Energy forestry
Encyclopedia
Energy forestry is a form of forestry in which a fast-growing species of tree or woody shrub is grown specifically to provide biomass
or biofuel
for heating or power generation.
The two forms of energy forestry are short rotation coppice
and short rotation forestry
:
s" such as coal
, natural gas
and oil
, is that while they are growing they absorb the near-equivalent in carbon dioxide
(an important greenhouse gas
) to that which is later released in their burning. Whereas by burning fossil fuels we are increasing atmospheric carbon unsustainably, by using carbon that was added to the earths carbon sink millions of years ago in processes which took millions of years to complete, and this is a prime cause of global warming
.
According to the FAO
, compared to other energy crops, wood is among the most efficient sources of bioenergy
in terms of quantity of energy released by unit of carbon emitted. Another advantage of generating energy from trees, as opposed to agricultural crops, is that trees do not have to be harvested each year, the harvest can be delayed when market prices are down, and the products can fulfil a variety of end-uses.
Yields of some varieties can be as high as 12 oven dry tonnes every year. However, commercial experience on plantations in Scandinavia have shown lower yield rates.
These crops can also be used in bank stabilisation and phytoremediation
.
Growing trees are relatively water intensive.
The system of energy forestry has faced criticism over food vs. fuel, whereby it has become financially profitable to replace food crops with energy crops. It has to be noted, however, that such energy forests do not necessarily compete with food crops for highly productive land as they can be grown on slopes, marginal, or degraded land as well - sometimes even with long-term restoration purposes in mind. For more information see issues relating to biofuels
and Food vs fuel
Wikipedia pages.
Biomass
Biomass, as a renewable energy source, is biological material from living, or recently living organisms. As an energy source, biomass can either be used directly, or converted into other energy products such as biofuel....
or biofuel
Biofuel
Biofuel is a type of fuel whose energy is derived from biological carbon fixation. Biofuels include fuels derived from biomass conversion, as well as solid biomass, liquid fuels and various biogases...
for heating or power generation.
The two forms of energy forestry are short rotation coppice
Short rotation coppice
Short Rotation Coppice is coppice grown as an energy crop. This woody solid biomass can be used in applications such as district heating, electric power generating stations, alone or in combination with other fuels.- Species used :...
and short rotation forestry
Short rotation forestry
Short Rotation Forestry is grown as an energy crop for use in power stations, alone or in combination with other fuels such as coal. It is similar to historic fuelwood coppice systems.- Species used :...
:
- Short rotation coppice are crops of PoplarPoplarPopulus is a genus of 25–35 species of deciduous flowering plants in the family Salicaceae, native to most of the Northern Hemisphere. English names variously applied to different species include poplar , aspen, and cottonwood....
or WillowWillowWillows, sallows, and osiers form the genus Salix, around 400 species of deciduous trees and shrubs, found primarily on moist soils in cold and temperate regions of the Northern Hemisphere...
, grown for 2 to 5 years before harvest. - Short rotation forestry are crops of AlderAlderAlder is the common name of a genus of flowering plants belonging to the birch family . The genus comprises about 30 species of monoecious trees and shrubs, few reaching large size, distributed throughout the North Temperate Zone and in the Americas along the Andes southwards to...
, AshAsh treeFraxinus is a genus flowering plants in the olive and lilac family, Oleaceae. It contains 45-65 species of usually medium to large trees, mostly deciduous though a few subtropical species are evergreen. The tree's common English name, ash, goes back to the Old English æsc, while the generic name...
, BirchBirchBirch is a tree or shrub of the genus Betula , in the family Betulaceae, closely related to the beech/oak family, Fagaceae. The Betula genus contains 30–60 known taxa...
, EucalyptusEucalyptusEucalyptus is a diverse genus of flowering trees in the myrtle family, Myrtaceae. Members of the genus dominate the tree flora of Australia...
, PoplarPoplarPopulus is a genus of 25–35 species of deciduous flowering plants in the family Salicaceae, native to most of the Northern Hemisphere. English names variously applied to different species include poplar , aspen, and cottonwood....
, and SycamoreSycamoreSycamore is a name which is applied at various times and places to three very different types of trees, but with somewhat similar leaf forms....
, grown for 8 to 20 years before harvest.
Benefits
The main advantage of using "grown fuels", as opposed to "fossil fuelFossil fuel
Fossil fuels are fuels formed by natural processes such as anaerobic decomposition of buried dead organisms. The age of the organisms and their resulting fossil fuels is typically millions of years, and sometimes exceeds 650 million years...
s" such as coal
Coal
Coal is a combustible black or brownish-black sedimentary rock usually occurring in rock strata in layers or veins called coal beds or coal seams. The harder forms, such as anthracite coal, can be regarded as metamorphic rock because of later exposure to elevated temperature and pressure...
, natural gas
Natural gas
Natural gas is a naturally occurring gas mixture consisting primarily of methane, typically with 0–20% higher hydrocarbons . It is found associated with other hydrocarbon fuel, in coal beds, as methane clathrates, and is an important fuel source and a major feedstock for fertilizers.Most natural...
and oil
Oil
An oil is any substance that is liquid at ambient temperatures and does not mix with water but may mix with other oils and organic solvents. This general definition includes vegetable oils, volatile essential oils, petrochemical oils, and synthetic oils....
