When I bought my house, I didn't realize that the stream that travels its acres is perennial and spring-fed ... which seemed like the perfect scenario for a microhydro generator. These units make a lot of power all day and night, unlike solar and (usually) wind. It works by siphoning off a portion of water to run through a pipe, then through a generator, and then back into the creek. Voilà! So I did the measurements and found 140 gallons per minute, which is about enough for the purpose, but less than a 20 foot drop in elevation, which is the killer. Microhydro usually requires either high head or high volumes to pencil out, but I have barely the minimum of each.
At best, it would account for 20 percent of the house's needs -- not quite good enough for me to think too deeply about the capital expense or the fact that the town's Conservation Commission probably wouldn't allow the use. Other nearby commissions have also been unfriendly to residents employing or proposing it on their properties, even though microhydro is not a consumptive use and requires no dams.
I have some small consolation, though, knowing that all the electricity in this portion of my county's grid is already 100 percent hydro, due to its proximity to the Deerfield River (one of the most developed rivers in the country, with small dams working up a good portion of its length from southern Vermont into western Massachusetts). Which is nice, in a way: the next nearest power plant to my community uses coal from a mountaintop removal mine in Appalachia, so this somewhat green power is welcome.
So I was interested to see news that small hydro is possibly on the verge of a boom, with new estimates of 30,000 MW of potential small hydro capacity in the U.S. alone. This would build on small hydro's ubiquity in the industry, if the article is right that 80 percent of the existing hydro projects in the U.S. are low power (under 1 MW) or small hydro (1 to 30 MW).
The industry is saying it can get more power out of falling water without any more dams:
"The kind of projects we're talking about would not involve large dams or any inundation of property. These would all be run-of-river projects," says Hall.
This includes submerging weirs to raise the level of a river and create energy from the difference in water level, or excavating power channels that divert water through a power house and back into the water body. Depending on the size of the project, there are still some environmental concerns associated with these methods; however, they are considered to be a much more sustainable way of harvesting energy from a moving body of water.
Unfortunately, this sounds like more "industrial-light" uses on more portions of more rivers, but that certainly could be the lesser of two evils.
The rest of the article focuses on the regulatory hurdles that generally hinder new hydro projects. Also of interest here is mention of a company installing microhydro in wastewater treatment plants -- not a bad idea, and one that Jon Rynn was kicking around in Gristmill recently. Maybe you could capture the heat of that water, too, either before or after the turbine ...
In any case, I'm still thinking about attempting microhydro on my own seven acres: it's sure to get more attractive as electric rates climb.
‘Heretic’ battles straw man
Comments
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GreyFlcn Posted 1:06 pm
28 Mar 2008
But in order to stimulate new growth, industry leaders say they must correct misinformation about the power source and get the permitting process moving faster for both project upgrades and installation of new technologies like hydrokinetics.
For many people, hydropower conjures images of towering hydroelectric dams that flood land, displace communities and kill aquatic wildlife. But that perception may be changing here in the U.S. as the industry installs more small- to micro- sized systems and proves that it is just as much a part of the distributed energy economy as other renewables that get far more attention.
In fact, large hydroelectric dams above 30 megawatts (MW) only make up 8% of the total hydropower plant population in the U.S., according to the Hydroelectric Power Resources Assessment Database. The other 80% of plants in the U.S. are low power (under 1 MW) or small hydro (between 1 MW and 30 MW).
Article Continues...
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GreyFlcn Posted 1:07 pm
28 Mar 2008
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Pangolin Posted 2:44 pm
28 Mar 2008
I'm all for small hydropower that doesn't involve dams or pipes. Run your smelt through a pelton turbine and you have a hydrolyzed fish protein in suspension. No good unless you are a jellyfish or freshwater clam.
There's a lot of power available but it needs to be collected in ways that don't harm any more fish. Units that are placed in the flow of the water and the fish can freely swim around will be much easier to get approval for.
Verdant Power's units in the East River and the Gorlov Helical Turbine seem to fit this requirement at first glance. Both of these types appear to be undergoing field testing.
Put the Carbon Back
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Sam Wells Posted 3:40 pm
28 Mar 2008
I had the opportunity to visit a real mill-race paddle wheel sawmill in Connecticut, where the owner (tho' slightly crazy) built furniture and fixed wooden sailboats. A fairly large iron pipe ran the length of the building about 70 feet. This was turned slowly by the water wheel, 24 hours a day.
He had power lathes, routers, and joiners that could spin up to several thousand RPM, all done with these old leather belts. Very cool.
Now folks all that took was about 3-7 knots of water flowing down a stream or small river. Yes, the paddle wheel was quite large and needed good bearing mounts on both sides. Think about it though, it would spin the opposite direction of a top-drop mill. No vertical needed.
Onward through the fog
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archigeek Posted 2:48 am
29 Mar 2008
The mellotron is your friend.
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bigTom Posted 3:35 am
29 Mar 2008
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Sam Wells Posted 3:43 am
29 Mar 2008
However, the dams messed up the fish that spawned up the rivers and we're still seeing the consequences today. Enviros talk about blowing up dams so that the Atlantic and Pacific salmon would come back, for example. Small hydro could be a solution ... or aggravate a problem that has been growing for over a century.
But there may be ways such as to collect water in a 24-inch intake pipe and simply run the pipe downhill until you get about a 150-foot drop. The force of that water coming out the end would be tremendous - and indeed one would have to build a capture weir because the force of the water could even wear down rocks. Indeed it will act as a powerful siphon (any beer brewer would know this). A high-speed hydro-turbine would be used at the business end of the pipe. Then in the weir one could also make electricity from the slower flow from the weir to the receiving waters.
