That depends on how you penalize wind for being unreliable. You can get a lot of power for cheap if you average over a suitably long time period, but that doesn’t mean you always have that amount of power available: Sometimes you have significantly more, and sometimes you have none. If we had perfect energy storage systems, this wouldn’t be a problem, and the problem scales less than linearly as you install more windmills (because it won’t generally be calm at all sites at once), but for right now, it’s still enough of a problem that coal is still more economical.
I’m considering having one of this company’s mini hydro plants installed in a steam that flows year round through a property I own in Hawaii. There are several in the area already in operation
Interesting concept for those going off grid.
Hello all, I just joined the board and wouldn’t usually post but this is sort of something I am doing right now.
I am putting in a “hybrid” solar-wind generation system. I am buying a decent amount of solar panels (between 15 and 20), and 3 of the small lightweight tubine systems.
Also just so you know many power company’s have a buy back incentive program. In Tennessee (where I live) the TVA buys your power for about 3 cents a kilowatt more than you pay for it under a ten year contract. There is also a $500 grant associated with this program, and of course it is a tax deduction as well.
I used an anemometer to get an idea of the windspeed in my location for a year. This gave me raw numbers to work with to see how much I could expect out of the turbine and I have a great location for the solar.
I looked into the water mini-tubines thinking I could buy a property with a decent stream, etc. However I quickly learned that there are many issue that have to be addressed concerning the rights of others both up and downstream as well as the Corp of Engineers around here.
I have also considered a natural gas well as there are many in this area and that would seem like a decent addition to a hybrid set up, but I havent looked at drilling costs etc. I do know that there are many properties which already have one in this area that was drilled, discovered and capped. I also know of a couple farmers who use one to power everything on their farms except the tractors etc.
Anyway long post, but if you live in Tennessee the TVA’s program is really worth looking into.
Later,
Sixth
The TVA has increased the grant to $1000 (sorry just checked) just do a search for TVA Green Power Switch Generation Partners. I hope you all might have a similar program in you area as well. It guarantees that TVA will buy your energy produced at 3 cents above what you would pay per kilowatt hour. I think that is just incredible but havent heard of this program anywhere else, just found it doing my research…
Sixth
Welcome to the Dope, sixthscents, glad to have you around.
That sounds great that you are setting up a practical and profitable alternative energy source. But why would a power company pay you more than they sell electricity for? Wouldn’t that lead to bankruptcy if every user/supplier did that?
And what will be the total cost of your installation? And size (in KW)?
I’m all for programs like that to encourage individuals to invest in green energy, but it seems to me that paying more than you charge is just asking for abuse. What’s to stop someone from running an extension cord from their neighbor’s house to their own, and transferring energy from the grid straight back onto the grid for a profit they share with their neighbor?
i would expect the utility would know what to expect from your installation, the wind and sun during that month, your usage history.
I just retired from 10 years on the board of directors of an irrigation district, dealing with canals and drainage. One of the more interesting projects we undertook was just this sort of thing - to install low-head generators at various locations in our canal system. Irrigation canals generally use a very gradual grade in order to cover the most territory possible, but there are a few places where they traverse a sudden drop in the terrain. These are usually handled with a “drop structure” - commonly a steeply sloped concrete chute with a splash basin at the bottom. Where these had 100 ft. or more of fall, we installed a generator. The type of generator is almost entirely self-contained, it can be dropped in almost anywhere with minimal preparation, requires only occasional maintenance and a monthly checkup. In this case the power is sold into the local grid and the returns are passed to the irrigators in the form of a rebate on their annual water bill.
Of course the canal system only runs about 6 months out of the year, but it’s during the summer season when power use is at its highest. We have a buyback program here too, wherein the local utility is required to buy co-generated power at a set rate…it is indeed higher than local rates, but the utility does not lose money on it, the region generates surplus power and sells it into the grid at a higher price than local rates.
Co-generation facilities don’t have to be fancy or high-priced. I know of one place where a gentleman had a vacation cabin next to a swift-flowing mountain stream. He had built a simple old-fashioned water wheel, turning a belt drive to an ordinary home generator. I don’t know what it cost him to set up, but it couldn’t have been very much. Strictly a jury-rigged affair. He powered his vacation cabin and sold surplus power to the local utility. It didn’t make him a lot of money, but some. It had been running mostly trouble-free for over twenty years.
SS
To drive home the point that the power you can get is proportional to the flow rate times the height of the dam, note that on the web page linked above, the first thing you need to know in estimating the power output is the head, i.e. how high the input from the stream is above the unit. If you want 1000 Watts, you need to buy the LV1500 and use all four nozzles. The unit is specified only for a head greater than 60 feet and numbers are given only for 69 feet and above. To get 1000 Watts, you need to use four half inch nozzles, which gives close to the highest efficiency (55%). You’ll need 147 gallons per minute to get 250 Watts per nozzle with a 69 foot head. Let’s suppose that your hydro unit is down a steep cliff from your water source, so you only need about 100 feet of pipe. You’d better use at least 3" pipe to minimize the head loss. A table on the web shows a head loss of about 4 feet for 100 feet of 3 inch PVC, so you need a total head of 69+4 = 73 feet.
