US Virgin Islands, will soon see their electricity coming from a novel source - towering fields of grass. 1,000 acres on the wetter west side of the Caribbean island have already been sown with Giant King Grass, a proprietary variety of tall-growing elephant grass that will be harvested to feed an anaerobic digester. The digester will produce bio-gas that will, in turn, power a 6MW turbine.
Biomass-based electricity is one of a number of clean energy options being explored by the US territory, as it seeks to slash its Business-As-Usual fossil fuel use by 60%, by 2025. As well as making full use of plentiful solar and wind resources of the three islands, waste-to-energy plants are being evaluated for their potential to form a flexible power source to be called upon when renewables flag.
Giant King Grass is marketed by VIASPACE, who claim it avoids many of the pitfalls of other biofuel sources. The grass grows best on marginal land, that is unlikely to be used for food crops. It is also non-invasive, is not genetically-modified, and requires no pesticide and little fertiliser. The harvested grass itself will be stored in silage bags, enabling a stockpile of fuel to be built up. This would prove a backup supply in case of disruption of the crop by hurricanes.
The company behind the operation on the site - Tibbar Energy - says the 20-year project will provide jobs for 25 workers over the whole lifespan of its operation. The biggest drawback is that such biomass is relatively land intensive, compared to other renewables, for smaller islands. But for larger islands, with tracts of land unsuitable for traditional agriculture, power-from-grass could be useful additional strut in their building of a new clean energy framework.