Published: Thursday, 4th March, 2010 1:56pm

First crop of willows harvested for renewable heat source

by Editorial Department

Comments (0) | Print | Email

David and Trevor Thompson with Patrick McDonald, Farrelly Brothers contractors taking a break from the willow harvest.

With oil prices continuing to fluctuate upwards, suitable alternatives such as willow chip for heating homes and businesses could be a viable alternative.

The growing and utilisation of willow chip as a renewable energy source has now turned full cycle for David and Trevor Thompson who farm at Blaney and Letterbreen. They invested in short rotation willow cropping as a farm diversification project in 2007 and now three years later are reaping their first harvest.

A specialist contractor, Farrelly Brothers from Co. Meath were commissioned to cut the first commercial willow harvest. Around 16 acres of their own willow crops were harvested last week with a number of other farmers also availing of the service.

The willows standing as tall as 16 to 20 feet were harvested with a conventional self propelled harvester with a few additional modifications and using a specialist willow header as shown in the accompanying photograph. The machine chips the willows and blows them into silage trailers travelling alongside. The Thompsons tip the trailers into their purpose built drying shed. The shed with perforated floors blows heat through the willow chips to dry them in six weeks. The heat is blown from a special generating plant built as part of the complex. The Thompsons have installed a combined heat plant using the dried chips as a fuel source to heat the adjoining farmhouse.

David Thompson estimates that reasonable yields of willow could return around four tonnes to the acre and each tonne of dried chip is worth £75 a tonne. He estimated it would take £600 of wood chip to heat an average house for the year.

When the Thompsons and other farmers introduced willow growing onto their farms a few years ago they availed of a 100 per cent grant. That is now reduced to 50 per cent for assisting with planting and maintenance.

Another bonus for growers is using sludge as a fertiliser. Landowners can charge a gate receipt to allow sludge to be spread on the willow crop which also boosts yields. Farmers can continue to claim their Single Farm Payment and an Energy Crop payment.

The willow growing cycle begins in the spring with planting. A year later the growing shoots are cut back using a conventional topper and then allowed to grow a further two years before the first harvest. With different plots staggered over several years, a continuous harvest can be maintained each year. The yield from the crop increases after the first year as it encourages new shoots to develop.