Project - The Hydro-Electric System Design & Discussion

RE: Project - The Hydro-Electric System Design & Discussion

dang74 — Sun, 23 Oct 2022 21:42:44 GMT

One low tech suggestion for dealing with the variability of water flow from the stream is to schedule the CNC stuff during months with ample water flow. Conversely when the stream slows down do low current stuff. So your work will be divided into seasons, which if you think about it us how 'we' used to live before the industrial revolution.

RE: Project - The Hydro-Electric System Design & Discussion

beacon_dave — Sun, 23 Oct 2022 11:47:18 GMT

"...I think this qualifies as a "low head" system..."

According to the definition at:
https://www.energy.gov/energysaver/planning-microhydropower-system

"...Low head refers to a change in elevation of less than 66 feet (20 meters), and ultralow head refers to a change in elevation of less than 10 feet (3 meters)..."

RE: Project - The Hydro-Electric System Design & Discussion

robogary — Sat, 22 Oct 2022 18:22:54 GMT

This is an interesting idea to investigate. The upfront cost seems the scary part, maybe its possible to do in stages and use savings to build the system up. One thing I've wondered if the stream has a constant flow , to deflect flow during the peaks during storms to another path to avoid destroying the generator. I'd also wonder if the generator could start out attached to an old fashion wooden waterwheel for a little while to gather physical performance data, and experiment with bucket width and wheel diameter. I didnt research, maybe curves exist for this experiment already.

RE: Project - The Hydro-Electric System Design & Discussion

DAB — Sat, 22 Oct 2022 17:51:25 GMT

You indeed have a low head, but you can still get some useable power, just do not expect to power your house.

Maybe charge your cell phone batteries.

RE: Project - The Hydro-Electric System Design & Discussion

beacon_dave — Sat, 22 Oct 2022 16:00:57 GMT

Do you have the elevations which these two photos were taken at?

What's the access to the stream like along its length? Is it all above ground or do parts of it disappear underground?

Can you perhaps float your 2" poly tube down the stream when there is a bit more flow to make it easier to install?

Any signs of wildlife using the stream? If you successfully divert most of it through 200m of pipe, then you will start to change the environment in that 200m section. With motorised valves you could however create managed pools along the route.

RE: Project - The Hydro-Electric System Design & Discussion

beacon_dave — Sat, 22 Oct 2022 14:22:35 GMT

"...Currently, it is October and the dryest part of the year in my area. There is still flow in the stream right now. Not much, but it is running..."

Best time to get your groundworks done for the intake I'd imagine. Or at least some useable anchor points to work off.

Will be interesting to observe the site over a full year to see how it changes. ESP32-CAM project?

RE: Project - The Hydro-Electric System Design & Discussion

beacon_dave — Sat, 22 Oct 2022 14:09:58 GMT

"Many people run a generator for several hours every couple of days, or as needed ... And with gas prices around $6.70/gal right now, It's the most expensive way to generate electricity that I can think of. "

You have a forest... You can generate with steam power instead of gas! [emoticon:c4563cd7d5574777a71c318021cbbcc8]

RE: Project - The Hydro-Electric System Design & Discussion

beacon_dave — Sat, 22 Oct 2022 14:03:17 GMT

"...I have looked into building my own, and that's not off the table, but there are off-the-shelf options available that are within the budget. If they are more efficient and can generate more power, that is going to be very attractive..."

Off-the-shelf may get you started quicker, but when it comes to optimising the system then it may become more problematic.

I can see a couple of tricky bits in the design for an optimal system all year round.

Working with nature here, so wide range of changes in water supply throughout the year from virtually none to flash-flooding. Whereas generation appears to tend to be optimised for steady rate.

You perhaps either tame the river e.g. Hoover Dam style (no project too big !) or alternatively need to adapt the generation such that it can dynamically changes to the supply (we have microcontrollers!).

My gut feeling would be that you have multiple generators that you bring online as the supply increases and divide the supply between them. That way you can have a lighter more efficient generator optimised for the lowest flow rates and as soon as it maxes out a second identical one kicks in to make use of the surplus. Alternatively, you completely divert the input from the light flow generator over to a medium flow generator and then over to a high flow generator. Each optimised for a different range of flow rates.

If you attempt to do this by switching nozzles alone, then your generator needs to be designed to be strong enough for the max nozzles / max flow scenario, however that means that during low flow rates there are going to be extra losses due to the increased weight and friction.

If you build your own, then Clem's super strength engineering resin might be worth trying for the turbine blades.

/challenges-projects/element14-presents/f/forum/51028/i-am-3dprinting-nails

Being able to 3D print your own would allow for optimising the design.

The intake screen / collection box looks like it can be a bit problematic as well. Eventually you want to optimise for different flow rates so as not to waste any of that precious water. However, at the same time you want to keep the debris out which generally requires some overflow flushing going on. Perhaps this could be made dynamic where the flushing is periodic rather than continual so as not to waste water.

Just looking at the autumn leaf fall here in the back garden, and the wet leaves rapidly smother a drain, so I suspect it wouldn't take much to smother an intake box and divert the water over to top.

You could perhaps have multiple collection boxes in a ladder to handle different flow rates as well as redundancy should one clog. Debris traps could be placed between them. Alternatively, a siphon intake could perhaps solve a lot of surface debris problems.

RE: Project - The Hydro-Electric System Design & Discussion

beacon_dave — Sat, 22 Oct 2022 12:28:52 GMT

"...As you can see, we get about 16m of elevation drop over about 200 meters in distance. I think this qualifies as a "low head" system..."

It may be low, but it could be a lot worse. [emoticon:c4563cd7d5574777a71c318021cbbcc8]

This 12/24V DC turbine for example is rated for 3' to 10' of head (about 1 - 3m):

https://www.langstonsalternativepower.com/micro-hydro/6-low-head-hydro-pvc-housing-12-24-volt/

Looks like they are prop impeller-based judging by this unboxing clip:

https://www.youtube.com/watch?v=KiKWyY7ugSM

There is a video of a similar one in operation using a siphon intake from a reservoir pond here:

https://www.youtube.com/watch?v=V82SVeVXKcA

However, this 250W+ Turgo generator system looks like it may be closer to what you have to work with in the way of head and penstock length:

https://www.youtube.com/watch?v=Flz4_OE4CGI

25PSI at the turbine so perhaps less problems with connecting hoses [emoticon:c4563cd7d5574777a71c318021cbbcc8]

RE: Project - The Hydro-Electric System Design & Discussion

beacon_dave — Sat, 22 Oct 2022 11:44:46 GMT

For those new to this there is a short video series on YouTube of a guy setting up a micro hydro system from scratch that may help visualise some of the areas mentioned above.

https://www.youtube.com/watch?v=zPIec9VCrOY&list=PLTrfbWw_mKRL5Ae_x1Q4-1pOs0NJGwnzi

Plumbing appears to start getting a bit tricky at around 50PSI.