Simple PV Solar Heating DIY for Beginners (detailed guide) 12V 24V 48V electric heaters 2023
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- Опубліковано 16 вер 2024
- I made this detailed video for beginners who want to try using DIRECT DC solar panel feeds to heat their home, shop or office. The concept is sound, works well, and I've been using it to heat my home for years. If you are interested in a more advanced PV solar heater design, check out my modified DC space heater series: • Heating my home with s...
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The intent here is to show how to extract heat easily from solar panels using common off the shelf DC heaters. Plus there is extra information for those who want to learn more. Topics: PTC elements, resistance elements, DC brushless fans, direct PV operation, install tips, safety recommendations, fire prevention, resistor voltage divider behavior, DC converters, monitoring.
Samples of various off the shelf low voltage DC heaters will be shown operating directly off of solar panels, and lots of safety and technical information. These 12/24/36/48V DC car and truck heaters are easy to get and require little to no modification to run off of solar panel arrays. This is also called PV-to-Load (PV2L).
For years I have been using excess solar power to heat my home with various types of DC heaters. It makes no sense to burn charge controllers, batteries, inverters and heat pumps (which can cost over 80-100x more than a simple resistance heater) when PV can provide heat directly at minimum cost, a minimum level of technology and with few moving parts. Solar PV electric heating is a great way to reduce dependence on gas, wood burning, grid power and other heating sources.
If you are interested in heaters that don't have fan noise, check out my modified AC(DC) space heater video series below.
Hope this video helps you out! Thanks for watching - DD
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Quartz Infrared Solar Space Heater Video Part 1
• Heating my home with s...
Part 2:
• Home Shop Heating with...
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#solarpower #pv2l #pvtoload #solarheat #solar #offgrid #offgridsolarpowersystem #offgridsolar #offgridandongrid
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Be careful hooking these heaters up to solar panels, they are a fire risk and should be treated with the utmost caution and respect. I am very careful when using them. Don't burn your house down with solar panels!
Example (PTC) 12V 100W Heater
amzn.to/3ZGORrc
amzn.to/3ZKF9nU
24V Small PTC heater
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12V 600/800W (non PTC) Car/Truck cab heater
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12V 600W (non PTC) Car/Truck cab heater
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12V 400/600W Car Truck Cab Heater (non PTC)
amzn.to/3mtojuI
12V 800W dual Car Truck Cab Heater (non PTC)
amzn.to/40bZPnr
24V 500W car and truck cab heater
amzn.to/3MTm6Dg
24V 800W car and truck cab heater
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100w monocrystalline 12v solar panel (Newpowa)
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100w monocrystalline 12v solar panel (Eco-worthy)
amzn.to/48iAFHZ
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Have been wanting to do this for years! Thanks for doing all the hard work for me! Glad I stumbled on your channel 👌
You're welcome hehe... music to my ears :) it's a fun project
Thank you, going to try it in the garage fireplace. I have lined it with heavy fire bricks to collect the thermal mass. I have no heating in the garage, anything would be great at -30. I have mos of everything I need, just hook it up.
@earlliverseed1617 Welcome, that's very cold I hope you can get some heat
Man I like the idea of pv direct heating. I'm wanting to do about the same thing but using a metal bucket of sand. I have been looking up this stuff and doing some studying lol. I figure it'll be a lot slower heat but hopefully it will help keep under the house warm
Me too... It's a great way to use excess solar power... every bit helps
perfect video well done
Thanks a lot!!!!
I’ve been running propane in hunting blinds. And well I’m sitting in one as I type this. I say self there has to be way to do solar. And I find you. I might message you
Maybe it could at least reduce the propane usage, I use my solar heaters to reduce heating bills
I'm trying to go solar electric but I started buying parts before I found utube unfortunately I bought a 75 watt solar panel with a charge controller since then I found out the proper charging parameters for sealed lead acid batteries and found the unit hasn't got proper charging parameters also as I was starting my second go round I I bought 2 100 watt panels and a 30 amp pwm charge controller over the years I've ended up with 3 1750 watt modified sine wave inverters then I found utube and found out pwm isn't too good should be mppt but would work I'f I can figure out how to get the charging parameters fixed my modified sine wave inverters are no good for electronics what I like to see is a video on fixing the problem with both of these a video on fixing the charging parameters and a video on making modified sine wave inverter to pure sine wave inverter I did find one on using a triplite lc1800 line conditioner but while the price is reasonable the shipping costs aren't
Hello, thanks for commenting... good topics and ideas... I've been curious about those line conditioners. I will address some of these things when I'm able to make some more videos. Stay tuned :)
I need to try this!
