The issues was put forward in 2001 officially and the technical research on the integrated heating project of solar pond was fulfilled in November, 2002. The main achievements are as follows:

3.1 Seawater solar pond

3.1.1 Membrane materials of high cost are not adopted and cement boards are used to protect slopes. The water level of the circumference of solar pond is raised to maintain the working water level of the solar pond.

3.1.2 Underground brine wells are digged far away from the coastline. The natural sea water is replaced by the water made up elaborately with the sea water. Brine solar pond is built suitable for the existence of the cultivation objects in sea water.

3.1.3 In the lower convective area of the solar pond, devices of hydrogen-increase and deodorization and system of forced water circulating are fixed to support the seawater solar pond to realize the healthy cultivation technology.

3.1.4 When the environmental temperature is -15"C, the lowest circulating temperature of the solar pond less than two meters is 10.0"C.

3.1.5 The seawater solar pond can meet the demands of the over-wintering temperature of some cultivation objects of warm water kind, such as mullets, basses, lefteye flounders, portunids, scylla serrata forskal, puffers, American snappers, penaeus japonicus and so on.

3.1.6 The pond is the first large-scaled underground brine solar pond that runs successfully in China. It meets the demands of the over-wintering of the cultivation objects.

3.1.7 The pond is the first one to combine brine solar pond, shallow-styled solar-pond and conservatory-modeled solar pond to work and to integrate heat. It is a typical model of satisfying over-wintering and cultivating young products successfully.

3.1.8 It paves the road for the national solar pond technology and for achieving commercialization and industrialization.

3.1.9 It provides a new technology-supporting system for the project of “building on-the-sea China.”

3.2 Shallow-styled solar pond.

3.2.1 The pond realizes streamlined production of bio-baits (mono-cellular algae) for the first time in China. It meets the demands of first-phase bait-supply in the process of raising river crabs.

3.2.2 The pond can provide cultivation water of 400m of 15"C to 25"C daily.

3.2.3 In May, the temperature of the pond sets a record, which is 7"C higher than the natural water temperature. It is practicable to rely on solar energy only for heat.

3.2.4 Shallow-styled solar pond 3000m underground is in operation successfully. It provides hot water of 3000m daily, which is 15 times more than that of the upground one.

3.2.5 Combining upground solar pond and conservatory-modeled solar pond can both improve the effect of heat-integration and make use of photosynthesis to produce mono-cellular algae to meet the demand of cultivation.

3.2.6 The cement-brick of the upground solar pond is low in cost. The underground solar pond is soil-structured. The heat-preserving ability of soil is great and can save up a large quantity of water, which satisfies the industrialized production.

3.2.7 The integrated heating of the shallow-styled solar pond underground and upground attempts successfully to supply heat to the aquatic industry in an industrialized way for the first time.

3.2.8 It opens up a new field for the industrialization of the high-efficiency shed agriculture.

3.3 Conservatory-modeled solar pond.

3.3.1 The solar pond is placed in the greenhouse. It is convenient for heat-integration, heat-preservation and over-wintering cultivation in spring and winter.

3.3.2 Farm-oriented dropless shed-membrane is low in cost, good in photopermeability and thus adopted to be lighting membrane.

3.3.3 Because the southern side and parabolic side select light at the same time, the temperature rises quickly in winter. The effect of heat-integration and heat-preserving is good and the temperature is 15-20"C higher than the natural one in ordinary circumstances.

3.3.4 Seawater solar pond is connected into the conservatory to provide convenience for fresh water from the seawater solar pond. It is also convenient to increase hydrogen and remove odor in the lower convective district.

3.3.5 Translucidus side of the greenhouse can endure the attack of force 11 wind and remain intact.

3.3.6 During spring and winter in 2001 and 2002, twelve cultivation objects in seawater of warm water kind

passed winter safely in the conservatory-modeled solar pond, including portunus trituberculatus, scylla serrata forskal, eriocheir sinensis, penaeus chinensis, penaeus japonicus, paralichthys olivaceus, scophthamus maximus, pagrus major, puffers, scapharca suberenata, venerupis variegata, sea snails and so on. The contribution percentage of the solar energy is 100%.

3.3.7 In the years of 2001 to 2002, the industrialized production of breeding river crabs is successfully carried out in the conservatory-modeled solar pond.

3.3.8 In May and June of 2002, the experiment of forced control and promoting growth of the young river crabs of later period was implemented in the last ten-day period of May. Commodity crabs of 75g to 100g each were raised that year.

3.3.9 Seawater solar pond, shallow-styled solar pond and conservatory-modeled solar pond are combined to work for two periods with water body of 500m, which creates the high-efficiency working technology in the district of saline and alkaline land and tidal-flat areas.

3.3.10 It provides experience for the agricultural and industrialized development in the saline and alkaline land and it also provides powerful technology-supporting system for the strategic structural adjustment of countryside and agriculture in the Northern coastal area of China.