Miscanthus (elephant grass) is a tall, woody, perennial, rhizomatous grass, originating from Asia, it has a high rate of growth and is now a viable low cost fuel widely grown in the UK and increasingly used in biomass installations.
The ETA Hack boilers installed by Asgard Biomass are designed to burn chopped or pelleted miscanthus as well as wood chip and wood pellets.
Miscanthus has a similar energy density (by mass) to wood chip (3.6 kWh/kg), however a low ash melting point (approximately 1,220°C compared to wood chip at >1,400°C) tends to cause clinkering in the hearth, so boilers need to be specifically designed for its use.
Miscanthus can be grown on low grade land, once established a viable and productive crop is maintained for over fifteen years. Its leaves shed, returning nutrients to the soil. The canes are harvested during winter. The plant has a low mineral content that results in good fuel qualities. Annual yield is relatively high: 3 to 6 tons per acre, with low moisture content.