Comparative wind / hydraulic

[Grelinette]

Wind power at a maximum efficiency of around 60% (Betz's law)
Hydraulics of around 80% (law of…?)

But would a process using both simultaneously, have a good yield?

A hydraulic flow circulated by a water pumping wind turbine, coupled with a hydraulic turbine:
for example, a water tower or height reserve supplied by a pumping wind turbine and whose falling water would activate a turbine.
What would this process be worth?

[Christophe]

The only interest would be the storage of energy for later use (phase shift) because the overall yield would necessarily be worse than one or the other solution ...

And the potential energy that can be stored in water implies an immense reserve of quantity of water.

We could estimate the energy contained in a water tower of a few tens of m3: by feeling this should not exceed a few tens of kWh ...

Example: a 20m high water tower containing 50m3 contains potential energy (therefore maximum usable) of E = mgh

E = 50 * 000 * 9.18 = 20 MJ
Gold 1 kWh = 3,6 MJ

We therefore have 2.55 kWh potential ... or 2 kWh actually recoverable ... therefore even lower than my "feeling" ...

Me I Goure?

[chatelot16]

betz law is not a return

the law of betz, it is the relation between the kinetic energy of the mass of air which passes in the wind turbine, and the energy that the wind turbine can capture

the kinetic energy of the air mass, is not an available energy: to slow this air mass down to zero it would have to make room in a parallel universe in another dimension

so the betz formula indicates what energy is available, and a good wind turbine can capture almost 100% of this available energy

[Christophe]

Yes chatelot16, but in the end it defines the overall performance of the wind turbine ...

There is no equivalent law in hydraulics to my knowledge since we are talking about efficiency in relation to the potential energy of the waterfall ...

Amazing isn't it? The difference must come that one is compressible and not the other ...

[chatelot16]

wind power looks like hydraulic water: on rivers with a slight slope: there is no possibility of water storage: so we can only produce what the river wants to give

the different hydraulics is the large dam that can store over the whole year

indirectly large dams can control downstream dams: when the large dam turbines water, it also increases the power of all dams downstream

there is no meter on the wind or on the water of the rivers ... the yield does not matter: what matters is the ratio between the price of the material and the energy supplied

a hydroelectric plant is much more profitable than a wind turbine: that's why we've been doing it for a very long time

for the wind turbines it was more difficult

the number of sites to install hydraulics is limited, and it floods surfaces ... we cannot build dams anywhere and flood everything

there is still a lot of room to build more wind turbines

there are also a lot of small dams that could produce electricity, which have turned the mill currently unused

[chatelot16]

for betz and hydraulics the difference is that the water goes exactly where you want in a pipe, a canal, or a river

in the case of the wind turbine the air passes where it wants

if the wind turbine slows down the air too much, nothing passes through the wind turbine, all the air bypasses it: zero power

if the wind turbine lets the air pass too easily, the air passes through at its usual speed, but the wind turbine does not recover any energy

the optimum is between these 2 extremes and was calculated by betz: and that gives the available wind energy

I find it confusing to give it in the form of a report with this kinetic energy which is not available at all

unlike the carnot output: when you have 10kWh of heat, you have the choice to use these whole 10kWh to heat water ... or to make only 2kWh of mechanical energy with an engine whose efficiency is by 20%

when the wind turbine recovers 100% of the available power of betz, there is no power lost in heat anywhere

[EricN418]

The vertical wind turbine is much more efficient than the conventional wind turbine that we see at the edge of our road and much less annoying, both visually (no strobo effect) than acoustically with little or no noise.

As for hydraulics, it is more tidal energy that is in vogue. So it's not accessible at the individual level but the government has launched 3 or 4 tidal farm projects in Brittany and in the north of France in the Atlantic and the Channel. Scotland has started building the largest tidal farm in Europe, it looks really promising.

Brittany already produces quite a bit of electricity like that in its estuaries.

I would link the articles well but Gaston would hit me on the fingers

[Grelinette]

In my region (Paca) we have a canal of several hundreds of kms which seems to me to present an interesting potential for hydraulics:

https://www.google.fr/search?q=canal+de ... CAkQ_AUoAQ

This canal passes by very many small towns, some of which have wind projects. The installation of tidal turbines would ultimately be much simpler and economical, and perhaps also more profitable over time because the canal has an almost constant flow 24/24 and all year.

Are there "portable hydraulics" that could be installed in such canals? ...

[raymon]

Yes question can we put hydraulic in this type of channel there is that of edf also:
https://www.google.fr/search?q=canal+ed ... 80&bih=571 Already operated with a dozen power stations, but ...
I have a central pico of 5 kw on a sprinkler channel and in Provence lots of falls on these channels are not exploited not only over the water but real fall of 3-4m with 5m3 seconds for example on the Carpentras canal!

http://fr.wikipedia.org/wiki/Canal_de_Carpentras

Crapone channel in the 13:
http://fr.wikipedia.org/wiki/Canal_de_Craponne

No fish no ecological impact to use this water. In Mérindol on the Carpentras canal, the association APTE has been trying for 10 years to restart an old mill they do not succeed, saying they have the support of the elected representatives of the people ...
big administrative problems ...

Thank you AREVA

[chatelot16]

no illusion on this channel: the flow must pass: the slope is low and just enough to advance the water at the right speed

it would be possible to recover energy but that would reduce speed: it would be necessary to make the channel wider .... impossible to recover energy without major modification

the calculation has already been made for the construction of this kind of channels: wherever the slope is steep enough to justify the production of energy there are already turbines

bulk turbines at the bottom of a river or a canal have the problem of betz: water can pass by the turbines it is difficult to recover all the energy available

by putting a dam and a turbine we use everything ... and we can also store water for a few hours to produce more during peak hours

basically when the slope of a river is low there is no energy to recover ... when the slope is steeper the solution has been known since the middle ages: a succession of dam and mill

the channel which is in picture is part of a system where there are already turbines where it was profitable to put some

perhaps, given the increase in the price of energy, it will become profitable to modify it to make better use of energy? widen the canal to decrease the slope, and put a dam every 10km?