Yep, our lawn tractor had a little Murphy problem. Somehow he knew I would drive the tractor over a tree root, sling a chunk of that root about 30′ and that was when what could go wrong did. This particular mower deck has counter rotating blades driven by a special timing belt so you can synch them to not smash into each other. When that belt breaks Sears online parts reaches into your pocket, removes your wallet and takes $130.49 plus shipping. Ouch! I’ll just bet that crazy Irishman (aka Murphy) enjoyed himself immensely while I was gasping and squirming over that price. So I set out to turn the tables on Murphy.

Within minutes of logging in to eBay and doing a search using the part number I was looking at a $75 price and $6.10 shipping. The belt arrived Wednesday afternoon and by the time Janice got home from work the moment of truth was at hand. That is if I could find the ignition key. Oh yeah, in my pocket along with motorcycle and truck key rings.

The moment of truth, engine warmed up and running, mower deck height adjusted and me nearly paralyzed. Ease the engine speed up, grasp the mower engage lever and take a deep breath before moving it to engaged position. In that moment between belt not engaged and engaged was dreaded anticipation there would be an unmistakable sound of blades smashing together. That would have provided Murphy further proof what can will go wrong and one more victory. Or maybe all would work as anticipated and mean what could go wrong for Murphy did. Wouldn’t that be sweet?

Lever still in hand still hesitating while the mind went through an instant replay of my work to assure nothing was overlooked. Almost unintentionally I flipped the lever to engaged position, mower deck shuddered side to side and then: the hum of two blades whirling beneath my feet. One pass up and back was enough to satisfy the ego. It was time to call it a day, halt the physical stuff for a Wednesday, wonder into the house and brag to Janice. Hey Murphy, take that!

Thursday brought forecasts of several days rain making it a good day to mow. Again all worked smoothly and I was feeling pretty smug over this little victory. That is except as I began the first pass and recalled a previously unheard sound the truck made at 75MPH and above. Dog gone it Murphy!

Each of the 36 cells produces .5 volt and 3.5 amps or 1.75 watts in bright light. So let’s do a little math here:
At .5 volt X 36 cells connected in series you get 18 volts which is considered good for charging a 12 volt battery (or bank of batteries). In other words: .5v X 36 = 18v

At 18 volts X 3.5 amps you get 63 watts. In other words: 18v X 3.5amps = 63 watts

Connected in series? Think of a flashlight that uses three C batteries. Each battery goes in the same way meaning the positive post of one battery is in contact with the negative post of the next. With three 1.5 volt C batteries placed that way there is a total of 4.5 volts to the bulb. If you have a flashlight that uses only two batteries it is 3 volts. If you have one that uses 4 batteries it is 6 volts. It’s the same when putting solar cells together – positive to negative and by chaining all 36 cells positive to negative there will be 18 volts in bright light.

There is a bit more than just connecting a solar panel to a battery or bank of batteries. There’s a chance of over charging, using more electricity from the battery than the panel can provide or even discharging the battery when low light causes reverse flow of electricity from battery back into the solar panel. Reverse flow can be prevented with diodes which prevent current flow from battery to solar panel. It is not a method I would use with other than very low power solar panels.

Solar charge controllers are designed to prevent battery overcharge, battery discharge beyond a preset level (usually 10.5 to 11.5 volts) and reverse discharge. Charge controllers vary from less than 5 amps to high amperage. For the sake of the storage shed experiment I’m looking at a $23, (shipping included) 15 amp charge controller from an eBay seller.
Project progress so far is limited to solar cells ($70), personal knowledge and experience (hopefully to prove of value), charge controller @ $23 if that’s the one I buy, various and sundry materials to mount cells into a panel (jury is out on that expense so far), power inverter (oh yeah, haven’t mentioned that yet), 12V battery (may just be a battery borrowed from a camping trailer for now) and who knows how many bits and pieces from the neighborhood hardware store. Yep, you’re seeing it as I do: this ain’t exactly what ya call free electricity. Then again, everything has it’s price.
The plan was to post this last evening (Thursday) but experience dictates not to publish to the blog when staying awake is a major problem. This morning (Friday) rolls around and while catching up on emails the doorbell rings. Amazing: USPS with a package addressed to me. Sure enough, solar cells!

Part three coming soon.

Other projects captured my interest and I thought nothing more of it until two days ago when I happened upon a link that took me to that very same site. Well that got me questioning how logical it would be to buy that information, build the “under $200” wind powered generator and use it to provide some part of our electric use. So I did a bit of rough calculating.

Information download: $50

Wind generator: $200

Wow, shouldn’t take much time at all to pay for itself. That is until you dig into the FAQs. You see the unit is built with the “goal” of generating 500 watts at winds of 20 MPH or above. Um, I’m here in North Dakota, on the plains, we get quite a lot of wind but I can guarantee we seldom see 20 MPH sustained winds. But OK, for the sake of this let’s just say we have 500 watts generated 24 hours per day. In the course of a month (30 days) that would mean 360 kilowatts. At a current per KWH rate of $.05/KWH there would be an $18 per month saving from my electric bill.

Sounds good so far don’t it? With higher output unit we could supply all we need for the house and even sell the excess back to the electric company. But there’s that 20 MPH wind to consider. Let’s get closer to realistic and say we have pretty consistent 10 MPH winds. Now we’re only generating 250 watts and maybe saving $9/month. Oh and did I mention the electricity generated is probably not 120 Volt 60 cycle alternating current so you’ll need to charge battery banks (not inexpensive) and use an inverter just so your appliances will work. Inverters are notoriously inefficient so after generating that 250 watts and charging the batteries you may end up getting 125 watts (I don’t know, possibly more or less) from that 500 watt generating system. If you decide to build a much higher capacity unit at much higher cost, the cost of charging equipment, expense for greater capacity battery bank(s) and the much larger inverter needed to supply larger amounts of electricity to your appliances adds up.

Of course the bottom line question is will it pay for itself? I sincerely believe it will but I also believe before that break even point you could have paid the electric company for a long time. You likewise will have repairs and maintenance above and beyond the initial costs and may need to pay qualified people to assure your system is properly connected.

Tempted though I may be, I think it’s not for me. I’m sure glad there are people out there willing to undertake these endeavors and I expect incredible advances are being made every day. I’m fascinated and that fascination will never go away.