Backyard Aquaponics
A place to discuss aquaponics

that's a lot of power to use up Sleepe, how about a stack of electric kettles and have a tea party for your neighbours?

You need to store the energy, one method is to pump as much water up as high as you can get it as quick as you can then use an on demand micro hydro unit to power other things later on.

Pete.

That's the system I have partly in place here, except it will be pumped by solar power. One of these days I'll get around to finishing it! You do need a lot of water and a lot of head to store much energy though- I have 85m and a 23000litres here, but that will only give me about 3kWh.

For how many hours Gordon?

At least the same volume is required at both ends.

I built a boat in my shed and needed to do a buoyancy test, so I built a temporary tank inside the shed and pumped 7500 Lt up 8.0 m over 140 m in 1.5 hrs in solar time (daylight). Did my tests and measurements then let it drain all the way back down into the bio pond. Watching all that water rushing back down got me thinking about hydro.
There's plenty of info around on micro hydro power but unless we need it a part of an off grid source or energy storage system it seems an unusual proposition.

Pete.

3kWh is 3kWh, the amount of extractable energy stored, accounting for pelton wheel/alternator etc losses. ~500W for 6 hours, or 250W for 12 hours, doesn't really matter until you try to do it quickly, say at a rate of 3kW, when you will get significantly less energy, unless you spend a fortune on large diameter pipe, as the 63mm pipe I have would have too much frictional loss at 3kW. I'd lose over 1/4 of the stored energy due to friction at 3kW, so there'd only be a bit over 2kWh of stored energy in my 23000l.

BTW, the rate of power to lift 7500kg up 8m in 1.5 hours is only about 110W @100% efficiency, but I bet your pump was using a lot more power than that!

So Sleepe what did you finally do ?

What I meant was for how long does it take for your system to (intermittently or not) efficiently use the 23 KL, or does the solar powered pump(s) replenish the head before it runs out.

What is the water stored in top and bottom?

Pete.

Hard to say, as it isnt all hooked up yet! However, I'll be testing for the best efficiency, and using it at that rate.
Poly tanks top and bottom.
I'll be using it to reduce daily depth of discharge on the Lithium battery.

You really don't have surplus power... you have excess capacity.

If you put a small load on the generator, then the governor closes the throttle to keep the engine speed constant without using as much fuel... if you load it to capacity the governor will open the throttle to maintain the engine speed and it will take a lot more fuel to do it.

It is slightly more "efficient" to match the capacity of the generator to the peak load; but the difference in efficiency between 20% load and 100% load isn't enough to worry about unless you're using the generator as your primary power source.

excellent post badger
Plus if a diesel gen set is just ticking over its a lot quieter than revving it head off

Ended up running it about every three weeks to charge the internal battery and run a charger to keep up the larger battery bank plus anything else I can find to load it up.
For some reason I was under the impression it was not good to only lightly load diesel engines, there again I don't have much to do with diesels apart from the tractor which is old as and just seems to keep going.

It's not good to lightly load them all the time, it glazes up the bores.

It's OK to do it occasionally. The other day I had an 80KVA generator running a caravan for 12 hours. Even with the air conditioner running it was only using 1500W on one phase. Then I started up a pump and it had 30,000W of load for the next 5 days whilst I pumped 20,000,000L of water against a 35m head.

Every now and again start it up and plug a few big tools into it, or kitchen / household appliances. Steal the wifes vaccuum and clean the shed whilst you cook up a feed in her electric frypan and boil the kettle for a cuppa.

Adding a 15A input (as fitted to a caravan) to your house with a changeover switch for blackouts should only cost you $3-450

I've got the same generator as yours but the 3 phase version among the various generators in the shed at work. It's a nice motor, the chinese did a good job of copying a yanmar. I use it to run 3phase bore pumps

Thanks Sean, probably the kitchen appliances are the go at least it will result in a "free" Sunday dinner.

If you've still got an electric HWS you could plug that in for about 3 Kwh.

Pete.