Carbon Intensity Of Electricity Generation Research Articles

Comparative analysis of CO2 emissions of electric ride-hailing vehicles over conventional gasoline personal vehicles

Ride-hailing services have become popular due to their convenience, affordability, and accessibility. Increasing cost of car ownership, traffic congestion and parking shortages are fostering this global market growth. Though four-wheeler ride-hailing vehicles are fuel efficient, researchers have determined that the emission reductions from fuel efficiency alone cannot compensate for the additional emissions caused by "deadheading," the issue of driving without passengers on ride-hailing trips. We suggest that electric vehicle-based ride-hailing services have the potential to reduce utilization CO2 emissions, which are emissions released while using (driving) the vehicle. However, skeptics challenging this hypothesis cite CO2 released during electricity generation (carbon intensity) needed for recharging batteries and the inherent issue of deadheading in ride-hailing services. We compared ride-hailing vehicles to gasoline-powered passenger cars, the largest source of carbon emissions within the transportation sector. In many cases, ride-hailing vehicles are electric and have newer models, so they emit less CO2 per kilometer. We conducted a quantitative analysis, using a mathematical model to estimate the utilization of CO2 emissions for electric vehicles per ride-hailing trip kilometer, considering carbon intensity of electricity generation, electric vehicle fuel efficiency, and deadheading. We compared our results with average estimated utilization CO2 emissions to gasoline-powered passenger cars. Additionally, we performed a sensitivity analysis, which involved adjusting the input variables within plausible ranges to assess their impact on our model results. According to our analysis, despite deadheading, improved vehicle fuel efficiency and cleaner electricity generation result in lower CO2 emissions for electric ride-hailing vehicles than gasoline personal vehicles.

TARGET INDICATORS OF UKRAINE'S LOW-CARBON POWER SECTOR DEVELOPMENT

Ukraine's commitments as a party to the Paris Climate Agreement to reduce greenhouse gas emissions with a gradual increase in ambition provides for low-carbon economic development with decarbonization of its sectors. The Ukraine’s power sector with a 20% contribution to total GHG emissions, due mainly to the fossil fuel combustion at thermal power plants and CHPs with a significant share of coal in the fuel balance, must make a transformation of its structure to reduce the carbon intensity of electricity generation with the expected increase in electricity consumption. The purpose of the article is to review Ukraine's current and prospective obligations regarding its low-carbon development and the formation of relevant target indicators for the development of Ukraine's power sector. The main obligations have been determined regarding low-carbon development contained in the Updated Nationally Determined Contribution of Ukraine with a 65% reduction in GHG emissions in 2030 compared to 1990, the National Economic Strategy for the period until 2030 with the declared achievement of carbon neutrality of the economy by 2060 and carbon neutrality of the energy sector with the maximum reduction of coal use laid down in the Energy Strategy of Ukraine until 2050. The introduction of a carbon border adjustment mechanism with taxation of electricity imported in the EU from 2026 may become a certain obstacle to the import of electricity when the electricity markets of Ukraine and the EU are united, and will become another factor in the need to increase the share of low-carbon and carbon-free generation.

Decarbonization through carbon intensity mitigation: evidence from global and income-based panels

Along with emission reduction targets, carbon abatement policies increasingly target the reduction of carbon intensity. In this context, uncovering factors that reduce carbon intensity is a timely research subject and carries significant policy implications. The goal of this study is to explore the dynamic relationships between carbon and energy intensity, renewable energy, economic development, structural transformation, and globalization in a global panel comprising 126 countries and two income-based subpanels. Robust System-GMM estimators indicate that increasing renewable sources in the energy mix can assist countries in mitigating the carbon intensity of electricity generation. Moreover, current results highlight that economic growth is the most effective mitigating factor of carbon intensity at the global level, revealing that on average, countries have managed to decouple economic and pollution (carbon intensity) growth. Results document these links both in the short-and, most importantly, the long-run setting. Other important results reveal that the mitigating effect of renewable energy is stronger with the increase of economic development, whereas structural transformation only decreases carbon intensity in low- and middle-income countries. Consequently, consistent long-term climate policies that promote these mitigating factors and decrease documented driving factors such as energy intensity could work synergistically across multiple SDGs of the 2030 Agenda.

