Life at the end of the road

April 7, 2009

Out of character

Filed under: daily doings, life off grid — lifeattheendoftheroad @ 3:38 pm

It’s almost 4:00pm and I’m sat in my living room surrounded by rainbows! No I have not been on the wine or funny mushrooms it’s this solar powered crystal thingy that someone bought me years ago. It’s stuck to the living room window, when the sun shines on the panel it spins this bit of glass around filling the room with little rainbows, OK, I know it’s a bit airy fairy but I’m an old hippy at heart ๐Ÿ™‚ anyway I don’t often get to see it because normally wild horses would have to drag me in the house when the sun is shinning.

The Kiss

The Kiss

Today however I am totally wrecked after a full day fitting solar panels on the roof of my mates house yesterday followed by a late night standing by a hydraulic engineer on the Loch Striven.

Monday 6th April

Was a very fine day indeed and after the usual bout of feeding I set off for Torran and

http://www.uniquescotland.com/raasayschool/index.html where I was going to fit 4 x 85watt solar panels to the roof to complement the ‘Harris Hydro Turbine’

and now I must go and feed the pigs ๐Ÿ™‚

Harris gets a new home

Filed under: daily doings, hydro, life off grid — Tags: — lifeattheendoftheroad @ 8:41 am

Sorry again ladies, I’ve been trying to write this for 3 days and on the whole it’s pretty dull stuff unless like me you are a little obsessed with making electricity ๐Ÿ™‚

Monday morning

It’s 6:00am now and I’ve been up for an hour after what can only be described as the ‘sleep of the dead’! yesterday was a day of hard graft and both me and my mate were pretty worn out by it all. The weather was grey but dry and mild, well at least it was until about 2:00pm when the rain came on. The agenda for the day was to move his ‘Harris Turbine’ nearer to his house which would reduce it’s current head by some 10 or 15m and I’ll just stop there because I’ve realized that I’m probably talking gibberish to most people reading this blog ๐Ÿ™‚

The ‘Harris Hydro’ water turbine

The main power supply at my mates ‘off grid’ holiday cottage http://www.uniquescotland.com/raasayschool/index.html is a 24v water turbine that supplies a large battery bank. The bank in turn provides DC power to an inverter that converts it to 230v AC for use in the house. A hydro turbine extracts the power from the water via a wheel (runner) that is turned by a jet of water. The runner drives a generator that makes electricity, the greater the flow and the higher the pressure (head) the more power (watts) that can be made. I installed this turbine which was supplied by Hugh Piggot of http://www.scoraigwind.com/gear/index.htm last January and it has on the whole been a success.

The amount of theoretical power you can get from a water supply is very simple to work out, it’sย  Head x Flow x Gravity = power, when head is measured in meters, flow in liters per second and gravity at 9.81 meters per second then the available power in the water is given in watts so for instance my mates set up was 30m of head and 1.5 lt per sec of flow which is 30 x 1.5 x 9.81 = 441 watts. This is the available power but in reality due to friction, conversion and electrical losses you can expect around 60% of that so about 250 watts. Which over a 24 hour period is around 6kwh which is more than enough for the average household.ย  It did however suffer from two problems, lack of water in the summer and blockages by dead leaves in the autumn both problems which we addressed late last year by raising the water intake some 100 meters higher, above the tree line and in to a loch. This epic involved laying nearly 500m of 63mm MDPE pipe over a peat bog, down a cliff and through a forest, all of which is described in great detail

https://lifeattheendoftheroad.wordpress.com/2008/08/21/such-a-perfect-day/

including removing it from the tree tops! However connecting this to the existing pipe work would have given a head in the region 0f 130m and a pipe run of around 600m. Which would have given a serious amount of power but would have been pushing the envelope a little in terms of pressure for the pipe joints and the turbine which would have been operating at well over 200psi. With this in mind we had decided to move the turbine nearer the house thus reducing head/pressure and also making the cable run shorter which would help with the higher currents being generated. First though it was the long walk to the loch at the end of the pipe.

Old sheiling new fence

Old sheiling new fence

Which is somewhere along this fence which disappears over the horizon through that middle nick

Old shieling high above Torran

Old shieling high above Torran

A shieling being a place where cattle and sheep would be taken during the summer to make use of the upland grazing and protect the arable crop land http://www.c-e-n.org/shielings.htm . On our long trek across the peat and heather we saw a fine stag and a golden eagle soaring above the aptly named Bienn na h iolair (hill of the eagle)ย  arriving at Loch Malaichti with our spades we set about digging in the very long pipe.

Now you see it

Now you see it

Burying the pipe would make it less likely to freeze and would make filling the pipe with water much easier after we had removed the filter for cleaning.

Now you don't!

Now you don't!

After hours of digging and a spell in the loch with waders we got the water flowing

Serious water flow

Serious water flow

The large blue pipe is the 63mm one from the loch, the 100mm grey one is the original supply to the Harris turbine that feeds into that black header tank, the supply to the turbine comes out of that tank about half way up to stop stones and stuff going down the pipe. As the turbine will now be fed directly from the loch the header tank was taken out and the blue pipe connected directly to the Harris Turbine ‘pennstock’ (supply pipe).

With pipe laid, water flowing we dug up the old turbine base which I made from a washing machine drum and drain base

Now you see it

Now you see it

and set it in the new location

Now you don't

Now you don't

When in it’s original location with around 30m of head and between 1 and 3 lts per second of water going through the turbine we were getting between 112 and 330 watts out of it which is about 4 or 12 amps at 28v.

1 large nozzle, 2.9 bar and 12 amps

1 large nozzle, 2.9 bar and 12 amps

This model of Harris Turbine has 4 nozzles, 2 large and 2 small, for flow of around 1 lt per second 1 small nozzle seems to work best, as more water becomes available you can shut 1 small and open 1 large, then shut one large and open two small. I don’t remember us ever having enough water in the burn to run two large ones for very long and I can’t remember what the max output we got was, as I’ve said on many occaisions I’ve a memory like a hen ๐Ÿ™‚

Once plumbed into it’s new spot we were getting 20amps, around 560 watts with 1 nozzle barely open, the pressure gauge off the scale and water spraying out of every joint!. By putting a piece of pvc waste pipe aroun each joint and 3 heavy duty jubilee clips we stopped the leaks and had it producing 25amps or around 700 watts again with one nozzle valve not yet fully open. As the ammeter only went up to 25, the system is fused at 32 and we were on the limit of our 25mm square cable we left it at that, for now ๐Ÿ™‚

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