During this time, global wind markets started expanding at a rate of several gigawatts every year, closely watched by the planners in the Brazilian electricity system, which was — and still is — heavily dominated by the hydropower generation that until recently made up 80% of the country’s electricity production.
The first Brazilian wind map was published in 2001 by the Ministry of Mines and Energy and the state-owned utility Eletrobras. It was further developed by Brazilian firm Camargo-Schubert using data from US energy consultant AWS Truewind (now Truepower).
The atlas revealed a tremendous potential for wind power development, around 143GW of possible installed capacity. At that time, this exceeded the country’s total installed power generation capacity by 50%.
The 143GW figure was calculated by integrating all the areas with annual mean wind speeds higher than seven metres per second at a height of 50 metres. Then, after a rather conservative approach estimated 80% of that land was not feasible for wind farms because of environmental, topographic or other constraints, the remaining area was assessed as being suitable for wind farms at a typical rate of 10MW per square kilometre.
Several further regional wind atlases have been produced using higher masts, now up to 100 metres, and more detailed measurements. These formed the basis for many of the projects won at the wind power auction last December. Based on results of these regional atlases, many agents of the Brazilian wind sector predict the potential to now be at least 300GW due to more powerful and taller turbines. Camargo-Schubert is working to produce a more accurate figure.
Close to grid
A fortunate conclusion from the first Brazilian wind atlas was that the most favourable areas for wind power development were located close to the existing national interconnected power grid and near major cities where demand would be highest. So, while the first wave of projects were sited along the Atlantic coast, this knowledge resulted in a faster expansion of inland wind power.
Today, 70% of Brazil’s power is still supplied by hydropower. But strong seasonal fluctuations and growing electricity demand mean it is proving more problematic, with electricity shortages in 2001 affecting the Brazilian economy. To counter this, the country has been investing in fossil fuel-based power plants over the past decade, exposing the country to high and volatile fuel prices.
The intense price competition at the recent wind energy auction has put wind power developers under immense pressure to analyse carefully the risks involved. This includes thorough analyses of annual climate variations.
Meanwhile, the government’s planning authorities are also modelling various climatological and statistical scenarios to determine the feasibility of integrating wind power into the national electricity grid. One of the findings is that, in the long term, wind speeds are much more stable, with fewer seasonal and annual fluctuations than water resources for hydropower production.
For example, in the north-eastern region of Brazil, while the fluctuating hydro capacity in the power plants of the São Francisco River resulted in power shortages in 2000 and 2001, the theoretical generation of 9GW of wind power in the region suggests a more stable and predictable supply. The two sources are also complementary, with wind speed strongest at times when water supplies are low.
Exploiting the country’s tremendous wind resources would not only bring environmental benefits, but also a sustainable improvement of Brazil’s energy security.
Odilon Camargo is principal of consultancy Camargo-Schubert Wind Engineering