Growing willow for energy is nothing new for the UK – it’s has been done for very nearly the last 40 years – but with today’s mounting interest in both energy saving and renewable energy, the idea is becoming increasingly popular.
While the whole issue of growing energy crops instead of food has been heavily criticised of late, unlike approaches which divert edible materials to biofuel production, growing willow coppices doesn’t take the food from anyone’s table.
In addition, since the economics of the whole thing works best when the wood produced is burnt relatively close to where it was grown, coppiced willow helps reduce “energy miles” – and an energy saving in transport means better energy efficiency overall.
It’s not really something that’s likely to work in the average back garden – although you can certainly do it for a bit of fun – but on a larger scale and particularly for rural communities, it can be a worthwhile option to consider.
How Does It Work?
Willow “whips” – long, thin cuttings taken when the trees are dormant, during winter – are planted in the spring, in long rows to make eventual harvesting easier. Apart from needing the ground around them to be weeded to keep down competition until they become established, willows are a fairly undemanding crop to grow and thrive in the British climate.
In many places, they will put on around 6ft (1.8m) of growth a year, which means that by the time they are ready for harvest – after three years – the whips will have become sizeable trees.
Harvesting takes place in the winter, normally using a converted sugar-cane harvester, which travels along the rows, cutting the willows at the base and dicing the wood into 4 inch (10cm) “billets” which are then stored and allowed to air dry.
Once dry, the wood can be delivered for use – normally for local heating schemes, although in 2004 the huge Drax power station near Selby began using willow material alongside coal to generate electricity and number of other large power stations have also done so since then.
Energy Saving and Energy Efficiency
For large premises, especially farms, local schools of nursing homes, willow can be an ideal heating solution, especially since it can be grown either on site, or very close by, which makes a great deal of sense from the perspective of both energy saving and carbon reduction.
Compared with the transport cost of coal or oil to relatively remote areas, where gas is not available, the straightforward economic part of the energy saving is obvious, while additionally, there is also the saving in diesel – another fossil fuel – to consider. With much reduced delivery distances, locally grown willow clearly scores highly in the sustainability stakes.
Burning willow requires a specialised type of boiler, with an automatic feeder and associated controls to ensure everything keeps working at its best – and these do not come cheap. However, the systems themselves normally have a very long lifespan – often as much as 30 years – and if properly serviced seem remarkably robust in operation.
Aside of the design of the boiler itself, the main influence on overall energy efficiency tends to be the heat distribution system – responsible for moving the heat around to where it’s needed – and the levels of insulation in the buildings themselves.
However, making sure that lofts, walls and pipes are properly insulated is a major part of any energy saving project – so using willow doesn’t make much in the way of extra demands in that respect.
Carbon Neutral, Renewable Energy
Technically known as “Short Rotation Coppicing” – often abbreviated to SRC – this form of energy production is sustainable and carbon neutral, which accounts for much of its appeal. After harvesting, the trees once again begin growing from the root which remains in the soil, providing a new energy crop every three or four years, for around 30 years or more of useful life.
Since when the trees are burnt, they only release the carbon they took up when they were growing – rather than the “pre-historic” carbon released by fossil fuels – they don’t make a net contribution to the atmosphere and hence the claim to carbon neutrality.
A growing number of farmers have started producing willows, so in addition to providing energy, there are benefits to the rural economy and employment, while the coppiced woodland makes a valuable habitat for birds, mammals and other forms of wildlife.
Although this form of renewable energy isn’t always going to be the most appropriate, it can be a very effective alternative way of heating fairly large buildings and if nothing else, it gives a whole new meaning to the expression “grow your own”!
Source: Energy Saving Community
Monday, August 01, 2011
Willow Facts and Information
Willows all have abundant watery bark, sap which is heavily charged with salicylic acid, soft, usually pliant, tough wood, slender branches, and large, fibrous, often stoloniferous roots. The roots are remarkable for their toughness, size, and tenacity to life, and roots readily grow from aerial parts of the plant.
