Taiwan’s land resources are limited. The previous high-level national land-use policy had a complete and comprehensive plan to avoid impacts on land originally used for fisheries and aquaculture and to maintain food security and promote new types of green fishery. The shared industrial model of electricity generation and fishery is a solution to balance the competition between energy policies and fishery development. This study used economic benefit evaluation of the combination of fishery and green-energy production to focus on two topics-photoelectric farming of clams and demonstration of a three-dimensional photoelectric shellfish nursery hothouse—in order to understand the key technologies of shellfish farming and green energy co-development. This study has the potential, from the perspective of financial and economic development, to provide R&D teams with references for technology product application and development strategies. Cost was estimated through monetization conversion analysis of the costs, benefits, risks, and other parameters of the fishery and electricity symbiosis. The results of the analysis of benefits, cash flow and related financial indicators will provide decision-makers and investors in the symbiosis with a reference to assist stakeholders engaged in fishery and electricity co-production to effectively reduce investment time and capital costs and shorten the learning curve.