Model analyses for sustainable energy supply under CO2restrictions

This paper aims at clarifying key points for realizing sustainable energy supply under restrictions on CO₂ emissions. For this purpose, the possibility of `solar breeding system' is investigated as a key technology for the sustainable energy supply. Then we describe our mathematical model simulating global energy supply and demand in ultra-long term. Depletion of nonrenewable resources and constraints on CO₂ emissions are taken into consideration in the model. Computed results have shown that existing energy system based on nonrenewable resources shifts to a system based on renewable resources in the ultra-long term with appropriate incentives     

Renewable energy development in China: Resource assessment, technology status, and greenhouse gas mitigation potential

China has become the third largest energy user in the world, and its coal-dominated energy structure implies high CO₂ emissions. The amount of CO₂ emissions from China may surpass that of the United States within 20–30 years, making China the world's largest source of greenhouse gases by 2020.

Currently, renewable energy resources (except for hydropower) account for only a fraction of China's total energy consumption. However, China has abundant solar energy resources. More than two thirds of China receives an annual total insolation that exceeds 5.9 GJ/m2 (1,639 kWh/m²) with more than 2,200 hours of sunshine a year. Wind energy potential in China is about 3,200 GW, of which 253 GW is deemed technically exploitable. China has a wide range of biomass resources that can be used for energy supply and high temperature geothermal resources suitable for power generation located mainly in Tibet and Yunnan provinces.

Renewable energy technologies have been actively deployed in China. Although PV power stations have not being connected to the national grid, total installed capacity was 3 MW in 1994. Solar water heaters are by far the largest solar thermal application in China with a total installed capacity of 3.3 million m² in 1994. By the end of 1995, total installed capacity of grid-connected wind power plants had reached 36 MW. Also, over 140,000 small wind generators ranging in size from 50 W to 5 kW have been deployed with a total installed capacity of 17 MW. China is a world leader in the development and application of anaerobic technologies for the production of fuel gas and waste treatment and has by far the largest biomass gasification R&D capacity in the.

Although renewable energy is projected to play a small role in future electricity generation, it is expected to be much more significant in the total energy sector. Under one scenario, renewable energy other than hydro provides up to 4% of the total energy supply and 88 million tons of carbon emission reduction by 2020. The estimated growth in greenhouse gas emissions, as well as serious local and regional environmental pollution problems caused by combustion of fossil fuels, provide strong arguments for the development of renewable energy resources.     

A comparison of CO2 emissions from fossil and solar power plants in the United States

We present estimates of the lifetime carbon dioxide emissions from coal-fired, photovoltaic, and solar thermal power plants in the United States. These CO₂ estimates are based on a net energy analysis derived from both operational systems and detailed design studies. It appears that energy-conservation measures and shifting from fossil to renewable energy sources have significant long-term potential to reduce CO₂ production caused by energy generation. The implications of these results for a national energy policy are discussed.     

Sustainable electricity generation fuel mix analysis using an integration of multicriteria decision-making and system dynamic approach

To achieve a national energy access target of 90% urban and 51% rural by 2035, combat climate change, and diversify the energy sector in the country, the Zambian government is planning to integrate other renewable energy resources (RESs) such as wind, solar, biomass, and geothermal into the existing hydro generation–based power system. However, to achieve such targets, it is essential for the government to identify suitable combination of the RESs (electricity generation fuel mix) that can provide the greatest sustainability benefit to the country. In this paper, a multicriteria decision-making framework based on analytic hierarchy process and system dynamics techniques is proposed to evaluate and identify the best electricity generation fuel mix for Zambia. The renewable energy generation technologies considered include wind, solar photovoltaic, biomass, and hydropower. The criteria used are categorized as technical, economic, environmental, social, and political. The proposed approach was applied to rank the electricity generation fuel mix based on nine sustainability aspects: land use, CO₂ emissions, job creation, policy promotion affordability, subsidy cost, air pollution reduction, RES electricity production, RES cumulative capacity, and RES initial capital cost. The results indicate that based on availability of RESs and sustainability aspects, in overall, the best future electricity generation mix option for Zambia is scenario with higher hydropower (40%) penetration, wind (30%), solar (20%), and lower biomass (10%) penetration in the overall electricity generation fuel mix, which is mainly due to environmental issues and availability of primary energy resources. The results further indicate that solar ranks first in most of the scenarios even after the penetration weights of RES are adjusted in the sensitivity analysis. The wind was ranked second in most of the scenarios followed by hydropower and last was biomass. These developed electricity generation fuel mix pathways would enable the country meeting the future electricity generation needs target at minimized environmental and social impacts by 2035. Therefore, this study is essential to assist in policy and decision making including planning at strategic level for sustainable energy diversification.     

