Evaluating renewable portfolio standards and carbon cap scenarios in the U.S. electric sector

This report examines the impact of renewable portfolio standards (RPS) and cap-and-trade policy options on the U.S. electricity sector. The analysis uses the National Renewable Energy Laboratory's Regional Energy Deployment System (ReEDS) model that simulates the least-cost expansion of electricity generation capacity and transmission in the U.S. to examine the impact of a variety of emissions caps—and RPS scenarios both individually and combined. The generation mix, carbon emissions, and electricity price are examined for various policy combinations simulated in the modeling.     

Is the choice of renewable portfolio standards random?

This study investigated factors influencing the adoption or intention to adopt renewable portfolio standards (RPS) by individual states in the United States (U.S). Theory of adoption of innovation was applied as a conceptual framework. A logistic model was used to achieve the task. Gross state product (GSP), growth rate of population (GRP), political party dominancy, education level, natural resources expenditure, and share of coal in electricity generation were used as explanatory variables. Results indicated that the model predicts the dependent variable (state's choice of adopting or not adopting RPS) 82 times correctly out of 100. Results also suggested that education followed by political party dominancy, GSP and GRP are shown to have large impacts on the probability of RPS adoption.     

The economic costs of reducing greenhouse gas emissions under a U.S. national renewable electricity mandate

The electricity sector is the largest source of greenhouse gas emissions (GHGs) in the U.S. Many states have passed and Congress has considered Renewable Portfolio Standards (RPS), mandates that specific percentages of electricity be generated from renewable resources. We perform a technical and economic assessment and estimate the economic costs and net GHG reductions from a national 25 percent RPS by 2025 relative to coal-based electricity. This policy would reduce GHG emissions by about 670 million metric tons per year, 11 percent of 2008 U.S. emissions. The first 100 million metric tons could be abated for less than $36/metric ton. However, marginal costs climb to $50 for 300 million metric tons and to as much as $70/metric ton to fulfill the RPS. The total economic costs of such a policy are about $35 billion annually. We also examine the cost sensitivity to favorable and unfavorable technology development assumptions. We find that a 25 percent RPS would likely be an economically efficient method for utilities to substantially reduce GHG emissions only under the favorable scenario. These estimates can be compared with other approaches, including increased R&D funding for renewables or deployment of efficiency and/or other low-carbon generation technologies.     

Supply amount and marginal price of renewable electricity under the renewables portfolio standard in Japan

The Renewables Portfolio Standard (RPS) in Japan requires that approximately 1.35% of each retail supplier's electricity sales in FY2010 come from renewable energy sources (RES), for example, photovoltaics, wind, biomass, geothermal, and small hydropower. To help retail suppliers and renewable generators develop effective strategies, this study provides a quantitative analysis of the impact of this measure. We assume the supply conditions for electricity generation from renewable energy sources (RES-E) based on regional resource endowments, and we derive the cost-effective compositions of renewable portfolios, RES-E certificate prices, and additional costs to retail suppliers. The future prospects of RES-E are assessed based on technology, region, and year up to FY2010. The analysis reveals that wind power and biomass power generated from municipal waste will provide the majority of the total supply of RES-E under the RPS. It also indicates that the marginal price of RES-E certificates will be approximately 5.8 JPY/kWh (5.2 USc/kWh) in FY2010, in the case wherein the marginal price of electricity is assumed to be 4 JPY/kWh (3.6 USc/kWh). In order to elaborate on this further, sensitivity analyses for some parameters of RES and the price of electricity are provided. The dynamic supply curves of RES-E certificates are also indicated.     

When renewable portfolio standards meet cap-and-trade regulations in the electricity sector: Market interactions,profits implications,and policy redundancy

Emission trading programs (C&T) and renewable portfolio standards (RPS) are two common tools used by policymakers to control GHG emissions in the energy and other energy-intensive sectors. Little is known, however, as to the policy implications resulting from these concurrent regulations, especially given that their underlying policy goals and regulatory schemes are distinct. This paper applies both an analytical model and a computational model to examine the short-run implications of market interactions and policy redundancy. The analytical model is used to generate contestable hypotheses, while the numerical model is applied to consider more realistic market conditions. We have two central findings. First, lowering the CO₂ C&T cap might penalize renewable units, and increasing the RPS level could sometimes benefit coal and oil and make natural gas units worse off. Second, making one policy more stringent would weaken the market incentive, which the other policy relies upon to attain its intended policy target.     

Energy, economics and environmental impacts of renewable energy systems

The renewable based electricity generation technologies were assessed against a range of sustainability indicators using data obtained from the literature. These indicators are cost of electricity generation, greenhouse gas emissions and energy pay-back time. All the three parameters were found to have a very wide range for each technology. For grading different renewable energy sources a new figure of merit has been proposed, linking greenhouse gas emissions, energy pay-back time and cost of electricity generated by these renewable energy sources. It has been found out that wind and small hydro are the most sustainable source for the electricity generation.     

