New to Hydro Power alot of questions

[Tom Nolan]

I have a 10' river in front of my house. At 150lbs if I stepped into I would end up 100' out in the ocean with how fast it runs
I have a lot of reading to do but the elevation drop is only about 10' on a 120' run.
I have string lights around my deck that I would like to power from the river and then I got thinking.
Could I not use the river to run a pool heater.
The pool heater would be a 10Kw.
I have no heater now because at .13Kwph it's just not worth it.
Is there any options on using power from the river?

Thanks for any advice

[Rob Beckers]

Hi Tom,

Hydro power is not my strength, but since nobody else is answering I'll give it a try.

EcoInnovation, a New Zealand manufacturer of small water turbines that go under the "PowerSpout" name, published a nice chart that shows head (how high you can drop the water down from), vs. flow rate, vs. output power from a turbine. You can find a copy at https://s1.solacity.com/docs/EcoInnovation/PowerSpout-Model-Selection-Chart-Metric.pdf

You don't mention flow rate, but if you can create a 10 foot drop you'd need around 1000 liters per second (about 16,000 GPM) to intersect that 12 kW output power line (i.e. your pool heater). That's a lot of water! Powering the string lights may be easier...

What that graph shows very well is how things get a heck of a lot easier if you have more pressure (head) to work with.

Some people have built relatively simple undershot water wheels (though with 10' you can do an overshot wheel), and generated a kW that way. The advantage is that you don't need to change the water flow for a waterwheel, no need to divert part to keep it high. A waterwheel just drops in the water.

-RoB-

[Abdullah khan]

Here's a helpful reply you can post:

Re: New to Hydro Power - a lot of questions
Hi Tom,
Great to see someone thinking about harnessing their river! Rob gave some excellent points. I wanted to add a few thoughts:
With a 10-foot head on a 120-foot run, you're working with low head hydro, which does limit your options somewhat, but it's not impossible.
For your string lights — this is very achievable! A small low-head turbine or even a simple waterwheel could easily handle a few hundred watts for deck lighting. That's a realistic starting goal.
For the 10kW pool heater — as Rob pointed out, you'd need enormous flow rates. However, consider this alternative: use the river to generate whatever power you can (maybe 500W–2kW realistically), and use that to offset your electricity bill rather than running the heater directly.
My suggestions:

Start small — power the string lights first and learn the system
Look into Archimedes screw turbines which work well with low head situations
Check out the PowerSpout PLT model specifically designed for low head applications

What is the approximate flow rate of your river? That's the key missing number that would help everyone here give you more specific advice.
Good luck!