Open-data based carbon emission intensity signals for electricity generation in European countries – top down vs. bottom up approach

Dynamic grid emission factors provide a temporally resolved signal about the carbon intensity of electricity generation in the power system. Since actual carbon dioxide emission measurements are usually lacking, such a signal must be derived from system-specific emission factors combined with power generation time series. We present a bottom-up method that allows deriving per country and per technology emission factors for European countries based on plant specific power generation time series and reported emissions from the European emissions trading mechanism. We have matched, 595 fossil generation units and their respective annual emissions. In 2018, these power plants supplied 717 TWh of electricity to the grid, representing approximately 50% of power generation from fossil fuels. Based on this dataset, 42 individual technology and country-specific emission factors are derived. The resulting values for historical per country carbon intensity of electricity generation are compared with corresponding results from a top-down approach, which uses statistical data on emissions and power generation on national scales. All calculations are based on publicly available data, such that the analysis is transparent and the method can be replicated, adjusted and expanded in a flexible way.

The role of distinct electricity sources on pollution abatement: Evidence from a wide global panel

In this study, we examine the contribution of nuclear, fossil (coal, oil, and gas), and renewable (hydro, solar, wind, biofuel) electricity sources to pollution in the globalization era, as measured by total greenhouse gases (GHG) produced by electricity per capita. We conduct an empirical investigation in a global panel of 163 countries which assesses both the concurrent and individual effects of alternative energy sources. Additionally, we implement a second model to assess the roles of various electricity sources on the carbon intensity of electricity generation. Robust GMM estimators show that fossil electricity is a major polluter and a driver of carbon intensity. Furthermore, nuclear and renewable energy reduce pollution on a global scale, with wind emerging as the most efficient energy source in the global fight against pollution and climate change. Moreover, globalization as measured by trade openness tends to reduce the carbon intensity of electricity production (CI), whereas biofuels have an increasing impact on CI. The findings have important policy implications, indicating that shifting to nuclear and renewable energy sources could help countries achieve their sustainable development goals more efficiently.

Combined energetic, economic and climate change assessment of heat pumps for industrial waste heat recovery

The recovery of waste heat represents a promising opportunity to reduce greenhouse gas (GHG) emissions from industrial sectors. The current development of heat recovery technologies can provide industries with several options for retrofitting their heat generation systems. Although past studies estimated the resulting savings in GHG emissions for specific industries or facilities, work is still needed to fully substantiate the expected benefit and the competitiveness of these alternatives, taking into account data at country scale (e.g. long-term reduction targets, energy cost, etc.). Hence, in this study, a new methodology is developed to determine the minimum conditions for waste heat recovery solutions to enable compliance with the targets from the Paris Agreement, taking 2030 and 2050 as reference years. It is applied to several industrial sectors for 24 EU countries, focusing on mechanical heat pump solutions (MHPs). Results indicate that all countries are compliant in 2050 for MHP integration with low temperature lift (like ammonia production) and 21 countries are compliant for high temperature lift (like food industry). The main constraint to the development of the MHP technology in 2030 is found to be economic, while in 2050, the main barrier for countries that do not reach the reduction targets is a too high carbon intensity of electricity generation. To accommodate the relatively long lifetime of the heat production system, the future MHP roadmap should therefore anticipate these potential barriers including carbon footprint of electricity network, working fluids and gas to electricity price ratio. In addition to meeting the 2030 requirements by a large margin, this strategy would factor in constraints associated with the long-term investments in MHPs. To further expand such foresight analysis, our methodology can be duplicated to other technologies than MHPs, so it can help industry decision-makers select the most suitable waste heat recovery options for a given industrial process in a specific country.

Low emission vehicle integration: Will National Grid electricity generation mix meet UK net zero?

