Hydroelectric power on a residential scale
It is well known that energy is generated by building dams over giant underwater turbines; however it is possible to use micro hydro generators (<100kW) or pico hydro generators (<5kW) on more modest water flows. In this section we explore where the technology can be used in a small scale area, for example the home or a community project. More about industrial size dams and solutions can be found in the green commercial section.
Obviously, there is a fundamental requirement on a steady stream of moving water, however they have an advantage over solar power (both solar PV and solar heating) and wind, in that they can run day and night and in any weather conditions provided the we don’t have a prolonged drought period where streams and brooks can dry up.
The amount of energy produced is reliant on two things:
The flow of water
The flow of water is simply the quantity of water flowing in the water source, which is measured in litres per second.
The head
The other key factor is the head – this refers to the pressure at which the water hits the turbine blades, and is the vertical distance from the water source to the generator. The larger the distance that the water falls before it hits the blade, the higher the head. Ideally both the flow and the head will be high, however if one of these is particularly high, while the other is low there is still the potential for a rich source of electricity.
You can estimate the number of kilowatts of energy produced by multiplying the flow (litres/sec) by the head (m) and multiplying by 9.81 (gravitational constant). Remember a typical house uses 4500kWh per year.
How does micro hydroelectric work?
The type of turbine that is used varies depending on the type of flow available, however typically a residential generator uses a pipe to collect water from a river or a stream. Using gravity the water moves through the pipe ‘downhill’ and a generator situated within the pipe acts to change the kinetic energy from the water flow into electrical energy.
When you have high head (the vertical distance from the water source to the generator), you are best using an impulse turbine (such as a Pelton turbine). This turbine is not submerged in the water, instead it sits in the air, and consists of buckets around a central hub. The nozzle at the end of the pipe converts the water into a fast moving jet. This jet of water is directed at the buckets, and the force of the the water causes the turbine to spin generating the power. The smallest type of high head turbine requires a head of at least 10-14 metres, and a water flow of 3-4 litres/ second, and this is rated at producing 200 watts of power.
For medium head water flows, it is best to use a reaction turbine. With a 3-12 metre head and a water flow of 45 litres/ second, you can get a reaction turbine that will produce about 3000 watts of power. Obviously as with the high head turbines, if either the head or the flow increases, you will see dramatic increases in the potential electricity your system is capable of generating.
For low head water flows, you obviously require a high flow rate, and in this situation an old style water wheel is the best. So the water fills the buckets which fill up, then pulling the wheel down, so the next bucket is filled, and this process is continued so the wheel spins (albeit very slowly). However the advantage of this type of system is that any potential blockages just simply wash through the system. Gearing can be used in conjunction with water wheels to increase the speed that the generator spins to help electricity production. Water wheels are also aesthetically pleasing on the eye!
Summary of micro hydroelectric power
If you are lucky enough to have a water flow source on your property that either has high head or sizeable flow, a micro hydroelectric generating system may be the perfect solution for your energy needs. Despite potential seasonal fluctuations in flow and head, a micro hydroelectric system will provide you with electricity 24/7, with very little maintenance necessary.
hi
i have a stream coming from fields entering the rear of my garden that drops into a 2m+ manhole and is then piped under my garden. we have a flow of water around 8 months of the year coming through this and possible more depending on how much rain falls? would we be able to use your system or would it not pay us back?
Is 45 litre water per second produces 3000watt power in one second
3000 watts is per hour.
hi we have a quickly flowing river at the end of the garden and and own the field at the opposition side. We are looking at renewables and am interested in hydro electric as a supply to a Eco house project and a revenue. We are looking for a company to help us with this project.
Hope you can help
Mrs j winn
Dear Mrs Winn
Kindly contact me for recommended suppliers of Hydro Power in the U.K.
Hello, I’m looking at a project at TD86RL
The document is very much educative.it has taught me alot.there is a fast flowing stream at my home and I think it is un uterlised resource.is it possible to support me produce electricity from this?
Would you also be able to give me a list of supppllers , I also have a small river inn my garden and would love to use it
Hello, I happened to visit a community in the mountain. They don’t have electricity. I built a paddle wheel conected to a shaft and to a pulley to an alternator. There is an abundantwater but I can’t produce a good rpm. Please help me help this community in the mountain. Thanks
Hi Daniel, its important that the horizontal velocity of the water leaving the launder is about the same as the tangental speed that you want the wheel to turn, water wheel launders usually have a sluice gate in them that holds back some head in the launder so the water coming out under the gate is the required velocity
Hi.
Could I please have a list of hydro installers/suppliers in the north West England please. I have a head of 13m with a flow of 2.9lps which increases in the winter months and would like to discuss viability. Thankyou
COMMENT (*)hello we have a creek flowing through aur property I will need you’re technical guardence in the selection of the right size of a three phase waterpump to provide electricity at aur school in the village
Your website is really rather misleading with respect to Micro Hydroelectric Power. I called for some general advice and was told that you have no one with expertise to discuss, nor could you recommend anyone. Disappointing response.
Here Davey, take it easy and look, ya scorcher. Just get a solar panel strapped to your heid. That’ll give enough power for all your requirements and you can stop annoying everyone on here.
Hi David, thanks for your comment. Unfortunately micro hydroelectric is extremely rare – we have to concentrate on more common enquiries. Unfortunately we don’t get Funding from the Government or a third party so we have to direct resources where they get the biggest results. I suggest ringing the energy saving trust (who receive approximately £6m of Government funding each year) and see if they can help!
