I realize this thread is 11 months old but it came up randomly in my news feed. I’ve put together some math for a small scale water wheel and a couple links of where that math came from. I also tested the torque of my creek with a home made paddle and torque wrench and it matches the math which is a good sign. Took me a couple days to sort it all out in my mind but it’s actually fairly simple if you can measure how fast your water is or can move and factor in how many square inches or feet of that moving water you can use. I’ll paste the info below and the links also. I did math to power an electric car but it’s easy to covert or simplify.
Water wheel car charger calculation estimates
Need about 400 square inches of contact in water moving at 5 FPS to get about 600 continuous watts. 600x24=14.4KWH
That’ll produced about enough energy to basically get her free miles on a Tesla Model 3 electric car with my average of 15000 miles per year.
Calculated about 15KWH of battery use on average per day. In this scenario.
4 inch pipe has an area of about 50 sq inches @ 5fps=75W or 1.8KWH per day
4 ft drop = 15 FPS or 225W 5.4 KWH day
6 inch pipe has 113 sq inches
5fps = 150w. Or 3.6kwh day
4 foot drop 15 FPS 450W or 10.8kwh day
An 8 inch pipe has 200 square inches.
5 FPS should be 300w or 7.2 kWh day
4 ft drop 15 FPS 900w or 21.6 kWh day
Need an 8 inch pipe and a 2-4 foot drop to create enough power from a water wheel to fuel the Tesla model 3 I don’t have yet, year after year
https://www.backwoodshome.com/design-calculations-for-no-head-low-head-waterwheels/
http://wentec.com/unipower/calculators/power_torque.asp