Implications of carbon cap-and-trade for US voluntary renewable energy markets

Many consumers today are purchasing renewable energy in large part for the greenhouse gas (GHG) emissions benefits that they provide. Emerging carbon regulation in the US has the potential to affect existing markets for renewable energy. Carbon cap-and-trade programs are now under development in the Northeast under the Regional Greenhouse Gas Initiative (RGGI) and in early stages of development in the West and Midwest. There is increasing discussion about carbon regulation at the national level as well. While renewable energy will likely benefit from carbon cap-and-trade programs because compliance with the cap will increase the costs of fossil fuel generation, cap-and-trade programs can also impact the ability of renewable energy generation to affect overall CO₂ emissions levels and obtain value for those emissions benefits. This paper summarizes key issues for renewable energy markets that are emerging with carbon regulation, such as the implications for emissions benefits claims and voluntary market demand and the use of renewable energy certificates (RECs) in multiple markets. It also explores policy options under consideration for designing carbon policies to enable carbon markets and renewable energy markets to work together.     

A review on global wind energy policy

With the increasing negative effects of fossil fuel combustion on the environment in addition to limited stock of fossil fuel have forced many countries to inquire into and change to environmentally friendly alternatives that are renewable to sustain the increasing energy demand. Energy policy plays a vital role to mitigate the impacts of global warming and crisis of energy availability. This paper explores the wind energy industry from the point of view of the wind energy policy. It is noticed that energy policy could help increasing wind power generation as well as stimulating the energy industry. It may be stated that without specific energy policy, a country would not be able to solve the acute problems like reducing greenhouse gases (GHGs) emission, scarcity of energy, etc. This paper discussed the existing successful energy policies for few selected countries. Based on literatures, it has been found that FIT, RPS, incentives, pricing law and Quota system are the most useful energy policies practiced by many countries around the world. Then, status of wind energy policy for Malaysia was investigated and compared with few selected countries around the world.     

Renewable energy — the way forward

This paper outlines the growing need of energy in the developing countries and the acute population growth, which will exceed 10 billion by the year 2050. It describes the achievement and progress made in geothermal, hydro-power, biomass conversion, solar thermal technology, wind energy conversion and the ever increasing usage of photovoltaics. The paper also addresses the barriers and problems which face renewable energy users and producers. It is evident now that global warming is setting in and is going to change the climate as well as the terrain of many countries unless drastic measures are taken. The recent Kyoto meeting emphasised the importance of limiting CO₂ emissions and to abide by some form of agreement to reduce emissions. Countries such as India, China and Indonesia, which represent nearly half the world's population, are actively involved in using renewable energy as the only means of sustaining their energy growth. It concludes that renewable energy penetration into the energy market is much faster than was expected a few years ago and by the year 2020, 10–15% of our prime energy will be met by renewable energy.     

Energy demand and CO2 emissions reduction options in Nigeria

This paper presents policy options for reducing CO₂ emissions in Nigeria. The policies were formulated based on a thorough analysis of Nigeria's current energy consumption patterns and the projected evolution of key parameters that drive Nigeria's energy demand — primarily the rate of industrialization, the demand for transportation services, and the expansion of Nigeria's population. The study shows that the most promising options for reducing CO₂ emissions in Nigeria are improving energy efficiency and increasing the use of natural gas and renewable energy sources.     

Renewable energy sources in Turkey for climate change mitigation and energy sustainability

In Turkey, there is a much more potential for renewables, but represent about 37% of total energy production and 10% of total energy consumption. This share is not enough for the country and the governments should be increase to this situation. Renewable energy technologies of wind, biomass, hydropower, geothermal, solar thermal and photovoltaics are finally showing maturity and the ultimate promise of cost competitiveness. With respect to global environmental issues, Turkey's carbon dioxide emissions have grown along with its energy consumption. States have played a leading role in protecting the environment by reducing emissions of greenhouse gases. In this regard, renewable energy resources appear to be the one of the most efficient and effective solutions for clean and sustainable energy development in Turkey. Turkey's geographical location has several advantages for extensive use of most of these renewable energy sources. Certain policy interventions could have a dramatic impact on shaping the relationship between geological, geographic and climatic conditions and energy production. This study shows that there is enough renewable energy potential in Turkey for fuels and electricity. Especially hydropower and biomass are very well.     

