Wind Power

[Doggy Styles]

Cutting use is almost certainly the easiest way to reduce problems but nobody wants to do it either.

It's impossible anyway while our population is rising at a rate of knots. Anything you save will be used by someone else.

[TykeMerc]

Originally Posted by TykeMerc
True

Some impressive photographs in that lot.

I've no objection to wind farms so long as they're NOT IN MY BACK YARD.

Well there are quite a few around here, I'd guess several dozen in a 10 mile radius. I live in the Pennines, but as my house is in an urban area, more direct NIMBYism isn't a factor...

[Doggy Styles]

That's nano.

I said micro.

Does that mean we'd all have to have stream running through our gardens? That would be nice.

What about using sewage flow under the garden to drive small turbines.

[EternalOptimist]

Does that mean we'd all have to have stream running through our gardens? That would be nice.

What about using sewage flow under the garden to drive small turbines.

too susceptible to brown-outs

[RichardCranium]

How much electricity could be generated per annum by rainfall coming down from the average UK rooftop?

Average UK rainfall is about 900mm (but varies regionally from about 550 to 3000mm).

Let's be generous and put you in the rainy West or North West getting 1500mm.

Let's say your roof is 10m x 10m in area = 100m². You'll get 150m³ of water.

Let's say your drainpipes are 10m high, that water will be falling at about 10m/s when it gets to ground level.

1 litre of water weighs 1kg.
1 m³ contains 1000 litres. So 1m³ of water weighs 1000kg. You get 150,000kgs of water per year.

1 newton is the force released from decelerating a mass of 1kg by 1m/s/s.

Decelerating 150,000kgs of water from 10m/s to stationary quickly in a turbine, say 1/10th of a second, might release 150,000 x 10 x 10 newtons = 15Mnewtons. On average over a year (31.5 million seconds) that comes out at about 0.5 Watts. Assuming an efficient generator.

So you could have a 100W lightbulb on for 1 hour in every 200 hours.

##############

Double checking...

Power = Head x Flow x Gravity

Head = 10 metres.
Flow = 150,000 litres per yr = 0.005 litres per second
Gravity = 10m per second (near enough)

Power = 10 x 0.005 x 10 = 0.5 Watts. √

###############

Apparently, water turbines are very efficient compared to wind and work at about 70% efficiency.

Answer = about 0.35 Watts.

Even pico hydro power is FAR more powerful (about 300W)

[DimPrawn]

Average UK rainfall is about 900mm (but varies regionally from about 550 to 3000mm).

Let's be generous and put you in the rainy West or North West getting 1500mm.

Let's say your roof is 10m x 10m in area = 100m². You'll get 150m³ of water.

Let's say your drainpipes are 10m high, that water will be falling at about 10m/s when it gets to ground level.

1 litre of water weighs 1kg.
1 m³ contains 1000 litres. So 1m³ of water weighs 1000kg. You get 150,000kgs of water per year.

1 newton is the force released from decelerating a mass of 1kg by 1m/s/s.

Decelerating 150,000kgs of water from 10m/s to stationary quickly in a turbine, say 1/10th of a second, might release 150,000 x 10 x 10 newtons = 15Mnewtons. On average over a year (31.5 million seconds) that comes out at about 0.5 Watts. Assuming an efficient generator.

So you could have a 100W lightbulb on for 1 hour in every 200 hours.

##############

Double checking...

Power = Head x Flow x Gravity

Head = 10 metres.
Flow = 150,000 litres per yr = 0.005 litres per second
Gravity = 10m per second (near enough)

Power = 10 x 0.005 x 10 = 0.5 Watts. √

###############

Apparently, water turbines are very efficient compared to wind and work at about 70% efficiency.

Answer = about 0.35 Watts.

Even pico hydro power is FAR more powerful (about 300W)

I think common sense would tell you that the trickle of water down a drainpipe on the days it rains isn't going to power the 200 x 50 watt GU10 bulbs I have downstairs.

[minestrone]

Average UK rainfall is about 900mm (but varies regionally from about 550 to 3000mm).

Let's be generous and put you in the rainy West or North West getting 1500mm.

Let's say your roof is 10m x 10m in area = 100m². You'll get 150m³ of water.

Let's say your drainpipes are 10m high, that water will be falling at about 10m/s when it gets to ground level.

1 litre of water weighs 1kg.
1 m³ contains 1000 litres. So 1m³ of water weighs 1000kg. You get 150,000kgs of water per year.

1 newton is the force released from decelerating a mass of 1kg by 1m/s/s.

Decelerating 150,000kgs of water from 10m/s to stationary quickly in a turbine, say 1/10th of a second, might release 150,000 x 10 x 10 newtons = 15Mnewtons. On average over a year (31.5 million seconds) that comes out at about 0.5 Watts. Assuming an efficient generator.

So you could have a 100W lightbulb on for 1 hour in every 200 hours.

##############

Double checking...

Power = Head x Flow x Gravity

Head = 10 metres.
Flow = 150,000 litres per yr = 0.005 litres per second
Gravity = 10m per second (near enough)

Power = 10 x 0.005 x 10 = 0.5 Watts. √

###############

Apparently, water turbines are very efficient compared to wind and work at about 70% efficiency.

Answer = about 0.35 Watts.

Even pico hydro power is FAR more powerful (about 300W)

Where the hell did you get your Engineering degree from?

If I could buy a .35 watt device that could life a 150 ton weight over the course of a year then I would cut you in on a slice of the profits.

[DimPrawn]

Where the hell did you get your Engineering degree from?

If I could buy a .35 watt device that could life a 150 ton weight over the course of a year then I would cut you in on a slice of the profits.

I think you are confusing energy with power. It's 5ml (a teaspoon) per second flow, which isn't going to generate much power.

[minestrone]

I think you are confusing energy with power. It's 5ml (a teaspoon) per second flow, which isn't going to generate much power.

You are confusing knob head who probably has a tulipe degree in arts with a minestrone BEng(Hons)

[minestrone]

What is the cost of a Kg of water in England?