I have a pond fed by a small brook at the top of my garden, the outlet is piped to the bottom of the garden about 5 meters below the bottom of the pond. The minimum flow rate is 20L/s (roughly 43cfm) and is often an order of magnitude greater. Is this enough to get a usable amount of power from? If so has anyone got any suggestions for suitable turbines?
Thanks
Power = Head x Flow x Gravity
5m x 20L/sec x 9.81 = 981 W
Or something around 580 W with 60% efficiency.
There is a
nice calculator on the Powerspout website that will let you get good estimate of the potential for your site. In addition to head and flow, you need to take into account frictional losses in the pipe run which depend on pipe diameter and length.
Even though gravity is obviously the source of potential energy here, it's force (9.8 N/kg) is not part of the equation.
BTW - Powerspout makes very nice microhydro turbines that will work with your site.
Power = Head x Flow x Gravity
5m x 20L/sec x 9.81 = 981 W
Or something around 580 W with 60% efficiency.
Thanks, that's what I worked out too but it just
felt more than a bit high for such trickle lol.
But now I can hit Google with a bit more confidence to try and find suitable turbines and their reviews.
EDIT:
There is a nice calculator on the Powerspout website that will let you get good estimate of the potential for your site. In addition to head and flow, you need to take into account frictional losses in the pipe run which depend on pipe diameter and length.
I'd most probably use new pipe for this, maybe even just a heavy duty hose depending on how things work out and keep the existing setup for dealing with overflow. I have checked if I am allowed to do this and as long as I don't majorly disrupt the flow to downstream, or start introducing nasty chemicals, I can do whatever I want between where the water enters and leaves my property.
BTW - Powerspout makes very nice microhydro turbines that will work with your site.
Thanks! Just having a decent recommendation will give me moire of an idea of what to look for.
I'd most probably use new pipe for this, maybe even just a heavy duty hose depending on how things work out and keep the existing setup for dealing with overflow. I have checked if I am allowed to do this and as long as I don't majorly disrupt the flow to downstream, or start introducing nasty chemicals, I can do whatever I want between where the water enters and leaves my property.
I think there is some slight difference in frictional losses depending on the pipe material but the major factors are pipe diameter and length.
Thanks! Just having a decent recommendation will give me moire of an idea of what to look for.
I would go with Powerspout if I were you. I have one of their Pelton turbines that I'm hoping to install this summer. You can find Youtube videos of Powerspout installations. They are a Kiwi company.
Harris Hydro here in the states and Energy Systems and Design in Canada also make well regarded microhydro turbines.
Also - their is a fairly active Yahoo microhydro group with good info and advice available.
Have you seen this project? Really inspirational.
http://ludens.cl/paradise/turbine/turbine.html
Yeah - I've seen that. It is a very nice but very large system! As Dave would say - you could fly to the moon with 4kW of power!
There's a nice gallery of photos from smaller systems
here
Even though gravity is obviously the source of potential energy here, it's force (9.8 N/kg) is not part of the equation.
Absolutely it's part of the equation.
We can work out the available power as (volumetric flow) x (pressure difference).
Volumetric flow (20 L/s) is 0.02 m3/s.
Pressure difference (5 m head) is (density) x (gravity) x (elevation difference) = 1000 kg/m3 x 9.81 N/kg x 5 m = 50 000 N/m2 = 50 kPa
Hence power is 0.02 m3/s x 50 kPa = 1 kW
But of course efficiency losses in the system mean you would not get all of that.
Even though gravity is obviously the source of potential energy here, it's force (9.8 N/kg) is not part of the equation.
Absolutely it's part of the equation.
I guess my language wasn't precise enough (Ha ha! I should have known better on an engineering forum!). Of course it is part of the underlying calculation. What I was referring to is the point that people who design microhydro systems do not generally use 9.8 kg/N in the standard equation used to estimate potential power production at a site. Obviously you can do it that way as you have (though you need to include the density of water as you have and which the previous poster left out).
