Making SunSense of it All

Solar power does far more than lowering our electric bill

We have just put a lot of money where our mouths (especially mine) have been--talking the talk of treading the planet and a human lifetime with a smaller energy and resource footprint.

We just started getting regular service from a newly-installed 10KW solar array of 32 panels in our yard and pasture, perfectly aligned and pitched for maximum harvest of photons.

And I have to admit, spending that kind of money (with 26% of that rebated in our taxes for 2019) you kind of expect there to be bells and whistles; to hear the actual thrum of light being converted to electrons and a deep voice quietly declaring from time to time that "the human comfort in this home is brought to you by the Day Star, materials science, engineering excellence and the good intentions of these home-owners."

But there was nothing audible or visible to divide the day before without solar from the day after when it was turned on and streaming into our meter. Had the moment come for buyer's remorse? What have we done? Have we made the best choice for those dollars saved all these years?

Well I'm finally seeing the wisdom of what we have done, though at first glance, it seemed precious little. The massive array (during these short hours of daylight and the sun low above the horizon) is only making 5 to 6 dollars a day worth of energy if the sun is not obscured by clouds or fog. But even this time of year, that is equal to or greater than our average daily electrical usage, the monthly bill divided by 30.

So this system will, over the course of the next year, years and decades, employ the energy from the sun so that we don't have to use the carbon-based energy in mountaintop-removal coal or fracked natural gas. And we don’t add to CO2 in the atmosphere.

It helps to put kilowatts generated into practical measures. The app that connects the home-owner to the system expresses daily KW production in equivalents of hours running a 100 watt lightbulb. I get it. Or a refrigerator. I get it.

But it also expresses daily and cumulative production in terms of "trees saved." [See above.] And I think the terminology is very confusing, so we must dig deeper.

What it should say is "tree-equivalents of carbon avoided going into the atmosphere." No trees are saved but carbon release is avoided. And that carbon amount is equal to x tree saplings planted or x mature trees left standing.

There is a really helpful conversion tool from EPA.gov that will let you convert, say 1000KW of energy produced by standard utility means (but that we will have produced from sun energy in the nest week or two) into equivalent greenhouse gas emissions or other energy use avoided.

Here is the equivalent carbon “savings” when we produce 1000kw of solar energy:

I still don't grok the math that equates 430WK with "saving" 8 trees, but I understand the concept and I wiil figure out the numbers eventually. It tells me that the more solar and wind we use, the better off we (all of us) will breathe; the more normal our climate future will be; and the better we can live in harmony with the planet that sustains us.

Yes there are costs. But after the first two weeks, I'm starting to see the pay-back.