The Carbon-tax debate

This paper discusses recent topics related indirectly to energy production and marketing and related highly to energy policy and economy. These topics are: (1) background to carbon taxes including environmental issues — global warming and CO₂ emissions, fuel substitution and the encouragement of non-hydrocarbon fuel use; (2) climate-change convention and related conferences including those at Rio de Janeiro — objectives and achievements, and Kyoto-objectives; (3) carbon-tax proposals, including implications for oil, coal and gas: (4) The OECD view including evolution of general taxes on hydrocarbons, the carbon tax as a government revenue-raising objective, CO₂ emissions in the OECD; (5) the oil-producer's view including discrimination against oil, the impact on the incentives to use oil and gas; (6) the developing countries' view, including the need to increase fuel use for industrialisation, financial constraints on energy use, and CO₂ emissions in the developing countries.     

How to stimulate renewable energy power generation effectively? – China's incentive approaches and lessons

The renewable energy power generation (REPG) in China has experienced tremendous growth in the last decade. To understand this rapid growth, it is necessary to explore how Chinese government triggers the remarkable development of the industry. This paper offers a systematic analysis of the incentive policy system for REPG in China, covering wind power, solar photovoltaic, small hydropower (single-unit power generation capacity less than 50 MW), biomass power and geothermal power. The incentive system contains laws, regulations, policies and industrial plans issued during the 11th and 12th “Five-year Plan” periods (2006–2015). Four major incentive strategies of the Chinese government are identified: research and development incentives, fiscal and tax incentives, grid-connection and tariff incentives, and market development incentives. The results show these incentive methods have played a significant role in promoting the development of REPG in China, but still there are some problems associated with them. International comparisons of the incentive policies with those of Denmark, Germany and US, as well as the strategies to further improve the Chinese incentive approaches are discussed. This comprehensive analysis of China's incentive policy system for REPG helps to understand China's experience in promoting renewable energy, contributing to better decision-making in policy.     

Will Germany move into a situation with unsecured power supply?

Together with a huge number of other countries, Germany signed the Paris Agreements in 2015 to prevent global temperature increase above 2°C. Within this agreement, all countries defined their own national contributions to CO₂ reduction. Since that, it was visible that CO₂ emissions in Germany decreased, but not so fast than proposed in this German nationally determined contribution to the Paris Agreement. Due to increasing traffic, CO₂ emissions from this mobility sector increased and CO₂ emission from German power generation is nearly constant for the past 20 years, even a renewable generation capacity of 112 GW was built up in 2017, which is much higher than the peak load of 84 GW in Germany. That is why the German National Government has implemented a commission (often called “The German Coal Commission”) to propose a time line: how Germany can move out of coal-fired power stations. This “Coal Commission” started its work in the late spring of 2018 and handed over its final report with 336 pages to the government on January 26th, 2019. Within this report the following proposals were made: ① Until 2022: Due to a former decision of the German Government, the actual remaining nuclear power generation capacity of about 10 GW has to be switched off in 2022. Besides, the “Coal Commission” proposed to switch off additionally in total 12.5 GW of both, hard coal and lignite-fired power plants, so that Germany should reduce its conventional generation capacity by 22.5 GW in 2022. ② Until 2030: Another 13 GW of German hard coal or lignite-fired power plants should be switched off. ③ Until 2038: The final 17 GW of German hard coal or lignite-fired power plants should be switched off until 2038 latest. Unfortunately the “Coal Commission” has not investigated the relevant technical parameter to ensure a secured electric power supply, based on German’s own national resources. Because German Energy Revolution mainly is based on wind energy and photovoltaic, this paper will describe the negligible contribution of these sources to the secured generation capacity, which will be needed for a reliable power supply. In addition, it will discuss several technical options to integrate wind energy and photovoltaic into a secured power supply system with an overall reduced CO₂ emission.     

