How I got started with solar

I was pushed over the line by a large Natural Gas bill...

I have always been aware of how much energy is used in my home. My house is connected to utilities just like everyone else: Water, Electric, Gas, and a septic tank.

As the bills arrive each month I look for trends up or down to see how it varies. Like any one else there are times when the bills are high, an extreme cold winter or a very hot summer. Extra heating and cooling will add to the cost of electricity and gas. Over time you will have a sense of what to expect as you use energy. That knowledge allows you to spot something that doesn't fall within your expectations.

After 20 years of watching the numbers, it all became pretty routine, until...

Fast forward to February 2001 when it all came tumbling down, or skyrocketing would be a better word to describe the event.

First, let me show you a typical gas bill for winter months.

[ photo of typical winter heating natural gas bill ]

$65.90 you see here is right inside the average for this time of year. It might vary between $50.00 and $70.00 depending on how cold it was.

January 2001's bill should have triggered a flag telling me things are changing, but it didn't quite register yet.

[ photo of bill just before the big one ]

And now the one that blew the top off everything.

[ photo of the big one ]

I have NEVER gone into three digit territory with natural gas use EVER, but here we are! This is the RED FLAG that started me looking at everything. Past bills. Gas meter numbers. Looking for leaks. You name it, I checked it out.

What I finally found is in the photo above, the gas company raised the price. Not just an incremental change like you would expect with most consumer products and services. This was monumental. A $60.00 gas bill going to almost $120.00 is DOUBLE territory. That got my attention, and got me interested in solar!

From that day the thermostat on the wall kept going lower every day until I finally turned it off completely. Permanently.

I want freedom from this unstable source of energy.

That's when SOLAR ENERGY came into my life

I did a great deal of thinking about how to cut ties with the natural gas company and still heat my home during the cold winter months. Everyone has observed the effect of sun shining through the windows and onto the floor, the wall, table and chairs, it makes all of these things warm. I wondered if there was a way to purposely capture this "free" heat from the sun and distribute it throughout the house.

Research on this subject revealed something called a flat plate solar collector, used for heating air forced through it. The design looked simple enough. An insulated box with a glass window on the side facing the sun. A flat metal plate inside the box with an air space on both sides. An insulated flexible hose for cold air inlet and another hose for warm air outlet. A fan or blower to move air across one side of the flat plate.

That description made me recall a recent experience I had while installing rain gutters and down spouts on my house the previous fall. All the gutter materials are made out of galvanized steel. Some of the down spouts were leaning up against the house in preparation to be installed. It was a sunny day and when I went to pick one of them up to install it I nearly burned my hands on it.

Remembering this little bit of information led me to consider a design using down spouts instead of the harder to build flat plate system. The design seemed a little easier than dealing with a huge flat metal plate that would have to be supported in the middle somehow to keep it from bending. The idea of using rigid down spouts made good sense. They are hollow tubes which makes them rigid like a pipe, but thin walled so they are light weight too. I could run them from one end of the box to the other without having to design some kind of support structure in the middle. OK, it's time to do an experiment to see if it will work.

Solar Heating first attempt (the experiment)

I started small with just two 10 foot long down spouts in a very quickly constructed box. The "box" is a concrete form tube about 12 inches in diameter that I cut in half the long way. I didn't even put glass over the front of the box, just some translucent plastic tarp material, and insulated the inside of the concrete form tube with foil covered bubble wrap stuff. Yeah, duct tape everything together. This is just an experiment to see if I can capture any heat at all. Here's what it looks like.

[ photo of solar warm air heat collector ]

It sits on the walkway on the South facing side of the house. An insulated flexible duct hose connects the cold air inlet and warm air outlet of the solar heater to the house. The white square on the right is where the warm air enters the house. The swamp cooler is normally attached here but I removed it for this experiment.  The left end is where one of the crawl space vents is located. I removed the vent grill and stuffed the hose through the opening into the house. This is where the cold house air comes into the solar heater to be warmed up. I spliced the cold air hose into the furnace duct system to pull cold air from all of the floor registers in each room of the house. Yeah, there's a reversal here. Instead of warm air blowing out of the floor registers, there's cold air being pulled into all of them.

[ photo of entrance point of cold air from house ]

The purpose of the wooden box at the ends is to convert the single 8 inch diameter insulated duct hose to attach the ends of the rain gutter down spouts. The foam insulation seen here is also used inside the box to reduce heat loss to the outside cold temperatures.

[ photo of down spouts inside the "insulated box" ]

Pretty crude construction here with duct tape, plastic wrap, foil covered bubble pack insulation. Let's not forget this is just an experiment. We want to find out if this will work at all.

[ photo of duct boost fan blower ]

[ photo of inside duct boost fan blower ]

This little duct booster fan doesn't move much air. With all the bends in the airflow path, air movement isn't very brisk. Nevertheless it did manage to move some air through the system. I could feel warm air entering the house at the end of the insulated duct hose. The temperature at this point measured about 8 deg F warmer than the ambient temperature inside the house. Not bad!

So, does it work? YES, it does! And no, this thing didn't heat the house to a toasty 72 degrees, but it did heat the air circulating through the solar heater with a small duct "booster" fan. It wasn't very hot, but warm air is entering the house from sun shining on the down spouts outside. Amazing. Free warm air without having to buy expensive natural gas. The important thing here is that it proves the concept works.

The price of natural gas during the 10 year period following the 2001 "event"

[ Chart 1 ]

The chart above shows the HIGH and LOW price homeowners pay for one therm of natural gas during that year. In the event year, 2001, the low price was about $0.60 and high price was $1.00. That price jump is what started my solar energy quest.

Data to create this chart came from gas bills I receive in the mail from the gas company.

This should be a WAKE UP CALL for anyone using natural gas

Look what happened in 2007... the low $1.50 and high $2.48. Wow! That's a huge jump from the $0.60 I used to pay for gas. It looks like pricing stability for natural gas ended in the year 2000.

The next step in solar heating

Take the concept of solar heat collector and build one capable of supplying usable heating for the home. I do exactly that in the next post. It's bigger. Better design. And may actually keep the neighbors from complaining about the ugly stuff in my back yard. Well, maybe...

Gregg Scholfield   3-26-2013