Some people just use weight (instead of gravity and density), others just use a constant since density (at a given temp!) and gravity are constants (at least here on earth with a water based system!). This greatly simplifies it for those of us in countries not using the metric system!
For example here in the US the equation most people use is [net head (feet) × flow (gallon per minute)] ÷ 10 = Watts. (this equation includes typical efficiency losses due to pipe friction).
I was just speaking from the perspective of practical experience versus theory. Sorry for the confusion.
Some people just use weight (instead of gravity and density), others just use a constant since density and gravity are constants (at least here on earth with a water based system!). This greatly simplifies it for those of us in countries not using the metric system!
Well, quite. Sometimes customary units are simpler. For example, if you want to raise 160,000 lb/hr of water through a height of 16 ft the power requirement is simply 160,000 x 16 = 2,560,000 ft-lb/hr. Now you are simply left to converting ft-lb/hr to whatever unit of power you are interested in, e.g. 1.3 hp or 1 kW.
Using the us units for such a calculation is just stupid - its hard to remember how to convert things like ft*lb/hr to Hp. There is a good reason science uses metric units.
In many coutries you may need a permit to use natural hydroelectric power.
Using the us units for such a calculation is just stupid - its hard to remember how to convert things like ft*lb/hr to Hp. There is a good reason science uses metric units.
I'm not gonna disagree with that in theory. Personally I wish we would have fully converted to the metric system long ago. I have been using it for decades in my professional life.
But .. For practical purposes - feet on the ground, real life work - it makes things more difficult in this case. It is not easy to find a metric tape measure or metric volumetric tools. Besides - in this case it turns out that the equation that provides a very good estimate is trivially simple using feet and gallons.
In many coutries you may need a permit to use natural hydroelectric power.
Yep, that is generally true here in the US.
I have a email friend Manfred who I share a fondness for antique radios with. One day Manfred decided to build his own paradise in the mountains of South America. Being a clever fellow he made sure there was water higher than the house he planned to build. The end result was a self made hydro system , 5 K watt if memory serves , to heat and cook in the house. I know you are going to like this from what I am reading which is why I am making this post. He is an excellent photographer so the complete construction from beginning to end is well documented. Try to imagine you are doing this not him to live a life that could have been. Enjoy.
http://ludens.cl/paradise/paradise.html
I have a email friend Manfred who I share a fondness for antique radios with. One day Manfred decided to build his own paradise in the mountains of South America. Being a clever fellow he made sure there was water higher than the house he planned to build. The end result was a self made hydro system , 5 K watt if memory serves , to heat and cook in the house. I know you are going to like this from what I am reading which is why I am making this post. He is an excellent photographer so the complete construction from beginning to end is well documented. Try to imagine you are doing this not him to live a life that could have been. Enjoy.
http://ludens.cl/paradise/paradise.html
Cool that you know him! His project pictures were already posted and discussed. See above. Yes very nice, large! microhydro system. 5kW = 120kWh per day - enough to power 10 homes! WHat does he do with all the extra power? He must have a large diversion load..
Yes I can see now from an earlier post that this has already been brought up. It puts a smile on my face that such a esoteric detail from myself in Canada and a Mr Manfred on some remote mountain is south America would strike a common cord with a group half way around the world in EEVblog in Australia. My connection would be a yahoo group called antique radios. How cool is that. It shows the power of the internet. I can recommend that you tax Mr Manfred on the finer details of the center of gravity of a Wankel engine at high RPM. If you thought the 5 K watt hydro power project was cool his precise understanding of a Wankel engine will knock your socks off.
Beware that federal, state and local regulations may come into play: look up anything and all about waterways, watersheds, ponds, dams, water rights, ground water supplies; the list goes on.
Tim
Definitely.. Decades ago I spent a summer living at a place that had a setup like that, feeding into a pipe pointed at a pelton wheel. I forget what the power output was in watts but it was enough for a (open from the top) refrigerator and lighting and similar. All 12 volt stuff. It was fun living like that for a bit.
