[tobytoby]

Has anyone any knowledge or plans/equipment/batttey storage on how to tap into the possible free power that runs at the bottom of my field? I have looked on the web, but it is all based on harnessing the power to sell back into the grid? - Has anyone tried to do similar, does it work, is it worth the hassle?
It should be possible, especially as we get plenty of rain in the west coast of Scotland?

[mab]

if your burn has enough power then it should be possible; the trouble is there's not likely to be an off-the-shelf solution for such small-scale hydropower.

If you're electrically / mechanically minded you could get ideas from this forum on diy renewable energy (sorry dan, not trying to divert people away, but there's too much info to transfer here).

http://www.fieldlines.com/board/

if you want off the shelf you might be better with a small wind genny / solar panel and battery. I think rutland - who make fence energisers - also make wind gennys for this purpose - they're good generators, but not cheap.

mab

[tobytoby]

i have access to a 1m2 solar panel, but as yet i have not done anything with it help - i usually end up taking the more challenging route?

[lazybee]

A friend of mine, well colleague really. Gets a large part of his income from renewables. When I told him I had a river on my land he said if it was him he would fit a heat source system.  If you have a small river it can be used the same way as ground source heating. A river is much more efficient for heat exchange than the ground and you don't need so much piping. If only my river was closer to the house as I would have installed a system. A hydro system is very expensive. Someone I used to work with (John Riley, mentioned in the link) http://www.saos.co.uk/documents/CairngormMonitorFarmMeetingRenewableEnergyMar09.pdf a couple of years back has one on his farm near Aberdeen, He had a disused plant on his land and started it up again. I know he gets a good income from it though.

[mab]

a 1m2 panel - do you know what it's output is (amps / volts)? or which type of panel (mono/polycrystalline / amorphous)?

If it is a crystalline panel, at that size it ought to be adequate to support a fence energiser like mine (ESB200) by itself (though you probably want at least a 90Ah battery (deep cycle)).

[tobytoby]

Thanks Mab

I will check spec & outputs and revert.
Would it be possible for you to post a diagram/photos of your set up - i know hee haw about electricity, but i know a man who does who could set it up for me? What was your set up costs?

[lazybee]

Hello, by far the simplest way to check the output and to avoid confusion, is to put it out in the sun and put a multimeter on it. I have a small panel about 30cms square operating my 12v motor front gates.

[tobytoby]

Lazybee - Thanks

Mabs - The techy info is as follows;

Max output 1.8Amps
Max output  40 watts - max system voltage DC600
Its a Polycrystalline unit

What do you think i could run from it or charge up?
Thanks in anticipation

[mab]

Hmm...  I was expecting slightly more amps for that size of panel. Does it give a Voc (open circuit) or Vmp (max power) value?

1.8A; Is that Isc (short circuit) or Imp (max power) - I assume the latter. It might struggle in midwinter without some help. It'll be a case of try it and see.

what you need is a battery
A charge controller
A fuse - don't forget this as the battery can start a spectacular fire if shorted.

Would it be possible for you to post a diagram/photos of your set up

Don't think I've got a diagram - and it would just be confusing; My system has a sun tracking solar panel (~280W) two 24v batteries, one 12v battery, and runs the lights, radio, laptop (including the TVcard), fridge, solar waterheater pump, fence energiser and, in sunny weather, the inverter. I've almost got it to run the washing machine, except that the w/m keeps turning on it's heating element which overloads my inverter - Bah!  The load from the energiser is almost insignificant in that lot.

There's a diagram on this website - if you ignore the inverter bit:
http://www.kitenergie.com/information.php?info_id=94

Solar panel:
According the theory, you should mount the solar panel south facing at (90°-(Your latitude+24°)) up from vertical - e.g. for me at 52° north I should mount it at 14° from vertical. This seems steep but makes the most of the winter sunshine. If the winter months have a lot of overcast days then you might want to point the panel up more than this, so that it 'sees' more of the overcast sky (I tend to leave mine at ~45° midwinter for this reason).

Battery:
OK, you need a battery - Ideally a deep-cycle, but these are very expensive, so you may prefer a 'leisure' type.

what size? This is where it gets difficult - it depends on how sunny it is where you are, and how long you can go without a bright day.

An energiser like mine uses up to 120mA -so that's taking 2.9Ah out of the battery every 24 hours, or 20Ah in a week. Batteries should not be discharged below 50% of their rated capacity as a general rule - the deeper you discharge them the sooner you will need to replace it.

A 100Ah battery would give you 2 1/2weeks of power without ANY charge. In reality, batteries work more efficiently at low discharge rates so you would get more than 3 weeks for 50%

With 1.8A from your panel and battery losses you will need 1.5 hrs of full sunshine to make up a days loss. A bright overcast might give you 25 - 50% of the 1.8A. a dull day might give you <5%. Obviously, the problem is midwinter when days are short and dull. To make matters worse, batteries don't like being cold.

personally I would look for something like 90-100Ah - depending on what I could find cheap.

charge controller:

If you've got a 'flooded' type battery (i.e. one with caps which you can top up with deionised water and not a sealed /gel/AGM type) then you probably don't need a charge controller - 1.8A won't seriously overcharge a 100Ah battery, but you may need to top it up more often in the summer.

