碳交易机制下可再生能源投资价值与投资时机研究

中国承诺2017年启动全国性碳排放交易系统,在碳交易机制下,可再生能源项目可以通过CCER交易获得额外收益。由于碳价格是随着市场条件而随机波动的,碳价波动性使得可再生能源发电项目投资具有了期权性质的权利,即未来不确定性可能包含更高的价值。可再生能源企业在做投资决策时,可以选择立即投资,也可以选择推迟投资,等待更多信息来提高项目收益,而立即投资的项目回报必须足够高以克服等待期权的蕴含价值。为了研究碳价波动下可再生能源项目投资,本文采用实物期权法的三叉树模型,测算了三类可再生能源发电项目投资的npv及其实物期权价值(ROV)。根据延迟实物期权决策规则,三类项目均执行期权延迟投资决策。本文还计算了在无政府补贴和有政府补贴两种情形下,三种可再生能源项目在不同时点的栏杆价格,以确定项目的投资时机。栏杆价格随着政府补贴的增加而逐步下降,说明政府补贴会促进可再生能源项目投资;栏杆价格随着时间的推移而逐步上升,意味着时间跨度越大,不确定性越大,需要更高碳市场价格来确定投资时机。本文对影响可再生能源项目投资因素敏感性进行了分析,结果表明碳价波动率与可再生能源发电项目的栏杆价格呈现正相关的关系,说明碳价波动性增加了企业投资的期权价值,却推迟了企业开展投资的时间。随着中国碳交易体系的不断完善,碳价波动幅度会趋于平稳,从而促进发电企业进行可再生能源发电项目投资。

Study on the investment value and investment opportunity of renewable energies under the carbon trading system

China has promised to start the national carbon trading system in 2017.In the carbon trading system,the renewable energy projects may obtain additional benefits through the CCER(Certified Carbon Emission Reduction) trade.As the carbon price fluctuates along with the market condition,such fluctuation enables the renewable power projects to acquire the rights of an option,i.e.it may contain an even higher value due to the uncertainties in the future.While making an investment decision,the renewable power companies may choose to make the investment immediately,or postpone the investment and accumulate more information to increase the return of investment;and for immediate investments,the return must be sufficient to exceed the potential value of a waiting option.To study the investment in renewable power projects subject to the fluctuation of carbon price,this paper adopts the trinomial tree model of real options to estimate the net present value(NPV) and real option value(ROV) of three types of renewable power projects;according to the decision-making rules of real options to defer,all the three types of projects will exercise the option to postpone the investment decision.This paper also calculates the benchmark prices of the three types of renewable projects at different times,in the two situations of having no government subsidy and having the government subsidy,so as to determine the investment opportunity of a project.The benchmark price decreases gradually along with the increase of government subsidy,indicating that the government subsidy will stimulate the investment in renewable projects.The benchmark price also increases gradually along with the lapse of time,indicating that the uncertainty will increase together with the time span and thus requires an even higher carbon price to determine the investment opportunity.This paper also analyzes the sensitivity of factors affecting the investment in renewable projects and draws the conclusion that the fluctuation of carbon price is positively related with the benchmark price of renewable power projects,which indicates that the fluctuation of carbon price increases the option value of an investment but postpones the time of investment.A s the China's carbon trading system improves gradually,the carbon price will reach a stable status,thus stimulating the power companies to invest in the renewable projects.