Of course, you can get more power with lower head using a different unit and more flow, but the efficiency will be reduced. The smaller unit is specified down to a 46 foot head, with an efficiency of 33%, so you’ll need two of these units and much higher flow to get a kilowatt.
(Caveats: I have not read the article in question nor am I a power systems engineer.)
One possibility is that the cost for coal-fired plants in Japan are more expensive to operate than wind: Japanese coal is mostly imported.
Maybe I know where we could use use one of those. Also, I think I remember some mechanical device for using water power to pump water up hill. A dearly loved part of my college experience is under assault by the regulators. It is a cabin built in the 30’s needing vast structural repairs. Doing so meeting modern codes and deed restrictions is a mess. Flush toilets without electricity? Being in Pennsylvania, we do have a hill. Put a tank at the top and pipe water down to it? Or a small generator, and pump. The cabin is mostly used weekends. The generator and pump could run 24/7. The mechanical thing would be less likely to be stolen. We have talent and resources we might be able to go from a diagram and description.
I wonder if we could get a permit for a small dam?
The article excluded fuel costs.
It also requires you to have a downstream channel with twice the cross section of the upstream.
True that - about 1/3 of the lawsuits filed in RI during the 1800s were over water rights.
The first problem with the notion of just sticking turbines or water wheels into the river is that rivers don’t have a constant rate of flow, they rise and fall all of the time. Now, falling isn’t so bad as far as these things go, you would just be unable to generate power. Rising, on the other hand can be a very bad thing because flowing rivers have an incredible amount of power, and if you put your water wheels or turbines directly in the river, you would find yourself replacing them every few months when the river rose. To say nothing of the general repairs caused by logs and other debris crashing into them all of the time.
It is possible to put turbines deep in the water, where the amount of turbulence and debris is less, which is an example of the run of the river system mentioned above, but it can be pricey, and still most involve some kind of raceway system or dam that diverts the water (even if not really creating a pond) for maximum efficiency as well as providing a way to protect the equipment during high water, or when you need to make repairs.
Next up, making a small hydro that you are basically plugging a house into can work, but if you are generating large amounts of power, you need to be able to transfer it somewhere. Sadly, very few of the best hydro sites happen to be smack dab in the middle of urban areas. So once you get into the investment of generators, transmission lines, some sort of water diversion system and what not it becomes a matter of saying, screw it, lets build a dam and really get the most power out of our investment.
I spend a lot of my time explaining the basics of water power to kids and one of our mantras is 'the weight of the water does the work". For mass production of electricity, the gain from using a dam, as well as the economy of scale really does come into play in most situations.
As for the question above about old mills turning their water power systems back on, there are a few of those projects going on around here. For example, the Slater Mill in Pawtucket is in the process of installing a rehabbed turbine into their raceway system. They are a special case in that the plan was originally to generate enough power to sell, but since there is a risk from having the vibrations of a full on turbine shaking apart a 220 year old wooden mill, they are going to throttle back and run it just enough to take themselves off the grid. That would be the seventh hydro site on the Blackstone River, though not all of the others are currently operating.
I have had two other proposals for restoring old hydro systems float across my desk in the past few months. I don’t really know much about the current engineering as my role is more on the historic preservation of those mills and raceways end of things, but as energy costs have gone up, it has become more attractive.
You can have a small hydroelectric generator at a relatively small river. The American Optical factory (which was located at the Quinebaug River in Southbridge, MA, on a set of channels and canals that no longer exist to power belt drives in the 19th century) made use of a holding pond and a couple of dams to control water level, and used to have an electric generator there until circa 20 years ago. After the beginning of the 20th century, though, they switched to oil-powered generators for electric power, and used the pond for cooling. Nevertheless, they kept the generator in place and used it – no point in not making use of essentially free power – until they sold it to a town in Vermont. Presumably they still use it for their power.
The problem is, as others have stated, that small dams can’t supply the electrical needs of , say, a county. But there’s no reason you couldn’t have a small hydro generator on your own property to provide your own power. Heck, it has to be better overall than solar generated on your roof. The headache is that you have to continually keep cleaning out the debris traps on the dam (a constant job at the AO plant). In winter you have to keep the dam complex from freezing up, and you have to keep the generator lubricated and in good repair. Most people can;'t be bothered with that, and prefer to buy their power from the grid.
Compare these numbers to existing large-scale hydroelectric installations. Hoover dam puts water through a drop of 700 feet. Three Gorges dam has a drop of almost 600 feet. In other words, from the Ohio River to its delta, the Mississippi has only half of the energy in it (on a per-volume basis) that either of these dams can get out of its water. Moreover, owing to relatively flat geography, there’s no good place to dam the Mississipi without flooding a lot of productive farmland. Lake Mead is pretty big, but it’s nothing like what you’d get if you tried to impound the Mississippi to any significant height.