Jump to content
House Price Crash Forum

Archived

This topic is now archived and is closed to further replies.

gadget

Brazil's Energy Issues

Recommended Posts

Interesting article - thanks for posting.

The article also shows the dangers of being too over reliant on one source of power. In Brazils case Hydro which is vulnerable to droughts. It looks like a diverse approach using wind and bagasse (from sugar cane) is the way forward. Wind coincidentially is strongest in the dry season so works well with solar.

Share this post


Link to post
Share on other sites

Interesting article - thanks for posting.

The article also shows the dangers of being too over reliant on one source of power. In Brazils case Hydro which is vulnerable to droughts. It looks like a diverse approach using wind and bagasse (from sugar cane) is the way forward. Wind coincidentially is strongest in the dry season so works well with solar.

Really quite eye-opening how much of a renewables super-power Brazil is.

Share this post


Link to post
Share on other sites

Yes, HEP doesnt seem to be favoured much by the political class lately. I recall Tasmania was once something like 100% HEP covered, now its well below that and some stations have been mothballed.

Even our antartic whaling outpost of south georgia once had a HEP plant, now it relies on diesel generators and diesel being shipped in.

Share this post


Link to post
Share on other sites

Really quite eye-opening how much of a renewables super-power Brazil is.

Dam-based hydroelectricity is about the cheapest form of electricity there is, IIRC. Only problem being that you need the right geography - you need a bit river in a big valley.

Share this post


Link to post
Share on other sites
Guest eight

Dam-based hydroelectricity is about the cheapest form of electricity there is, IIRC.

Cheaper than tapping next door's mains?

Share this post


Link to post
Share on other sites

Dam-based hydroelectricity is about the cheapest form of electricity there is, IIRC. Only problem being that you need the right geography - you need a bit river in a big valley.

I seem to recall that Brazil has a rather big river flowing through a lot of it...

(not so sure about how much of a valley it's in though)

Share this post


Link to post
Share on other sites

I seem to recall that Brazil has a rather big river flowing through a lot of it...

(not so sure about how much of a valley it's in though)

They get a lot of hydro energy from a dam in Paraguay at a cheap rate negotiated years and years ago.

Share this post


Link to post
Share on other sites

I seem to recall that Brazil has a rather big river flowing through a lot of it...

(not so sure about how much of a valley it's in though)

Its the absence of much of a head of water on the Amazon (main body) that I suspect has dissuaded the Brazilian PTB to dam it. Also the amazon itself is a long way from the big cities so the transmission costs would be very high.

A simple formula for approximating electric power production at a hydroelectric plant is: P = \rho hrgk , where

P is Power in watts,

\rho is the density of water (~1000 kg/m3),

h is height in meters, (which explains why no one has bothered to dam the Great Ouse, Thames etc (other than micro schemes)

r is flow rate in cubic meters per second,

g is acceleration due to gravity of 9.8 m/s2,

k is a coefficient of efficiency ranging from 0 to 1. Efficiency is often higher (that is, closer to 1) with larger and more modern turbines.

Share this post


Link to post
Share on other sites

Its the absence of much of a head of water on the Amazon (main body) that I suspect has dissuaded the Brazilian PTB to dam it. Also the amazon itself is a long way from the big cities so the transmission costs would be very high.

A simple formula for approximating electric power production at a hydroelectric plant is: P = \rho hrgk , where

P is Power in watts,

\rho is the density of water (~1000 kg/m3),

h is height in meters, (which explains why no one has bothered to dam the Great Ouse, Thames etc (other than micro schemes)

r is flow rate in cubic meters per second,

g is acceleration due to gravity of 9.8 m/s2,

k is a coefficient of efficiency ranging from 0 to 1. Efficiency is often higher (that is, closer to 1) with larger and more modern turbines.

on a similar subject, how possible/economical would it be to have huge battery store ships take energy from decent hydro-electric areas (eg scandanavian countries) and transport them to cities around the world that need it ?

I'd guess not very economical, but who knows.

Share this post


Link to post
Share on other sites

on a similar subject, how possible/economical would it be to have huge battery store ships take energy from decent hydro-electric areas (eg scandanavian countries) and transport them to cities around the world that need it ?

I'd guess not very economical, but who knows.

Don't think suitable battery tech exists - cheaper to put in some interconnectors, this is in progress I think.

Share this post


Link to post
Share on other sites

on a similar subject, how possible/economical would it be to have huge battery store ships take energy from decent hydro-electric areas (eg scandanavian countries) and transport them to cities around the world that need it ?

I'd guess not very economical, but who knows.

In the case of Scandinavia or Iceland HVDC interconnectors is the answer.

However there are remote hydro resources where HVDC is too far. Example would be the the Inga falls on the Congo river with a potential of 40GW. One way of exporting that energy would be to make ammonia which can then be used in fertiisers, flue gas desulphurisation, or even fuel as diesel engines only need minor modification.

Also there is a tidal site in the Sea of Okhotsk (Russian Far East) with a potential of about 80GW. Very remote so electricity could be used to make Ammonia and ship to China, Japan etc.

Share this post


Link to post
Share on other sites

on a similar subject, how possible/economical would it be to have huge battery store ships take energy from decent hydro-electric areas (eg scandanavian countries) and transport them to cities around the world that need it ?

I'd guess not very economical, but who knows.

Very uneconomical I would've thought. The energy density of batteries is really pretty lousy. Shipping energy about only makes economic sense when it's in a much better energy density medium like oil.

Share this post


Link to post
Share on other sites

Dam-based hydroelectricity is about the cheapest form of electricity there is, IIRC. Only problem being that you need the right geography - you need a bit river in a big valley.

That's a bit of a blanket statement.

From the article wind is coming out cheaper than recent hydro projects:

Recent windpower auctions, with hundreds of private-sector bidders, produced winning bids of 90-100 reais per megawatt-hour (MWh), a price that is hard to beat. Belo Monte was given an initial budget of 16 billion reais, which had risen to 19 billion reais by the time of the auction. Norte Energia’s winning bid for Belo Monte offered a price of 77.97 reais/MWh. Since then, its budget has risen by a third.

Share this post


Link to post
Share on other sites

This would be a great scheme and provide plenty of work for Egyptians in the construction phase plus lots of additional benefits including increased rainfall in an arid area. When Egypt was a net oil exporter this sort of scheme would have been a good investment for that revenue stream.

http://mragheb.com/NPRE%20498ES%20Energy%20Storage%20Systems/Pumped%20Storage%20Qattara%20Depression%20Solar%20Hydroelectric%20Power%20Generation.pdf

Politics gets in the way of this which could provide a large chunk of Israels and Jordans electrical needs

http://deadseapower.com/

Both would be useful additions to the proposed Desertec/ Supergrid especially as they can be built as peaking plant with pumped storage. Additionally no dangers of a drought affecting output.

Share this post


Link to post
Share on other sites

  • Recently Browsing   0 members

    No registered users viewing this page.

  • 242 Brexit, House prices and Summer 2020

    1. 1. Including the effects Brexit, where do you think average UK house prices will be relative to now in June 2020?


      • down 5% +
      • down 2.5%
      • Even
      • up 2.5%
      • up 5%



×
×
  • Create New...

Important Information

We have placed cookies on your device to help make this website better. You can adjust your cookie settings, otherwise we'll assume you're okay to continue.