Right on! I wish this tech was commonplace, hoping manufacturers see these videos and start making safe high-quality PV heaters we can buy off the shelf. I have 6 PV heaters in my living room, bedroom and back room running straight off PV. Started doing this years back before yt.
One more video coming out about driving DC loads with PV directly called "science of solar" hope to have that one live soon!
Heater playlist linked below, if it helps :)
ua-cam.com/video/TJG-ZnqJR9w/v-deo.html
I just got my 2 BTC heaters today. A 120 and a 70w Sun went down before I could test them. I will borrow the 30Ah lithium battery and use one of my 200w bifacial panels to run it with. Wish me luck.
@OFFGRID_Trucker Sounds awesome, hope they work well for you. A volt meter or Watt meter can also be very helpful
@@solarpoweredge I have one of those inline ones I will plug into it.
Excellent! I used one with my PTCs, which made it possible to calculate the most efficient element and also series vs. parallel
@@solarpoweredge Saw this and thought of you... ua-cam.com/users/shortsR7_gwe47QN4?si=ZlPlECP38_ZzuS-6
Do squirrel cage fans give a better air flow than axial fans and would they be better in this application
@errolfoster1101 Do you mean those fans that look like a snail shape (centrifugal blower type)? If so, yes.. those seem to give better results, and push air a lot harder. But they are sometimes more challenging to fit into the design.
@@solarpoweredge that's right I have them as ventilation fans and they work very well
FYI 1st link is an unavailable product.
Wow thank you for telling me... they must have sold out, I updated the links
try Noctua fans they last well over 10 years & are silent.
Good idea!
well dang was hoping I could make this work in greenhouse to keep it warm over night. One of the first things I heard in video was not to run unattended 🙁 Do you have any suggestions?
Thermal cutoff fuses.
Those cab heaters are a bit sketchy. But ceramic DC PTC heater would probably be fine in an outbuilding, if it's a quality unit. Check end of video for some examples (there are many kinds). They throttle down if heat gets too high. So built in thermal protection.
To add warmth to the greenhouse overnight, you need to heat a thermal mass during the day. A reasonable solution is to get a metal 55gallon drum and put an appropriate size immersible fish tank heater in it. Lets say your solar array can produce at most 800 watts, and when the two 400 watt panels are connected in series, produce say 90 volts DC. YOu can then safely run that through a 20 plus amp 150 volt DC circuit breaker/solar disconnect device accessible from a metal box at greenhouse entrance, to the positive power wire ( use 12 gauge or thicker wire from panels to breaker then onto the heating element. Use a 1000 watt 115volt AC type heating element which should be safe to run sitting inside 55 gallons of water (yes add some antifreeze to keep it from freezing down to 10F ). Since the 55 gallons of water is very large (use a IBC tote for 250 plus gallons even better), provides a massive sink for the heat from the immersed heating element and also the drum provides a large surface area for the heat to radiate into the greenhouse. For a small 20x10 lightly insulated and well sealed at night greenhouse with good sun on the panels every day, this will help a lot. You can calculate the BTU's stored each day based on sun angle time of year, how much direct sun daily, watt/hours produced daily, BTU's generated by element into the drum or IBC tote. Of course 800 watts of solar mid winter is probably more like 600 watts generated in full sun due to atmoshperic filtering of low sun angle. Setting up a larger ground mount array of 4000 watts (3000actual mid winter) into a few IBC totes for a larger say 30x12 greenhouse could nip an overnight freeze from happening, keeping things at 40F when outside is 20F. The nice thing about using 115volt AC 1000 watt elements is that you can easily just plug them into an actual (12 gauge or 10 gauge, long extension cord) to a homes AC supply to handle days where solar won't work due to snow or a few days where clouds block the sun. This can be left running without surpervision, no problem and I built such a barrel with heating element and solar panel 200 watt as a test a couple of years ago, worked fine but was not producing enough heat, needed much more than a 200 watt pane.
How about space heating at night, cheaply and with similar simplicity?