Federal policies for renewable electricity: Impacts and interactions

Three types of policies that are prominent in the federal debate over addressing greenhouse gas emissions in the United States are a cap-and-trade program (CTP) on emissions, a renewable portfolio standard (RPS) for electricity production, and tax credits for renewable electricity producers. Each of these policies would have different consequences, and combinations of these policies could induce interactions yielding a whole that is not the sum of its parts. This paper utilizes the Haiku electricity market model to evaluate the economic and technology outcomes, climate benefits, and cost-effectiveness of three such policies and all possible combinations of the policies. A central finding is that the carbon dioxide (CO₂) emissions reductions from CTP can be significantly greater than those from the other policies, even for similar levels of renewable electricity production, since of the three policies, CTP is the only one that distinguishes electricity generated by coal and natural gas. It follows that CTP is the most cost-effective among these approaches at reducing CO₂ emissions. An alternative compliance payment mechanism in an RPS program could substantially affect renewables penetration, and the electricity price effects of the policies hinge partly on the regulatory structure of electricity markets, which varies across the country.     

Additionality of wind energy investments in the U.S. voluntary green power market

In the United States, electricity consumers are told that they can “buy” electricity from renewable energy projects, versus fossil fuel-fired facilities, through participation in voluntary green power markets. The marketing messages communicate to consumers that they are causing additional renewable energy generation and reducing emissions through their participation and premium payments for a green label. Using a spatial financial model and a database of registered Green-e wind power facilities, the analysis in this paper shows that the voluntary Renewable Energy Certificate (REC) market has a negligible influence on the economic feasibility of these facilities. Nevertheless, voluntary green power marketers at least implicitly claim that buying their products creates additional renewable energy. This study indicates the contrary. Participants in U.S. voluntary green power markets associated with wind power, therefore, appear to be receiving misleading marketing messages regarding the effect of their participation. In the process of completing this analysis, a potentially relevant factor in explaining investor behavior was identified: the potential for the overlap of voluntary REC markets with compliance REC markets that supply utilities need to meet their obligations of Renewable Energy Portfolio Standard (RPS). The majority of state RPS rules allow for regional or even national sourcing of RECs, meaning that projects are generally eligible to provide compliance RECs to utilities not only in their home states, but in several other states.     

Cost-effectiveness of renewable electricity policies

We analyze policies to promote renewable sources of electricity. A portfolio standard (RPS) raises electricity prices and primarily reduces gas-fired generation. A knee of the cost curve exists between 15% and 20% goals for 2020 in our central case, and higher natural gas prices lower the cost of greater reliance on renewables. A renewable energy production tax credit lowers electricity price at the expense of taxpayers, which limits its effectiveness in reducing carbon emissions, and it is less cost-effective at increasing renewables than a portfolio standard. Neither policy is as cost-effective as a cap-and-trade policy for achieving carbon emission reductions.     

Impacts of a renewable portfolio generation standard on US energy markets

This paper analyzes the impacts of imposing a Federal 20 percent non-hydropower renewable generation portfolio standard (RPS) on US energy markets by 2020. The US currently has no RPS requirement although some state RPS regulations have been adopted but not uniformly enforced (see http://www.eia.doe.gov/oiaf/analysispaper/rps/index.html for a recent summary on RPSs in the US). The renewable portfolio standard (RPS) requires that 20 percent of the power sold must come from qualifying renewable facilities. The analysis of the 20 percent RPS was developed by using the December 2001 version of the National Energy Modeling System (NEMS) of the Energy Information Administration (EIA) and the assumptions and results of the Annual Energy Outlook 2002 (AEO2002) reference case. ² A policy that requires a 20 percent non-hydro-electric RPS by 2020 appears to be effective in promoting the adoption of renewable generation technologies while also reducing emissions of nitrogen oxides by 6 percent, mercury by 4 percent and carbon dioxide by about 16.5 percent relative to the reference case in 2020. Electricity prices are expected to rise about 3 percent while the cost to the electric power industry could rise between 35 and 60 billion dollars (in year 2000 dollars in net present value terms).     