Assessing greenhouse gas (GHG) emissions produced from electric vehicles (EVs) and hydrogen vehicles (HVs) requires understanding of the carbon intensity of electricity generation. Without the decarbonisation of electricity generation, environmental benefits of low emission vehicles (LEVs) will be diminished. The UK aims to produce net zero emissions by phasing out and banning the sale of new conventionally fuelled vehicles (CFVs) by 2035 in favour of LEVs. A comparison of the UK’s planned and future electricity production systems between 2020 and 2050 was conducted to analyse different vehicle-type mix scenarios: (1) 100% CFVs, (2 A/B) 100% EVs/HVs, (3 A/B) EVs/HVs integrated from 2035 and (4 A/B) EVs/HVs integrated from 2025 onward. This was conducted using four energy scenarios from the UK National Grid: two degrees, steady progression, consumer evolution and community renewables. This study does not consider the embedded carbon costs of the construction and decommissioning of vehicles. Results demonstrated that while the four electricity generation scenarios reduce the projected emissions they fail to achieve low emission targets. The two degree scenario produced the lowest level of emissions under each vehicle-type mix scenario. Technological improvements of CFVs are not enough to meet targets. Therefore, phasing out and banning the sale of new CFVs from 2025 (rather than 2035) would provide a stronger impetus to reduce transport emissions. Although these targets are possible, encouraging a change in transport modes from individual travel to public transport whilst simultaneously replacing buses and trains with electric or hydrogen alternatives would see a greater emission decrease.

State of Climate Action: Assessing Progress toward 2030 and 2050

To keep the window open to limit global warming to 1.5 C, countries need to accelerate transformation towards a net-zero emissions future across all sectors at a far faster pace than recent trends, according to this report from World Resources Institute and ClimateWorks Foundation, with input from Climate Action Tracker. For example, the report finds that to get on track for the emission cuts required by 2030, the world needs to: Accelerate the increased share of renewables in electricity generation five times faster; Phase out coal in electricity generation five times faster; Reduce the carbon intensity of electricity generation three times faster; Accelerate the uptake of electric vehicles 22 times faster than the significant rates of adoption in recent years; Accelerate the increase in the share of low-carbon fuels by eight times faster; and Accelerate the increase in annual tree cover gain five times faster. The rapid transformation needed to halve emissions by 2030 will require significant financial investments, technology transfer and capacity-building for developing countries. While climate finance has increased significantly in recent years across the public, private and philanthropic sectors, it is still not at the scale needed to revolutionize our energy and transportation systems, accelerate energy efficiency and protect forests. Estimates indicate that between $1.6 and $3.8 trillion per year will be needed through 2050 to transform the energy system alone. Experience has shown that transformative change can happen at an exponential, non-linear rate. Systemic changes that once seemed impossible have ultimately been achieved, such as technological advances with cars, phones and computers. A rapid transition to a zero-carbon future offers the same opportunity — but only with smart and proactive investments in key sectors. The report outlines opportunities within all six sectors to align emissions trajectories with what the science suggests is necessary to avoid the worst climate impacts. Countries, businesses, philanthropy and others must urgently put in place policies, incentives and financial investments to accelerate us toward that safer, prosperous and more equitable future.

How China's electricity generation sector can achieve its carbon intensity reduction targets?

As the largest sector with decarbonization potential, electricity generation is critical for achieving carbon intensity reduction targets of China by 2020 and 2030. This study combines temporal decomposition and scenario analysis to identify the key drivers and provinces with increasing carbon intensity of electricity generation (CIE) and designs four scenarios by integrating efficiency improvement and structural adjustment in 30 provinces of China, and estimates the possible reduction of CIE by 2020 and 2030. Results show that 1) CIE in China decreases by 7.25% during 2001–2015. The estimated CIE during 12th FYP in this study is 25% lower than the estimation using IPCC emission factors, which is closer to China's reality. 2) Driving forces of CIE changes in 30 provinces vary greatly across provinces. The increasing CIE in four worse-performance regions (i.e. Northeast, South Coast, Southwest, Northwest) is mainly caused by energy mix effect and geographic distribution effect. The CIE growth in South Coast is also related to thermal power share effect. 3) Both 2020/2030 targets can be achieved by regulating the drivers for CIE growth in 30 provinces (i.e., RAK scenario). CIE decline is concentrated in three types of provinces, namely provinces with large economic size, strong policy support and clean energy implementation. The findings and recommendations provide insights into achieving 2020/2030 targets for CIE reduction.