I believe the cheapest and simplest way is to use a heat mass with a DC heating element inside... it could be a large tank of water or sand. If I do any experiments I will certainly post and share the results
As far as heating. Pv directly to your element is waste of electricity. Day time fine.Good to know take no offense. You must add a battery as when pv is 0 you are cold.
That said now its on. Where do you find heat and power?
Hi, consuming excess solar power (dump load) for supplemental heat has worked very well and requires no complicated circuitry or tech. At night can use other heat source - and of course batteries. I am looking into using diode chains for more efficient heat extraction 90% or better.
I have 400w of panels to try thus. Suggested heater size? 400W?
Hi, towards the end of the video, those PTC heaters were running off of 4x 100W 12V mono panels. I routinely see 100-220w (340-750btu/h) not much but it makes a difference in a small room. They are very poorly aimed for winter, almost straight up at the sky.
Scenario A, if your panels literally can output 400W, then in theory a 350-400W heater will work. Or 4x 100W PTCs.
Scenario B, if you mean they are "sized" as 400W (like mine), then I'd suggest experimenting with 2x 100W PTC heaters in parallel for starters. You can run one or both depending on the sun and conditions. Having multiple smaller heaters is good for testing, you can vary the load depending on the conditions, without complicated electronics. Just switch them on or off.
I recommend having a basic multimeter/voltmeter to watch the panel voltage when testing. Matching the heaters to the panels can sometimes require experimentation to see what works. Too powerful of a heater that isn't matched to the panels will collapse the voltage (they try to draw more power than the panels can provide) and there won't be much heat.
@@solarpoweredge they a 100w panels and I have 4.
Roger that, the small 100w PTCs are a good fit then. I did see some small 100-200w car resistance heaters, have not tried those. The 24v PTC heaters worked better for my panels, and the 12V one I ended up rewiring for 24V. Some of the 12V heaters just have too low a resistance and they drag the panel voltage down to nothing.
@@solarpoweredge i think ill go with the 24v then. Thanx for all the help. Ill keep ya posted.
No problem! OK Sounds like a plan
Do you have any inexpensive solar panel recommendations? I'm trying to heat my home office. Unfortunately the room is somewhat large, but if nothing else, I could just have the heater(s) blowing directly on me. The extra safety feature of the PTC heaters seems nice. I'm considering the "24V 800W car and truck cab heater" (last link your description). Do you recommend used solar panels or not? what specs should I look for?
Hello, a few hundred watts would still give you some supplemental heat. The larger the room the less noticeable though. I used 3 100w panels with some PTCs in a small back room, it made all the difference (after a few hours). Every bit helps. It was tricky to get the elements matched not to mention the fans.
In my personal opinion the key is to look at dollar per watt, while keeping in mind that used solar panels put out less watts, as they have aged. Used panels need to be tested by a competent professional. I prefer brand new panels and to take good care of them, easier to get the payback, returns and no mysteries about how they were handled or thrown on a truck. Have had the experience of used panels and will never do it again. Just sharing my thoughts on the subject. If you can find good used panels, that would be a nice option.
If you can get a hold of 2-4 100w 12v solar panels, they can run a ~12-24v PTC just fine if the resistance is matched. That 800w cab heater probably no less than 4 panels. It's tricky to match the heater to the panels but it can be done. 12v panels usually push about 16-18 volts at max power, the specs are all similar.
I did some searching on amazon keywords "100w solar panel". In the description are a couple of links to 100w panels I found (if that's what you're looking for). They have a couple 100w panels less than a dollar per watt. They are somewhat brand name. I avoid the no-name panels. Note: you can also search amazon directly if you don't want to use those links.
Hope this helps answer your questions, mostly just my opinion. If I missed anything or if I can assist you with a setup just let me know, I try to keep up with the comments.
@@solarpoweredge Thank you for the quick reply! If I got 4 12v 100w panels, I assume I would just wire them all in parallel if I wanted to stay at 12v, or wire 2 pairs (pairs wired in parallel), in series with each other for 24 volts. Is there any danger in having too much current, or will the heaters just draw as much current as they need? I understand that the fans are sensitive and I should run a 24v fan on a DC converter or across the midpoint of the heater element (if it exists), since the panels wired in the 24v configuration might produce 30v+. Would I be ok running a 24V heater connected directly to the 4 solar panels wired in a 24V configuration, or would they also get damaged if the panels start producing over 30V?
