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Flowing water is THE most efficient way of generating electricity.

Guys take washing machine motors and make small generators that they plonk into a stream and generate power.

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I was thinking along the line of having a 100 000l dam at the top of a slope, a 10 or 20m drop and another dam to catch the water. You pump it up by solar during the day which is feasible, and run it back overnight to produce enough to maintain your battery charge. Getting valves to open and close at specific times is easy enough.

From powerspout's website 100 000l over 6 hours is about 5l/second, at a 20m head gives you 450W at 80V.

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  • 2 weeks later...

DeepBass9, I'm also considering something like 100KL as a long-term solution similar to yours.

Batteries are a FAR more efficient way of storing power (92% round-trip efficiency for LiFePO4 batteries vs something like 40% efficiency for small-scale pumped storage), but if I'm pumping with excess solar / wind, then I don't really care about the efficiency. Battery replacement costs also play a BIG role. If I'm going to have to spend R50k+ every 5-10 years, then I'd rather make the effort up-front and install pumped storage, which my grandchildren will still be using with minimal maintenance.

I've looked at http://rainqueentanks.co.za/, who make a 100KL reservoir with a 10m diameter for about R25,000, which is a LOT cheaper than plastic tanks. Easier to transport too, as they can sell you the loose sections and the plastic liner folded up.

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  • 5 months later...
On 4/25/2016 at 2:39 PM, hakonnissen said:

DeepBass9, I'm also considering something like 100KL as a long-term solution similar to yours.

Batteries are a FAR more efficient way of storing power (92% round-trip efficiency for LiFePO4 batteries vs something like 40% efficiency for small-scale pumped storage), but if I'm pumping with excess solar / wind, then I don't really care about the efficiency. Battery replacement costs also play a BIG role. If I'm going to have to spend R50k+ every 5-10 years, then I'd rather make the effort up-front and install pumped storage, which my grandchildren will still be using with minimal maintenance.

I've looked at http://rainqueentanks.co.za/, who make a 100KL reservoir with a 10m diameter for about R25,000, which is a LOT cheaper than plastic tanks. Easier to transport too, as they can sell you the loose sections and the plastic liner folded up.

damn! 100KL! That'a boat load of water! And a big storage vessel. Pity I live in the city where something like this would be neatly impossible to implement. 

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9 hours ago, SilverNodashi said:

damn! 100KL! That'a boat load of water! And a big storage vessel. Pity I live in the city where something like this would be neatly impossible to implement. 

I looked at that site, realised two things. That's a standard farm dam used for livestock in Namibia... although "Nampower" is now rolled out to farms more widely so lots of farmers resort to using a 5000 liter plastic tank and pumping on demand so they aren't as common anymore. And second, my father has such a dam on the farm, some meters up. I cannot remember exactly, just that the pipe running from the borehole up the hill is a high-pressure line (has to be) with connectors that sit on the outside of the pipe. I also remember how we had to fix a problem one day and that the pressure was so high that I could not get a stopper into the pipe (just the weight of the column of water, not connected to the dam upstream). So he sort of has the exact setup there to make something like this works... except perhaps, I believe it's a 2-inch pipe running up that hill, might not have enough volume for large throughput, but baseline... likely an option.

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31 minutes ago, plonkster said:

I looked at that site, realised two things. That's a standard farm dam used for livestock in Namibia... although "Nampower" is now rolled out to farms more widely so lots of farmers resort to using a 5000 liter plastic tank and pumping on demand so they aren't as common anymore. And second, my father has such a dam on the farm, some meters up. I cannot remember exactly, just that the pipe running from the borehole up the hill is a high-pressure line (has to be) with connectors that sit on the outside of the pipe. I also remember how we had to fix a problem one day and that the pressure was so high that I could not get a stopper into the pipe (just the weight of the column of water, not connected to the dam upstream). So he sort of has the exact setup there to make something like this works... except perhaps, I believe it's a 2-inch pipe running up that hill, might not have enough volume for large throughput, but baseline... likely an option.

2" is PLENTY! ;)

Put a hydro turbine in it and see what it does. And then build a system like this, but you'll need two days, one downhill where the water can flow to at night, and one uphill where it can be pumped back up freely during the day. 

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50 minutes ago, SilverNodashi said:

It depends where you are. I drove past some dams on my way to Middelburg yesterday that was plenty full. Some farmer's "spul punte" was running full blast at 7am in the morning. 

Now you make me wonder what a Spilpunt is in English. I believe it is a SPILpunt, because it pivots around a "spil", a fixed point. Afrikaans is such a beautiful and hard language... :-)

Pivot-point?

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8 hours ago, SilverNodashi said:

 Some farmer's "spul punte" was running full blast at 7am in the morning. 

At one time centre-pivots were hellishly expensive and were affectionately known as "skuld punte". Cost have come down and it is often the cheapest irrigation system to install, especially the big 30-50ha ones. The costs for the length of the pivot increases linearly  whereas the area covered increases exponentially. 

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1 hour ago, Chris Hobson said:

At one time centre-pivots were hellishly expensive and were affectionately known as "skuld punte". Cost have come down and it is often the cheapest irrigation system to install, especially the big 30-50ha ones. The costs for the length of the pivot increases linearly  whereas the area covered increases exponentially. 

I remember many moons ago there was an article in the Landbouweekblad about a farm who built his own pivot -- because commercial ones were so expensive. I think he used a small petrol engine to drive it.

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  • 1 month later...

Back to the power spout.....
I am considering putting one or two of these in my stream. I have two 2,5 ha dams. 150m from the spillway of the top dam I would have a head of about 7m. This is below the house which is convenient for cables to my inverter room. My setup is as follows:
9kw pv
3x60 amp Mppt
24x2v mte 25 FNB cells
10kw Microcare inverter.
My problem is a 20m lap pool with a 1,5 kw pool pump. Without the pool I have 3 days autonomy.

My question about the power spouts is that at R32 000 are they a good deal. I am going to probably need two to deal with summer and winter flows. I been given 34 x 6m x 250mm plastic pipes for the penstock. I would need to do the civils on the spillway for the penstock inlet. I think this will cost about 100 to 120k for the whole lot. The power spouts should produce between 500 w to 1300 w.

What say ye?



Sent from my iPhone using Tapatalk

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I have made provision for an extra 3kw pv. The problem is that when it's sunny I have plenty of power. When it's cloudy I have not enough. Typically I produce from nothing to 600 w on a cloudy day. Adding 3kw pv would not help.


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