Solar PV MPPT board for Hot Water heating

[Xringer]

The rubber seals on the heating elements in my 74 gallon tank started leaking first.
Then the large seal holding the HX coil joiner plates (for cleaning out the HX).
I guess the rubber wasn't rated to last under higher temps, it dried up and got brittle.



I've been thinking about a hot-air collector panel for my cold basement problem.
Saw some on Ebay for $1,000+ !!
If I try hot air, It's going to be a full DIY job..

[Mikesolar]

That's the interesting part. There needs to be much more testing of products before they go out the door. I'll bet the rubber was SBR not EPDM or Viton, both of which would have taken the heat. The control might also have let the tank heat up too high as well. Who knows!!!

I have a very good way to do it with just a standard tank and an external HX, many have been in for 20 years.

Defo, the air collector could be a DIY pop can type. Go for it.

[creeky]

paid .80/w for my last 500 watts of solar. maybe it's time to try a solar hot water heater.

[Xringer]

The snow is off the 800w array. But still blocking the middle of the 500w tracker array..

The clouds are still coming in this afternoon, but I'm seeing some neat cloud-edge effects.
Best yet from the 800w array is 105.5V x 9.25A = 976 watts! ( a pulse of 3330.25 BTU Into the water tank).
That's 176 watts over the panels specs. These are nice panels!

[creeky]

if you're thinking of a pop can solar air heater you might want to drop by builditsolar. Gary (?) has done a neat test on solar air heaters and they have a design/plan for a window screen solar air heater that tests out really well.
I'm building mine as soon as the snow goes.

and thanks XRinger for this post. I am putting in a solar water preheat system and now I'm seriously considering the panel/controller route. though 175 for the controller plus 200 for the 250 @ 48v panel plus electric water heater ... gettin' mighty 'spensive.

[MN Renovator]

Originally Posted by creeky

if you're thinking of a pop can solar air heater you might want to drop by builditsolar. Gary (?) has done a neat test on solar air heaters and they have a design/plan for a window screen solar air heater that tests out really well.
I'm building mine as soon as the snow goes.

and thanks XRinger for this post. I am putting in a solar water preheat system and now I'm seriously considering the panel/controller route. though 175 for the controller plus 200 for the 250 @ 48v panel plus electric water heater ... gettin' mighty 'spensive.

It's funny that you mention that because I just ran into that two days ago looking at solar air heating options. I conveniently bookmarked the link, here it is: Solar Air Collector Performance Testing for DIY Collectors

[Xringer]

Originally Posted by MN Renovator

It's funny that you mention that because I just ran into that two days ago looking at solar air heating options. I conveniently bookmarked the link, here it is: Solar Air Collector Performance Testing for DIY Collectors

That's very interesting. Ever since I used SunTex screens to cool off my Den,
http://ecorenovator.org/forum/renova...n-project.html
and noticed they didn't reflect solar, but absorbed it, I wondered if it could
be used in a flat-plate solar hot air collector.. And now, I know!

The Phifer 90% sun blocking screens at Lowes looks like the the SunTex stuff.
But maybe even better. Gotta go back and read Gary's construction info!

Edit:
Heck, it's the same stuff..
http://www.wholesalescreensandglass....Suntex_90.html
~~
I was just thinking about the solar gain from the light reflected off a foot of white snow..

[TackyTeddy]

Disregard ...... We Got the Wring Instructions

But will let ya know how it goes ............................

So at our monthly Solar meeting I talk about get this unit and give it a try. We'll this meeting someone came in with one.

But no instructions for wiring. Looking at all the pictures at teckluck you can see the wires go to the disconnect pull but can't see what wires are connected to what.

So if any one knows how the Red & Black (solar feed) would connect to my load (the water heater) as I only see one lug space on the board for only one load wire?

Thanks

[TackyTeddy]

Xringer

"No I'm currently testing out the 800w array connected directly to the lower
heating element in my new GE water heater w/ A7 on top.
(No MPPT being used yet)."

I've viewed the other posts here and didn't see you using a MPPT, unless I missed it.

So did you ever go with the (techluck) or any other type of MPPT?

If not why, cause I just don't understand how much you would have gained on your system as it stands now with the direct feed.

Anyone know what % gain over a direct feed with any type MPPT.

Thanks

[Xringer]

I'm still using direct connect.. But now I'm using the 500w array too.
I've found the 500W array can charge my 48v bank and also make hot water..



I did make one hack to the system this summer. Our water was getting too hot,
so I made a rig to short out the 800w array.



When the tank hit's 72c, the SSR will kick on and short out the PV power..

Now that the summer seems to be kicking in, we are using a lot of hotwater,
so the short hasn't kicked in yet..