Growing willow for biomass has many benefits. It provides an alternative to oil as a fuel, a viable alternative to conventional tillage, it is good for the environment and perhaps most importantly of all, it provides a means of disposing of materials like sewage sludge and brewery waste, profitably, safely and cleanly. Large sums of money are currently spent on disposing of waste materials but willow has the ability to absorb many of these safely and then turn them in to cash.
In order to examine the potential of willow as an alternative farm crop, the Royal Dublin Society agricultural committee spent two days visiting sites in Northern Ireland where practical experiments on willow for biomass are taking place.
The first visit was to Loughgall Horticulture and plant breeding station in Armagh lead by Malcolm Dawson. He took us first to a 2yr old coppice plantation where he explained the steps necessary to achieve a vigorous crop. Initial ground preparation is the same as for any tillage crop and willow yields on the same basis. Good land produces good crops. My knowledge of willow extended to how it thrives in damp wet heavy places but Malcom stressed its suitability for good land where it will yield accordingly.
Willow will grow if a cutting is simply stuck in the ground. Planting should take place during springtime up to mid April and this can now be done mechanically.
By the end of September the cuttings will have grown approximately 2m and these are then cut back to encourage coppicing. The crop will be harvested three years later and every third year after that for approximately 30 yrs, which is the average length of one rotation. Willow can be cut and chipped in one operation during harvesting but to justify owning a harvester would require 1000 ha of coppice for a season. So cooperation is the key to progress in this area and the possibilities are endless.
In Sweden, using willow for energy is now a highly developed industry and their costs are lower than inIreland, due to the economies of scale. Cropestablishment costs in Ireland are in the region of £1800 sterling per hectare and as little as one third of this or £600 per ha in Sweden. Growing and management costs are approximately 40% higher in Ireland but if we develop the back up and infrastructure available to Swedish farmers then our costs will reduce accordingly. Willow, like so many other things, grows faster in Ireland and would make an ideal crop on setaside land which is at present a wasted asset.There is a lot of interest throughout Europe in utilising willow as a fuel and funding is available for pilot projects.
On day two we visited Brook farm near Londonderry, where John Gilliland farms extensively. John is head of the Ulster Farmers Union and grows 42 ha of willow on set-aside land as part of a project to commercially develop short rotation coppice willow as a fuel. He has installed a fully working commercial unit on his farm where willow is converted to fuel using a gasifier. This fuel is then piped to a combined heat and power unit, which generates 600,000 kwh of electricity annually. Thermal energy is also recovered from the cooling and exhaust systems. This is used for heating of houses, drying grain and drying freshly harvested willow chips. To manage this project and market the technology and equipment needed, a company, Rural Generation Ltd, has been formed and they now are in a position to assist farmers who wish to avail of their experience. They can be contacted at Brook Hall Estate, 65-67, Culmore Rd, Londonderry, Northern Ireland.
Rural Generation have developed many uses for willow chip and Michael Doran their business development manager was clearly enthusiastic as to the potential of SRC. He expressed some frustration over dealings with Government departments which farmer’s nationwide would agree with when he said that some departments are now simply acting as departments of enforcement.
Rural Generation are pressing ahead regardless and one product which is now in great demand is willow for poultry bedding. For this purpose, the willow is processed to produce a fluffy bedding, which the hens prefer and is especially in demand for broiler houses. An important bonus is that the salicylic acid in willow attacks ammonia thereby improving the environment of poultry houses.
They have also developed a special machine for burying sewage sludge in growing willow crops and the vigorous root structure of the willow enables this heavy machinery to travel on land, which would otherwise be impassable. As sludge is currently exported from Northern Ireland for disposal in England, burying it locally for fertilising a crop can earn up to £2500 per ha.
They also market boilers for farm and domestic use, which burn willow chip and other fuels such as used poultry litter. I recall the great popularity of big bale burners in the early seventies following on the first oil crisis. These burners were purchased by many tillage farmers who could always be recognised by the fact that most of them had no little or no eyebrows as a result of blasts of heat when feeding their burners. I was glad to see that the design has improved since those days!
Joe Barry, Crann