If you don't have a charge controller then you need to have a diode (rectifier) in series with the solar panel; this stops the battery draining through the panel when its dark. Some panels have a diode built in to the junction box some don't.

Diode: http://cgi.ebay.co.uk/10-x-1N5408-3A-1000V-Silicone-Rectifier-Diode-/130458400581?pt=UK_BOI_Electrical_Components_Supplies_ET&hash=item1e5fed3745

If you do have a charge controller then something like this might be what you want (I can't recommend a particular type - I make my own). If you have a sealed battery, then you need a controller, but you need to make sure that you can set the controller voltages to match the battery manufacturers specification.

http://cgi.ebay.co.uk/12-24V-200W-Solar-Panel-Charge-Regulator-Controller-/270757142666?pt=UK_Gadgets&hash=item3f0a62208a

The advantage of a controller like the one shown is that it protects the battery from overcharge, but also from overdischarge - it disconnects the load if the battery voltage drops below the setpoint.

What do you think i could run from it or charge up?

Depends how much sun you see. 

Well my gut feeling is that it'll run the energiser for 10 months of the year, and maybe 12. In midwinter you're not likely to have much to spare to run other stuff. I turn my fridge off for the winter and I still sometimes have to turn to the grid for power.

If you want to use it to power other stuff for the rest of the year, then you could probably run LED lights & a small radio assuming your not using them every day/ all evening.

most 12v LED lights or 12v fluorescent will run quite happily on the battery.

As an aside I found these a few weeks back and did some tests:
http://www.tlc-direct.co.uk/Products/LTMR7WW.html

They will work on any voltage from 9.5 up to 30v - I use them on 24v - though it probably invalidates the warranty. 

[Plantoid]

Not sure if you need permission from a water authy to " interfere " with the  flow of the water etc or planning permission.

 Is there enough fall to get a six foot or more head  if you tap in higher up the stream & run a 19 mm or bigger alkathene pipe down to the generator ?
 Make a small overshot water mill running a car/lorry alternator  via a belt drive or chain  drive to gear things up .
Use the height of the stream and pipe the head water to the wheel rather than try and make a mill stream
  Then have a bank of four or five heavy duty  batteries in parallel and use the generated power to charge them .
 You might also be able to use an inverter & diode set up off the bank of  batteries to give you a few hours of 240 volt as well.


 Several years ago I saw a very simple overshot wheel that had just an eight foot head piped to four feet above the wheel and aimed down onto a plastic spoked/rimmed solid rubber tyred wheel off a wheel chair.
 The alternator was chain driven off a push bike main crank & rear gear set with a simplex bike type tensioner .
The alternator was some six feet above the wheel & in a water protecting case with just holes for the chain and a power cable to the battery bank at the side of the stream .
 The water catcher vanes were some carefully cut 3 inch rain down pipe elbows , blocked off so they filled up  and some sort of  solvent  glue used to fix them to the rim of the wheel chair wheel .
The mounting bearings for the wheel were shielded from water  and packed with a light all temperature  grease.

[mab]

That's a really cool waterwheel plantoid; I don't suppose you know what flow rate was needed to make it work?

mab

[tobytoby]

Thanks all - some relly good info and views

Mab -

Open circuit voltage - 26.7 volts
Short circuit Current - 1.94A

The panel size is actually 885mm x 366mm - not 1m2 as previously quote (beer goggles on??)

[mab]

Ah, OK   

using a standard controller/ no controller, I expect you'd get around 1.85A on a blue day = about 25W.

Voc=26.7v - that's quite high actually - i guess that would put the max power point at around 20-22v then (hence it's rated 40W).  To get the best out of this panel would require a MPPT charge controller (max power point tracker); these use a voltage converter which keeps the panel operating at its optimum voltage - with one of these you might get 2.6-2.8A into the battery. But they are NOT cheap  .

m

[Plantoid]

That's a really cool waterwheel plantoid; I don't suppose you know what flow rate was needed to make it work?

mab

A solid rod or water  from the pipe that reached out just over 4 feet & into the  hoppers on dropping down side of the  wheel .
at the headderr  they had a plastic  5 gallon central heating header tank connected to the feed pipe set in the  stream bed  with am angled  mesh over it to keep crud out of the pipe , this was about 6 inches under the water .
 The feed pipe was a 1 inch pipe alkathene pipe .

 You don't realy need much flow in the stream if you sink a sump ..I've dug quite a few  sumps in streams with less than an inch of water in the stream and  used a Hamworthy pump set to fill 500 gallon rubber inflatable reserviors to make emergency  treated drinking and washing water in a few minutes with outever having the  sumps run dry.

[mab]

Thanks for that Plantoid; I don't have enough water to generate power where I am ATM but am interested in ideas like this for possible future plans.

The feed pipe was a 1 inch pipe alkathene pipe .

That's quite a modest size but with a fast flow and a good drop there's a useful amount of energy.

cheers

mab