Prospects of Ocean Energy Utilization and Proposals for the Development Strategy in China

Ocean has been considered as the last resources treasury in the earth, also called sea of energy. In the 21st century, ocean will play an important role in providing living space, foodstuff, mineral, energy and water resources for the human beings, so does the ocean energy. From the viewpoint of technique and economic feasibility and analysis on the sustainable energy resources and ecological balance of the environment, tidal energy among the ocean energy will be utilized in a larger scale as a ripe technology, wave energy will be developed in an industrialization way, which in the near future will be carried out the fixed device since the floating device is suitable for large scale development; ocean temperature differential energy, as a strategic energy will be further developed and implemented in line with the development of ocean comprehensive project and combining with the establishment of individual living space on sea and industrial base; current energy will be scale utilization in part of area. 

The large-scale utilization of tidal energy relates to large infrastructure construction project, which requires a long-term course in financing and assessment on environment impact. Generally speaking, large-scale tidal power station takes several decades time to construct, or even lasts than one hundred years. Therefore, feasibility study should be firmly taken. At present, attention should be also extended to the research of the sets technology. Regarding the investment policy, it can take into account the joint investment by state government, local government and enterprise; or foreign fund by introducing the technology in accordance with the experience of hydropower. 

After more than 10 years in demonstration and application, the wave energy can be developed steadily approaching to be commercialized, and has technique potential in reducing the cost and increasing the utilization efficiency. Along with the development of technology in wave, marine engineering and turbine generator sets, the utilization cost of wave energy is likely to be lessen 2-4 times than the present situation in 6 to 10 years, which may reach the cost lower than 10,000 Yuan for per kW. 

Now, Japan and other countries of EC has started a new round of competition on wave energy technology which will be more obvious in the coming 5 years. Unlike the propaganda in 1970s when the wave energy was a hot issue, more attention will be extended on the practical benefits in technology and its commercial benefits in the project being constructed in Japan and EC. The technology of wave energy in China has minor difference with the advanced standard. In view of the situation that the resources in the region that abounds in wave energy are 5-10 times to China, and the advantage in the manufacturing cost in China, wave energy utilization sector is therefore of brighter future to develop export-oriented enterprise, which has good beginning in the wave power generation device for small scale navigation buoys. Therefore, focus should be reinforced on the commercialized work of the hundred kW scale generator. After promoted in small quantity, export-oriented device can be designed and manufactured according to the wave energy resources in Europe. Due to the difference of resources, after being reconstructed, hundred kW scale device in China can achieve the MW level in Europe. So the cost for per kW is likely to be lessening 2 to 3 times. 

From the viewpoint and demand of 21^st century, priority should be given to the utilization of temperature differential energy, which should be taken into account the utilization of energy, marine hi-tech and comprehensive concerns on national defense. The utilization of ocean temperature differential energy can provide sustainable energy, fresh water, living space and can be developed in line with mineral and marine breeding so as to solve the resources problem for the substance and development of human beings. 

The research tasks needed to develop include, in foundation aspect, focus research on heating circulation process in low temperature difference to solve effectively transfer the heating, load problems in heating generator sets in low pressure, and relative heating power circulation and in marine environment. The kW scale experiment modeling circulation device should be established and its relative data analysis and research should be conducted to provide the design technology. In technology project aspect, hundred kW scale comprehensive utilization device should be arranged as early as possible, and can be considered in combining with the marine development in south sea and territory defense project so as to build a comprehensive equipment that can provide energy, fresh water, air conditioning and marine breeding in an individual environment on sea. 

China is one of the countries whose current energy density are the highest in the world, which may be advantageous for the development of current energy. The hundred kW scale demonstration device should be firstly constructed for the current energy. And the installation under the sea, maintenance of the generator and the living problems on the marine environment should be settled. Like the wind energy, it can be developed from a certain individual capacity to standardized equipment so as to reach the goad of industrialized production and decreasing of cost. 

In view of the above-mentioned, the utilization of ocean energy in China, should be focusing on the development of hundred kW scale wave and current power generator and the industrialization of the equipment in the near future, should develop 10 thousand kW scale tidal power station in accordance with the project; should reinforce the technology research on the comprehensive utilization of temperature differential energy, while 10 thousand kW scale temperature differential energy comprehensive marine living space system and marine ecological farm should be taken into account for a medium and long term schedule. It is worthy to be noted that the utilization of ocean energy has closed relationship to the field of energy, marine, national defense and territory development, which should be considered in the viewpoint of sustainable and overall situation that has not yet received due attention