Original Installation Overview

SS #2
Tonight I am going to give a short summary of the original design for the
Solo Solar project. More details later.

The system was installed in 1979-81 at the same time we put an addition on the
back of our home adding a kitchen, laundry room and enclosed back porch. This
is an hydronic drain-back system for space and domestic hot water heat assist.
For those new to the terminology ( and I'm not really a terminology guru myself
) that means that water is used to transport and store heat for assisting in
heating the living space and the hot water used for showers, laundry, cooking
etc. The "drain-back" part is about the way we keep the pipes and collectors
from freezing when the sun isn't out and it's cold.

Heat is stored in 1250 gallons of hot water in an insulated tank buried in the
ground under the addition. Boy was it fun installing that!! This water is
heated by pumping it through collectors on the roof when the sun is shining.

There 6 collectors measuring 4 x 8 feet each mounted on the south face of a free
standing wall at the peak of the roof of the addition. They are mounted
vertically to take advantage of reflection from the shallow sloping roof. Also
there is reflection from the back of the roof on the rest of the house.

The collector plates are copper coated with "black chrome". The glazing is
glass and the boxes are aluminum with isocyanurate foam insulation in the back.

There will be sketches and photos of all this later.

Domestic water heating is accomplished by preheating the cold water before it
goes to the conventional electric hot water heater. To do this I used 100 feet
of 3/4" diameter copper pipe which was expanded into a coil which hangs about 6
inches inside the wall of the storeage tank down in the water to pick up the
heat through the wall of the pipe.

The tank is a special heat tolerant fiberglass version of a farmer's stock
watering tank. In fact it was made in a barn at a small operation for
manufacturing --- stock watering tanks. It was insulated with 3 inches of
polyurethane foam which was then coated with plastic roofing cement (that black
gooey stuff ) and dropped into the pit. But first I constructed a drainage
system to keep the pit sorta dry so that the insulation would not deteriorate
over the years. More details about that later. It involves 8" ADS pipes, lots
of tiny holes in them, gravel, sand, a sump pump and control system.

To transfer the heat into the living space a section was cut out of the 14" cold
air return duct to the exterior gas furnace. This section was replaced with a
special duct box containing a reconditioned refrigeration coil. The idea is
like a car heater. Pump hot water from the storeage tank through the coil, turn
on the fan in the furnace to move return air across the coil to pick up the heat
and blow it back through the delivery ducts to send the heat to the rooms.

Ahhh . . . and now the control system. The Solo Solar ( SS ) currently operates
on control system version 2.0. Designed and built by me. Pumps and valves are
driven by Motorola solid state relays which require very little current and have
never failed. The temperature sensors are AD590 current mode IC's. The heart
of the control is a small computer board by New Micros Inc based on the 68HC11
mircoprocessor running the Forth computing language. I built designed and built
interface circuitry to multiplex 16 sensors ( don't use that many - I'm addicted
to overkill ) drive 16 SS relays, and run a three line LCD display. Then I
wrote a lot of fancy code to do it all. Parameters are set, troubleshooting
done, and data collected through the serial port of an old PC.

It ain't perfect but it works amazingly well and requires very little
maintenance. It has been an ( can't find the right adjective ) adventure.

Okay that is the overview. In future posts I will share stories about the many
lessons I have learned by doing this - both technical and for life.

SOLO SOLAR

SOLO SOLAR OPENS UP - #1

Hello , World! My name is Art Kennedy. I am a city bus driver in Eugene and Springfield, Oregon, USA. That photo over there was taken by my friend Pam on a break in the drivers' room at the Eugene Station. Do you see that word in red letters on the bulletin board in the background? Yep, been a union member for almost 35 years now.

This is my very first attempt at blogging so let me state my purpose up front. In 1980 I began working on a very interesting solar energy project in my home. It has been almost 100% my own design and construction. I say almost because of course it has not been done totally from scratch and I have benefitted from the ideas and experiences of others.

I will be going into lots of detail in future posts but for now I will sum up by saying that the system has worked out very well in some ways and not so well in others. I am well aware of which is which and have ideas for bringing it all up to snuff but I am not so sure that I still have the energy (!) and inspiration to make it happen.

The name of this blog comes from the fact that until now I have been rather possessive about the project in much the same way an artist might be jealous of control over the creation of a painting or sculpture - hence, SOLO SOLAR. The time has come for this to change . . .

. . . so here it comes SOLO SOLAR OPENS UP !

Warning, I take a long time to tell a story but if you are interested in alternative energy I think you will find it interesting.

Let me hear from you.

Best, Solo Solar