The potential of trees for energy
Further exploration of sustainable tree-based bioenergy could help improve the lives and livelihoods of communities around the world.
Most of the energy used in the world comes from fossil fuels, which are not sustainable as sources will eventually run out. The use of fossil fuels also contributes to greenhouse-gas emissions, global warming and climate change.
How much energy do we need?
Over half of the world’s energy comes from oil and natural gas, while renewable sources of energy only contribute around 13%. This means world energy sources will run out much faster than expected if people do not explore, and shift to, renewable sources soon. In addition, according to Philip Dobie, senior fellow at ICRAF, speaking on 15 September 2015 during ICRAF’s global Science Week in Bogor, Indonesia: ‘All fossil energy sources have either reached or passed their peak production’.
Of the renewable energy sources, 77% comes from bioenergy, of which 87% is woody biomass from trees and shrubs. Using trees for energy has a huge potential, as plants efficiently convert solar energy into biomass, which is easier for people to harness and store than other energy sources like solar, wind and geothermal.
Development of nations is largely dependent on energy and electricity. People need energy for cooking their daily meals and boiling water for drinking. Farmers need energy and electricity to use their agricultural tools and irrigate their farms. Post-harvest production and processing is also restricted if there is limited energy.
How about energy from trees?
Biomass has sometimes been seen as a source of energy to be avoided because obtaining it contributes to deforestation and degradation and its use can have negative health impacts. However, using biomass as an energy source can actually help improve and provide livelihoods and it need not negatively affect biodiversity because biofuel plants can be integrated into agroforestry systems.
Fuelwood and charcoal provide many people across the world with energy for their daily activities. In Africa, 80% of households’ energy comes from these sources. The trend of using charcoal is going up, especially since, compared to other biomass it is lightweight, cheap and easily accessible by communities.
Even developed countries are increasingly using biomass as a source of their energy. The European Union, for instance, generates more than 100,000 GWh of electricity from biomass every year and much of it is derived from trees. In Finland, 23% of the energy is derived from wood, which is more than the total generating capacity of most countries in Africa.
There are also debates on food versus fuel, specifically, how growing trees for bioenergy competes with food production. However, this need not be the case. ICRAF research on trees has helped increase crop productivity by promoting the use of fertiliser and multipurpose trees. Indian farmers are using oil from ‘undi’ trees (Calophyllum inophyllum) to operate pumps for irrigating their farms. In the Philippines, researchers are looking at how nipa palm (Nypa fruticans) can be used as biofuel as well as feed for livestock. Gliricidia, which is used for off-grid electricity generation in Sri Lanka, is intercropped with coconut trees.
How should we tackle tree-based bioenergy?
ICRAF researchers emphasize that there is no ‘one-size fits-all’ tree for every country. What might work in one country might not work in another. For example, India is harnessing seven native species for bioenergy production, while in Sri Lanka Gliricidia is largely used. It is, therefore, important to identify which tree species have the potential for oil production and would also work well in agroforestry systems. Mapping vegetation suitable for a given region could help with understanding this better.
A systems perspective could also help in increasing the uptake of sustainable bioenergy. For example, producers might not invest in efficient methods of producing bioenergy because the costs were larger than their incomes. However, the full production process should be considered when developing sustainable tree-based bioenergy: from the producers to the end-users. Policies should also support such sustainable practices and create incentives for the use of more efficient stoves and equipment.
There is a growing interest in, and need for, sustainable tree-based bioenergy; rightly so, because bioenergy from trees can improve not only the lives and livelihoods of communities but also the state of the environment.
This work is linked to the CGIAR Research Program on Forests, Trees and Agroforestry