Huge potential for miscanthus in energy sector

A new Rotorua bio energy company has gone from 30 plants to 150,000 in its first full year of business.

Miscanthus New Zealand Limited imported 30 of the tall, woody grass plants from the United Kingdom in 2010 and now has more than 150,000 plants on nine sites throughout the country.

Managing director Peter Brown put the success to date down to thorough research, hard work and continued support.

"There is no other plant in New Zealand that can be used for energy production that comes close to competing with miscanthus for the amount of useable energy able to be produced annually per hectare planted."

Related to sugar cane, the perennial, hybrid grass grows to 3.5-4m each year. It is harvested annually, regrows each spring without replanting and can be used as feedstock for co-firing with coal or in biomass power and heat generation.

Brown said interest in planting miscanthus had come from a range of sources, with Maori trusts, agricultural contractors, large energy users, pellet manufacturers and research institutions all expressing interest in establishing larger areas this spring.

"I have been surprised by some of the people coming forward. If, as seems likely, we can convert even a proportion of this interest into actual sales, we will have a busy year, with the prospect of even greater activity in the future as the level of commercial awareness grows."

Brown is involved in propagating the plants, which are sterile, so will not self-seed, and selling these to growers. But he told The Daily Post he was talking to everybody from growers to potential users to increase awareness of the potential for the plant, which can generate almost three times the energy per tonne of wood chips.

"It's advantage comes from its low moisture content.

"After harvesting you can skip the drying stage and it has a higher calorific value."

He said wood chips were about 60 per cent water and produced about 6GJ of energy per tonne. Miscanthus, which requires neither time nor cost for drying, is capable of producing 15GJ per tonne.

Miscanthus New Zealand is also continuing research into optimum growth conditions and potential uses for the energy source, as well as the most efficient methods and conditions for propagation.

Brown said he was encouraging farmers to plant marginal farming areas on their land in the grass, with accessibility for a truck and trailer for harvesting the main factor limiting potential land use.

Miscanthus does not appear to be adversely affected by frosts.

One of the key advantages for farmers is that they can expect returns in the second year of growth, whereas more traditional plantations such as pine, which could take 30 years to reach harvest.

It is also better than fossil fuel resources because it absorbs carbon dioxide when it is growing, offsetting the emissions made during burning.