Draft PPS18: Renewable Energy
Annex 1 Technology: Energy Crops
B22. Energy crops are renewable materials which can substitute for fossil fuels. They offer the opportunity for the full potential of biomass to contribute to meeting renewable energy targets. The most common energy crop grown in Northern Ireland is short rotation coppice willow.
B23. Short rotation coppice willow (SRC) is a specialised form of forestry plantation and involves growing willow at close spacing and harvesting at regular intervals (normally every second or third year). The crop is established during the Spring (March – June) by planting around 15,000 cuttings per hectare. After one year these are cut back close to the ground, which causes them to form multiple shoots (i.e. to coppice). The crop is then allowed to grow for 2-4 years, after which time the fuel is harvested by cutting the stems close to the soil level. The cut stems again form multiple shoots that grow on for a further cycle to become the next harvest. This cycle of harvest and re-growth can be repeated many times, up to an expected lifespan of 15-20 years. The shoots are usually harvested during the winter as chips, short billets or as whole stems, 25-50mm diameter and 3-4 metres long.
B24. Other energy crops of interest in Northern Ireland include oilseed rape, energy grasses and cereals grown for energy production,. For example miscanthus, canary reed grass and switchgrass have been the subject of recent trials in Northern Ireland. Of these the most promising to date has been miscanthus. It is of tropical origin and uses sunlight more efficiently to produce higher yields than native plants. It grows well in the south of the UK but is also being successfully grown towards the North of England and in Ireland. It is similar to coppice in that it is perennial, and harvested in the winter, but on a one year cycle compared to 2-4 for SRC. The fuel has a similar calorific value per unit weight as wood and could possibly be used in the same power plant or those designed for agricultural residues. The potential advantages compared to SRC are that the harvested fuel is relatively dry, standard agricultural equipment can be used, and the yield potential is higher (10-20 oven dried tonnes per ha per year as opposed to around 10 oven dried tonnes per ha per year for SRC).
B25. Energy crop production will only be viable if the financial rewards and associated risks make it more attractive than existing agricultural enterprises. The experience of producing energy crops on a commercial scale in Northern Ireland is still limited and the establishment costs can be high, especially for SRC. Research carried out by the Forest Service following completion of a Challenge Fund mechanism to support the growing of SRC Willow has provided evidence that the average cost of establishing one hectare of this type of crop is approximately £1950. It has become clear that the economic success of growing SRC is closely linked to proximity of drying and end user facilities to the plantations themselves. It has also been recognised that a minimum area of 3ha should be established in order to produce sufficient material on a regular basis to improve economic viability.
Energy Crop Scheme
From 2004 an Aid to Energy Crops Scheme has been available in Northern Ireland. An aid of €45 per hectare can be payable in respect of energy crops grown. Energy crops are defined as crops supplied essentially for the production of biofuels, and electric and thermal energy produced from biomass (Council Regulation (EC) No 1782/2003 Article 88 ). Aid is conditional on the producer having a contract in place with a processor. Aid is not payable for energy crops grown on land that is required to be set-aside from production but, as previously allowed, set-aside land can still be used to grow energy crops. Applications for the Aid for Energy Crops Scheme are made on an annual basis and closing date is mid-May each year.
In 2004, the Department of Agriculture and Rural Development (DARD) Forest Service introduced a three year Challenge Fund for SRC energy crops to encourage the establishment of SRC for renewable energy generation. The Challenge Fund operated under the Rural Development Regulation Plan 2000-2006. To date, approximately 400 hectares have been planted or approved for planting under the Scheme and a further 410 hectares have been approved for the 2007 planting year.
At present, the economics of SRC for heat production, without a planting grant, suggest that it could represent a viable alternative enterprise for growers when the price of domestic heating oil is in excess of 35 pence per litre. The attractiveness of SRC as a crop is, however, significantly improved if it can also be used for bioremediation purposes and where the latter activity can either generate an additional income stream (through gate fees) or reduce costs elsewhere on the holding.
The biggest long term constraint on the production of SRC in Northern Ireland is the availability of a local end user (the bulky, low value nature of chipped willow mean that it is necessary to keep transport distances and costs to a minimum). Other constraints have also been identified - proximity to drying equipment, the availability of suitable land in terms of soil type, topography and road access to planting sites.
The three year SRC Challenge Fund has now closed to further applications and has been subject to an initial internal review. Drawing on the findings of this process. DARD Forest Service have recently announced continued support for SRC under the Woodland Grant Scheme.