The leaves are typically elongated but may also be round to oval, frequently with a serrated margin. Most species are deciduous; semi-evergreen willows with coriaceous leaves are rare, e.g. Salix micans and S. australior in the eastern Mediterranean. All the buds are lateral; no absolutely terminal bud is ever formed. The buds are covered by a single scale, enclosing at its base two minute opposite buds, alternately arranged, with two small, opposite, scale-like leaves. This first pair soon fall, and the later leaves are alternately arranged. The leaves are simple, feather-veined, and typically linear-lanceolate. Usually they are serrate, rounded at base, acute or acuminate. The leaf petioles are short, the stipules often very conspicuous, looking like tiny round leaves and sometimes remaining for half the summer. On some species, however, they are small, inconspicuous, and fugacious (soon falling). In color the leaves show a great variety of greens, ranging from yellowish to bluish.
Willow Flowers
Willows are dioecious with male and female flowers appearing as catkins on different plants; the catkins are produced early in the spring, often before the leaves, or as the new leaves open.
The staminate (male) flowers are without either calyx or corolla; they consist simply of stamens, varying in number from two to ten, accompanied by a nectariferous gland and inserted on the base of a scale which is itself borne on the rachis of a drooping raceme called a catkin, or ament. This scale is oval and entire and very hairy. The anthers are rose colored in the bud but orange or purple after the flower opens, they are two-celled and the cells open longitudinally. The filaments are threadlike, usually pale yellow, and often hairy.
The pistillate (female) flowers are also without calyx or corolla; and consist of a single ovary accompanied by a small flat nectar gland and inserted on the base of a scale which is likewise borne on the rachis of a catkin. The ovary is one-celled, the style two-lobed, and the ovules numerous.
Willow Cultivation
Almost all willows take root very readily from cuttings or where broken branches lie on the ground. There are a few exceptions, including the Goat Willow (Salix caprea) and Peachleaf Willow (Salix amygdaloides). One famous example of such growth from cuttings involves the poet Alexander Pope, who begged a twig from a parcel tied with twigs sent from Spain to Lady Suffolk. This twig was planted and thrived, and legend has it that all of England's weeping willows are descended from this first one.
Willows are often planted on the borders of streams so that their interlacing roots may protect the bank against the action of the water. Frequently the roots are much larger than the stem which grows from them.
Ecological Issues Regarding Willow
Willows are used as food plants by the larvae of some Lepidoptera species. A small number of willow species were widely planted in Australia, notably as erosion control measures along watercourses. They are now regarded as an invasive weed and many catchment management authorities are removing them to be replaced with native trees. Willow roots grow widespread and are very aggressive in seeking out moisture; for this reason, they can become problematic when planted in residential areas, where the roots are notorious for clogging French drains, drainage systems, weeping tiles, septic systems, storm drains, and sewer systems, particularly older, tile, concrete, or ceramic pipes. Newer, PVC sewer pipes are much less leaky at the joints, and are therefore less susceptible to problems from willow roots; the same is true of water supply piping.
Willow Uses
Medicine
The leaves and bark of the willow tree have been mentioned in ancient texts from Assyria, Sumer and Egypt as a remedy for aches and fever, and the Ancient Greek physician Hippocrates wrote about its medicinal properties in the 5th century BC. Native Americans across the American continent relied on it as a staple of their medical treatments. This is because willows contain salicin, a substance that chemically resembles aspirin. Salicin is metabolized in to salicylic acid in the human body, which is a precursor of aspirin.
In 1763 its medicinal properties were observed by the Reverend Edward Stone in England. He notified the Royal Society who published his findings. The active extract of the bark, called salicin, was isolated to its crystalline form in 1828 by Henri Leroux, a French pharmacist, and Raffaele Piria, an Italian chemist, who then succeeded in separating out the compound in its pure state.
In 1897 Felix Hoffmann created a synthetically altered version of salicin (in his case derived from the Spiraea plant), which caused less digestive upset than pure salicylic acid. The new drug, formally Acetylsalicylic acid, was named Aspirin by Hoffmann's employer Bayer AG. This gave rise to the hugely important class of drugs known as non-steroidal anti-inflammatory drugs (NSAIDs).
Willow Manufacturing
Some of man's earliest manufactured items may have been made from willow. Basic crafts such as baskets, fish traps, wattle fences and wattle and daub house walls were often woven from osiers (rod-like willow shoots). Thin or split willow rods can be woven into wicker, which also has a long history. The relatively pliable willow is less likely to split while being woven than many other woods, and can be bent around sharp corners in basketry.
