anudder solar post, kinda sorta sumpin like
Well, I have talked about solar in a couple of different forms/layers/ what have you, now its time to go into further forms of solar energy. The biggest solar engine on this planet is the planet itself, specifically, the weather system. It is completely dependent on solar activity and motion and declination of the planet in orbit. If our planet were completely vertical in axis to the sun and in a perfectly circular orbit, our weather patterns would be so predictable as to be detrimental to the health of our species (do a little digging and you will see I am right)
But the fact that our planet is tilted, and does tend to wander a tad around in an elliptical orbit (and the fact that we have a satellite that wanders around pulling on our oceans helps a lot too) means we have another access to solar power that is available even if the sun is NOT shining directly overhead. The real trick is going to be how to collect that energy, and how to rectify it for our usage.
The most advantageous method is to, in some way, harness it into a rotary motion. From there, we can either tap into that motion to generate electricity, or mechanical.
So, what aspects are we talking about here? Wind, Water, Tidal, and even heat exchange though that one gets really complicated and requires quite a bit of hardware that isn’t easily produced in a small shop environment.
Lets talk water right now. There are several ways to tap into that source, but they all have one aspect in common: that water must be in motion (that heat exchange thing is the exception but I won’t go into that anymore in this post) Falling or flowing, it has to be going somewhere and that is where we will tap into it. We can use over wheels, under-wheels, or turbines (the old tub-wheel mills were actually pretty high-tech turbines for the time. See FoxFire 2 for details on making one.) You can dam a stream for better control, but before you go doing that, you really need to make sure that the volume is sufficient FIRST. Low volume before before damming is still going to be low volume after damming. If you have low volume before damming, you can raise that output, but only for short periods, after which you need to let your reservoir refill. Another option of streams is in head. Head is the build up of pressure over distance and height. The further your water falls (horizontally) over a shorter distance(laterally), the more power you can access. You may have a stream that only flows at a few gallons a minute but does so from great height: a decent diameter pipe feeding into a small nozzle will have a great amount of pressure and can drive a turbine at high speed. That turbine can then be geared for mechanical advantage to a lower rpm but greater torque. (Remember when you were struggling in math class trying to figure out how you were going to use all those equations? Well, here it is. Hope you can bone up on it fast if you are going this route.)
There are ways of tapping into a river without damming it at all. Your output may not be very high, but it will be extremely consistent. One way I have thought about doing this is to mount under-wheel paddle wheels on either side of a canoe, similar to the old steamboat on the Mississippi. Those wheels will be geared to a PMA and the power cable will ride on the fixing cables that hold the canoe in center stream. No matter the water level, the canoe will stay in mid-stream, and due to its buoyant nature, will allow debris in flood season to pass underneath. (for the most part. A large break water could be mounted upstream to deflect large wayward floating trees and the like without disturbing the main flow too much.) Something similar would work in tidal spills in certain areas. (remember, beaches are, in most circumstances, considered public domain, as are most rivers. Some of these ideas are future based where government is so broken that we could do these things with little to no flashback.)
Now, instead of just using the water to generate electricity, it could also be harnessed for mechanical usage directly. The old grist mills and many old saw mills were of this nature. There is a reason that most sawmills in the Pacific northwet(!) were located along rivers. Not only were the logs brought to them on those rivers, but they used that water to power the saws and other machinery in cutting them up. One can even use the motion of water to pump itself. One method (and there are several) is to make a spiral water wheel. Using pipe and a pickup funnel you make the spiral in the opposite direction of the expected wheel motion: IE if the wheel turns counter-clockwise as you look at it, the spiral should be clockwise from outside edge to center. The center ‘hub’ is actually a pipe that attaches to the center of the spiral and extends to shore where you can further plumb the output to a location of your choosing. Set up the ‘power wheel’ like a steam boat paddle and you can pump that water quite a distance with no other effort on your part. I am not 100% on the math, but I seem to remember that the distance/height that could be pumped was on the order of 100:1; in other words, if you wheel was 10′ in diameter, you could pump that water 1000′ uphill. Of course this is dependent on flow of the stream, how efficient your blades are on the wheel, size of pipe etc, but the ball park figure was quite impressive.
All of this assumes a 24/7 source of water. In the case where a dam is needed, this could be fine where you only need the power for a few hours a day. An example is the ‘model’ grist mill in a state park here-bouts. They moved the mill from its original location and placed it on a pond with low volume. The dam they incorporated provides enough head to move the stones, but the volume is so low that they can only run the stones for ½ an hour and about 4 hours between sessions to refill the pond to sufficient levels. (it’s actually interesting to watch. They open the sluice valve and the lake starts to drain. Fast enough to actually leave ducks standing in mud if they aren’t wary.) That is fine as they only operate it as an educational exercise for school kids. In a real world exercise, this would not work at all unless the mill only needed that power for very short bursts. (like in my shop. I may only need to run a machine for a few minutes at a time with several hours between operations. I would still rather have a large reserve on tap for those times where I am doing production work and need a steady run on power.) For generation of electricity, this won’t work at all. A body would have to be dedicated to functioning of the dam and production 24/7 to get it to work intermittently: There are other methods that would work much better.
Remember, the reason we want that power is to ease our own burdens. The last situation would treble those burdens.
And that brings us to tidal power. Really, at this stage, this is a large corporation effort, not some little shop item. Unless you live on a boat that is. Anchored off shore with a small anchored turbine may get you some power, but there are other methods that are more tried and true, therefore less expensive. I would love to see some ‘Yachtie’ come up with something (if someone hasn’t already) One aspect I have seen is to use a floatation device surrounding a pipe. The pipe houses the coil and is fixed in place, the floatation device contains a magneto. This operation is similar to those shake and use flashlights you may be familiar with. The wave action is what causes the magneto to pass back and forth over the coil, and that generates an alternating current that can be rectified for use or storage.
