Ali’s post about how a 3-year old thinks about a power failure got me thinking about self-sustainability again.
He huffed and he puffed
My neighbor (Russell Kuck) has a wind turbine in his back yard. I’ve never met him (he lives a couple miles away), but I have talked to him on the phone about his setup; he has the pole-mounted wind-turbine that runs down into about $3K worth of batteries, from there it feeds into a grid-tied inverter (a fancy doo-dad that converts the turbine’s DC electricity into normal, house-usable AC electricity; anything extra is shoved back into the power lines, making your meter run backwards).
He says he gets about one full day’s worth of power “free” per month out of it. He notes that his turbine is 48W, and that even though high wattages are more effecient than low wattages, it does take some time before the winds are high enough to push the windmill up to its power-generating threshold. If he were to do it again he’d go with a lower wattage wind turbine; not as effecient, but more suited for the average wind out where we live.
And then there’s solar
Utah is almost universally perfect for solar power generation. In the summer it’s sunny. In the winter it’s sunny (except during those blasted inversions!!). I’ve priced it out, and for right around 5 grand I can get a direct grid-tied, active tracker getup. The downside: no batteries to run things when the grid is down, and the sun’s not shining. The upside: no batteries to maintain and replace every 5 to 10 years. Another downside: I think I left my spare $5K in my other pants.
Why not on the roof?
You’ve seen solar panels before, but they’re usually been mouted high up on someone’s roof, right? The idea there is that your roof if basically wasted space. You’re not using it for anything but keeping the rain off your head, right? So why not use all that square footage to do something productive, like generate electricity?
Well, in my case it’s because my roof is multi-pitched and has only a small amount of area pointing South. Not only that, the peaks of the other ends of the house shade the (small) South-facing portion. In short, my roof does not lend itself to solar panels or shingles.
I could always put my panels on a pole in the back yard…
Why an active tracker?
Trackers are widgets that move your solar panels with the sun. The more perpendicular the angle of the sun is to your panel, the more electrical output you’ll get from your panel.
Passive trackers are just that, they’re passive. That’s both good and bad. Passive trackers have little to no moving parts (moving parts break much more often than good old “non-moving” parts). Passive trackers use the sun’s energy to allow the panel to pivot as the sun rises and sets. Unfortunately they only track on one axis, and they are fairly slow (they rely on the morning sun to heat up the pivoting mechanism to tilt the panel from the position it was in when the sun set the prior night to the position of the rising sun.
Active trackers are much more complicated (and more prone to breakage) than their passive siblings. They typically monitor the energy being produced at a certain tilt, then move the panel slightly to see if the energy generation goes up or down. It repeats this process on two axis until it gets the highest level of production, then repeats the process periodically at the sun moves across the sky to keep the panel perpendicular. The result, typically an increase of 160% in the amount of electricity generated versus an optimally fixed panel.
Now what
Now I need additional capital to appropriate to this project… Ideas on how I can do that?
