Off Grid Via Slow Moving River?

einstein writes "I live out in the middle of nowhere, and I lose power at the drop of a hat. My house is right next to the Susquehanna river, and all the kinetic energy going past my house makes just want to go off grid. Most homebuilt hydro power is lower volume/high speed. What would be a good, unobtrusive way to generate electricity from a high volume/low speed body of water? I'm between two large hydro dams, so the water level is fairly constant, but does tend to fluctuate 4-6ft in the winter due to ice floes and melting snow. I think maybe a miniature version of one of the recent submerged tidal generators might work... Does anyone have some suggestions on how I might go about this project?" More than a few people have done this before.

The Romans

[panxerox]

did something similar, they had a line of floating grain mills across the Tiber (no ice there though) in the late empire period. Find a good high current area and build a paddlewheel boat basically with the drive attached to a generator and use anchors in the riverbed. It might not generate a steady high elec current so you might want to put in a bank of batteries and converter for peak demand. Since the paddlewheel is in the back the boat draft would break up at least thin ice. With underwater turbines your talking alot of cost both in construction and maintainance. Hers another option http://www.hydrogenappliances.com/hydromauro.html

High torque

[680x0]

I bet you could build a low-speed, high-torque paddle wheel (it would need to have a lot of surface area being pushed on by the river). Then, using gear ratios, you can convert that to high-speed, low-torque that may be needed by your generator. Not being a mechanical engineer, I'll leave it at that. :-)

does this remove energy from the current?

[polished look 2]

ok, say this person puts in a paddle-boat or what-not which drives a generator. Does this remove energy from the river? will the downstream hydro-electric plant have less energy?

hydroelectric power

[gordona]

You'll probably have to divert some water through a small sluice, but you'll have to find out if you legally can do this. You can emphasize that it will be 100% conservative, ie., no water will be consumed. A turbine in the sluice can be geared to drive an generator at higher speed. Will no doubt have to play with the size of the sluice and the gearing etc, since you will have essentially no head to play with.

Wind Power

[Denix]

I'm not an expert on this but I believe you would also get wind off the river. So you could combine water turbines and windmills.

Re:Stay on-grid while generating power

[gleekmonkey]

A friend of mine makes over $600 a month by staying on the grid and setting up a few wind towers.

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[account_deleted]

Comment removed based on user account deletion

Permits?

[pherris]

While it does sound like an interesting idea I suspect that the county and/or commonwealth will want you to pull somekind of permit. After they stall you for a year or two just to come up with the regulations they most likely want engineering data concerning possible damage to the riverbed and the generator's effect on river currents. Of course this really makes no sense but local politics never did.

Years ago my family spent a few years trying to get a 30' fix pier (that others on our street could use for free) built by our property. Between the hassles of the town, state and MEPA we gave up. Strangely a few years later a neighbor (and state senator) who opposed to our project build his own from our prints 100' away. I guess we didn't grease the right gears.

My advice, make it small, discrete, quite and easily removable. Be forward that running your own generator over a long period is probable cause for the DEA to search your house as a suspected grow-op. It sounds crazy but again it's all about politics.

Bonne Chance.

Is your land hilly?

[WindBourne]

One thing that you can do is use a small hydraluc ram to move water up a hill. Once in a small, resivoir you then allow gravity to do its work. Nice thing about this approach, is that if you use a big enough pipe/ram, you can pump up enough water for using on other projects such as irrigation or a simple open flowing water stream.

And for many here, the ram does not use electricity.

The Standard Way to Do This...

[nightwing2000]

Which is also unobtrusive, is a turbine that looks like a jet engine. A tube with a series of fans inside; if the current is decently fast, it will turn enough to create electricity. If the current is not fast enough, then you don't get eanything.

Unfortunately, making a long-term sealed generator and submersible it is probably not a home project. I suppose it also depends on what sort of stuff coming down the river might eventually plug the rotors. But at least it would be submerged and hidden. As long as it does not impact river navigability (and you don't chew up a few swimmers with the blades, ha ha) who's going to notice and complain?

If you don't actually have a drop, the usual waterwheel, dam, etc. solutions won't work. You could try that Roman trick, if you are allowed to moor a barge in the river; put a big paddlewheel in the barge; hook it to a bunch of auto alternators, and get some power inverters?

If you had the paddlewheels mounted in the center of the barge and enclosed in an insulated deckhouse and turning all the time, probably (?) they would not freeze. (Just HOW cold does it get there? Flowing water, of course is never below zero...)