The role of electric vehicles in a decarbonized economy: Supporting a reliable, affordable and efficient electric system

Reductions in the carbon intensity of electricity generation, coupled with technological improvements in the end uses that it can power, have created opportunities for the electrification of large segments of the economy. As the largest source of greenhouse gas (GHG) emissions in our economy — 29% of total 2017 U.S. energy-related emissions — electrifying transportation is a key opportunity. Although the technology needed to decarbonize ground transportation exists today, an affordable and reliable transition will require a focus on policy and regulatory changes. Accommodating and correctly managing this growth in electric transportation will be critical to the development of a low-carbon future. If not properly planned for through direct and indirect charging controls, this new load could produce major impacts on the power system and its operations. However, managed correctly, EVs can serve as a useful tool and asset for grid managers and can be accommodated even under aggressive EV adoption models.

Energy benefits of green-wall shading based on novel-accurate apportionment of short-wave radiation components

Climber green wall can alleviate urban heat island and conserve energy, mainly attributed to shading of solar irradiance by vegetation, yet the mechanism has remained poorly understood. The radiation properties of transmissivity, reflectivity and absorptivity, and thermal properties of the building envelope equipped with green wall, jointly govern radiation transfer processes. This field-experimental study monitored in-situ the radiation regime of a climber green wall on a windowed building envelope using high-precision radiometers. The northeast-oriented green wall in humid-subtropical Hong Kong has Lonicera japonica climbers, with 0.24 leaf area index. Radiation properties and shading-induced energy savings were determined in summer and validated. An innovative radiation apportionment model (RAM) was developed to determine the short-wave transmissivity, reflectivity and absorptivity of the climber canopy which were respectively 0.382, 0.074 and 0.543 in sunny weather and 0.449, 0.098 and 0.454 in cloudy weather. For further model development, the extinction coefficient (κ) obtained from Beer’s Law was estimated at 4.00 and 3.34 in respective weather conditions. According to RAM outputs, shading alone could shield against insolation up to 497 W/m2 behind the canopy and 356 W/m2 in the indoor space. Taking the electricity tariff and the carbon intensity of electricity generation of a local power company, the average daily energy savings at 0.226 kWh/m2 were translated into monetary and carbon units, registering approximately USD0.03 and 0.062 kg CO2 respectively. The extrapolated seasonal savings from a total of six green walls installed at the experimental site could reach USD75.8 and 157.9 kg CO2.

China’s electricity emission intensity in 2020 – an analysis at provincial level

In order to maintain the 2°C climate change target, global carbon intensity of electricity generation needs to achieve a short-term target of 600 g/kWh by 2020. This target is important for China, which has been the largest consumer and producer of electricity since 2011. China has set ambitious targets to reduce its electricity carbon intensity in the 13th five-year plan. For a country as large as China, the outcomes of these policies rely on the implementation strategies and effectiveness of each province. In this study, we estimate the carbon intensities of power generation in China’s provinces by 2020. Results show that despite progress in renewable energy growth most provinces are expected to have carbon intensities well above 600 g/kWh by 2020. Renewable energy sources can help reduce carbon intensities in most provinces, but the magnitude of such impacts depends on the coordination among provinces. The over-dependence on coal power generation has made carbon capture and storage a necessity for China’s provinces to reduce their carbon intensity for power generation. Therefore, government support should be addressed sooner rather than later.