State renewable energy electricity policies: An empirical evaluation of effectiveness

Over the past decade, state governments have emerged as US energy policy leaders. Across the country, states are adopting policy instruments aimed at carbon mitigation and renewable energy deployment. One of the most prevalent and innovative policy instruments is a renewable portfolio standard (RPS), which seeks to increase the share of renewable energy electrification in the electricity market. This analysis evaluates the effectiveness of state energy programs with an empirical investigation of the linkage between state RPS policy implementation and the percentage of renewable energy electricity generation across states. We use a variant of a standard fixed effects model, referred to as a fixed effects vector decomposition, with state-level data from 1998 to 2006. Results indicate that RPS implementation is not a significant predictor of the percentage of renewable energy generation out of the total generation mix, yet for each additional year that a state has an RPS policy, they are found to increase the total amount of renewable energy generation. These findings reveal a potentially significant shortcoming of RPS policies. Political institutions, natural resource endowments, deregulation, gross state product per capita, electricity use per person, electricity price, and the presence of regional RPS policies are also found to be significantly related to renewable energy deployment.     

U.S. state policies for renewable energy: Context and effectiveness

Over the past decade, state policies on renewable energy have been on the rise in the U.S., providing states with various options for encouraging the generation of renewable electricity. Two promising policies, the Renewable Portfolio Standard (RPS) and the Mandatory Green Power Option (MGPO), have been implemented in many states but the evidence about their effectiveness is mixed. In this paper, we argue that recognizing the natural, social, and policy context under which MGPO and RPS are adopted is necessary in order to measure their true effectiveness. This is because the context rather than the policy might lead to positive outcomes and there is the possibility for sample bias. When controlling for the context in which the policies are implemented, we find that RPS has a negative impact on investments in renewable capacity. However, we find that investor-owned utilities seem to respond more positively to RPS mandates than publicly owned utilities. By contrast, MGPO appears to have a significant effect on installed renewable capacity for all utilities regardless of the context in which it is implemented.     

A methodology for analysis of impacts of grid integration of renewable energy

Present electricity grids are predominantly thermal (coal, gas) and hydro based. Conventional power planning involves hydro-thermal scheduling and merit order dispatch. In the future, modern renewables (hydro, solar and biomass) are likely to have a significant share in the power sector. This paper presents a method to analyse the impacts of renewables in the electricity grid. A load duration curve based approach has been developed. Renewable energy sources have been treated as negative loads to obtain a modified load duration curve from which capacity savings in terms of base and peak load generation can be computed. The methodology is illustrated for solar, wind and biomass power for Tamil Nadu (a state in India). The trade-offs and interaction between renewable sources are analysed. The impacts on capacity savings by varying the wind regime have also been shown. Scenarios for 2021–22 have been constructed to illustrate the methodology proposed. This technique can be useful for power planners for an analysis of renewables in future electricity grids.     

The environmental and economic effects of regional bioenergy policy in the southeastern U.S.

The unique generation, landownership, and resource attributes of the southeastern United States make the region an important test bed for implementation of novel renewable energy policy interventions. This study evaluates the environmental and economic implications of one such intervention, a hypothetical region-wide renewable portfolio standard (RPS) with biomass carve-outs. It utilizes the Forest and Agriculture Sector Optimization Model with Greenhouse Gases (FASOMGHG) to assess the multi-sector and interregional allocation of forest harvest activity, and then uses the Sub-Regional Timber Supply (SRTS) model to assess intraregional variation in forest composition and greenhouse gas (GHG) mitigation potential. The analysis finds that existing resource conditions influence the regional distribution of land use and harvest changes, resulting in a spatially and temporally diverse forest carbon response. Net forest carbon in the Southeast is greater in the RPS Scenario than in the No RPS Scenario in all but the final years of the model run. Accounting for displaced fossil emissions yields net GHG reductions in all time periods. Both research methodology and findings are also applicable to a broader suite of domestic and international policies, including European Union renewable energy initiatives and GHG mitigation under Section 111 of the U.S. Clean Air Act.     

Prioritizing investment in residential energy efficiency and renewable energy—A case study for the U.S. Midwest

Residential building energy use is an important contributor to greenhouse gas emissions and in the United States represents about 20% of total energy consumption. A number of previous macro-scale studies of residential energy consumption and energy-efficiency improvements are mainly concerned with national or international aggregate potential savings. In this paper we look into the details of how a collection of specific homes in one region might reduce energy consumption and carbon emissions, with particular attention given to some practical limits to what can be achieved by upgrading the existing residential building stock. Using a simple model of residential, single-family home construction characteristics, estimates are made for the efficacy of (i) changes to behavioral patterns that do not involve building shell modifications; (ii) straightforward air-infiltration mitigation measures, and (iii) insulation measures. We derive estimates of net lifetime savings resulting from these measures, in terms of energy, carbon emissions and dollars. This study points out explicitly the importance of local and regional patterns in decision-making about what fraction of necessary regional or national emissions reduction might be accomplished through energy-efficiency measures and how much might need to concentrate more heavily on renewable or other carbon-free sources of energy.     