Re:Stay on-grid while generating power

[Anonymous Coward]

If you stay on the grid make damned sure somebody from the local power company inspects your setup. If the power on the grid goes out and the power company employees are working on the lines, your power generation feeding the grid could be enough to kill somebody.

Convert the river to youre needs.

[NoMercy]

Split the river, so next to the original you have a very very low gradient river channel, carrying the water down-stream with little loss of height, then let it out of a small channel, a lower volume of higher speed water, sutable for driving small generators, there's a old water-mill by a village near here which uses the system, wheels gone, but the jet of water is still there squirting out into the lower part of the river.

Re:Dear Slashdot

[Jozer99]

Yes! First, get some spectacularly fuzzy socks. Then, wire every one of your door knobs into a giant capacitor, and have that trickle into a battery.

but how to deal with the hippos?

[Anonymous Coward]

I had a discussion about this sort of idea with the owner of a hotel I stayed at in Zambia last year (http://www.naturalmysticlodge.com) Its right on the banks of the Zambezi and we were discussing the options for making use either the solar or water power available. One of the snags with stuff like floating waterwheels tho was the local wildlife. Theres a hippo who comes by pretty much every evening to snack on the lawns, and having something that large bump your homebuilt water wheel could really mess with it.

Re:yes, but investigate 'net metering'

[pla]

do they sell at the same rate they buy from? depends on the state..

I'd worry about that, too...

Looking at my own electric bill, it divides almost perfectly in half, with 50% going to electric "supply", and 50% going to "distribution". So, even if they paid me the same rate they charge me, it would seem that, no matter how much I produce, I could at best break even (since presumeably I would make the money on supply, but still have to pay almost the same rate for distribution).

I dunno. But personally, I'd stay on the grid (unless something major happened, in which case, I'd make damn sure I had an overly-dramatic Very Big Switch I could throw to disconnect me) just for the convenience factor in case something goes wrong with my own production system (generator breaks, stream dries up, whatever).


As an aside, though, I still consider wind the way to go (though would certainly not suggest we completely skip solar, but I would consider solar more of a backup system than a primary one). With hydroelectric, you need year-round running water with a decent head. With solar, you need a fairly high-capacity storage system for the 60-80% of the day when you can't generate enough to match usage. With any sort of combustion, you need fuel. But with wind? It doesn't even really matter where you live - an 80' tower will produce a few kW just about anywhere. Aside from the "ugly" factor, including a wind turbine into the cost of every new house would reduce our current electric grid from a critical utility, to little more than a backup system. When I finally "settle down", I consider that a major point in my decision of where to buy property - If I can't have a wind turbine due to local BS laws and zoning regs, I won't live there.

Re:Stay on-grid while generating power

[vikingpower]

Absolutely: DO stay on the grid. For 2 obvious reasons: 1) what if, you never know, your installation breaks down beyond repair ? 2) it's profitable I am in a monastery in the Netherlands. We are going to generate our own electric power, with windmills ( we are very close to the North Sea shore, have 200+ days of wind per year ). Not only for the monastery-house itself, but also for the candle factory with which we earn our money: heating paraffine eats kilowatts. But even under these favorable circumstances we would be mad to go off the grid.

Re:The most cost-effective solution ...

[Tristandh]

They may be able to produce 600V, but that doesn't say anything about the power they deliver. I reckon electric eels can only give a short burst of current (1 Amp), enough to defend themselves. So you get very unpredictable supply of power, and you would need many eels, since I don't believe an eel could provide current for more than a fraction of a second. High power, short burst, and thus little energy...
From your post I get the impression it has been done, but I think it wouldn't be easy and you'd need to apply quite some circuitery to get some usable output.

Grain Mills

[Ironsides]

Old grain mills were always built by the side of a river and hill. A bit of water would be diverted from a stream, to slew gate. It would then flow to the top of a 30 foot paddle wheel with buckets to keep the water in. The wheel turned a shaft that was then geared down to turning the mill wheel. If you have seen the movie 'The Princess Bride', they have something similar in there where they are torturing the main hero. The buckets are important as they keep the water in until they are horizontal, getting the most out of gravity. Something similar should be possible if you have a hill near you. If you can get a picture of the mill at Appomatix Court House you should be set.

Re:does this remove energy from the current?

