Hot Water by Solar Electric direct via MPPT ?

[OldSmokey]

I have a home made version of this.

https://www.ebay.com/i/272088626625?rt=nc&_trkparms=aid%3D222007%26algo%3DSIM.MBE%26ao%3D2%26asc%3D20160908110712%26meid%3De1a815df671b48789666c5aa0369587a%26pid%3D100677%26rk%3D6%26rkt%3D30%26mehot%3Dpp%26sd%3D222908806209%26itm%3D272088626625

that's all you need. use the panels for something more productive.

[asdex]

I have been heating water with a 24 volt 900watt element in my cylinder. Once the battery bank is charged the charge controller reaches 100% SOC and it's auxiliary relay switches a solid state relay which connects the bank to the element .this worked very well but I found the charge controller was reporting incorrectly when the batteries were changed therefore they were being undercharged. With some tweaking it would work fine. Efficiency doesn't really come into it once your batteries are charged. We did had to light our fire at least once a week to give the how water an extra boost and kill any germs.

[LucMan]

One of my friends is a retired plumber who loves my idea. His own daughter got screwed by some company selling water heating systems, paying several times what he could have done it for. This is an industry that should be thriving. Instead, the crooks are dooming it to failure.

DIY is great if someone is capable of completing the work required.
Most of the time homeowners or non professionals are not skilled enough in the construction trades to install a safe and reliable system on thier own. It is to their advantage to hire a contractor.
Contractors need to pay their workers, provide insurance, and have many other expenses that a DIY would not have, increasing the cost of the install.
Maybe you should go out and volunteer your services to install solar for other people in your area to help the solar industry thrive!

[J.P.M.]

Having done further research since I first replied to this topic. The price for thermal is such that one could recover a PV investment in a timely fashion compared to actual thermal panels. and better yet, less to ware out or leak even. I still think there are better ways. but PV direct to induction is feasible even preferable if money is no object. Would even be easier to get astethic approval for the PV than an ugly, bulky thermal systems. at first glance it seems idiotic, then I consider HOA's Welcome Wagon and building code. I am glad we live in a voluntary HOA,

Mostly, I'd agree, provided the PV power went to a heat pump water heater, particularly in moderate climates, where a decent thermal system can have an annual net efficiency of something like 30%, including standby and solar circuit line losses. FWIW, mine's about 32%.

However, with all possible candor, to replace the approx. 9 EE6 BTU/yr. DHW load would take an additional 1.6 or so kW capacity added to my system mat ~ $3.50/Watt. If I were to do it again, and did not already have a solar thermal DHW unit, I'd have gone that way, or better yet, if available added about 800 - 1,000 Watts to the PV system size, added a heat pump for the DHW load and not worry about the solar plumbing.

[Logan005]

Having done further research since I first replied to this topic. The price for thermal is such that one could recover a PV investment in a timely fashion compared to actual thermal panels. and better yet, less to ware out or leak even. I still think there are better ways. but PV direct to induction is feasible even preferable if money is no object. Would even be easier to get astethic approval for the PV than an ugly, bulky thermal systems. at first glance it seems idiotic, then I consider HOA's Welcome Wagon and building code. I am glad we live in a voluntary HOA,

[TurkeyBob]

Just great. Regarding the $15K price tag on a drain back system, this is exactly why I am building a system with dedicated electrical panels. People say it won't work, but it will. It is costing about $2K, including the electric tank and the solid state relay for DC switching. This is only for a small system for two people, so the cost does not apply to everybody. However, with the dropping cost of electric panels, getting away from the complications of a drain back or Glycol based system is becoming cost effective. One of my friends is a retired plumber who loves my idea. His own daughter got screwed by some company selling water heating systems, paying several times what he could have done it for. This is an industry that should be thriving. Instead, the crooks are dooming it to failure.

[inetdog]

Don't hold your breath waiting for ten posts, the PM system is turned off.

[TurkeyBob]

Look here: http://forum.solar-electric.com/disc...uit-thermostat
It can be done and most people are wrong about it. It is a simple matter of the math: BTU's vs gallons and temperature rise needed. The MPPT thing is a bunch of whooey.
I am the HandyBobSolar guy that they kicked off and I will not post on any more forums just to get into arguments with experts. You will see that I did some experimenting, and after reporting the results was told by moderators that it doesn't work. I would be sending a PM, but cannot do so until I have posted 10 time and that probably won't happen. If you find my blog, I have a page devoted to forums. People with closed minds drive me crazy.

[LucMan]

I bet in places where solar hot water systems are common
(https://en.wikipedia.org/wiki/Solar_water_heating lists a few)
materials and installation are way cheaper than around here.
Volume really helps drive prices down.

Local building codes and climate raise the costs of thermal more than anything. When an architect and or an engineer have to get involved, plus the building permit and incidental fees prices escalate.
Tha average cost here for a 2 panel 80 gallon storage drain back system installed is $15000. We only install drain back systems because of the extreme winter temps, and lack of maintainance required.
Thermosiphon Batch heaters in warm climates of course are the least expensive.

[Wy_White_Wolf]

Extremely horrible idea. If you want to heat water with solar, use Solar Thermal panels. Heck of a lot cheaper, more efficient, and actually works. You could not use a MPPT controller, nor would you want to if possible.

While I agree a thermal system would be better. The MPPT that is in the article is actually a LCB like we use to run pumps solar direct. They are using the term MPPT soley because it's a buzz word. With panels dropping below a dollar a watt PV hot water is becoming more of a possibility.

WWW

[Sunking]

I only mentioned ground as an afterthought when I said "just two conductors" Surely ground doesn't generate any power, lol.

And yes, I am suspicious of the gadget that started this thread; I'm learning that it doesn't add up. As long as I'm learning, I'm happy.

73, Mark

There you go, now you get yet it. Using Solar PV to heat water is about as big of a waste of resources as you can imagine. Even worse than a solar battery system

73's

SK

[DanKegel]

I'd question the $9K price for a solar thermal collector.

I bet in places where solar hot water systems are common
(https://en.wikipedia.org/wiki/Solar_water_heating lists a few)
materials and installation are way cheaper than around here.
Volume really helps drive prices down.

[J.P.M.]

I could see that working in the Summer here when attic temps are >115F

On the subject of efficiency as different from possibility, it would work, but the low efficiency would make it a non cost effective waste of time and resources. Not my house/money/life/etc, but also not something I'd waste my time on.

[reptiles]

Mark you really do not understand power, If you did, then you would know ground has no function with respect to power. Secondly to generate 8 Kwh per day is going to require a 2000 to 4000 watt panel system depending on your location. Anything you take off grid is going to cost you many times more than the power company will charge you for it for the rest of your life. You cannot do what you want th eway you think you can. You just do not understand the technology and how to apply it.

73's to ya

KF5LJW out.

I only mentioned ground as an afterthought when I said "just two conductors" Surely ground doesn't generate any power, lol.

And yes, I am suspicious of the gadget that started this thread; I'm learning that it doesn't add up. As long as I'm learning, I'm happy.

73, Mark

[reptiles]

depending on your latitude, I have found 500' of black PEC 1/2" tubing in the attic a great source of warm water and a great way to preheat water for an instant on water heater. Cheap and easy to install.

I could see that working in the Summer here when attic temps are >115F