Hi, Where can I buy the ‘quick-install’ pico hydro system that is shown at the head of this page? (painted blue, that looks like a sluice gate chained to the bank)
Nick, did you get a direct response to this post? I was going to ask the same question
Can you supply an underwater hydro generator? What details do you need to confirm regular wattage ?
Hi,
I have a customer who runs a large fish farm in Devon and they are looking for some micro hydro electric power generator units to supply their site as they have plenty of water flowing through their site.
Can you recommend any potential suppliers of this type of system in the UK
I have a small cascade adjoining my property in France which has a head of circa 4 feet and a continuous flow of circa 25 litres/sec.
What power generation would you expect from this?
I would like a no obligation quote for a hydro electric system in my river in Sussex Tn3 9 jb
I have enough water , can I built a dam and use this?
Hi I have been looking at your site. I have a water mill which has a head of 6m, and lake of approximately 5 acres behind a dam (the damn is graduated 1-8m deep). The sluice probably has a flow of about 8 litres a second. In terms of watts this would give me a wattage of approx 470 – is this watts a second, so to get a kilowatt hour (kWh) do I have to multiply by 60 to get a minute, and then by 60 to get the hour and divided by 1000 to get the kWh? It seems very high. The water is running 24/7 and the damn – fed by 2 rivers and natural springs has never run dry. Can you advise?
470 Watts is just under half a kilowatt so you will get about 10 units (kWh) of electricity per day or 3,500 kWh per year. 470 Watts (or Joules per second) is the power or rate of energy generation, and a kWh is a quantity of energy (equal to 1,000 Watts for an hour or as in this example 470 watts for 2hrs 7mins)
Hi. I live in an old mill where, unfortunately we’re unable to resurrect our old turbine. However, we have sluice gates which were used to divert superfluous water in days gone by. They are 2m tall and are letting water out underneath them for c.80% of the year. c.1 cumecs of water over the year. If I could channel the water through simple piping fixed at the bottom of the gates towards a turbine, could I use that considerable pressure towards a pico-hydro turbine to generate enough electricity for domestic purposes (ideally including a heat pump for heating). Richard
Hi. I live in an old mill. The mill pond, mill race etc is all still there. Is there anyone who can advise on micro-hydro options?
Hi We have a 60 acre lake that has a disused 6inch pipe running on the bed through a rock filled dam. The water level is almost always circa 3m above the pipe. The pipe terminates a few metres past the dam. Would the weight of the water above the pipe be sufficient to generate power and if so how much?
Good evening, we have a stream running through our garden with a waterfall. At this time of year the water flow is substantial and there must be an opportunity for Micro Hydroelectric Power. I’m happy to pay for installation of such a project, would you be able to recommend a company who might be keen to do the works? We’re in The New Forest.
Are batteries needed for this system, To be used for three homes +workshop
Hi there, Could you guys send me survey form that would suit your system? also looking to see your spec sheet. We are very interested in doing this for a few of our sites
Hi there,
Thank you for posting your site, really helpful.
I am looking for a company that can install a small wheel in a river that runs through our property. I have no idea where to begin. Are you able to suggest a couple of companies that might be of help? Thank you so much.
Kind regards,
Rod
I find it funny that different sized hydro setups are “micro” and “pico’ when there’s no actual relationship with those terms and they have just jammed in a scale value used in science.
It’s just a hydro setup with a certain output!
Hi, Im located inn the Canterbury foothills of New Zealand and have got 24.5m of head over 1300 m length and the water volume far exceeds my requirements.
Using a simple conc pipe intake feeding out of ground flexible plastic pipe connected to a Pelton type turbine/generator and domestic battery storage system im wondering about what pipe dimensions and pipe class would work? Also what micro turbine/ generators are available to produce approx 5kw of power? Any thoughts or ideas would be appreciated
My property has a river flowing through with about 3 to 4 thousand gallons of water a minute flowing.
I have a dam on the river and I am wondering if there is a way to use the water to make electricity
Lads,
What is the Dam unit shown in the above photo?
Thanks
Hello. I’m very interested in H.E.P but my stream is normally a mere trickl. However when we get rainfall it picks up and when there’s alot of rain it becomes a raging torrent – I suppose it wouldn’t be cost effective ? Wife liked the idea of a water wheel but I’m thinking a small impellor type system might be more feasible ?
I am
Interested in purchasing a ready to go kit for our farm – we have a stream with a lock built in and it has flow above and a 6gt drop off the other side of the lock
I am
Interested in purchasing a ready to go kit for our farm – we have a stream with a lock built in and it has flow above and a 6gt drop off the other side of the lock
Hi I have a 7m head with a 20L/s flow this is a minimum flow rate it can get very large after a lot of rain 100s of L/s in winter mostly, any ideas on capacity to use all year round ?
Many thanks
Where can I buy this marvelous micro hydroelectricity plant?
good afternoon, could someone please contact me regards hydropower
Is 45 litre water per second produce 3000 watt in one second as flow is per second
i have three lakes that drain into a 48″ manhole the water runs continuously 50 gallons per minute or more
i am looking to install a hydro electric generator to power the house and sell back to power company
can you steer me in the correct direction
i am in orange ct over 600 acres drain into my property and have 5 springs
Hi, do you know of any installers in North Yorkshire?
Hi, I have an old watermill, very high flow, existing weir under the house but only 2M head, would be interested to see if there is something that could be done?