rain catchment + water turbine = Pico Hydro Power
 

a recent project in rain collection got me interested in Pico Hydro Power

it rained the other day and filled a 50 gallon drum in 10 minutes

so why not make some electricity too?

has anyone had any experience in this?



Pico hydro - Wikipedia, the free encyclopedia

Make: Online : Bucket-borne hydroelectric generator



http://blog.makezine.com/upload/2008...ro062708_2.jpg
http://blog.makezine.com/upload/2008...ro062708_3.jpg

Unless you live in a place where it rains often, then this may not be cost-effective. The output would not be kilowatts, but only a few watts. How often does it pour, and for how long (answer may vary denpending on where you live)? Most rain is not more than a drizzle for hours at a time, and there is not much energy in a gutter that is just dripping, probably not enough to overcome internal friction. Collecting water on the roof until there is a certain amount and then letting it rush down onto the turbine may be better, but holding a ton of water on the roof isn't a good idea.

On the other hand, maybe there is a better way to it? Maybe a formula for how much power is to be had per roof area, where the inputs are volume of water per area unit per time unit (how intense) and head of water (height difference between roof and turbine). Very interesting... Now I have something to think about :)

It is pretty easy to calculate from gallons of water to pounds, and measure the vertical fall, etc, to get the potential HP (33,000 lb-ft per minute) and get from there to watts. One problem with tiny pelton wheels is that as you scale down, the boundary layer in the nozzle starts to dominate, and efficiency drops. I'm fond of systems with stored water and two ponds or tanks separated in elevation instead of a battery to store available wind power or whatever. However, for low-draw, on-demand generators, I think we will find that small, positive displacement diaphragm pumps will be very suitable, running backwards.

thats kinda what i was thinking about

collecting water in tank/drums and once the level is high enough,
releasing a valve to push the water towards the turbine

it may only be for x amount of time, but its power

might be good when theres a flood and the power goes out

why dont water towers use these?




and it rains a lot in hawaii

The average annual rainfall over the entire state
is equivalent to 8,000 billion gallons of water

Water towers are only tall enough to generate the desired working pressure for sprinklers, etc. There would be no point in pumping water to a higher tower and then recovering some of the pump power with a turbine.

no pumps

i meant water reservoirs not filled through a pump

just by rainfall

It's a neat idea but I feel like others have said, it's awful complicated set up with many moving parts (things to break). It can charge 11 cell phones which was the intended purpose I guess, but that's still only like 50 watts max. (Total guess there)

Thats almost a single light bulb and only during peak rainfall.

Wouldn't a solar cell phone be better? How big of a panel is necessary to get the 5V 0.7A necessary to charge a phone?

(3.5Watts)

i believe there are $20 pico generators that have an output of 300-500 watts

Believe it or not, in Colorado it's illegal to catch rainwater unless you have water rights, and hardly anyone in Colorado has the water rights to their own property. I know people who've gotten in trouble catching rainwater to water their horses and trees.

Water law in the west is complex, and mostly ridiculous.

Hm... Seems like rain water isn't really property water until it reaches the property... so if you're catching it out of the air, and the water rights apply to water on the property, it's not really subject to water rights laws, eh?

I mean, unless Colorado's title laws allow land ownership to the area of the land deed, including area below ground and above ground, in which case, whoever owns the water rights to that property would still have property rights to the water falling from the sky.

However, if CO's deeds don't include the area above the land in their ownership (which must be in detail, of course), noone can say anything about capturing rain water, as ownership doesn't take place until it becomes property water.

Someone should look into that, really.

Like I said, water law is complex. Mineral rights laws too. You can "own" a piece of property and not have the rights to streams that flow across it, or under it, or the rights to gold that is discovered on your property, or oil or natural gas that is discovered beneath your property, or even the trees growing on your property.

Believe me it's being looked into all the time, and the people benefiting the most are lawyers.

I know all about mineral rights. There are 1,000 companies trying to buy them from people out here because of shale oil and natural gas pockets in PA.

NY doesn't have to worry about it, because in NY, your land isn't really yours, from what I'm told. In other words, the deed only covers the ground you can see, and no depth of earth.

There is a high doller remote hunting/fishing camp that I had delivered stuff to. They had a 2 inch pipe running 100 feet down a stream (with about 15 feet of head) they ran a small fridge and an FM radio.

No wonder the next wars will not be over oil, but over water:(

So what happens when you dig a hole?

I've been told that in certain parts of NY, all land modifications require a permit.

I can't verify this, because I don't live in NY, and wouldn't own land there if you gave it to me. (Because I'd sell it at a ridiculously low price as soon as possible, just to get rid of it.)

Of course, I'm only repeating what I've been told by landowners in NYS, as I have no real experience in dealing with Deed laws up there.

I live in PA. You can make walls from tires here.

"So what happens when you dig a hole?"

Giant radioactive worms pop out demand to see your permit.

Were you ever able to discover anything with the 50 gallon drum? I"m really looking into this myself for third world countries.

This is something I am also very interested in.
We have constant trickle of spring water on the hillside where we live. (low volume) but we have 50m of head to get the pressure up.

My idea ...
to collect various sources of water - roof /spring/ land drains into a holding tank ... 1000 litre IBC (cube) tanks are freely available
look up Intermediate bulk container - Wikipedia
.. and it would be possible to "daisy chain" them if capacity was required.

The original poster talked of opening a valve to start it all off... however I think this is may not be necessary. A simple Bell Siphon could automate this

Rainwater starts to fill the holding tank(drum).
Siphon hits tipping point near full tank and starts to flood generator pipe.
Drives Generator until holding tank is depleted - up to the point where the siphon is broken.
If rain continues to fall the tank will fill again and the cycle will begin again automatically.

So the generator will cycle ... it doesn't sound ideal but in a situation where there isn't a huge volume of water it could be used to charge batteries.
Also in the situation where a direct connect system falls below the required flow to drive the generator - not enough torque - this would build up enough of a buffer to mean the water is not wasted by just trickling past the generator...


Hopefully what I have written is understandable!
I would be interested to know if anyone has tried something similar...
or if it is just a dumb idea:o

What are the odds of having two consecutive first-time posters?

Rain is one thing but why not hook up a turbine to your house water supply? Everyone uses some water; mains pressure can be quite high.

I guess it is the expense of adding a turbine to your mains supply for very little gain. Running a tap in the house to fill a kettle would produce "next to nothing"

What I am imagining is Dinorwig on a much smaller scale ;) ( electricmountain dot co dot uk ) ... buffering the water and letting it flow with enough force to produce a reasonable amount of power albeit for a 'short' time /not constant

What is your flow rate? 50m of head is good, but the flow has to be there.

My parents have an underground stream that flows 4gpm with a 25ft head, which is useless. They also have a creek with perhaps 400gpm flow and 1ft of head; equally useless. A solar charger is better, cheaper, and less complex.

Pico hydro power doesn't make any sense.

Interesting topic. It may not be useful to most, but as the Wikipedia page says, if you have the water flow it can help offset solar in the winter. It might also depend on how much power you actually use. For instance, my living room/dining room overhead light is a 2W LED, putting out a 25W incan equivalent. It's enough to eat, talk and play board games. I imagine if someone had a very sparse living situation in a cabin or similar they could power a good amount of their daily electricity use with pico hydro. If a couple lights and a phone charge are all you really need, and you have the water flow, why not?