Welcome! You're right about wiring in parallel. Matching the heater to the panels can be tedious. It took me a while to get those PTCs running smoothly. In fact I ended up running 36v. You will probably have to test the panels first. It depends on the resistance of the heating element used with the panels, which governs what the voltage gets pulled down to. Those PTCs vary in their resistance while physically looking identical. Here's the key... 12v solar panels usually want to be around ~16v for best power output. Therefore it is necessary to monitor the system voltage. Should connect the heater and measure the voltage as heater warms up. A small voltmeter, wattmeter or multimeter would work.
If the voltage collapses and stays down (in good sun conditions), you probably need more current and less voltage (maybe parallel vs series).
A PTC heater self regulates, if it gets too hot it throttles down.
As long as the wires are thick enough and connections secure, current isn't an issue. Using a proper DC PV breaker is a good practice too. They don't cost much and give you an ironclad way to shut down the system if anything goes wrong.
@@solarpoweredge I'm going to make my purchases. Planning on getting 4 100W panels. Do you recommend the 12v or the 24v version of the 800w heater? I can wire the panels in 12 or 24v configurations. I'm going to wire a DC regulator/converter in before the fan. I was thinking of getting this one:
valefod DC-DC 5A Buck Converter 4-38V to 1.25-36V Step-Down Voltage Regulator
do you think that will work or do you recommend a different regulator/converter? Thanks!
Sounds like a plan... the DC converter should work fine. Both heaters can work. Since it's 400w of solar and heater is 800w, bumping up to 24v heater is probably a little better for your setup. If the panels can't run the heater, it might be possible to step the panels down to 12v as a backup option for more amps. I suspect some of the 24v heaters can be rewired for 12v internally, but can't say for sure as they're all different.
Can you list your sources for parts?
Hello, yes, they are on my Solar Thoughts Blog, which is linked in upper right hand corner of the UA-cam channel page. Please see the post titled "Simple PV Solar heating for beginners"
If I post links directly on the videos it seems my video traffic drops pretty bad. Maybe I'll try it again later though.
I updated the description with the links, will give it a try. Sorry for the inconvenience. Also there are other DC heater options besides what I listed, it's worth checking around first.
Has anyone done this with DC heat pumps?
I'm sure it's technically possible There are heat pumps with DC/solar assist. And 48V versions too. But they are pretty expensive and complicated machines, vs. simple DC heaters that anyone can use and maintain.
You speak a lot about voltage swings. Can you put a charge controller inline to compensate for this?
Right on... good question I'll try to be more exact. Solar panel(s) are 100% unregulated, imagine a solar electric powered heating element that "just so happens" to be running at 1000w 55v but can't run a penny more. One freezing day, the sun comes out from behind the clouds (solar panels are more efficient when cool) and we get 65v 1100w - and the heating element just melts. I've sure melted a few here while testing.
The solution is to make sure the heating element is never dissipating its maximum wattage at any time, so it can never burn from a voltage swing. It just puts out a bit more power. This means "under rating". It means balancing the resistance (ohms) which itself is a moving target, with the potential solar panel voltage and power range, again a moving target.
To answer your question, you can absolutely put a charge controller and battery in between. I've done it before and I suspect quite a few folks are doing it also. You could absolutely charge a battery, and then attach a compatible 12/24v heating element to it, problem solved. Nice stable voltage. The sun goes down, you still get heat. But for me personally, that'd take some of the fun out. I like the purity of just clean solar straight to the element (hence my constant reference to PV-to-Load). It does not make much sense to wear out expensive batteries and charge controllers merely to produce some heat. But at least it saves the inverter. Some people do add an inverter and a 120v space heater. Honestly if I had a massive battery bank, say 100kwh+ I'd probably be willing to cycle it for DC heat overnight. But I'd still use PV2L heat whenever possible to save wear on my expensive electronics. This is all just my opinion, but I hope it's of some help :)
@@solarpoweredge So to use a charge controller you must have the battery inline? My thoughts were on the idea of maybe going panel / charge controller / capacitor / heater. Half think controller could be eliminated and run through the capacitor to control swing. I need to research this some more.
In theory some controllers could do this. I've even tested this kind of stuff (including the capacitors), but haven't recorded it, kind of feeling like no one would be interested or would get confused. Maybe there is interest after all!
Years back a professor friend started teaching me about capacitors and their uses. I know just enough now to get in trouble! LOL. I know I'll be interested.
