To achieve its carbon neutrality goal, China has invested broadly in energy infrastructure and the emerging integrated energy stations (IESs) projects will bring enormous opportunities. Accurate carbon emission accounting for IESs is challenging in view of the complexity of the manufacturing process and uncertainty in construction and operation processes. To overcome these challenges, this paper develops a novel quantitative carbon footprint analysis model for IESs from a lifecycle perspective, with production and materialization, construction, operation and maintenance, and disposal and recycling phases considered. The method is applied on a 110 kV wind power IES project in China, to analyze and calculate lifecycle carbon emissions, identify the key influence factors of carbon footprints and provide suggestions for carbon reduction. The findings can identify key influence factors and provide suggestions for carbon reduction for the development of IES projects.

Engineering, procurement, and construction (EPC) has been applied in China’s hydropower projects for its value-added advantages compared with traditional project delivery systems in theory. However, the actual performance of large EPC hydropower projects has been challenged by the complexity of the stakeholders’ interest demands and conflicts. The increasing use of target cost contracts (TCC) in the construction industry has provided a pain/gain share mechanism for the owners to incentivize contractors to complete projects within cost budgets. The added-value sharing ratio is the core element of TCC, and it predetermines how much proportion of savings the contractor can get paid if the actual cost is below the target cost, and how much proportion of overspend the contractor has to pay if the actual cost is higher than the target cost. In this paper, we consider the added-value sharing ratio under the framework of TCC based on the principal-agent theory, and look at how the added-value sharing ratio is influenced by various factors and how it affects the owner and the contractor in large EPC hydropower projects. Determination of the added-value sharing ratio in both discrete and continuous conditions are discussed, respectively. It is found that the added-value sharing ratio is relatively explicit in the discrete case, while the optimal added-value sharing model in the continuous case is more complex, which can be used to analyze the relationship between the added-value sharing ratio and the key influencing factors. Our research conclusions can provide both theoretical guidance and practical suggestions to contract design in the implementation of EPC hydropower projects, to some extent.

Aiming at the design of a project transaction mode, the case-based reasoning (CBR) method is used as a methodology to build a case-based reasoning system based on project performance predictions. Thirty-four cases are initially selected for the practical application. Based on the classical CBR, the performance forecast is added, an improved continuous variable interpolation scoring method is proposed, and three types of manual revision methods are proposed: owner’s preference for the project transaction mode, extreme value, and secondary learning. The innovative method is verified with Nanjing HF Project as an example, and the results show that the case-based reasoning system can optimize the selection and design of the project transaction mode, providing a certain guarantee for project performance and facilitating the transfer of construction experience and knowledge within the construction industry.