A new organization, The Ocean Energy Institute, has set up shop in Rockland’s South End, and aims to reduce fossil fuel use through supporting the development of new methods of generating both electricity and liquid fuels from marine sources. The group will be housed in the former MBNA complex on Water Street, overlooking the inner harbor.
Energy from the ocean can be extracted in a number of ways, both physical and biological. Electricity can be generated through the use of turbines similar to those used in hydroelectric plants. These turbines can be turned by both the rise and fall of the tide, or through both deep and surface currents, or through the action of surface waves. Each of these applications requires different engineering, but the principles are similar. Maine has been identified as one of the better tidal power sites in the world, and several small pilot level projects are already being discussed. Developers have identified potential sites in the Penobscot and Kennebec Rivers, as well as coastal sites near Cutler and in Passamaquoddy Bay. The Maine Maritime Academy has also announced the creation of an engineering test facility to develop gear for tidal projects.
For liquid transportation needs, a fuel similar to diesel fuel (WWF July 2007) can be extracted from marine algae, which would be raised in aquaculture-like facilities. This fuel can be burned directly in common diesel engines made today. The production facilities for this type of fuel would likely not be located in Maine, as there is insufficient sunlight year-round to support the growth of the microalgae, but the technology is of interest to many research groups, including the Ocean Energy Institute. Large marine algae, including wild seaweed species common in Maine, can also be used to produce ethanol, which can be burned in modified gasoline engines. The ocean is also thought to house large amounts of captured energy in the seafloor in the form of gas hydrates, formed by releases of natural gas which are solidified in place by the low temperatures and high pressures of the bottom of the ocean. The existence of these gas hydrates has been proven, but recovery remains a problem, as the substances boil off when brought to the surface.
A final form of energy is in the form of stored sunlight in the warm upper layers of the water column, which can be sustainably utilized through a process similar to a refrigerator in reverse. This process, known as Ocean Thermal Energy Conversion, or OTEC, uses the temperature differential between surface waters in the tropics and cold deep water brought up directly through a large pipe. A separate liquid (similar to Freon) is cooled with this water, run through the warmer water to extract the heat, and is thus expanded and used to power a turbine to produce electricity. A large temperature differential is needed for this to be effective, and there is currently only one large-scale working OTEC plant in the United States, at Keahole Point in Hawaii.
The Ocean Energy Institute has welcomed a limited number of researchers this summer, and will next develop a research agenda around the most promising technologies. Eventually this institution may include on-site housing for visiting researchers, a large meeting space for conferences and symposiums, and a demonstration tidal power plant, as well as functioning as a grant making and investment body supporting a variety of ocean energy projects. q
A former marine policy specialist at the Island Institute, Ben Neal is a graduate student at the Scripps Institution of Oceanography in San Diego, and is also on temporary assignment with the Ocean Energy Institute.