202 



The budget in the ocean current program in fiscal year 1979 is 

 $160,000; in fiscal year 1980, $175,000; growing to an estimated 

 $480,000 in fiscal year 1981. This growth from 1980 to 1981 reflects 

 the initiation of a model test program to supplement the ongoing 

 analytical studies and the feasiblity of large ocean turbines. 



The third element of the alternate ocean energy program is 

 salinity gradients. One of the more intriguing potential methods 

 for extracting energy from the ocean depends on the salt dissolved 

 in it. Two salinity gradient methods have been identified to gener- 

 ate energy from solutions of different salt concentrations that are 

 separated by special membranes. The methods are called reverse 

 osmosis and dialyctic batteries and are based on methods currently 

 used in water desalinization processes. 



In those cases, electricity is used to change salt concentration. In 

 our case we are using salt concentrations to produce electricity in 

 the reverse manner. 



Salinity gradient energy conversion using seawater and river or 

 groundwater as the two saline solutions has been investigated by 

 the DOE. We are finding that due to very high cost and large 

 membrane requirements, this type of energy conversion does not 

 appear to be economically feasible. 



Because of these results, and because of the need for significant 

 improvement in membrane life and performance to make even an 

 expensive system work, technology development will be discontin- 

 ued by the Office of Solar Power Applications until additional 

 research indicates improved feasibility. 



Turning now to the Department's activities in tidal power, the 

 wave and current research and development that I described to you 

 is being conducted, in the Office of Conservation and Solar Energy, 

 and the tidal power work in the Office of Resource Applications. 



As you know, energy may be extracted from the tides by means 

 of dams placed across the sea inlets. During periods of high tide, 

 seawater is allowed to flow into the inlet where it is retained for 

 release through electric generating turbines. 



France is currently operating such a system to supply electricity 

 to their grid. In an effort to determine the potential of tidal power 

 as an energy source for the United States, the Stone and Webster 

 Engineering Corp. of Boston was commissioned to review its feasi- 

 bility. Their two volume report resulting from this study was pub- 

 lished in March of 1977. They found that costs far outweighed any 

 benefits to be accrued through the lifetime of such tidal power 

 projects. 



The study has been criticized because they considered only large- 

 scale sites and no small-scale sites, and so subsequently the Depart- 

 ment of Energy funded a feasibility study to be conducted at Half 

 Moon Cove in Passamaquoddy Bay, Maine. This is underway and 

 the data is being compiled. The results should be available in 

 December 1980. 



In both cases, large and small tidal power projects, the costs of 

 the civil works play a pivotal role. The Department has reviewed a 

 number of proposals on tidal power development. None have shown 

 any significant economic advances in this area over present tech- 

 nology. Therefore, there is no additional support being requested in 