[FrankDrebin]

yes, but just momentarily

Huh? Let's not forget the law of conservation of energy. Of course a waterwheel/generator takes energy from the river as it puts out electrical energy. There is nothing "momentary" about it.

But this energy is otherwise "lost" to heat as the water flows downstream anyway. IIRC it was Joule [hometrainingtools.com] (whose energy scale we use today) that originally did the science on waterfalls, showing the water temerature at the bottom of the falls is higher than at the top. As water flows downhill, it pummels into itself, and the gravitation potenital energy is converted to heat.

A waterwheel simply takes some of this energy and converts it to rotation instead of heat. With a waterwheel in place, the temperature of the water will be ever-so-slightly cooler downstream.

The downstream reservoir has a level, and it is the difference between this elevation and the tailrace (water exit) elevation that determines the amount of energy the hydro plant can extract. The difference is called "head" (I kid you not).

So the energy of the water used by a waterwheel is not "stolen" from the downstream plant... because it would have already been "lost" to heat as it reached the reservoir anyway.

fascinating case study

[stiller]

Ok, this [homepower.com] really got me enthousiastic. This guy is truly a hydroelectric hacker. Check out those system charts, amazing!

That sounds like a good idea to me

[pimpbott]

In fact, I have seen people rig up homebrewed windmills fairly easily with bicycle parts to transfer the energy and to experiment with different gear ratios. Bike parts are tough, cheap, plentiful and easy to work on. It seems to me that you could build a paddlewheel boat fairly easily and link the paddlewheel to a generator with some old beater bike sprockets. Go with steel, aluminum wears to fast for constant use. Instead of lubing the chain with oil, use grease. A nickel plated chain will resist corrosion as well.

Re:That sounds like a good idea to me

[pimpbott]

Heck, for that matter, you could easily build a low rent rig with the paddleboat, a car alternator and a nice chubby bank of batteries. Paddlewheel boat drives alternator(s), slow charges bank of batteries, which outputs to an inverter. The boat will quietly charge your batteries until you need the juice. When your power fails, an auto-switch kicks you off the grid and over to the inverter powered by the batteries for the duration of your blackout. The tricks here is getting the alternator to spin fast enough to charge the batteries at a reasonable rate, and figuring out exactly how much battery you need (duration of blackouts) to run a big enough inverter. That is, figure out how much power you can live with and get an inverter rated at 1.5X that amount. If you stick with off the shelf parts, you should be able to do this fairly cheaply and easily, and keep reliability up there.

Re:Stay on-grid while generating power

[BJZQ8]

The school that I work for just installed a huge 68,000 watt solar panel system to provide electricity. There are 21 "Sunny Boy" inverters that do the DC-to-AC conversion, and we have a breaker in place that disconnects us from the outside if there is so much as one phase lost...which prevents us from frying linemen. In addition, the inverters themselves will switch off within 30ms if there is a total power interruption. If you want to see some pictures, here is a link. [k12.il.us]

Hydro Radio

[AikenDrumGotWired]

Since the poster did not state which branch of the Susquehanna he lives near I am not sure of he is close enough to the location of

• http://www.wjffradio.org/

for them to be able to render him any assistance or inspiration. WJFF is a public radio station that is run entirely off a hydro generator(water conditions permitting). It makes a nice little case study for those who say it can't be done, or for those who do not live in a state that has net metering laws, or one with intolerably cumbersome restrictions.

Re:Stupid Romans

[bombadillo]

You will have to post some links or recomend some litature to convince me about the middle ages were a time when tech was taken seriously. Perhaps it was due to the fact that they were re-discovering most that was forgotten or destroyed. After all it took almost 2000 years for society to start implementing things like sewage and plumbing systems into major cities.

Re:Don't forget your 60Hz and the phase!

[panxerox]

Rotery inverters are really cheap basically just a dc motor running an ac generator, you get around a 20% power loss due to inefficiancy but with waterpower you have no costs anyway.

Maybe a sling pump...

[Halvard]

A sling pump doesn't use electricity to pump, rather the stored energy of the moving water. So use that to fill a tank at higher elevation feeding a small turbine. With a sling pump you just have to moor it (or tie it off to a dock) on a body of moving water. Check out Rife Ram [riferam.com] for an example. I suppose if you were really industrious, you could use the runoff from the turbine to feed a hydraulic ram pump [itdg.org] to fill the tank back up or another tank to, say, water the garden and lawn.