Are renewables an alternative to nuclear power? An analysis of the Austria/Slovakia discussions

Politicians and publics throughout Europe have different views on nuclear power and renewable energy sources. Countries such as Austria and Denmark which have no nuclear power are rather hostile towards this energy source, and at the same time view renewable energy sources as one of the solutions in curbing CO₂ emissions. Other countries, such as Slovakia, which is less endowed in terms of renewables, view nuclear power as a electricity-generating source that can reduce dependency on fossil fuels and thereby CO₂. This paper focuses on the confrontation between two nations with different sets of electricity policies, namely Austria and Slovakia. Of particular interest for this study include an evaluation of Austria's anti-nuclear policy towards its Slovakian neighbour and an analysis of Austria's attempts to promote renewable energy sources in both Austria and Slovakia. In conclusion, a number of recommendations are put forward with regard to how Austria's future energy dialogue with Slovakia should look like and what types of projects Austria should consider funding.     

Mitigating energy-related GHG emissions through renewable energy

An inventory of greenhouse gas emissions from various economic sectors in Lebanon was conducted following the guidelines set by the World Meteorological Organization and United Nations Environment Programme Intergovernmental Panel on Climate Change. The inventory indicated that the energy sector is the major contributor (74%) to greenhouse gas emissions. This paper describes the inventory of energy related GHG emissions and assesses mitigation options to reduce emissions from electricity generation with emphasis on the usage of renewable energy including biomass, hydropower, solar and wind resources. Policy options for overcoming barriers hindering the exploitation of renewable energy resources are discussed in the context of country-specific characteristics.     

Mitigation assessment results and priorities for China''s energy sector

Energy-related CO₂ emission projections of China up to 2030 are given. CO₂ mitigation potential and technology options in main fields of energy conservation and energy substitution are analyzed. CO₂ reduction costs of main mitigation technologies are estimated and the multi-criteria approach is used for assessment of priority technologies.

The results of this study show (1) Given population expansion and high GDP growth, energy-related CO₂ emissions will increase in China. (2) There exists a large energy conservation potential in China. (3) Adjustment of industry structure and increase of shares of products with high added value have and will play a very important role in reducing energy intensity of GDP. (4) Energy conservation and substitution of coal by natural gas, nuclear power, hydropower and renewable energy will be the key technological measures in a long-term strategy to reduce GHG emission. (5) Identification and implementation of GHG mitigation technologies is consistent with China's targets of sustainable development and environmental protection. (6) Energy efficiency improvement is a “no-regret” option for CO₂ reduction, whereas an incremental cost is needed to develop hydropower and renewable energy.     

Atmospheric stabilization of CO2 emissions: Near-term reductions and absolute versus intensity-based targets

This study analyzes CO₂ emissions reduction targets for various countries and geopolitical regions by the year 2030 to stabilize atmospheric concentrations of CO₂ at 450 ppm (550 ppm including non-CO₂ greenhouse gases) level. It also determines CO₂ intensity cuts that would be required in those countries and regions if the emission reductions were to be achieved through intensity-based targets without curtailing their expected economic growth. Considering that the stabilization of CO₂ concentrations at 450 ppm requires the global trend of CO₂ emissions to be reversed before 2030, this study develops two scenarios: reversing the global CO₂ trend in (i) 2020 and (ii) 2025. The study shows that global CO₂ emissions would be limited at 42 percent above 1990 level in 2030 if the increasing trend of global CO₂ emissions were to be reversed by 2020. If reversing the trend is delayed by 5 years, global CO₂ emissions in 2030 would be 52 percent higher than the 1990 level. The study also finds that to achieve these targets while maintaining expected economic growth, the global average CO₂ intensity would require a 68 percent drop from the 1990 level or a 60 percent drop from the 2004 level by 2030.     

Solar energy: Markets, economics and policies

Solar energy has experienced phenomenal growth in recent years due to both technological improvements resulting in cost reductions and government policies supportive of renewable energy development and utilization. This study analyzes the technical, economic and policy aspects of solar energy development and deployment. While the cost of solar energy has declined rapidly in the recent past, it still remains much higher than the cost of conventional energy technologies. Like other renewable energy technologies, solar energy benefits from fiscal and regulatory incentives, including tax credits and exemptions, feed-in-tariff, preferential interest rates, renewable portfolio standards and voluntary green power programs in many countries. The emerging carbon credit markets are expected to provide additional incentives to solar energy deployment; however, the scale of incentives provided by the existing carbon market instruments, such as, the Clean Development Mechanism of the Kyoto Protocol is limited. Despite the huge technical potential, the development and large scale deployment of solar energy technologies world-wide still has to overcome a number of technical, financial, regulatory and institutional barriers. The continuation of policy supports might be necessary for several decades to maintain and enhance the growth of solar energy in both developed and developing countries.     

