The greatest load on the electric grid is typically on the hottest days with maximum A/C demand. It seems reasonable that if you want to cool off  something that is in the Sun, the first thing you do is move it to the shade. In the case of our homes we can bring shade to the thing that is getting hot.

The fact is that our level of energy usage is not sustainable. One way that we can cut our usage,  and will cut our usage in the future, is in reduced air-conditioning.

Solar income is by the square foot. Every square foot of shade that we put over an air-conditioned space is a reduction in the amount of energy that it takes to cool that space.  More shade… means  less a/c…. less electricity….. less coal burned…… less CO2….. less global warming….. less pain……

This shade vine project got started with a muscadine vine that continually climbs the guy wire to my electric pole. Muscadine is a southern grape that climbs to the top of a 50 foot tall tree with no problem.      So…. I must continually cut the vine back before it gets up to the transformer. As I was up trimming the vine a few years back, I looked over at the roof of my house, that will reach a temperature of 130-140 degrees F on a sunny summer day, and it occurred to me that if I had a wire for that vine to climb that went over my roof then it would put some shade on the house.

Taking care of the berry plants on the farm requires a lot of time working in the Sun and builds a strong respect for shade.  The power in sunlight is tremendous.  Sunlight powers all life on Earth.  If you have something that you want to cool off, first block the sunlight.  You can get a good idea of the power of shade on a hot summer day by locating a nice shade tree and going and standing in the sun for a few minutes and then go into the shade.      The relief that you feel when you get in the shade is similar to the relief that your air conditioner will feel if you shade your house.  You will also feel some welcome relief in your electric bill by shading your house or business.

With that in mind, I have been experimenting with methods to put shade where we need it. My house is built right where my grandfather’s house was built in 1911.  There are two big Oak trees that shade the yard and partially shade the house. In 1911 there were more big Oaks. During the forty years since I built this house, three big oaks… three to four foot diameter… have come down to the west of the house. A big Sycamore came down on the west side also. Losing those trees changed our world. The trees on the west had provided several hours of afternoon shade. Without the shade, the front porch, which hooks up with the original concrete steps from my grandfathers house, was uninhabitable in the afternoon. Even after dark, the porch was uncomfortably hot as the brick of the porch and the concrete of the steps had been absorbing solar energy all afternoon and now they radiated that sunshine back as heat.

I’ve been trying to figure out why there can be so little attention given to shade.  With A/C, one of the major sources of heat that we burn coal to remove, is sunshine.  The sunshine is providing energy at a rate of approximately 1000W/sqM . It heats everything that it strikes.  It seems reasonable that we would pursue a condition that reduces this solar component of the A/C energy equation.

to be continued….. Check our GreenRoof retrofit Page.