Sometimes. This off-grid thing. Just when one thinks she understands how the heck things work. That was the original question anyway, wasn't it? Does it work? Maybe that's why we'd always just got a, "Yes, it works…." that kind of just trailed off into the distance whenever we asked the question before we decided to go down this road. Thursday was mostly clear blue skies, sunshine, and solar thermal hot water. Emphasis on the solar hot water. Which was really magical because even though it was about 30 degrees (I think) outside, we had a temperature of 117 in the solar thermal loop. Couple of weird things. Well, not really weird. Maybe weird. Hell, I don't know. So, heat rises. I do know that. When the solar hot water loop heats the water, the loop comes into the bottom of the tank and it's heating from the bottom and both the bottom and the middle of the tank temperatures go up. That seems to make sense. What's NOT happening is when we are relying solely on the wood-fired loop that comes into the middle of the tank, the bottom of the tank is still cold---which can vary between just under 45 degrees to roughly 65 degrees. That wood-fired loop gets to be about 150 degrees and yet the middle of the tank will top out at 104 degrees with two stinky people that needed a shower a day ago running around. It appears that the way the tank is plumbed now isn't the best way for it to be plumbed. Mike was thinking we should have another tank where the wood-fired loop is plumbed to enter the bottom of the tank. I was thinking: 1) How much am I going to have to repeat myself this time; 2) Based on how hard I have to work to get to you to listen to me is going to directly correlate to how long it's going to be before I ever share with you another bite of any chocolate I may have on hand; and 3) We should plumb the tank so we can direct the wood-fired loop to borrow the solar loop entry point at the bottom of the tank on days that the solar loop isn't going to kick on AND make sure that when we re-direct the wood-fired loop to the aforementioned bottom of the tank through the solar loop's pipes that the solar loop is directed out to the dump zone so we don't have another near Secret Cabin melt down. It would be interesting to see what the temperatures in the various parts of the tank would be if we were pumping the 150 degrees wood-fired loop through the bottom of the tank. At the very least, it seems like we'd at least have more hot water because we'd be heating more water coming in at the bottom with the heat naturally rising through more water. Another note of interest: Those days that the solar thermal is making hot water. Wow. The recovery rate is really, really fast. In fact, when you use the hot water, the temperature in the middle of the tank actually goes UP. Yes, that's correct. Using the hot water makes the temperature go up. That does NOT happen when we're running on just the wood-fired loop. With just the wood-fired loop, after splashing around in the shower, the temperature in the middle of the tank will drop 10 degrees and it won't recover that heat loss for about twelve hours. Does the whole heat rising thing really make that big of a difference? I don't know.