Deploying high penetration of variable renewables represents a critical pathway for deep decarbonizing the power sector. The conflict between their temporal variability and limited system flexibility has been largely ignored currently at planning stage. Here we present a novel capacity expansion model optimizing investment decisions and full-year, hourly power balances simultaneously, with considerations of storage technologies and policy constraints, such as carbon tax and renewable portfolio standards (RPS). Based on a computational efficient modeling formulation, all flexibility constrains (ramping, reserve, minimum output, minimal online/offline time) for the 8760-hour duration are incorporated. The proposed model is applied to the northwestern grid of China to examine the optimal composition and distribution of power investments with a wide range of renewable targets. Results indicate that the cost can increase moderately towards 45% of RPS, when properly designing the generation portfolio: prioritizing wind investments, distributing renewable investments more evenly and deploying more flexible mid-size coal and gas units. Reaching higher penetrations of renewables is expensive and the reductions of storage costs are critically important for an affordable low-carbon future. RPS or carbon taxes to reach a same target of emission reduction in China will result in similar overall costs but different generation mixes.

China has set a goal of reducing its CO₂ intensity of GDP by 60–65% from the 2005 level in 2030 as its nationally determined contribution (NDC) under the Paris Climate Change Agreement. While the government is considering series of market and nonmarket measures to achieve its target, this study assesses the economic consequences if the target were to meet through a market mechanism, carbon tax. We used a dynamic computable general equilibrium model of China for the analysis. The study shows that the level of carbon tax to achieve the NDC target would be different depending on its design features. An increasing carbon tax that starts at a small rate in 2015 and rises to a level to meet the NDC target in 2030 would cause smaller GDP loss than the carbon tax with a constant rate would do. The GDP loss due to the carbon tax would be smaller when the tax revenue is utilized to cut existing distortionary taxes than when it is transferred to households as a lump-sum rebate.

An environmental fiscal reform (EFR) represents a transition of a taxation system toward one based in environmental taxation, rather than on taxation of capital, labor, or consumption. It differs from an environmental tax reform (ETR) in that an EFR also includes a reform of subsidies which counteract environmental policy. This research details different ways in which an EFR is not only possible but also a good option that provides economic and environmental benefits. We have developed a detailed dynamic CGE model examining 101 industries and commodities in Spain, with an energy and an environmental extension comprising 31 pollutant emissions, in order to simulate the economic and environmental effects of an EFR. The reform focuses on 39 industries related to the energy, water, transport and waste sectors. We simulate an increase in taxes and a reduction on subsidies for these industries and at the same time we use new revenues to reduce labor, capital and consumption taxes. All revenue recycling options provide both economic and environmental benefits, suggesting that the “double dividend” hypothesis can be achieved. After three to four years after implementing an EFR, GDP is higher than the base case, hydrocarbons consumption declines and all analyzed pollutants show a reduction.

The rebound effect, or the response to energy efficiency improvement, has drawn considerable attention from economists and policymakers. However, the magnitude remains quite controversial because of the differences in the definitions and methods being used. Originating from the definition of direct rebound effect, we develop an improved approach incorporating energy efficiency. The main advantages of the proposed approach are twofold. First, it enables us to estimate the demand elasticity of useful energy service with respect to energy service price. The estimates are more consistent with the definition of rebound effect and are more effective. Second, it decomposes direct rebound effect into substitution and output channels, enabling us to further understand the microeconomic mechanisms. Applying this method, we assess the direct energy rebound effect in China’s industrial sectors. We find that the direct rebound effect for the industry is 37.0%, and the substitution and output channels contribute to 13.1% and 23.9%, respectively. Substantial variations in the magnitudes and mechanisms occur by sector. For heavy industry, most energy rebound is induced by output expansion because of its sizeable cost decrease from efficiency improvements. Unlike heavy industry, most energy rebound in light industry comes from substituting energy service for other inputs because firms in light industry are more flexible in adjusting production inputs. Our results provide evidences for the importance of energy efficiency measures, and highlight the necessity of differentiated measures according to the sectoral characteristics.

Rural components are integral parts of China's economy, and hundreds of millions of China's residents still live in rural areas. Rural residents heavily depend on non-commercial energy due to the inaccessibility and unaffordability of commercial energy. Conventional use of solid biomass fuels threatens public health as well as environmental and ecological sustainability. Thus, rural energy transition must be promoted. By using a new dataset, we show China's rural energy transition to gain insights on where, how, and why this transition occurs in rural households. Unlike previous views, we find that after considering non-commercial energy, the per capita consumption of rural residential energy is considerably larger than that of urban counterparts. Moreover, migrations from rural to urban areas decrease rather than increase residential energy consumption. Furthermore, rural energy transition from low to high quality depresses energy consumption. Our results demonstrate how accessibility and affordability affect the fuel preferences of rural residents, thereby enabling us to identify the mechanisms of rural energy transition. We provide some insights and policy implications on the routes of China's rural energy transition, which may be further extended to other emerging and developing countries due to their similar rural energy use.