The role of public policy in optimizing renewable energy development in the greater southern Appalachian mountains

This research presents a third component of a comprehensive decision support system for energy planning that allows for combining existing electricity generating capabilities with increased use of renewable energy sources. It focuses on energy planning at the regional level, and concentrates specifically on the greater southern Appalachian mountains of the eastern United States: a region that was chosen for analysis not only due to its heavy dependence on coal for electricity, but also because of its potential for increased use of wind and solar power. Previous research used a geographic information system (GIS) model for identifying renewable energy potential to provide input data for a multi-objective linear programming (MOLP) model to determine the optimal constrained mix of renewable energy sources and existing fossil fuel facilities by balancing annual generation costs against the corresponding greenhouse gas emissions. This new component of the system analyzes three potential public policies—renewable portfolio standard, carbon tax, and renewable energy production tax credit—that have been used to foster increased renewable energy usage. These policies require minor modifications to the MOLP model for implementation. The results of these policy cases were then analyzed to determine the impact that these policies have on generation cost and pollution emissions within the region.     

A total fuel cycle approach to reducing greenhouse gas emissions: Solar generation technologies as greenhouse gas offsets in U.S. utility systems

Greenhouse gas emissions in the electric utility sector occur not only at generation facilities, but also during upstream processes that support the construction and operation of energy facilities. A total fuel cycle approach is used to evaluate the potential greenhouse gas savings that could result from the deployment of solar generation technologies in utility systems in the United States. Total fuel cycle analyses were completed for several renewable and conventional generation technologies to estimate the total greenhouse gas emission contribution from each generation technology. These results are used to develop total fuel cycle emission rates for planned electric capacity additions in the U.S., and these rates are compared with the emission rates that would occur if solar technologies were substituted for fossil generation capacity additions. Current projections for solar technology deployment are low relative to total capacity additions. Hence, even doubling the planned additions of solar technologies produces less than a 1% reduction in annual CO₂ and CH₄ emissions from new generation. However, the total lifetime greenhouse gas savings from increased deployment of solar technologies can be substantial. Increasing planned solar deployment by only 25% up to the year 2010 can create up to six million tons of CO₂ savings over the lifetime of the solar installations.     

Co-benefit analysis of incentives for energy generation and storage systems; a multi-stakeholder perspective

In this work, we are analyzing the advantages of energy incentives for all the stakeholders in an energy system. The stakeholders include the government, the energy hub operator, and the energy consumer. Two streams of energy incentives were compared in this work: incentives for renewable energy generation technologies and incentives for energy storage technologies. The first type aims increasing the share of renewable energies in the electricity system while the second type aims development of systems which use clean electricity to replace fossil fuels in other sectors of an energy system such as the transportation, residential and industrial sector. In this work, we are analyzing the advantages of energy incentives for all the stakeholders in an energy system. The stakeholders include the government, the energy hub operator, and the energy consumer. Two streams of energy incentives were compared in this work: incentives for renewable energy generation technologies and incentives for energy storage technologies. The first type aims to increase the share of renewable energies in the electricity system while the second type aims the development of systems which use clean electricity to replace fossil fuels in other sectors of an energy system such as the transportation, residential and industrial sector. The results of the analysis showed that replacing fossil fuel-based electricity generation with wind and solar power is a less expensive way for the energy consumer to reduce GHG emissions (60 and 92 CAD/ tonne CO_2e for wind and solar, respectively) compared to investing on energy storage technologies (225 and 317 CAD/ tonne CO_2e for Power-to-Gas and battery powered forklifts, respectively). However, considering the current Ontario's electricity mix, incentives for the Power-to-Gas and battery powered technologies are less expensive ways to reduce emissions compared to replacing the grid with wind and solar power technologies (1479 and 2418 CAD/ tonne CO_2e for wind and solar, respectively). Our analysis also shows that battery storage and hydrogen storage are complementary technologies for reducing GHG emissions in Ontario.