Field of dreams: Brazil’s biomass revolution22 February 2013
Brazil is already a world-leader in the use of bioenergy, particularly in the transport sector, but can the country go beyond this to make use of biomass in electricity production? Mark Brierley puts the question to Suani Coelho of the Brazilian Reference Center on Biomass (CENBIO).
Crawling along at 5mph in one of Sao Paulo's notorious traffic jams, you'd be forgiven for thinking the endless rows of stationary cars were just the same as any others caught in gridlock in innumerable other cities around the world. But more than 50% of the cars caught in Sao Paulo's congestion, named the worst in the world by TIME magazine, have one crucial difference from their international counterparts.
Sugarcane-based ethanol biofuel is now blended into more than half of Brazil's petrol-powered vehicles. In fact, the country is the world's second largest producer of ethanol biofuel and is considered a model example of the implementation of bioenergy.
But the potential for bioenergy is not limited to the transport sector; there are a number of other possible applications this versatile energy source can be used for, most obviously in electricity production. Either fired on its own or with other thermal power sources, biomass is a useful means of producing renewable energy from the waste of other industries, such as forestry and agricultural residues, or even municipal solid waste. Brazil's existing expertise in this field could prove crucial in meeting rising domestic electricity demands as the economy continues to grow at record pace. It could add another renewable energy source to the country's already well-developed green power mix.
In fact, Brazil can already boast that more than 70% of its electricity needs are met by hydroelectricity, thanks in large part to the massive 14GW Itaipu Dam, on the border with Paraguay. While it is a great achievement for a country of this size to achieve such a green power generation sector, depending on one type of electricity supply has also caused an inherent weakness in the system. In times of drought, reservoirs feeding hydropower plants are unable to generate enough electricity to meet demand and there are not enough alternative forms of generation capacity to pick up the slack. The energy crisis of 2001-02 followed record low rainfall across Brazil and caused rolling blackouts throughout.
Co-firing biomass in Brazil's thermal power plants is one of a number of possible solutions for reducing the nation's reliance on hydropower, while still keeping its renewable credentials. Brazil has over 15GW of installed thermal power generating capacity, so the potential for covering even a fraction of this with biomass is plain to see. With the country capable of producing more than 700 million tons of sugarcane annually for bio-ethanol, the residues from this could go a long way in the production of electricity. This is before you even take into consideration the numerous other possible sources of biomass beyond sugarcane.
But it isn't likely to be plain sailing. Around the world, the public image of biofuels has taken a hit in recent years for its part in the fuel versus food debate. Following the global food crisis of 2007-2008, many international commentators, as high up as the World Bank, blamed increased diversion of arable land to biofuel production had impacted on food stocks in several countries globally. However, Coelho doesn't see this as an issue for cogeneration in Brazil.
"Food security is not a problem because the biomass used is only residue from industrial processes," she explains.
But that does not necessarily overcome the bulky nature of biomass as a feedstock for power plants. In fact, storage problems have been cited as one of the biggest barriers to the widespread adoption of this form of electricity production elsewhere in the world. Again, Coelho doesn't see this as a major hurdle.
"There is no problem of storage of biomass because the residues are already in the plant [in the case of industrial power units]," she says. "The harvest season for sugarcane further reduces any long-term storage issues, removing this barrier altogether.
"Electricity surplus generation from the sugarcane sector corresponds to the dry season for hydropower plants and so they complement each other. In fact, with the introduction of harvesting of sugarcane without burning [green cane], there is additional biomass available [tops and non-burned leaves] and so electricity production throughout the year is feasible."
You would think this would cause a rush for more biomass cogeneration but, as an energy source, it faces stiff competition from renewable sources, notably wind power, which benefits from generous government incentives.
"Biomass-based electricity must compete with wind energy in terms of the price paid to purchase the electricity. Current tariffs paid are not economically attractive to investors" explains Coelho. "Considering that wind energy has strong incentives and tax exemptions, it is now more competitive than small hydro and biomass, since they receive no such incentives from the government."
This is why CENBIO's work is crucial to the success of biomass-based electricity. By funding research into new efficient technologies and promoting biomass as a viable alternative, or complement to, fossil fuel thermal power, it is hoped the Brazilian government will use the experience it has built up in the transport sector and extend this to electricity generation.
For this to happen, Coelho sees three things that need to change. Firstly, she says, the government needs to "lower taxes to allow for the purchase of more efficient cogeneration equipment, similar to the wind industry". Improving the efficiency of the process will allow the cost of biomass-based electricity production to compete against other forms of renewable energy. Secondly, "special funding policies need to be reintroduced, such as those that were offered in the past by BNDES, Brazil's national development bank," Coelho explains, adding that, finally, there must be "auctions organised by the government for each type of renewable energy."
Without this state support for biomass, there is not a level playing field when you take into account the generous government subsidies afforded to hydropower and wind energy. But Coelho is certain that CENBIO's continued efforts will pay dividends in the long run. In the meantime, her research will continue, making biomass-based electricity a more attractive proposition.
"CENBIO has recently started developing studies on more advanced technologies - including lifecycle assessments for biofuel production and electricity generation. We are also developing studies and analyses for energy production from rural and urban residues, mainly focusing on technologies not yet commercialised in the country."
By disseminating knowledge in the field, it is hoped the Government will pick up the baton and run with it. That's got to be an easier task than trying to get anywhere in Sao Paulo during rush hour.