I don't claim to know everything but... it's enough to melt things lol. I'll make a note to document some of this type of capacitor stuff when things open up in the future. Would probably make a cool video. DD
My 3-40.8V 360W solar panels in series I have 122.4 volt 1080W. Can run it direct to 120V 1000W AC heater?
If so can I run a 120V AC to 12V DC power adapter to run the fans?
High voltage DC is rather dangerous and so I don't recommend running it in heaters. I keep my heaters around 50v much safer, especially around pets and children
@@solarpoweredge I assume that if I only use 1-40.8 volt 360 watt solar panel that won’t be much heat. But I could run three panels to three heaters.
@scottfree8726 Maybe the 24v version of the car / cab heater would work with one panel? Even 3 in parallel and 3 panels. Hard to say without knowing the loaded voltage, but worth checking out!
Could i use a lipo 12v or 11.1v battery with a buck inverter? to power just one of these from a female 12v car socket?
Hi, the normal 12v car / truck cab heaters need about 20-30 amps. A good size 11-12 volt battery could certainly run the heater. Could also connect a solar panel to help the battery. In my opinion I would not connect a lipo to the car outlet though: better to create a standalone power system. Hope that helps, but if I misunderstood the question let me know :)
Thanks, i loved the video! So my heater is an off the shelf 150w 12v car heater I have wired up a voltmeter in line with the battery and entry terminals of the buck converter which outputs 10a 13.5v apparently. The heater is on the output terminals of the buck converter. Im looking for battery powered options i guess specifically as I wired in a 10amp fuse which blew today when i attached a 18v power tool battery. The amps just kept going up!! My question i guess sticking to battery (for home, shed, no power situations and considering some power cuts we had at home (UK) from the storms. For running a little fan heater like this for 30mins of a battery, which battery would you recommend? One that would be somewhat portable and available on The big "A" preferably. Im based in UK and thanks for your swift response!@@solarpoweredge
@futureproductions Welcome, glad you enjoyed it :) 150w makes things a bit easier! To test the idea, I recommend approximately a 20 to 100 amp hour 12v LiFePo4 battery.
If you search the big "A" website (can't put links here) for "12v LiFePo4" there are very many options. Note: a 100ah battery is quite heavy, whereas a 40-50ah battery is chunky but more suitable for portable uses. A 40-50ah battery should run your heater at least an hour (or more) without deep cycling or being too hard on it.
I hope this helps - if you can't find something suitable, let me know what size or budget and I'll update the description with a link to a suggested battery. Sounds like a fun project, hope it works out!
@@solarpoweredge Thanks so much i appreciate it! This is fun but im also a bit weary of the battery going pop. ive several failed attempts mainly the fuse. i hear these types of heater draw a lot to start with then drop down. gpt inists on it only drawing 8.5amps on paper so not enough to blow the 10 amp fuse but suddenly when connecting the 18v power tool battery it rose rapidly to 15 amps. It only ran for a minute then the 10 amp was fried so now im thinking of getting this battery and holder mount, what do you think?? Battery Adapter Power Wheels Adaptor for Makita 18V Also for Bosch 18V Battery BL1820 BL1860 BL1850 Dock Power Connector Holder with 14 Gauge Wire for Power Tool Batteries Mounting Frames. The budget for the lipo route you explained makes total sense but I was hoping to later use an ebike battery but for now a readily available power tool battery... would that work with a greater fuse based on what i mentioned. It explains that the buck converter has over discharge protection but im not so sure... Perhaps id need like you to also add a voltage regulator? Thanks once again, it great to hear from an expert. I also have a very small 12v panel im hoping to use on another project later, thinking to charge 18650s or something...
I forgot to mention the battery I wanted to use was this small cheap one like this: Replacement Battery for Makita Battery BL1815 BL1820 18V/1.5AH LI-ION low ah for sure... The only electric tutor at the moment is gpt and it is positive things can work when i keep asking it lol. I might upload a video of my dodgy wiring but at least its fused on the positive terminal with an automotive fuse setup. I also found something like this but it looks bulky. Im not sure if its portable and OK say for a backpack... I could use my 12 solar power panel with a cheap charge controller i found for only 8 pounds! but it would take ages to charge it so id need a safe charging option for this: Miady 12V 7.2Ah LiFePo4 Deep Cycle Sealed Battery for UPS, Burglar Alarm, Chairlift, Fish Finder, Electric Scooter and etc. Rechargeable & Maintenance-Free