Observing the renewable energy transition from a European perspective

Archive for the category “Brasil”

Getting Concrete – Wind Towers & Monopiles Beyond Steel

Nordex-Germany building 120 m concrete wind tower in Brazil.

Do wind towers need to be built from steel? Not necessarily, concrete will work as well (or even wood) or a mixture of concrete and steel. A lot depends on the local circumstances and availability of materials. In many cases concrete will be easier to acquire than steel, which requires mining and processing in blast furnaces, where concrete is made of universally much more locally available cement and sand. The price of concrete is about $200-300/m3. The price of steel is ca. $5000/m3. Density concrete 2.5 tonnes/m3, steel 8.0 tonnes/m3 (not that you can draw direct conclusions from these figures).

The advantage of having taller wind turbines is the exposure to higher average wind speeds, which consequently require a more constant wind profile over the height of the rotor and larger blades. The race for harnessing the most power from wind energy is bringing some manufacturers to a path of alternative materials like concrete… There are already several wind farms around the world using this alternative in Chile, Denmark, and there are upcoming new projects in Spain and the UK.

[] – Offshore Wind Energy Towards a Concrete Future
[] – Concrete towers for onshore wind farms

Iron Ore Mining for Wind Turbines

World map of countries that matter in iron production. Global annual production 3.3 billion ton. China (1.4), Australia (0.8) and Brazil (0.4) together produce ca. 82% of that amount.

For the global renewable energy transition to work, hundreds of thousands of steel wind towers, monopiles and nacelle’s need to be built. The good news is, the iron is there and currently relatively cheap.

Price iron ore: $85/ton [source]
Price steel plate: $470/ton [source]
(Steel plate can be used to manufacture monopiles and towers, see video at the bottom)

Weight of a large offshore wind turbine:

Tower head mass: 60 ton/MW [pdf]
Monopile 5 MW turbine: 2200 ton [source] (strong correl. with water depth)
Tower 5 MW turbine 100 m: 389 ton [pdf]

Rule of thumb 5 MW offshore wind turbine steel requirements: 300 + 2200 + 400 = 2900 ton

One million 5 MW offshore wind turbines require 2.9 billion ton or 88% annual global steel production.

Total world electricity consumption was 19,504 TWh in 2013. [source]
Annual electricity production 5 MW offshore ind turbine: 15 million kWh or 15 GWh

In other words: with 1.3 million offshore 5 MW wind turbines you have your global 2013 electricity consumption covered, if you ignore for a moment aspects like storage. And this time entirely fossil free, which was the purpose of the operation. But this ‘back-of-an-envelope’ exercise should give you an idea of the scale of the challenge.

[] – List of countries by iron ore production
[] – True giants of mining: World’s top 10 iron ore mines

Offshore wind turbine monopile production from steel plate.

Brazil’s Ethanol Revolution

Youtube text: The bio-fuel, ethanol, is generating a revolution in renewable energy that could help reduce the world’s thirst for oil. In Brazil, the production of ethanol from sugarcane is booming, but what is not clear is the impact it is having on the industry’s sugarcane cutters (uploaded March 21, 2011).


Read more…

Brasil has rare earths in abundance

Currently China produces 95% of the so-called rare earths. In that light the recent discovery of large deposits of rare earths in Brazil is welcome news for high-tech industrial consumers of these materials. Recent Chinese restrictions on the export of rare earth minerals has made this discovery even more valuable. The deposits were discovered by Vale, the world’s largest iron ore mining company.


Post Navigation