matter much. I have unplug the grid power since February and it has been running on Solar ever since and it got so HOT that it only run 3-4 hours then stop. I finally install a good Relay that work and it can shut itself off when the water get to 60C now. :) For the rest 4-5hours of sunlight, the panel doesn't do anything. I am still thinking to see what I can do to use the extra power, without complicating the system. So if you ask me, how much has it save me? I would say here in Arizona, 100% from Feb-October and 70% from Nov to Jan. Unbelievable. I'm sitting here and laughing at those people who kept saying why didn't I go with Direct Solar Water Heater, it only cost 3-4 times more and way more problem.... I just LOL all day when I hear people tell me that.

Good deal. I am on the right track. The relay idea sounds great when your up to temperature. Maybe you should get a couple of 1000 watt stackable tier grid inverters and just pump the extra power back in to your home grid. You might want to check with your power company on getting a bi-directional meter. If you make 1300 watts and pull 1500 watts at the same time your meter will slow way down and you will only be billed for 200 watts but I have heard that a standard meter will not go backwards which is a problem. It will increment up no matter which way the power is flowing so if you are making 1300 watts and the house is using say 200 watts your meter will go up as if you were pulling 1100 watts. So a bi-directional meter is a must. Get a credit on your bill that way. That is my plan soon. Another idea would be to get a off-grid sine-wave inverter and maybe 4 or 6 deep discharge marine batteries and use the extra power from your panels to charge the batteries. You would need some sort of charge controller that could handle your higher voltage and reduce it to 24 or 48 volts depending on how you wire the batteries and the inverter you get. You could power your refrigerator off just solar - making it free to run. It would probably run all night on 4 batteries since it cycles on and off and only needs 350 to 500 watts only when the compressor is running. Be sure to wire it where you can go back on grid power if you get several days with no sun. Some inverters have a transfer switch built in. Wire it to a switch so you can easily turn off the grid power to the inverter causing the internal transfer switch to turn on the batteries and solar feed. I have an Aims Power 3000 Watt inverter that works that way.

It can be problematic if you're running on low voltage and smaller wire. You would need to use the online calculator to see how much of a voltage drop it would be. It was not much for me, only half a volt or so because I ran double 10awg and 160volts VOC. 100ft of distance.

Yes I have. But I have not actually test it on the 120v/1400watts element to see if it would improve the output. However, upon my testing with some DC element I had laying around, my finding is that the lower the resistance the worst power it would give me. In another word, the lower the resistance, the more the underload voltage would be. I've measure the 240v/4500w, it's 12.3ohm and I calculate the 120/1400 is like you said, 9.6ohm, I was worrying it wouldn't improve anything. Also the other factor is most of the 120v element are short and tiny does not have the same surface area as the 240v one. I would think this would heat the water much slower. What do you think? I need to prove that it can significantly improve the power before I decide to DRAIN the new tank and replace it. :)

Hi Bryan, Found a old 120/1600watts (9.8ohm) element, tried it today... The result is it gave me the same power output, about 950watts. So I guess there's no reason to replace the element....

That is good to know. thinking about this it seems that you are getting about the same results on your grid tied element as you are on your solar fed element. I wonder if you wired your array in series if the higher voltage would have any effect. could tell us the source of your panels? they look exactly like the ones I bought from Sun Electronics a couple of years ago.

Hey, yes I have already tried it on higher voltage by series all the panels together to give me 240volts, but because higher voltage but not enough Amps... the result is worse. Open circuit voltage might be 240, but under load because there's not enough amperage, the voltage sage down to more than half = 120volts. So I was only getting 600-700watts... So far with my testing, I believe you need to find a sweet power between voltage and amps. These panels are SunPower sold by this company Fabtech, ebay ID santansolar, they are in Gilbert.

Send me a message.

Yes,.that's correct. 150.00ea panels, they are new...They are Mono-crystalline Not only that they are cheap, but they are the high efficient SunPower panels as well, 19%. The reason is that I got it from a local solar company here, these panels are REJECTED panels from the manufacture due to some imperfection they did not meet the test. Most have some type of blemish cosmetically of some sort. Some are producing 10watts less.... You can try to search in your local area via CraigList. You can always find someone importing large amount and sell them cheap.

Wow. That is incredible. Congratulations on your technical and bargain hunting ingenuity.