Willow wood is also used in the manufacture of boxes, brooms, cricket bats (grown from certain strains of white willow), cradle boards, chairs and other furniture, dolls, flutes, poles, sweat lodges, toys, turnery, tool handles, veneer, wands and whistles.
In addition tannin, fibre, paper, rope and string, can be produced from the wood.
Willow as Food
Poor people at one time often ate willow catkins that had been cooked to form a mash.
Willow in Agriculture
Willow bark contains auxins (plant growth hormones), especially those used for rooting new cuttings. The bark can even be used to make a simple extract that will promote cutting growth.
Willows produce a modest amount of nectar that bees can make honey from, and are especially valued as a source of early pollen for bees.
Willow grown for Energy
Willow is grown for biomass or biofuel, in energy forestry systems, as a consequence of its high energy in-energy out ratio, large carbon mitigation potential and fast growth. Large scale projects to support willow as an energy crop are already at commercial scale in Sweden, and in other countries there are others being developed through initiatives such as the Willow Biomass Project in the US and the Energy Coppice Project in the UK.
Willow may also be grown to produce Charcoal.
Willow and the Environment
As a plant, willow is used for biofiltration, constructed wetlands, ecological wastewater treatment systems, hedges, land reclamation, landscaping, phytoremediation, streambank stabilisation (bioengineering), slope stabilisation, soil erosion control, shelterbelt & windbreak, soil building, soil reclamation, tree bog compost toilet, wildlife habitat.
Willow Art
Willow is used as charcoal (for drawing) and in living sculptures. Living sculptures are created from live willow rods planted in the ground and woven into shapes such as domes and tunnels. Willow stems are used to weave baskets and 3 dimensional sculptures such as animals and figures. Willow stems are also used to create garden features such as decorative panel and obelisks.
Willow in Religion
Willow is one of the "Four Species" used ritually during the Jewish holiday of Sukkot. In Buddhism, a willow branch is one of the chief attributes of Kwan Yin, the bodhisattva of compassion. Willow is also one of the "nine sacred trees" mentioned in Wicca and witchcraft, with several magical uses. In the Wiccan Rede, it is described as growing by water, guiding the dead to "The Summerland", a commonly used term in Wicca to refer to the afterlife. Christian churches in northwestern Europe often used willow branches in place of palms in the ceremonies on Palm Sunday.
Willow in culture
In China, some people carry willow branches with them on the day of their Tomb Sweeping or Qingming Festival. Willow branches are also put up on gates and/or front doors, which they believe help ward off the evil spirits that wanders on Qingming. Legend states that on Qingming Festival, the ruler of Hades allows the spirits of the dead to return to earth. Since their presence may not always be welcome, willow branches keep them away. In traditional pictures of the Goddess of Mercy Guanyin she is often shown seated on a rock with a willow-branch in a vase of water at her side. The Goddess employs this mysterious water and the branch for putting demons to flight. Taoist witches also use a small carving made from willow wood for communicating with the spirits of the dead. The image is sent to the nether world, where the disembodied spirit is deemed to enter it, and give the desired information to surviving relatives on its return.
The willow is a famous subject in many East Asian nations' cultures, particularly in pen and ink paintings from China and Japan.
A Gisaeng (Korean Geisha) named Hongrang, who lived in the middle of the Joseon Dynasty, wrote the poem "By the willow in the rain in the evening", which she gave to her parting lover (Choi Gyeong-chang). Hongrang wrote:
"...I will be the willow on your bedside."
Willow trees are also quite prevalent in folklore and myths.[19][20] In English folklore, a willow tree is believed to be quite sinister, capable of uprooting itself and stalking travellers.
The Viminal hill, one of the Seven Hills Of Rome, derives it name from the Latin word for osier, viminia (pl.).
Willow In literature
In The Book of Psalms, Psalm 137 —
Upon the rivers of Babylon, there we sat and also cried in our remembering Zion. Upon the willows in the river's midst we hung our lyres.
