The DTI World Offshore Energy report published in 2002 estimates a global marine current resource in excess of 450GW – almost seven times the total generating capacity of all UK power stations. Tidal currents around the UK are strong in many areas and the New and Renewable Energy Centre (NaREC) argues that the UK has the best tidal resources in Europe, with the potential for 5% of its energy demand being met from this source. Over 20 UK companies are developing tidal technologies and several regional agencies are beginning to assess the potential for tidal energy generation.. First published in Cleantech magazine, November/December 2007. Copyright Cleantech Investor 2007