Spatial variation of emissions impacts due to renewable energy siting decisions in the Western U.S. under high-renewable penetration scenarios

One of the policy goals motivating programs to increase renewable energy investment is that renewable electric generation will help reduce emissions of CO₂ as well as emissions of conventional pollutants (e.g., SO₂ and NO_x). As a policy instrument, Renewable Portfolio Standards (RPS) encourage investments in wind, solar and other generation sources with the goal of reducing air emissions from electricity production. Increased electricity production from wind turbines is expected to displace electricity production from fossil-fired plants, thus reducing overall system emissions. We analyze the emissions impacts of incremental investments in utility-scale wind power, on the order of 1 GW beyond RPS goals, in the Western United States using a utility-scale generation dispatch model that incorporates the impacts of transmission constraints. We find that wind investment in some locations leads to slight increases in overall emissions of CO₂, SO₂ and NO_x. The location of wind farms influences the environmental impact by changing the utilization of transmission assets, which affects the overall utilization of power generation sources and thus system-level emissions. Our results suggest that renewable energy policy beyond RPS targets should be carefully crafted to ensure consistency with environmental goals.     

A comparative analysis of renewable electricity support mechanisms for Southeast Asia

This study evaluates the applicability of eight renewable electricity policy mechanisms for Southeast Asian electricity markets. It begins by describing the methodology behind 90 research interviews of stakeholders in the electricity industry. It then outlines four justifications given by respondents for government intervention to support renewables in Southeast Asia: unpriced negative externalities, counteracting subsidies for conventional energy sources, the public goods aspect of renewable energy, and the presence of non-technical barriers. The article develops an analytical framework to evaluate renewable portfolio standards, green power programs, public research and development expenditures, systems benefits charges, investment tax credits, production tax credits, tendering, and feed-in tariffs in Southeast Asia. It assesses each of these mechanisms according to the criteria of efficacy, cost effectiveness, dynamic efficiency, equity, and fiscal responsibility. The study concludes that one mechanism, feed-in tariffs, is both the most preferred by respondents and the only one that meets all criteria.     

Interactions between renewable energy policy and renewable energy industrial policy: A critical analysis of China's policy approach to renewable energies

This paper analyzes China's policy approach to renewable energies and assesses how effectively China has met the ideal of appropriate interactions between renewable energy policy and renewable energy industrial policy. First we briefly discuss the interactions between these two policies. Then we outline China's key renewable energy and renewable industrial policies and find that China's government has well recognized the need for this policy interaction. After that, we study the achievements and problems in China's wind and solar PV sector during 2005–2012 and argue that China's policy approach to renewable energies has placed priority first on developing a renewable energy manufacturing industry and only second on renewable energy itself, and it has not effectively met the ideal of appropriate interactions between renewable energy policy and renewable energy industrial policy. Lastly, we make an in-depth analysis of the three ideas underlying this policy approach, that is, the green development idea, the low-carbon leadership idea and indigenous innovation idea. We conclude that Chinas' policy approach to renewable energies needs to enhance the interactions between renewable energy policy and renewable energy industrial policy. The paper contributes to a deeper understanding of China's policy strategy toward renewable energies.     

The status and prospects of renewable energy for combating global warming

Reducing anthropogenic greenhouse gas (GHG) emissions in material quantities, globally, is a critical element in limiting the impacts of global warming. GHG emissions associated with energy extraction and use are a major component of any strategy addressing climate change mitigation. Non-emitting options for electrical power and liquid transportation fuels are increasingly considered key components of an energy system with lower overall environmental impacts. Renewable energy technologies (RETs) as well as biofuels technologies have been accelerating rapidly during the past decades, both in technology performance and cost-competitiveness — and they are increasingly gaining market share. These technology options offer many positive attributes, but also have unique cost/benefit trade-offs, such as land-use competition for bioresources and variability for wind and solar electric generation technologies. This paper presents a brief summary of status, recent progress, some technological highlights for RETs and biofuels, and an analysis of critical issues that must be addressed for RETs to meet a greater share of the global energy requirements and lower GHG emissions.     

美国能源结构及消费现状

美国石油储量220亿桶,石油消耗占美国总能耗的40％以上,是全球主要的石油生产国和消费国.美国煤炭可实现自给自足,每年消耗10亿t,90％用于发电.美国天然气储量6.73万亿m3,年消费量660 km3,页岩气产量占天然气产量的25％左右.美国拥有104个核电反应堆,总生产能力为806.2TWh.美国能源总消费量的8％由可再生能源提供,10％的电力由可再生能源提供,累计风力发电装机容量为43461 MW,拥有48 MW世界上最大的光伏发电项目,地热能安装能力2957 MW.