This Psalm is an ancient expression of Jews' yearning to return from the exile (Babylonian) to the Land of Zion.
Hans Christian Andersen wrote a story called Under the Willow Tree (1853) in which children ask questions of a tree they call willow-father, paired with another entity called elder-mother.[21]
The Wind in the Willows
Algernon Blackwood wrote a story called The Willows (1907) about two friends on a canoe trip down the Danube river who have a horrifying experience with the trees. This story was a personal favorite of H. P. Lovecraft.
Green Willow is a Japanese ghost story in which a young samurai falls in love with a woman called Green Willow who has a close spiritual connection with a willow tree. The Willow Wife is another, not dissimilar tale. Wisdom of the Willow Tree is an Osage Nation story in which a young man seeks answers from a Willow tree, addressing the tree in conversation as 'Grandfather'.
In J. K. Rowling's Harry Potter and the Chamber of Secrets, and Harry Potter and the Prisoner of Azkaban, there is an old tree on the school grounds of Hogwarts called the "Whomping Willow". It was planted in order to conceal a secret passageway that Professor Remus Lupin roamed through every full moon when he began his transformation into a werewolf.
In William Shakespeare's Hamlet, the character Ophelia climbed a willow tree when a branch broke and dropped her into the river below where she drowned. In Shakespeare's "Twelfth Night", Viola (disguised as Cesario) tells Olivia "Make me a willow-cabin at your gate/ And call upon my soul within the house." The willow here being an emblem of forsaken love. In Shakespeare's Othello, Desdemona's song before her death uses the willow imagery to highlight her lost love.
J. R. R. Tolkien's The Lord of the Rings also features a character known as Old Man Willow which traps some of Frodo's companions until they are rescued by Tom Bombadil.
In Persian literature, the recognized adjective for 'willow' is lunatic (مجنون), and lover (or lovers' heart) is compared to willow in many texts.
The willow is the symbol of wisdom. This is very clear in Disney's Pocahontas, in which Pocahontas asks the counsel of grandmother Willow.
Source: Wikipedia
The leaves are typically elongated but may also be round to oval, frequently with a serrated margin. Most species are deciduous; semi-evergreen willows with coriaceous leaves are rare, e.g. Salix micans and S. australior in the eastern Mediterranean. All the buds are lateral; no absolutely terminal bud is ever formed. The buds are covered by a single scale, enclosing at its base two minute opposite buds, alternately arranged, with two small, opposite, scale-like leaves. This first pair soon fall, and the later leaves are alternately arranged. The leaves are simple, feather-veined, and typically linear-lanceolate. Usually they are serrate, rounded at base, acute or acuminate. The leaf petioles are short, the stipules often very conspicuous, looking like tiny round leaves and sometimes remaining for half the summer. On some species, however, they are small, inconspicuous, and fugacious (soon falling). In color the leaves show a great variety of greens, ranging from yellowish to bluish.
Willow Flowers
Willows are dioecious with male and female flowers appearing as catkins on different plants; the catkins are produced early in the spring, often before the leaves, or as the new leaves open.
The staminate (male) flowers are without either calyx or corolla; they consist simply of stamens, varying in number from two to ten, accompanied by a nectariferous gland and inserted on the base of a scale which is itself borne on the rachis of a drooping raceme called a catkin, or ament. This scale is oval and entire and very hairy. The anthers are rose colored in the bud but orange or purple after the flower opens, they are two-celled and the cells open longitudinally. The filaments are threadlike, usually pale yellow, and often hairy.
The pistillate (female) flowers are also without calyx or corolla; and consist of a single ovary accompanied by a small flat nectar gland and inserted on the base of a scale which is likewise borne on the rachis of a catkin. The ovary is one-celled, the style two-lobed, and the ovules numerous.
Willow Cultivation
Almost all willows take root very readily from cuttings or where broken branches lie on the ground. There are a few exceptions, including the Goat Willow (Salix caprea) and Peachleaf Willow (Salix amygdaloides). One famous example of such growth from cuttings involves the poet Alexander Pope, who begged a twig from a parcel tied with twigs sent from Spain to Lady Suffolk. This twig was planted and thrived, and legend has it that all of England's weeping willows are descended from this first one.