Re:Township Approval

[jxs2151]

Oh jeeze people, just put the freakin' generator on the river, shut your mouth about it and wait for someone to tell you to stop.

With attitudes like this, we would have waited for the proper government bureau approval before dumping the tea in the harbor.

What ever happened to good old American rule breaking?

The paddelwheel method is the way to go

[rspress]

The paddelwheel method is the way to go but actually putting it in the river would not be.

More than likely this would be an illegal to do and dangerous as well. A better way to go would be a diversion channel that diverts a small amount of water from the river. At the top of the project or head would be a simple weir or gate to control the flow of water during the changing levels of the river. Depending on the amount of drop between the head and the wheel might give you higher speeds than the river itself could create. After the wheel you simply channel the water back to the river. The channeling back may be the hardest part of the project. As changing river levels might be harder to control and water may back up into the system. It depends on your situation. You may be able to gain a little elevation by using a shallower slope than the river has. Water needs at least a .15 of inch drop every 100 feet to move..and that is slow moving water.

In any case, you would need to survey the job and use an optical level or a laser level to determine the drop between where you pull the water out and where you put it back in. This could be a costly project depending of the generating needs and your state laws, county laws..etc. But the way stated above is probably the only way to do it legally.

Don't miss work done in India on this

[Anonymous Coward]

If you google for "micro hydel iit" you'll find
interesting hits on this topic. NOTE: Hydel is
the Indian-English term for Hydro power.
When I was working at IIT Delhi I interviewed
a young woman who had just completed a research
assistantship during which she and her professor
developed a generating unit that would fit your
requirements. They used a type of rotary pump
that is mass-produced cheaply in India (used it in
reverse of course), and they got good results.
Unfortunately I wasn't able to hire the young
woman, and I don't have any references for you.

Re: High volume, low speed

[pr0cess]

Some people build what's known as "microcentrals", which are esentially rotary water pumps working backwards. They make water flow into the pump so it turns the turbine and makes the engine act as a generator. I guess some modification is required to stabilize and clean the resulting current, but it shouldn't be too difficult to do. But no matter what system you're going to use, if you want a steady, reliable electric production you're going to need a water and some supplementary infrastructure (pipeline, energy dissipators, etc). That's where the city and environmental agency folks come in, and that's where it gets bumpy.

Old Fashion Rule breaking = Jail Time

[purduephotog]

True story:

My neighbor wanted to take down his tree. It was 150 feet tall. The city only allows licensed tree cutters, which wanted in excess of 500$ to do so.

So... we took it down. Six guys and a 1987 GM pickup truck.

Mind you it took 5 hours, and had I not removed the gutters from my roof to work on the soffits, the top of the tree would have removed them for me (and probably much faster with less trepidation).

So the city makes a drive by midweek... and he gets a phone call and a citation for a whopping fine for not having used a licensed tree removal service. Convincing them that 6 guys and a pickup truck actually did the work took some time, but eventually he won.

He was then cited for not having replanted a tree within 10 feet of the road within 1 week (another ordinance) and fined 150$.

Face it- the government can and will spank you if someone gets their panties in a big of enough twist.

Re:The Romans

[snerdy]

In Joe Sacco's excellent comic documentary "Safe Area Gorazde: The War in Eastern Bosnia 1992-1995" he talks about how the residents of Gorazde built floating water-powered generators in order to run lights and electric applicances like TVs and VCRs during the siege of their town. The generators were called something like "mini-turines?" (I borrowed the book from a friend and have since returned it.)

Personal hydroelectric power

[Ricdude]

http://www.realgoods.com/renew/shop/product.cfm?dp =1200&sd=1201&ts=1017104 [realgoods.com]

Jack Rabbit Submersible Hydro Generator

No Pipes or Dams! Power from any Fast-Running Stream or Tidal Flow!

The Jack Rabbit is a special low-speed alternator mounted in a heavy-duty, oil-filled, cast aluminum housing with triple shaft seals. Orginally designed for towing behind seismic sleds for oil exploration, this marine-duty unit is ideal for home power generation near a reasonably fast-moving stream. In a 9 mph stream (slow jog) the Jack Rabbit produces about 2,400 watt-hours daily. Ina 6 mph stream (brisk walk) it produces over 1,500 watt-hours. The 12.5" propeller requires 13" of water depth. A rock or timber venturi can often be constructed to increase stream speed and power output.