This general guide will show you how to change your standard electric hot water heater tank into a Solar Hybrid Hot Water Heater using only wires, no plumbing required and easy change back to what you had.
Save on your power bill using FREE ENERGY FROM THE SUN. You are already paying to heat your water, why not let solar provide some of that energy in a easy way?
When I first started to want solar hot water I considered piping in a collector from outside. Then I watched videos and e-mailed a few people that did that and found a few problems.
First, if you don't put in some sort of system to drain back the water you are going to have freeze problems and possible panel damage and leaks. Setting that up is not fun, you have problems with air in the system. It needs to be designed to totally drain or it will still have problems. And it still costs a lot and gets complicated. More stuff to worry about in the winter.
The other option is drain it every time the temp drops. Well, if you do that, there goes free winter hot water and what if you forget? I like simple and automatic stuff I don't have to mess with.
And then there's the plumbing, all over the place, maybe a 2nd exchange / heat storage tank that will develop leaks later as any tank does. And a pump that wears out or gets clogged. It's a maintenance nightmare and still a costly install.
So solar PV was the only way to go. I tried to go direct to the element. But the mismatch in the morning and afternoon is brutal, the panels are nowhere near their MPP and you get little total daily heat that way unless you have the extra space and want to throw lots of panels at the problem and just say "oh well". And then you can't use the standard thermostat and might over heat the tank!
Another choice would be to change the element. Have you ever seen the nut size on those things? What if I screw up the threads? Will it leak later? Do I really want to mess with a perfectly working expensive tank?
And without MPPT, you still have a mismatch in the morning and afternoon anyway, doesn't really get that much better for all the hassle.
Now there's this device that does MPPT and makes a Hybrid system. It's simple and just sits there quietly and works every day saving money with no worries and little up front cost.
Installing wires instead of pipes is much easier, and it gives you other options, like if the grid goes down during a bad emergency you can say heck with hot water and simply re-configure the panels for 24V by switching a couple of connections and have more power for an emergency inverter and batteries.
Simple is better.
This is what it looks like installed: (see pics and videos at
http://techluck.com)
It's pretty easy to install and is only 2 wires going to your panels and 2 to the lower heating element.
All of the connections are easily reversible so you can put the tank back the way it was.
What you do is leave the upper heating element connected to the power grid so that if the day is cloudy with little sun, the grid is used to provide hot water: (see pics and videos at
http://techluck.com)
The lower element is wired to the controller device and provides heat from the solar panels all day long which ADDS UP over the day to provide most of your hot water needs so the upper element doesn't come on very often. (sometimes not at all)
The elements stay the same, no change needed, the tank doesn't have to be drained. Just simple wiring modifications.
I hope this helps someone wanting to spend a lot of money on a plumbed system when this type of system is reasonable and simple to install yourself.
Search Ebay for "Solar Hybrid Hot Water Controller" or check this link for more info:
http://techluck.com/(originally posted this "guide" on Ebay in 2013)