Investigating driving forces of aggregate carbon intensity of electricity generation in China

In addition to total CO2 emissions, an intensity indicator is also important to assess CO2 emissions from electricity generation, allowing the spatial differences to be analyzed, which is crucial for regionally heterogeneous countries like China. This study analyzed the driving forces of aggregate carbon intensity (ACI), a measure of CO2 emissions per unit of electricity generation, in China between 1995 and 2014, using the LMDI method incorporating geographical effects. Both the entire study period and individual 5-year periods were analyzed. The results show that the geographic distribution effect, utilization efficiency effect, and thermal power proportion effect were responsible for a decrease in ACI during this period, whereas the energy composition effect showed an inhibitory influence on reduction. The dominant factor was the utilization efficiency effect, and the thermal power proportion effect showed the largest growth. Geographic distribution is a non-negligible factor in the reduction of ACI, and the regional ACI can be reduced by redistributing electricity generation to areas with lower ACI through trans-regional policy guidance. For future policies on reduction of ACI from electricity generation, this study proposes focusing on the thermal power proportion and geographic distribution effects to the same extent as on the utilization efficiency effect.

A regional analysis of carbon intensities of electricity generation in China

Index decomposition analysis (IDA) has been widely applied to study CO2 emissions from electricity generation. However, most have focused on emissions at the country level, less attention has been given to emissions at the regional level. To fill the gap, this study firstly utilized a Logarithmic Mean Divisia Index (LMDI) method to analyze the driving forces of aggregate carbon intensity (ACI) of electricity generation in China from 2000 to 2014. A regional attribution analysis was introduced to look into the contributions from 30 provinces to the driving forces. Then, a multi-regional spatial-IDA was further adopted to assess the emission performance of electricity generation in 30 provinces. The results of temporal-IDA and regional attribution analysis show that the ACI in China dropped notably by 14.5% from 2000 to 2014. Thermal efficiency improvement was a major driver for the decrease, due largely to the significant improvement in thermal generation efficiency in the eastern coastal regions. Clean power penetration reduced ACI remarkably as well, of which the western regions were the main contributors. The spatial-IDA results indicate that the emission performance of electricity generation in different regions varied significantly. While the western regions performed better in clean power penetration, the eastern regions performed better in thermal generation efficiency. Based on the findings, several regional policy strategies were recommended to further lower down ACI of electricity in China.

Production of carbon negative precipitated calcium carbonate from waste concrete

Mineral carbonation can contribute to climate change mitigation through the production of synthetic limestone (CaCO3) from calcium silicate minerals and gaseous CO2. Some carbonates, such as Precipitated Calcium Carbonate (PCC), have industrial applications and may provide sufficient economic incentive for sequestering CO2 should the product be a marketable commodity. Cement is a suitable source of calcium and can be recovered from waste concrete. The production of cement accounts for 9.5 % of global CO2 emissions, however up to 50 % of the manufacturing emissions can be mitigated at the end of the materials service life through mineral carbonation.The objective here is to sequester CO2 through the production of PCC via the recovery and carbonation of calcium from waste cement. The calcium is suitable for mineral carbonation and can be effectively leached using an acid (e.g. HCl). When calcium is completely leached, the solution will be slightly acidic and contain impurities such as iron and silica. The impurities can be removed by adding alkalinity prior to CaCO3 precipitation, via reaction with Na2CO3 in a separate reactor. The Na2CO3 is produced by the absorption of CO2 using NaOH, while the resulting NaCl solution is recycled via bipolar membrane electrodialysis. Overall transportation emissions and costs are reduced and the process could enhance current waste concrete recycling practices. Furthermore, the low carbon intensity of electricity generation in Eastern Canada allows for capture of 444 kg CO2 per tonne of PCC.