I don't know the math either, but I think it would depend mostly your panel Power vs Element resistance. But I believe the difference will not be more than 100-200watts. I have tried a MPPT controller just to see what I would get at peak time, it was about 1200w... direct was getting about 1050-1100w.

@@devildestiny555 thank you for quick answer. do you also has some comparison for non peak time, or shading? for peak time is easy, direct connection wins in terms of price / performance, without even calucating the risk of mppt controlers/inverters electronics dying.

hey, i just made a video how i solved problem of resistance miss match on cloudy day. you tried something similar? leave comment. ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-qERoI9ixW_k.html

@@mihanivazn2373 Why did you pull the video ?

No

Yes, the resistance in the element is what causing the low power output.... However, I am not sure if it's that much. 980watts comparing to 1300watts rated is not that off... Because the panel would ever rarely can achieves maximum rated power anyway. I may gain like 100watts by switching out the element... But it's not worth it to buy a new element, drain the tank and replace it... :) At least not for a 100watts.

I wonder if it would be better to just use a mppt grid tie inverter and hook up the element to house mains . Then your panels would be used to full capacity and not have to worry about not having enough hot water. and when you have enough water the panels would help power power the rest of the house.

Of course it's better to have a grid tie system. But that required a permit from the Power Company and a contract with them. If not, that's illegal and they have the right to come and shut off your power. It all depend where you're at...

They sell Grid tie inverters that have an external limiter, It measures incoming power and what is generated. It automatically reduces output power or shuts down when the power generated is close or matches that coming in. There meter would never see power going towards their grid. That is the kind i will install at my home, However our power company allows us to generate and net meter up to 10KW so I don't need the limiter installed on mine.

Much of the day solar panels do not put out significant power. Solar panels are current sources and once light levels drop, the current drops. A fixed load resistance will quickly drag the panel voltage down. 1/2 voltage is 1/4 of the power. MPPT or MPPC will keep the panel at the optimum voltage. I have a system like this and most of the day is less than 1/3 the maximum current. There art times when I only put 20W in, but that is cumulative and it adds up throughout the day. As a solar panel heats up it produces less power. Having a slightly higher resistance element than calculated probably yields better results. Every situation is different.

Solar thermal collector in my opinion was never the answer to heat water. It's expensive and cumbersome, required a lot of plumbing and maintenance (a lot of component can failed). Also, what happen when the outside temperature is extremely cold and it's a cloudy day... then you're screw. But on a cloudy days, solar PV can still put out some power to heat some water and not completely useless. Also, PV is so much cheaper now adays... Look at my set up, getting 1kw of power (5-6kw a day) for just 600 dollars, 800 if you add wiring and connectors. Tell me if you would rather run WIRE or PIPE?

You're right, wire is a lot more convenient and the total sum to set it up was very affordable. I guess STC is very situational. Thanks for the answer and the video - was very interesting.

Istaria , we are in Canada and have solar thermal 3 years now. Today with a 5 x 6' panel, water temperature of 56 F , today's air temperature reached a high of 31 F and the solar heated the tank to 85 F . From February to November it cover all our hot water needs. The system consists of tank, pump,controller, collector and lines.This is beside my kyocera pv panels, I would say thermal is more efficient,it starts earlier runs later and perform better in overcast conditions.

@@devildestiny555 if your in Florida and only using heat a few times a year this may be good option otherwise not enough storage to run much heat. Your set up would not work for most of the US. I have a solar thermal system with 750 gallon wood boiler. When properly designed, not much piping to it. No maintenance other than draining everything every other year like you would a standard water heater. My system heats my house, my domestic hw, and could heat a shop or out building.

In an existing installation, wire is cheaper than bringing down walls.

What are you talking about? Copper pipe vs wire? It's be way more expensive to replumb. 10g or 12g wire is dirt cheap.

Search for Ebay user name "santansolar" they are locally here in Gilbert Arizona.

Search for 200VDC High Voltage DC meter on Ebay or Amazon. You will see it. All though I wouldn't recommend using this meter... it has NO memory and the max KW it can remember is 100kw.... then it reset again. The only reason why I am stuck with this is because the 200VDC... Most of the other meter that has memory are only go up to 100Volts DC. This is the one I used on my other off grid solar setup... I like it much better if you're only need up to 100VDC. www.amazon.com/bayite-6-5-100V-Display-Multimeter-Voltmeter/dp/B013PKYILS/ref=sr_1_2?ie=UTF8&qid=1487175480&sr=8-2&keywords=bayite+power+meter