Harvesting Miscanthus For Biomass Energy
Lucy has been out helping with the harvesting of miscanthus, the crop which fuels the energy centre which provides heat for the Blue Lagoon and the Adventure Centre. Miscanthus is also known as elephant grass.
The miscanthus fields are pretty much adjacent to the Bluestone site, and it was quite exciting to watch the harvester chopping down these tall stalks of an almost sugar cane quality – honestly! And with the Cleddau estuary in the background, the setting was pretty picturesque as well.
Previously, the grass has been round-baled, but this year they tried a new method of harvesting – with a combine harvester. Then, the chopped material was transported to storage sheds near Bluestone where it will be mixed with wood chip and then burnt in the energy centre.
There are around 65 acres of miscanthus being grown by Paul Ratcliffe from PBE, the company who run the energy centre. Another 15 farmers in Pembrokeshire are growing miscanthus or willow for the energy centre.
Miscanthus is a sterile crop, grown from rhizomes with a production life span of more than 20 years. Growing to around 12 foot a season, the crop is harvested between February and April when the sap draws out of the stalks back into the ground, leaving dry organic material suitable to burn.
When miscanthus is established (after around three to four years) a potential yield of 20 ODT (Oven Dried Tonnes) per hectare per year is achievable.
We currently burn around 15-20% miscanthus to woodchip blend in the energy centre and plan to carry on harvesting this crop for the next 20 years or so.