Water power

[Thinking Aloud]

Some numbers...

The discharge of the entire River Eden is (according to Google) 51.82 m³/s, which is 51820 litres/sec.

Using that calculator I linked to above, and giving a 2m head, the power generated by the whole river flow would be around 1MW.

To make one of these run at full power you'd need a supply of 5.8MW - as a comparison.

[Jason]

Interesting factoid, if your average home consumes 1000KWh per month, you'd need 1.5KW* per home on the grid to meet peak demands. That gives you a rough idea of the viability of these micro-installations.

They built a pilot project for that external turbine I linked to last page in 2010 some place in Norway (on the Nea river). Here's the stats:
Head 24 m
Water flow 1.2 m3/s
Installed power 280 kW'

Apparently good head is important.

*Thinking about it a second longer, probably more like 2-3KW.

[MiM]

Some numbers...

The discharge of the entire River Eden is (according to Google) 51.82 m³/s, which is 51820 litres/sec.

Using that calculator I linked to above, and giving a 2m head, the power generated by the whole river flow would be around 1MW.

To make one of these run at full power you'd need a supply of 5.8MW - as a comparison.

Full power, meaning full acceleration, which it would use for only very short periods, for sure?

[Thinking Aloud]

Some numbers...

The discharge of the entire River Eden is (according to Google) 51.82 m³/s, which is 51820 litres/sec.

Using that calculator I linked to above, and giving a 2m head, the power generated by the whole river flow would be around 1MW.

To make one of these run at full power you'd need a supply of 5.8MW - as a comparison.

Full power, meaning full acceleration, which it would use for only very short periods, for sure?

Yes. The continuous rating is around 3.7MW.

[Cormac]

1KW hardly seems worth the expense. I have a 1.2KW generator that cost me $150.. I also have a 25KW diesel generator that cost me nothing.

Where'd you get the diesel beast? I'd love one!

But the difference is that the 1kw generator would be going 24/7/365 with no need for you to fuel it. You might need to replace the bearings and perhaps the impellor due to cavitation, but you'd have to replace parts on the generator too.

The wheel is a lot more low-tech, which is great for making cheap repairs and making your own parts.

[Cormac]

Oh, and incidentally, the 1kw miniturbine runs on a relatively low volume of water. So putting an array of them in is entirely feasible, and in the medium term, I'm fairly confident that it would outpace the equivalent costs in running a diesel generator when operating costs are considered over the medium to long term.

Also, you get to stick it to the man, and you can't put a price on that!

[Cormac]

If I had the technical know how, I'd build one of these in my back garden.

(We have a small river - and I've already checked it with the fisheries guys. As long as I'm not planning to dam the river, and prevent our salmon and trout from getting upriver, and I don't disturb our lampreys and crayfish, they'll be happy...).

[/rural idyll]

[JimC]

Too much flooding in them hills. You'd need some clever sluice gates and the like to keep the pressure constant enough for steady electricity generation. Possible but quite expensive I should imagine.

Also, there would be a certain amount of debris, which would periodically clog up the works, needing a lot of maintenance, I would think...

Plus the fish issue (although, careful design can make a fish ladder to one side, possibly losing 10% of the energy)

There are mini-versions of these, often homemade, running in hilly areas of Victoria to provide some power to single dwellings near streams.

[Jason]

1KW hardly seems worth the expense. I have a 1.2KW generator that cost me $150.. I also have a 25KW diesel generator that cost me nothing.

Where'd you get the diesel beast? I'd love one!

The local scrapyard gets a lot of industrial equipment. The guy there said I could take it or they'd melt it down for scrap so I had him load it in my truck with the forklift and brought it home. With a little bit of elbow grease I got her running - still needs a new injector though ($125).

[Cormac]

1KW hardly seems worth the expense. I have a 1.2KW generator that cost me $150.. I also have a 25KW diesel generator that cost me nothing.

Where'd you get the diesel beast? I'd love one!

The local scrapyard gets a lot of industrial equipment. The guy there said I could take it or they'd melt it down for scrap so I had him load it in my truck with the forklift and brought it home. With a little bit of elbow grease I got her running - still needs a new injector though ($125).

You lucky man!

Can you run it on veg oil?

[Gawdzilla Sama]

Ian will confirm that the USN likes to get their sailors involved in "civic" projects in overseas ports. I was involved in setting up a waterwheel generator for an orphanage in the Philippines once. Four days work by some thirty sailors using donated materials from the Subic shipyard. The next year when we came back some of us went to check on the thing to see if it needed any repairs. When we got there we were advised that the whole thing, including electric wires to the main building, had been stolen two weeks after we left.

[Rum]

Seems to me there is energy/power everywhere. Harnessing it is the issue.

[Thinking Aloud]

Seems to me there is energy/power everywhere. Harnessing it is the issue.

There is, but none of it is truly "free".

[JimC]

Seems to me there is energy/power everywhere. Harnessing it is the issue.

There is, but none of it is truly "free".

In the sense that its harnessing creates consequences which must be dealt with...

[Thinking Aloud]

Seems to me there is energy/power everywhere. Harnessing it is the issue.

There is, but none of it is truly "free".

In the sense that its harnessing creates consequences which must be dealt with...

Yes. Though gravity-based systems (river and tidal) seem to be the least consequential - stealing energy from falling or moving water theoretically means there's less energy available for erosion downstream.