NFU Mutual Smallholding Insurance

Author Topic: Anyone using microhydro?  (Read 839 times)

martcol

  • Joined Aug 2018
Anyone using microhydro?
« on: February 09, 2020, 11:33:02 am »
or, possibly more accurately, pico hydro?

We've a stream on our property (or boundry) and I've been researching the possibility of installing a small micro hydro plant. From what I've seen, there is a possibility of getting some quite useable amounts of energy from even 2-4 inch pipes.

Anyone using a hydro system, or designing one?

(Hope this is th eright place, if not, please move it!)
Voss Electric Fence

SallyintNorth

  • Joined Feb 2011
  • Cornwall
  • Rarely short of an opinion but I mean well
Re: Anyone using microhydro?
« Reply #1 on: February 09, 2020, 12:25:34 pm »
No, but please let us know how you get on!
Don't listen to the money men - they know the price of everything and the value of nothing

Live in a cohousing community with small farm for our own use.  Dairy cow, beef cattle, pigs, sheep for meat and fleece, ducks and hens for eggs, veg and fruit growing

martcol

  • Joined Aug 2018
Re: Anyone using microhydro?
« Reply #2 on: February 09, 2020, 02:12:44 pm »
Yes, I did think I might. I'm at very early planning stage, and will probably survey the stream this spring. In my research to date, I had not realised that you can get some usable amounts of power from very low flow rates. I also had not realised that taking water from the stream even if it all goes straight back in requires licenses (it can easily exceed the 20m3 per day extraction limits) I was hoping there may be someone in West Wales (ish) who had already gone through the process.

Penninehillbilly

  • Joined Sep 2011
  • West Yorks
Re: Anyone using microhydro?
« Reply #3 on: February 10, 2020, 12:11:09 am »
We did enquire, but were told you could only use a percentage of the flow, in our case we gave up at that point.

pgkevet

  • Joined Jul 2011
Re: Anyone using microhydro?
« Reply #4 on: February 10, 2020, 05:41:48 pm »
I must admit that when i looked into this (some years ago) if was a case of fall more useful than flow. if it was electrical power I was after then the cost of 200yds of pipe, the tubine and then cable to bring the power back up to the yard wasn't worth it for the tiny stream with a long slope. . The other stream I have is a raging torrent for 3 mths of winter but for the rest of the year it wouldn't run an undershot wheel with enough flow to be worth it or the costs of creating the same. Personally i wouldn't have worried about the legality - neighbours wouldn't care or report it and as a faite accomplis it wouldn't harm anyone (no fish or wildlife affected).
About the only justfication I could see for an economic project here would be if one was enthusiastic enough to cart car batteries down and charge them - of value if one used electric fences and like messing about - but of no real use to me.
« Last Edit: February 10, 2020, 05:48:49 pm by pgkevet »

mab

  • Joined Mar 2009
  • carmarthenshire
Re: Anyone using microhydro?
« Reply #5 on: February 10, 2020, 06:46:37 pm »
Yes, i have a micro-hydro installation: i have ~20m drop, i use a 90mm hdpe pipe (alkathene water pipe), and potentially could get 970w if i ever get it finished - there's more than enough water at the mo; it's currently running ~280w which covers my needs.

I'm following pgkevets strategy of installing 1st and i may sort out planning / permissions retrospectively. I think their standard requirement is to limit you use to 70 percent of the flow, leaving the remainder for wildlife which seems sensible.

what are you hoping to get from it? How much do you want to spend as it's likely to have quite a long payback period if using off the shelf kit? I paid £500 for the pipe alone.


Are you thinking of charging batteries or grid-tied?

pgkevet

  • Joined Jul 2011
Re: Anyone using microhydro?
« Reply #6 on: February 10, 2020, 10:30:45 pm »
sadly i wouldn't get 20m drop with 200m of pipe..probaly only 8M but potentially a much larger pipe. but still fall over flow.I you can get a consistent 970w/hr all year round then 20KWH is useful but needs to go to staorage - where the expense comes in...something like 2 powerwalls @ £5K each but still better value than rooftop solar.

mab

  • Joined Mar 2009
  • carmarthenshire
Re: Anyone using microhydro?
« Reply #7 on: February 11, 2020, 12:07:49 am »
well i get 20m drop with ~118m pipe; a theoretical 970w during wet weather (like the past few months); in an average year: 300w (potentially more but need to finish installation) for 6-8 months, and 6-8 weeks with insufficient water to run at all; and 50-250w the rest of the time. in 2018 i had 3 months without hydro, but plenty of solar; 2017 it ran right through without dropping below 150w.


for storage I have an ageing array of AGM (lead acid) batteries - 420Ah at 24v, but with the hydro running >200w the battery mostly sits at float voltage and is used to provide the start surge for freezers, etc. I tend to match my use to available power, using washing machine when the sun shines for e.g. so the battery really only gets used when the hydro is shut down and I'm relying on solar (930w of panels).


300w will run the fridge, freezer, lights, computer, router, radios, let me run the dehumidifier a few hrs and still dump enough energy to give me a hot bath every day - hence upgrading the system is low priority.


I do actually have a grid connection but try not to use it - the longest sustained grid free run was 9 months - and only had to switch to grid as the builder was running his cement mixer all day.

martcol

  • Joined Aug 2018
Re: Anyone using microhydro?
« Reply #8 on: February 13, 2020, 09:30:28 am »
Apologies for the delay in getting back - that storm caused quite a bit of tree damage. Another this weekend. Ho Hum.

We have a similar situation to some of you. A stream with a long run to reach 15-20m head. Probably 2-300m, and I'm looking at 90-110mm mdpe (alkathene). That will be the best part of 2k. We do have plenty of flow, though - stream is about 8ft wide and a foot to 18 inches in depth. I've calculated around 600watts at 60-70% efficiency.

Based on my research (early stages), I could use a pelton or Turgo wheel, utilising the full head but at lowish flow rates. I could also use a lower head but pull a lot more water and use a screw or prop type turbine.

It seems that for anything over 20m3 a day I will need an extraction license and maybe even a return licence for the water.

Despite the costs, which could approach 5k, 600W is around 15KW per day, which eliminates our electricity bills, and allows extra for some water heating, or possibly, looking forward, an electric vehicle. With that in mind, the payback time on the project is less than 5 years, and then we're earning money.

Clearly this is all theoretical, and will depend on me doing all the work, and a lot more research first.

I hadn't considered doing it and then approaching the authorities retrospectively, as I'd be concerned they'd tell me to rip it all out.

I started thinking about this by watching a pile of youtube videos, by the way. The best of which was Kris Harbour Natural Building. Worth a watch.

https://www.youtube.com/channel/UC5rT7F0PGNuD54rJ9kzgWzw

 

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