Only 80 ha of bamboo needed to generate 1 MW of electricity
Long-term fuel contract no more a concern with continuously available feedstock
By Eleanor Chen
The rising costs of biomass feedstock for power generation together with issues of availability and quality differences are challenges that many power plants face today. Energy plantations may provide the answer.
Such plantations ensure power plants are buffered against fluctuations in market prices. They also offer huge cost reductions when grown near power plants. Enter bamboo as a raw material in power generation.
“Grown using good agronomical practices, bamboo could be an economically viable fuel,” said Dr N Barathi, director of Growmore Biotech Ltd at the EU-Asia Biomass Best Practices and Business Partnering Conference 2012 organised by Biomass-SP in Kuala Lumpur recently. “One species grows at the speed of one-and-a-half foot a day and is capable of producing 100 tonnes per ha a year.”
Growmore Biotech from India has been exploring the possibility of generating quality feedstock at a lower price to make the biomass power industry viable in future. There is tremendous potential for biomass power plants. India alone aims to generate about 10 GW from biomass in the next decade. Secretary of the Ministry of New and Renewable Energy (MNRE) Deepak Gupta says India produced only around 1 GW in 2011.
Viable clean energy generation depends on uninterrupted fuel supplies at reasonable prices. Bamboo price is lower than briquettes and it is fixed. Investment is at the beginning, and after that, there is only the harvesting and fertiliser costs. As a result, it can be produced for less than US$20 a tonne in India.
Of the known biomass resources, bamboo is considered extremely suitable due to its high calorific value of 4,000 kcal/kg, low ash content of 0.5% and sustainable harvest. With its high biomass, using bamboo can reduce the land area required for power generation to as low as 80 ha in a high density energy plantation with closer spacing and faster growth.
Harvesting Beema bamboo: Cultivation can be done in all types of soil where there is sufficient water (photo credit: Clenergen)
“You need to have about 80 ha of bamboo to produce 8,000 tonnes of biomass to generate 1 MW of electricity, compared to at least 4,000 ha of oil palm or 500 ha of eucalyptus for the same amount of energy,” Barathi says.
Bamboo has many other advantages. It can be harvested every year compared to three to four years for other woody plants. Some species can yield nearly 100 tonnes per ha per year whereas other plants yield 25 tonnes.
There are over 1,200 bamboo species, from thin to thick, with long internodes, small internodes, from a few centimetres to 36 metres tall. Obtaining 100 tonnes per ha per year requires the best species. Wild bamboo is low yielding, very difficult to harvest and often has thorns. Most bamboo plants flower in nature after which
“Energy production requires thick wall bamboo. It is possible to select the best bamboo species based on climate, soil factor, sunlight availability, humidity, wind velocity and sunshine hours. Species alone is not enough. It is also important to have the right clone of species,” says Barathi.
One species called Beema is seen to be one of the best. This cloned and sterile bamboo does not require replanting for the next 100 years, compared to flowering bamboo. It has been engineered to have no thorns for ease of maintenance and harvesting, and increased wall thickness resulting in higher density.
After 10 years of breeding and fertilisation programmes, Beema is now grown from tissue culture and then micro propagated. It can be cultivated in all types of soil where there is sufficient water (see box story for more details).
With species like Beema grown in plantations near power stations, “a long-term fuel contract is no longer a concern as the raw material is continuously available and not dependent on the vagaries of supply and demand. There is no added challenge of increasing transportation costs,” says Barathi. He believes these advantages of an energy plantation will evolve in future.
However, to achieve high yields, soil, nutrients and especially rainfall need to be optimised. Companies seeking to invest in this energy production should do their due diligence as costs in other countries may differ from that in India.
• Beema: Super feedstock for power plants (click thru to read)