It should be noted that any of this takes a permit from the Army Corps of Engineers and the lead state agency. But if we can get rid of dams or improve them with fish ladders, while adding micro-hydro in a way that is environmentally benign, that would be great. -sammie
Onward through the fog
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Erik Hoffner Posted 4:01 am
29 Mar 2008
Erik
The Orion Grassroots Network: 1,200+ grassroots groups working for conservation & more
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GreyFlcn Posted 4:14 am
29 Mar 2008
And then when you have multiple dams, you end up getting a fraction, of a fraction, of a fraction, etc.
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Werdna Posted 1:11 pm
29 Mar 2008
Another thing, and this is perhaps a bit more difficult to explain. Each run of the river project is being produced by a private company, who would likely reap large profits without much regard for maintaining the ecosystems where the projects are built. Essentially, this means that private companies are building projects on public land and then selling the power back to us.
This is not an anti-privatization rant. BC has long had some of the cheapest energy in North America and power is provided by BCHydro, a public company (no coincidence there public company and cheap electricity). Deregulation of energy has caused a debacle in California, and it might to the same in BC.
More information here:
Map of Run of the River projects:
http://www.ippwatch.info/cms/index.php
Campaign to save BC's rivers:
http://ourrivers.ca/
Public opposition to a run of the river project in the Upper Pitt River (a major salmon run and recreation area) was enough to shut the project down:
http://www.livableregion.ca/blog/blogs/index.php/2008/03/ ...
And a moving video here:
http://www.livableregion.ca/blog/blogs/index.php/2008/03/ ...
I am not against run of the river projects in theory, but the problem is that in BC they are being created without regard to ecosystems.
Andrew Eisenberg
The gateway project is wrong---http://www.livableregion.ca
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Sam Wells Posted 1:33 pm
29 Mar 2008
Onward through the fog
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naught101 Posted 7:46 pm
29 Mar 2008
My friends in the Hunter valley (australia) have a 30L/min flow through their hydro setup (the creek flows much more than that), and only a two metre drop. When it's working, and combined with two 60W solar panels, they produce pretty much all the electricity they need (I think it's about 100W constantly, plus the PV). They don't use much - just lighting, a computer, and a small fridge really, but it's enough for them.
You have the maximum potential for a system 50 times what they have (assuming you use all the water, which I definitely don't think is a good idea)...
check out http://www.envirowiki.info, the knowledge database for environmentalists and activists.
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picassotrigger Posted 3:55 am
30 Mar 2008
Just wondering, Erik, if you've heard anything about the implementation of micro-hydro generation in the roof drainage systems of high-rise buildings?
My first thoughts were that considerable energy would be available to generate electricity as rain water dropped perhaps 100 stories through the drain piping, but I've since discovered that a terminal velocity of 10-15 feet per second is attained within approximately 15 feet of fall.
Volume within the drain pipe would be the big variable, based on some combination of roof area, intensity of precipitation, and number of existing drain pipes serving the roof.
It certainly would be convenient if a micro-hydro turbine generator could be tapped in to existing plumbing systems. Frequency of precipitation would be an issue, of course, but the payback period could be competitive with solar photovoltaic systems at higher latitudes.
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kiwiiano Posted 5:25 am
30 Mar 2008
Back up, Erik. A perfectly usable nano hydro can be cobbled together with minimal capital expense by using a water pump, a washing machine motor, a length of water pipe and a separate heating element on your hot water cylinder. The pipe dips into your stream as upstream as you can go and the pump/generator and return pipe as far downstream. Bury the pipe as much as possible and the CC will never know about it. (It's always easier to apologise than seek permission.) A friend here in NZ had that setup and did face the capital expense of having to install a bigger cylinder to stop it boiling.
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JMG Posted 5:41 am
30 Mar 2008
In rainy climes (Pacific NW), there is a LOT of water to handle at times. I've been dreaming about ways to use that water by putting it through downspouts made of the extra wide drain pipes, with an "archimedes screw" type rotor installed along its length and driving a small generator, capturing some of the power as the water then channels into a cistern (tapped with electric pump driven in part by the stored energy from the original rainfall).
So far the problem I id -- in addition to the amount of energy required to make it all vs. what you might get back -- is the noise. It would need some decent bearings, which would serve as sound conductors; worse, the shape is the same as a resonator in a big pipe organ ... ideal for sound transmission, in other words. So there's several routes for a lot of noise ...
But fun to think about. There's a kids' museum nearby ... maybe I'll go over and talk to them about playing with the idea.
Save your community: Cut greenhouse gas emissions 5% per year.
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Erik Hoffner Posted 7:27 am
30 Mar 2008
The other thing is the regulations: I just see it a a boondoggle. For eg: the conservation commission in a neighboring town tried to shut down a guy's generator b/c they claimed that it heated the water in the stream from the friction of the water hitting the turbine (!) and was therefore bad for cold loving trout. He then demonstrated that the setup actually kept the stream cooler, as the water in the penstock ran a shorter length than it did in its meandering streambed. But the con comm didn't back down, and he only beat the rap by showing that the commissioners entered his property without permission to gather evidence.
So there's a lack of understanding out there which seems risky.
As for the rooftop hydro idea, it's a good idea. I think in most cities it'd be smarter to keep that water in tanks on the roof and use that to both cool the building and water vegetable gardens. But in a rainy climate, could make a lot of sense.
Erik
The Orion Grassroots Network: 1,200+ grassroots groups working for conservation & more
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Erik Hoffner Posted 6:28 am
15 Apr 2008
"Run-of-river independent power projects have gained environmental steam, but are they really the right way to go?"
http://www.straight.com/article-111552/electric-companies ...
Erik
..
The Orion Grassroots Network: 1,200+ grassroots groups working for conservation & more
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tonyinnh Posted 1:27 am
05 Sep 2008
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