Partly operational: Extensive solar thermal/electric hybrid system
 

My very extensive solar power project that I have been working on for about 5 years (on and off, as time and money permits), is now partly operational.

Temperatures here are in Centigrade:

https://dl.dropboxusercontent.com/u/...%20Storage.png

As you can see, the annual geo solar heat storage, as well as the 3 x 375 USG buffer tanks are NOT yet online (gray lines). Even so, massive amounts of heat is captured and sent into the foundation of the house, as well as into the 375 USG main heat buffer.

I hope to have the system fully operational by this summer.

Looks very impressive.

Very nice setup.

What are the two three way valves in the solar panel to tank circuit for?

I am happy you ask that question :)

The primary circuit is a glycol-water mix, to prevent freezing, secured down to -20 C (-4 F). Despite that I have a function to run to keep it from getting below -10 (14 F), just in case.

Anyway, that primary system, consists mainly of three parts:

1. Solar panels (left)
2. Heat exchanger to secondary (plain water) system (middle)
3. Heat exchanger inside a 1000 liter (375 USG) hot water buffer. (right side)

With those two three-way valves, I can transfer heat between any or all of these three units, except, the middle heat exchanger is always active when the primary pumps is running - however - as long as the secondary system pump is off, then it doesn't matter, and in reality as I wrote, I can combine the three any way I want.

At the moment where it is just below freezing at night, sunshine at day up to around 10 C (50 F), it starts out with the solar panel and secondary system only (bypassing the hot water buffer in the top left corner of the schematic).

When the water from the solar panel gets sufficiently hot for the hot water buffer, the three way valve in the left side opens for flow into all three systems in primary, as can be seen here:

https://dl.dropboxusercontent.com/u/...gn%20SB102.png

It's not a lot at this stage. Due to a system orientation of 160 degrees (South-South-East), peak is around 11 am. Here at 1:52 pm, the heat is decreasing and transfer going down.

Note the updated design. You can also click certain items now, for more info.

Ask in PM if you want a code to see it live.

Can we get some pictures of the actual system?

Sure!

Before that, I can say that I am working on a presentation and information for a crowd funding run on RocketHub. I will announce it here when it launches, and will greatly appreciate your support to either spread the message, a small contribution or both. The initial support is essential. I have most of it installed by now, but need a little extra in materials and expertise help. The fund raising will enable me to finish totally this summer, so it's ready for winter.

What's inside the ground can't really be shown as it's obviously hidden. I do have some pictures somewhere from years back, when I dug it all out. Most visible are the solar panels, this is from mounting them:

https://dl.dropboxusercontent.com/u/...nergi_1024.jpg

Because of the weight of the panels, we had to replace a number of tiles with plastic tiles, to reduce the weight of the roof. Total weight of panels and mounts is over 1000 lbs. Each tile replaced by a plastic "tile" saves over 5 lbs. Those clear tiles are originally designed to allow light to enter an attic (in lieu of windows). It was an expensive move but the only way (or least expensive and complicated way) I could proceed (I am way beyond the point of no return here). tearing down the roof completely and rebuilding it in a stronger way was way beyond what was possible and feasible.

Panels being mounted, we rented a lift. Unfortunately, this lift had some problems which delayed us, but up came the panels:

https://dl.dropboxusercontent.com/u/...03%20-%205.jpg

I didn't want the panels to be active until needed, so we covered them in ... yes, what to do? Ended up getting some packaging paper and masking tape. That was all great until wind and rain tore it off - and it was a while before I could get back to finish it. More lessons learned.

https://dl.dropboxusercontent.com/u/...05%20-%205.jpg

We made a custom hydraulic connector to use between the panels, as I didn't want a lot of fittings/connections that could potentially leak:

https://dl.dropboxusercontent.com/u/...-connector.JPG

This S-shape is used in particular to enable movement by thermal expansion. It is soldered up so there are no joints apart from the entry and exit in each panel, and should "last eternally".

After mounting the panels, it looked like this:

https://dl.dropboxusercontent.com/u/...%20projekt.jpg

And with the scaffolding removed:

https://dl.dropboxusercontent.com/u/...s%20Panels.JPG

As you can see above, the panels are mounted very tightly: Just over an inch between them both horizontally and vertically. To fit 12 panels this way, we literally had to start right at the left edge of the roof, just above the upper limit of the three windows, up to the rooftop and just on the limit to the neighbour house (These are 4x attached houses). We even had to cover one window, which was south facing in the attic level (2nd floor).


The main junction of the system is located inside the staircase leading from ground floor to 1st floor. It's not too pretty but will be tidied up. With the limited space available, it will inevitable look a but messy, especially while still under construction:

https://dl.dropboxusercontent.com/u/...0-%20SB102.jpg

When I go live with the crowdfunding, and later on - the wiki/FAQ/DIY web site - there will be a lot more pictures and videos, along with animations. Here is an exclusive sneak peak of an animation, testing out various possibilities (I am not very seasoned with graphic design, but I will do what I can. Youtube is a great help for tutorials).

https://www.youtube.com/watch?v=9osQ7pPYaD8

I will get back with more information later - as I go "live" on the crowdsourcing.

Thank you for your support :)

Good news!

The underground heat storage was NOT leaking, as we thought previously. It has now been online for about 4 days, and working just great! I might throttle it down a bit, but at the moment, I am sending heat not only into the foundation and hot water buffer, but also 15 feet down below the house. This is so exciting - many things still need to be done, mainly those three extra buffer tanks I need to install.

Good times!

https://dl.dropboxusercontent.com/u/...015%200655.jpg

This is the new overview. Early morning, so it's not producing anything but sharply rising, as it will be a blue sky day according to the forecast. I shall try to remember to capture a screen shot when "the heat is on"

Sorry for all the metric stuff, like C rather than Fahrenheit :)

This is just before the system is peaking today. Not fully blue sky but pretty strong at almost 900 W/m2 (sensor in the plane of the solar panels, NOT the tangent of the Earth surface. Panels are on a 45 degree roof).

Note that the FLOW IS REVERSED and this cannot be seen in the drawing YET. Hence I have added some black arrows and crosses, to indicate the flow. Looking at the temperatures, it is obvious which way the flow is moving.

https://dl.dropboxusercontent.com/u/...015%201120.jpg

More later. Busy-busy!