Willows are often planted on the borders of streams so that their interlacing roots may protect the bank against the action of the water. Frequently the roots are much larger than the stem which grows from them.
Ecological Issues Regarding Willow
Willows are used as food plants by the larvae of some Lepidoptera species. A small number of willow species were widely planted in Australia, notably as erosion control measures along watercourses. They are now regarded as an invasive weed and many catchment management authorities are removing them to be replaced with native trees. Willow roots grow widespread and are very aggressive in seeking out moisture; for this reason, they can become problematic when planted in residential areas, where the roots are notorious for clogging French drains, drainage systems, weeping tiles, septic systems, storm drains, and sewer systems, particularly older, tile, concrete, or ceramic pipes. Newer, PVC sewer pipes are much less leaky at the joints, and are therefore less susceptible to problems from willow roots; the same is true of water supply piping.
Willow Uses
Medicine
The leaves and bark of the willow tree have been mentioned in ancient texts from Assyria, Sumer and Egypt as a remedy for aches and fever, and the Ancient Greek physician Hippocrates wrote about its medicinal properties in the 5th century BC. Native Americans across the American continent relied on it as a staple of their medical treatments. This is because willows contain salicin, a substance that chemically resembles aspirin. Salicin is metabolized in to salicylic acid in the human body, which is a precursor of aspirin.
In 1763 its medicinal properties were observed by the Reverend Edward Stone in England. He notified the Royal Society who published his findings. The active extract of the bark, called salicin, was isolated to its crystalline form in 1828 by Henri Leroux, a French pharmacist, and Raffaele Piria, an Italian chemist, who then succeeded in separating out the compound in its pure state.
In 1897 Felix Hoffmann created a synthetically altered version of salicin (in his case derived from the Spiraea plant), which caused less digestive upset than pure salicylic acid. The new drug, formally Acetylsalicylic acid, was named Aspirin by Hoffmann's employer Bayer AG. This gave rise to the hugely important class of drugs known as non-steroidal anti-inflammatory drugs (NSAIDs).
Willow Manufacturing
Some of man's earliest manufactured items may have been made from willow. Basic crafts such as baskets, fish traps, wattle fences and wattle and daub house walls were often woven from osiers (rod-like willow shoots). Thin or split willow rods can be woven into wicker, which also has a long history. The relatively pliable willow is less likely to split while being woven than many other woods, and can be bent around sharp corners in basketry.
Willow wood is also used in the manufacture of boxes, brooms, cricket bats (grown from certain strains of white willow), cradle boards, chairs and other furniture, dolls, flutes, poles, sweat lodges, toys, turnery, tool handles, veneer, wands and whistles.
In addition tannin, fibre, paper, rope and string, can be produced from the wood.
Willow as Food
Poor people at one time often ate willow catkins that had been cooked to form a mash.
Willow in Agriculture
Willow bark contains auxins (plant growth hormones), especially those used for rooting new cuttings. The bark can even be used to make a simple extract that will promote cutting growth.
Willows produce a modest amount of nectar that bees can make honey from, and are especially valued as a source of early pollen for bees.
Willow grown for Energy
Willow is grown for biomass or biofuel, in energy forestry systems, as a consequence of its high energy in-energy out ratio, large carbon mitigation potential and fast growth. Large scale projects to support willow as an energy crop are already at commercial scale in Sweden, and in other countries there are others being developed through initiatives such as the Willow Biomass Project in the US and the Energy Coppice Project in the UK.
Willow may also be grown to produce Charcoal.
Willow and the Environment
As a plant, willow is used for biofiltration, constructed wetlands, ecological wastewater treatment systems, hedges, land reclamation, landscaping, phytoremediation, streambank stabilisation (bioengineering), slope stabilisation, soil erosion control, shelterbelt & windbreak, soil building, soil reclamation, tree bog compost toilet, wildlife habitat.
Willow Art
Willow is used as charcoal (for drawing) and in living sculptures. Living sculptures are created from live willow rods planted in the ground and woven into shapes such as domes and tunnels. Willow stems are used to weave baskets and 3 dimensional sculptures such as animals and figures. Willow stems are also used to create garden features such as decorative panel and obelisks.