, is that while they are growing they absorb the near-equivalent in carbon dioxide
Carbon dioxide
Carbon dioxide is a naturally occurring chemical compound composed of two oxygen atoms covalently bonded to a single carbon atom...
(an important greenhouse gas
Greenhouse gas
A greenhouse gas is a gas in an atmosphere that absorbs and emits radiation within the thermal infrared range. This process is the fundamental cause of the greenhouse effect. The primary greenhouse gases in the Earth's atmosphere are water vapor, carbon dioxide, methane, nitrous oxide, and ozone...
) to that which is later released in their burning. Whereas by burning fossil fuels we are increasing atmospheric carbon unsustainably, by using carbon that was added to the earths carbon sink millions of years ago in processes which took millions of years to complete, and this is a prime cause of global warming
Global warming
Global warming refers to the rising average temperature of Earth's atmosphere and oceans and its projected continuation. In the last 100 years, Earth's average surface temperature increased by about with about two thirds of the increase occurring over just the last three decades...
.
According to the FAO
Fão
Fão is a town in Esposende Municipality in Portugal....
, compared to other energy crops, wood is among the most efficient sources of bioenergy
Bioenergy
Bioenergy is renewable energy made available from materials derived from biological sources. Biomass is any organic material which has stored sunlight in the form of chemical energy. As a fuel it may include wood, wood waste, straw, manure, sugarcane, and many other byproducts from a variety of...
in terms of quantity of energy released by unit of carbon emitted. Another advantage of generating energy from trees, as opposed to agricultural crops, is that trees do not have to be harvested each year, the harvest can be delayed when market prices are down, and the products can fulfil a variety of end-uses.
Yields of some varieties can be as high as 12 oven dry tonnes every year. However, commercial experience on plantations in Scandinavia have shown lower yield rates.
These crops can also be used in bank stabilisation and phytoremediation
Phytoremediation
Phytoremediation Phytoremediation Phytoremediation (from the Ancient Greek , and Latin (restoring balance or remediation) describes the treatment of environmental problems (bioremediation) through the use of plants that mitigate the environmental problem without the need to excavate the...
.
Problems
Although in many areas of the world government funding is still required to support large scale development of energy forestry as an industry, it is seen as a valuable component of the renewable energy network and will be increasingly important in the future.Growing trees are relatively water intensive.
The system of energy forestry has faced criticism over food vs. fuel, whereby it has become financially profitable to replace food crops with energy crops. It has to be noted, however, that such energy forests do not necessarily compete with food crops for highly productive land as they can be grown on slopes, marginal, or degraded land as well - sometimes even with long-term restoration purposes in mind. For more information see issues relating to biofuels
Issues relating to biofuels
There are various social, economic, environmental and technical issues with biofuel production and use, which have been discussed in the popular media and scientific journals...
and Food vs fuel
Food vs fuel
Food vs. fuel is the dilemma regarding the risk of diverting farmland or crops for biofuels production in detriment of the food supply on a global scale. The "food vs. fuel" or "food or fuel" debate is international in scope, with good and valid arguments on all sides of this issue...
Wikipedia pages.
See also
- BiomassBiomassBiomass, as a renewable energy source, is biological material from living, or recently living organisms. As an energy source, biomass can either be used directly, or converted into other energy products such as biofuel....
- BiofuelBiofuelBiofuel is a type of fuel whose energy is derived from biological carbon fixation. Biofuels include fuels derived from biomass conversion, as well as solid biomass, liquid fuels and various biogases...
- TreethanolTreethanolTreethanol is an ethanol fuel made from trees.Forest trees make up more than 90% of the total terrestrial biomass while performing functions such as carbon sequestration, producing oxygen, and promoting biodiversity...
- Energy cropEnergy cropAn energy crop is a plant grown as a low cost and low maintenance harvest used to make biofuels, or combusted for its energy content to generate electricity or heat. Energy crops are generally categorized as woody or herbaceous ....
- Non food cropsNon Food CropsThe term non food crop applies to the use of agricultural crop for uses other than human or animal consumption .The range of crops with non-food uses is broad...
- PoplarPoplarPopulus is a genus of 25–35 species of deciduous flowering plants in the family Salicaceae, native to most of the Northern Hemisphere. English names variously applied to different species include poplar , aspen, and cottonwood....
- Short rotation coppiceShort rotation coppiceShort Rotation Coppice is coppice grown as an energy crop. This woody solid biomass can be used in applications such as district heating, electric power generating stations, alone or in combination with other fuels.- Species used :...
- Short rotation forestryShort rotation forestryShort Rotation Forestry is grown as an energy crop for use in power stations, alone or in combination with other fuels such as coal. It is similar to historic fuelwood coppice systems.- Species used :...
- WillowWillowWillows, sallows, and osiers form the genus Salix, around 400 species of deciduous trees and shrubs, found primarily on moist soils in cold and temperate regions of the Northern Hemisphere...