效益分享型合同节水管理项目的投资风险分析

Analysis of Investment Risk of Benefit-sharing Water Saving Management Contract Project

合同节水管理是一种新型节水投资模式,节水服务公司作为主要参与者在投资合同节水管理项目中承受了较高风险。为此,本文从节水服务公司的视角出发,分析节水效益分享型合同节水管理项目的投资风险问题。首先,采用净现值评估项目投资经济价值,考虑到维护成本、节水量及水价的波动,利用几何布朗运动来处理项目寿命期内节水收益及投资的不确定性。在此基础上,结合合同期、收益分配比例等合同参数,分别模拟出用水户及节水服务公司的节水投资及收益,以节水服务公司利润净现值小于零的概率为评估指标,建立投资风险评估模型。随后,通过项目收益-风险均衡,构建了分别以用水户节水收益最大化、项目投资风险最小化为目标的合同期决策模型,确定出这两种场景下的最优合同期。最后,以实际试点项目验证了模型的适用性,研究结果显示,项目投资风险为53.63%;相比于未考虑收益-风险均衡的6年合同期,优化后给定两种场景下的最优合同期为7年与10年,相应的投资风险分别降低了10.65%及24.73%;进一步,敏感度分析结果表明,预期年节水收益对投资风险具有重要影响。本文可以为节水服务公司进行投资决策、设计合同节水管理项目合同期提供一定参考依据。

Water Saving Management Contract(WSMC)is an innovative water-saving investment model,and Water Service Company(WSCO)as the major player bears a relatively high investment risk.In this regard,the investment risk of benefit-sharing WSMC project is analyzed from WSCO's perspective.Firstly,the net present value(NPV)is used to assess the economic value of the project.The geometric Brownian motion is used to deal with the uncertainty of water-saving benefits and investment over the lifetime,considering the fluctuation of the maintenance cost,water-saving,and water price.On this basis,the water-saving investment and benefits of water users and WSCO are simulated separately by combining contract parameters including contract period and benefit allocation proportion,and the probability that the NPV of WSCO is less than zero is set as an evaluation index to establish the investment risk assessment model.Subsequently,contract period decision models are constructed through benefit-risk equilibrium,with the objectives of maximizing watersaving benefits for water users and minimizing project investment risk,respectively,and the optimal contract periods under these two scenarios are determined.Finally,the applicability of the risk assessment model is veri⁃fied with an actual pilot project,and the results shows that the project investment risk is 53.63%;Compared with the 6-year contract period without considering the benefit-risk equilibrium,the optimal contract periods for the two scenarios are 7 and 10 years after optimization,and the investment risk is reduced by 10.65%and 24.73%,correspondingly;Further,the results of the sensitivity analysis indicate that the expected annual water savings have a significant impact on the investment risk.Some information can be provided for WSCO to make investment decisions and design the contract period of WSMC project.