Willow in Religion
Willow is one of the "Four Species" used ritually during the Jewish holiday of Sukkot. In Buddhism, a willow branch is one of the chief attributes of Kwan Yin, the bodhisattva of compassion. Willow is also one of the "nine sacred trees" mentioned in Wicca and witchcraft, with several magical uses. In the Wiccan Rede, it is described as growing by water, guiding the dead to "The Summerland", a commonly used term in Wicca to refer to the afterlife. Christian churches in northwestern Europe often used willow branches in place of palms in the ceremonies on Palm Sunday.
Willow in culture
In China, some people carry willow branches with them on the day of their Tomb Sweeping or Qingming Festival. Willow branches are also put up on gates and/or front doors, which they believe help ward off the evil spirits that wanders on Qingming. Legend states that on Qingming Festival, the ruler of Hades allows the spirits of the dead to return to earth. Since their presence may not always be welcome, willow branches keep them away. In traditional pictures of the Goddess of Mercy Guanyin she is often shown seated on a rock with a willow-branch in a vase of water at her side. The Goddess employs this mysterious water and the branch for putting demons to flight. Taoist witches also use a small carving made from willow wood for communicating with the spirits of the dead. The image is sent to the nether world, where the disembodied spirit is deemed to enter it, and give the desired information to surviving relatives on its return.
The willow is a famous subject in many East Asian nations' cultures, particularly in pen and ink paintings from China and Japan.
A Gisaeng (Korean Geisha) named Hongrang, who lived in the middle of the Joseon Dynasty, wrote the poem "By the willow in the rain in the evening", which she gave to her parting lover (Choi Gyeong-chang). Hongrang wrote:
"...I will be the willow on your bedside."
Willow trees are also quite prevalent in folklore and myths.[19][20] In English folklore, a willow tree is believed to be quite sinister, capable of uprooting itself and stalking travellers.
The Viminal hill, one of the Seven Hills Of Rome, derives it name from the Latin word for osier, viminia (pl.).
Willow In literature
In The Book of Psalms, Psalm 137 —
Upon the rivers of Babylon, there we sat and also cried in our remembering Zion. Upon the willows in the river's midst we hung our lyres.
This Psalm is an ancient expression of Jews' yearning to return from the exile (Babylonian) to the Land of Zion.
Hans Christian Andersen wrote a story called Under the Willow Tree (1853) in which children ask questions of a tree they call willow-father, paired with another entity called elder-mother.[21]
The Wind in the Willows
Algernon Blackwood wrote a story called The Willows (1907) about two friends on a canoe trip down the Danube river who have a horrifying experience with the trees. This story was a personal favorite of H. P. Lovecraft.
Green Willow is a Japanese ghost story in which a young samurai falls in love with a woman called Green Willow who has a close spiritual connection with a willow tree. The Willow Wife is another, not dissimilar tale. Wisdom of the Willow Tree is an Osage Nation story in which a young man seeks answers from a Willow tree, addressing the tree in conversation as 'Grandfather'.
In J. K. Rowling's Harry Potter and the Chamber of Secrets, and Harry Potter and the Prisoner of Azkaban, there is an old tree on the school grounds of Hogwarts called the "Whomping Willow". It was planted in order to conceal a secret passageway that Professor Remus Lupin roamed through every full moon when he began his transformation into a werewolf.
In William Shakespeare's Hamlet, the character Ophelia climbed a willow tree when a branch broke and dropped her into the river below where she drowned. In Shakespeare's "Twelfth Night", Viola (disguised as Cesario) tells Olivia "Make me a willow-cabin at your gate/ And call upon my soul within the house." The willow here being an emblem of forsaken love. In Shakespeare's Othello, Desdemona's song before her death uses the willow imagery to highlight her lost love.
J. R. R. Tolkien's The Lord of the Rings also features a character known as Old Man Willow which traps some of Frodo's companions until they are rescued by Tom Bombadil.
In Persian literature, the recognized adjective for 'willow' is lunatic (مجنون), and lover (or lovers' heart) is compared to willow in many texts.
The willow is the symbol of wisdom. This is very clear in Disney's Pocahontas, in which Pocahontas asks the counsel of grandmother Willow.
Source: Wikipedia
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