Virginia-based Verdant plans to install six 35kW sub-surface turbines with 5m diameters, each turning at around 30rpm, to generate 200kW. The 18-month test programme is due to begin next month and, if successful, is expected to lead to the installation of up to 300 turbines by 2010 giving a capacity of more than 10MW.

Verdant’s business partner is the New York State Energy Research & Development Authority (NYSERDA), which has invested more than US$2M to date in the Roosevelt Island Tidal Energy Project (RITE). The company is also conducting a survey of a second tidal energy site in the Buttermilk channel of the East river, alongside Governor’s island – an area known as New York City’s Golden Triangle.

A NYSERDA study estimates that there is a potential 1GW or more of stream-based generation in New York state.

In addition to the New York development, Verdant is also at various stages of development with three other projects including Canada’s Cornwall Ontario River Energy (CORE) project that will generate 3 to 5MW from the St. Lawrence river near Cornwall where two prospective sites with a combined potential for 15MW of capacity are under consideration.

In the UK, the European Marine Energy Center (EMEC) project in the Orkneys will be the site for a commercialisation project with the output sold to local utility company Scottish Power and a development potential of 5MW. In addition, Verdant is working on Amazon Basin river projects in Para and Amazonas states, with a total capacity of 25MW.

Along with the 35kW system, Verdant has designed a second horizontal-axis turbine with a 2m rotor to generate up to 10kW in shallower rivers and water flows.