Estimating CO2 emissions reduction from renewable energy use in Italy

Many Public Administrations are supporting the installation of Renewable Energy Systems (RE, namely wind and photovoltaic), which provide almost carbon free sources of electricity, aiming to curtail CO2 emissions of the power generation sector. However, the real effect in terms of carbon dioxide reductions is still unclear, since the uncertainty and variability characterizing RE must be balanced by conventional generators. The model presented here simulates the technical constraints of power plants and the economic framework to be found in a national electricity market, and estimates carbon dioxide emissions. The results show that the reduction of CO2 emissions is lower than expected considering the amount of energy produced from renewable sources, and is related to the level of RE penetration and the season of the year; in summer the reduction is slightly greater, because of the higher production by Combined Cycle Gas Turbines (CCGTs) and the consequent decrease of that generated by the more pollutant coal power plants. The amount of reserve allocated by the Transmission System Operator (TSO) and the cycling on hourly basis have negligible effects on the carbon intensity of electricity generation. In the Italian system 1 kWh from RE displaces approximately 0.8 kWh from conventional power plants.

Key threshold for electricity emissions

To reduce greenhouse-gas emissions in the short term, and catalyse longer-term cuts, countries should reduce the carbon intensity of electricity generation to below a universal target of 600 tCO2e GWh−1 by 2020.

Energy and carbon payback times for solid oxide fuel cell based domestic CHP

Fuel cells already provide heat and power to people’s homes with lower direct CO 2 emissions and fuel consumption than traditional methods. However, their whole life cycle, including manufacture and disposal, must be considered to verify that these environmental impacts are actually reduced and not merely shifted elsewhere. The total carbon footprint and energy payback times have been widely reported for other emerging microgeneration technologies, but have not previously been calculated for fuel cell systems. This paper presents a life cycle assessment comparing solid oxide fuel cell (SOFC) based domestic CHP with the current embedded technologies in the UK. An inventory is given for the construction of a 1 kW stack and then its operation is simulated in detail using measured energy demands from hundreds of UK houses. Producing a 1 kW planar SOFC micro-CHP system was estimated to require 12–17 GJ of energy input and emit 700–950 kg of CO 2, although these impacts triple when including the production of replacement stacks needed over the 10 year system life. The carbon intensity of electricity generation from an SOFC was estimated to be 325–375 g/kWh, and is primarily determined by the operating efficiency as manufacturing only adds 10% to this. By displacing electricity generation in less efficient centralised power stations, operating an SOFC in UK homes would reclaim the energy and carbon from its manufacture in under 2 years; however, payback may not be possible if only high efficiency CCGT units are displaced.

Regional patterns of U.S. household carbon emissions

Market-based policies to address fossil fuel-related externalities including climate change typically operate by raising the price of those fuels. Increases in energy prices have important consequences for a typical U.S. household that spent almost $4,000 per year on electricity, fuel oil, natural gas, and gasoline in 2005. A key question for policymakers is how these consequences vary over different regions and subpopulations across the country—especially as adjustment and compensation programs are designed to protect more vulnerable regions. To answer this question, we use non-publicly available data from the U.S. Consumer Expenditure Survey over the period 1984–2000 to estimate long-run geographic variation in household use of electricity, fuel oil, natural gas, and gasoline, as well as the associated incidence of a $10 per ton tax on carbon dioxide (ignoring behavioral response). We find substantial variation: incidence from the tax range from $97 dollars per year per household in New York County, New York to $235 per year per household in Tensas Parish, Louisiana. This variation can be explained by differences in energy use, carbon intensity of electricity generation, and electricity regulation.

Carbon intensity of electricity generation and CDM baseline: case studies of three Chinese provinces

A difficult and persistent issue in the discussion of Clean Development Mechanism is estimating a carbon emissions baseline, against which tradable permits may be certified. This paper examines the proposition of adopting sectoral, as opposed to project level, baselines by conducting case studies of the electricity industry in three Chinese provinces. We find that complicated central planning, financial and institutional factors have been behind the declining trend of carbon intensity in electricity generation and its provincial variations. Government planned electricity development which incorporates many of these factors and the associated industry carbon intensity may serve as a second best baseline. However, the limitation of the baseline we examine in this study plus difficulties numerous studies have revealed in baseline setting suggests that using baselines based on counterfactuals of what would happen will in the end either miss good emission reduction opportunities, or compromise the integrity of the regime.