Quote from: Mechanical Menace on 2016-02-08, 13:02:15I have a pond fed by a small brook at the top of my garden, the outlet is piped to the bottom of the garden about 5 meters below the bottom of the pond. The minimum flow rate is 20L/s (roughly 43cfm) and is often an order of magnitude greater. Is this enough to get a usable amount of power from? If so has anyone got any suggestions for suitable turbines?
Thanks
I have a email friend Manfred who I share a fondness for antique radios with. One day Manfred decided to build his own paradise in the mountains of South America. Being a clever fellow he made sure there was water higher than the house he planned to build. The end result was a self made hydro system , 5 K watt if memory serves , to heat and cook in the house. I know you are going to like this from what I am reading which is why I am making this post. He is an excellent photographer so the complete construction from beginning to end is well documented. Try to imagine you are doing this not him to live a life that could have been. Enjoy.
http://ludens.cl/paradise/paradise.html
I liked the photos.
But as he has built it I don't think it has a chance of working for long.
How is the frequency controlled ? The generator is designed to run at around 1500 rpm to output 220v @50hz.
The home made transformers are they variable frequency?
Maybe he has some one controlling the water flow.
sorry nice photo shoot .
bill
Before we go any further.
1. can it work? yes but not very well.
2. How would i do it (not is if that matters)
3. how should it be done? (or how would you do it)
4. Before responding please go to the link and read it.
http://ludens.cl/paradise/turbine/turbine.html this is an interesting topic we see a lot of these (how should i say it BS ?) links.
Don't take this the wrong way but I loved the idea.
@bills: not sure of your point?
He built it, it apparently works, and it produces 4 kW at 50 Hz (regulated as explained in the link you disparage).
To call detailed explanations and documentation in the link BS is quite rude. Did you get out of bed on the wrong side this morning?
I feel that small scale hydro power is often overlooked these days and for the longest time I was part of that group.That was up until I visited a mountain hut in Bulgaria that was powered by a old cobbled together micro hydroelectric station.It was a amazing place that was off the grid long before that term was coined,everything comes in by foot or horseback and the power is from a small hydroelectric plant on a stream fed by snow melt.They really dont show or mention much about the hydro plant but nonetheless here are a few links,it's a truly gorgeous place nestled in the Rila mountains and worth the hike to get there.
http://www.ivanvazovhut.info/history_en.html http://gowhere.bg/en/guide/mountains/rila/ivan-vazov-hut/ivan-vazov-hut.htmlI say go for it and it isnt too hard to make a DIY pelton turbine although if you have enough flow I'd look into commercial options too as you'll probably see more power in the end.
Also one thing I see mentioned too often by people arguing against small scale hydro is they'll say you only have "X" amount of flow so it's only going to make so much power and I just love when they compare a 4kw hydro setup to a 4kw solar setup
.The part of the argument they neglect is that you dont have to go too far down stream to collect more power and that it runs nonstop (for the most part)
granted a lot depends on the setup but I saw a neat install where the outflow and bypass overflow from the main pelton turbine fed a old fashioned water wheel that was geared down to spin another generator.Granted the secondary wheel wasnt always on but it added capacity when flow allowed.
Good luck and if you go for it you'll probably be pleasantly surprised with the outcome no matter if you buy a commercial setup or go DIY with with as little as a bunch of spoons and a bike wheel attached to a alternator or 2 from a car.Once you have it setup and running it's going to quietly produce for you nonstop 24/7 365
You could dam the water supply and create a lake to use for your hydro power when you need it. I once did some restoration work on a Victorian water turbine that worked a saw mill. The lake or pond would fill over night and then the turbine would work the saw for about 6 hours during which time the lake would drain to abot half full at which time the head was to low to do much work. I have some photo's some where but as the work was quite a time ago the pictures are film, I will have to look them out and scan them. The turbine was fed with a 16 inch pipe as I recall and about 4 meters of head, the stream was very small and fed to the lake in a cast iron conduit that was about 800mm by 150mm.