As in any new idea, there is much room for growth and experimentation, I am not one for that in this discipline seeing my location and funding, but I digress.
Onward; Wind. Wind power is similar in application to water power. We can use it for generation or mechanical use. Pumping water is one of the oldest applications on these shores (and elsewhere) and there is still a company in Texas that produces those watermills that you remember from old westerns and movies. In Holland they used wind for pumping water (they are below sea level) and for powering gristmills. As for generating electricity, you don’t need a 200′ foot tower with 80′ blades. Those might be great in the west where the winds are good enough, and the land is so far out that very few would want to live there anyway. (I am weird, I love those areas, wind and all) The trick to tapping that “Ocean of Air” is to get above the ground turbulence. In Texas and other states, location of those water mills was dependent on where the well was. They built the tower to get above the ground turbulence into the better flowing stream of air. We will need to do the same for generation of electricity. Even in low wind areas, getting above the trees or at least into the tree tops (and clearing an area of trees around the tower) can get you into some decent power generation. Maybe not Kilowatts, but definitely some wattage. And typically, that generation takes place at those times when your solar panels would be at zero watts. A wind and solar panels hybrid system is nearly ideal for localized off-grid in a small package. There are some cons to using wind, such as needing a diverter on the charge controller. The reason behind this being that wind can over generate power and you need somewhere to put that instead of damaging your storage system: you never want your generator freewheeling without a load, you will burn out your coils otherwise. The pro of that being, you can divert that power into heating water or some other ‘appliance’ that doesn’t need a steady supply of juice (or absolutely has to have a fixed voltage or fixed AC supply) I noted while in Texas, that wind there was very dependent on the time of day. Mornings it blew one way, mid day, non-existent, evenings back the way it came, and usually into the late evening.(remember how I said that this is all ‘solar’ power?) A 40′ tower and a 500w generator would have provided far more power than I was using then, but I would have been able to leave my fridge running all day instead of cycling it as I was doing. (one aspect I am looking into is grounding the tower. I am not sure, but it seems to me that a metal pole or structure, sticking up at tree height level is a pretty awesome lightning attractant. While the pole will be grounded just being stuck in the ground, my question is: wouldn’t a ground rod ran 10′ deep be even better and a better protection for the gear at the top (and bottom seeing how they are wired together) of the tower? Or would this be redundant to the point of waste? I am likely to do so just to be on the safe side unless someone tells me that it would make the problem worse, which is also an issue I can see.)
Talking about wind, one area that is really open to invention and exploration is the capture method. I have seen several evolutions of the blades, from a few to what looks like a turbo-prop on steroids, to a squirrel cage like contraption, and several others. I have even seen one set-up in experiment using a 55 gal drum cut in half vertically, welding the two sections together off center and mounted upright on a hub. Slow speed, but turned in nearly calm air. (of course, that could have been due to modern bearings and zero load, but I wasn’t there in person so can’t say.) One thing about using the blade set-up: More blades means more torque at lower speeds, but less high-speed performance. Use that ‘rule of thumb’ when deciding on blade design in your wind area.
Another consideration for blade design is cut out speeds and how to ‘furl’ the tail-stock to prevent wind over-speed. Typically, the blades tend towards 6′ or more in diameter. Get that big ol’ fan moving at a couple thousand rpm’s and it could destroy itself very very quickly. Getting the tail-stock to ‘drift’ out of the wind will move the blades into an oblique to the wind; they will still move, but at lower speeds than head on. Keep this in mind for those of you that live in tornado alley. I am personally going to build an old ball style governor for mine. I will have to fine tune it by experimenting, but I know that we get wind gusts around here that about lift cars off the ground and I really don’t want my hub disintegrating and the blades becoming missiles during one of those.
I am hoping that by some reading this, that they will be inspired to do something to get themselves off-grid. It doesn’t take oodles of cash to do so, more time and effort than cash itself. (Granted, oodles of cash can go far in getting a body there, but it is not the only pathway) My shop, with a lathe, mill, Drill press, Torch set, welder, hand tools, foundry/casting processes will be a great way to build up those things I can not afford outright. (and that shop not being up and functional is killing me more than all the chicanery of our world and its growing tyranny.) I can’t afford nor justify purchasing a tower for a wind generator, but I can justify a large purchase of pipe and make my own. (typically for less than a third the price of a commercial unit.) I have to work harder than someone with the means to hire the installers and builders, but the end result will be that I know my system, literally, inside and out. I will know where I had to cut corners and where those cuts may come back and bite me later down the road. I will only cut corners like that if I believe that I can cover the inadequacy at a later date, but need the system now. On the same note, as noted in a previous post, there are some things I will go out and purchase simply due to it being cheaper than a start up cost for one-off items. Now if I were to start producing such items for others to purchase, of course I would make that leap. I am not stupid, I know that EVERYTHING is a business model, including living. (and to try and see it as anything else is just setting yourself up for someone to kick your ass later down the road, Namely, those that do see life as a business model; like our current PtwB.) Ah, but as things are going right now, just getting that shop up and running is a tribulation in and of itself. Not complaining, it is going to happen, just taking longer than I am happy with. (and the impatience is in direct relation to the number of ideas streaming through my skull on a daily basis.) So, take these ideas, let them ferment in your brainpan and see what wild ideas percolate to the surface after a few days. Then get busy.