A zero-emission vehicle, or ZEV, is a vehicle that does not emit exhaust gas or other pollutants from the onboard source of power. The California definition also adds that this includes under any and all possible operational modes and conditions. This is because under cold-start conditions for example, internal combustion engines tend to produce the maximum amount of pollutants. In a number of countries and states, transport is cited as the main source of Greenhouse gases and other pollutants. The desire to reduce this is thus politically strong.
Energy is sustainable if it "meets the needs of the present without compromising the ability of future generations to meet their own needs". Most definitions of sustainable energy include considerations of environmental aspects such as greenhouse gas emissions and social and economic aspects such as energy poverty. Renewable energy sources such as wind, hydroelectric power, solar, and geothermal energy are generally far more sustainable than fossil fuel sources. However, some renewable energy projects, such as the clearing of forests to produce biofuels, can cause severe environmental damage. The role of non-renewable energy sources in sustainable energy has been controversial. Nuclear power is a low-carbon source whose historic mortality rates are comparable to wind and solar, but its sustainability has been debated because of concerns about radioactive waste, nuclear proliferation, and accidents. Switching from coal to natural gas has environmental benefits, including a lower climate impact, but may lead to a delay in switching to more sustainable options. Carbon capture and storage can be built into power plants to remove their carbon dioxide emissions, but is expensive and has seldom been implemented.
A fossil fuel power station is a thermal power station which burns a fossil fuel, such as coal or natural gas, to produce electricity. Fossil fuel power stations have machinery to convert the heat energy of combustion into mechanical energy, which then operates an electrical generator. The prime mover may be a steam turbine, a gas turbine or, in small plants, a reciprocating gas engine. All plants use the energy extracted from expanding gas, either steam or combustion gases. Although different energy conversion methods exist, all thermal power station conversion methods have efficiency limited by the Carnot efficiency and therefore produce waste heat.
A carbon offset is a reduction or removal of emissions of carbon dioxide or other greenhouse gases made in order to compensate for emissions made elsewhere. Offsets are measured in tonnes of carbon dioxide-equivalent (CO2e). One ton of carbon offset represents the reduction or removal of one ton of carbon dioxide or its equivalent in other greenhouse gases. Both the Oxford Principles for Net Zero Aligned Offsetting and the Science Based Targets initiative's Net-Zero Criteria argue for the importance of moving beyond offsets based on reduced or avoided emissions to offsets based on carbon that has been sequestered from the atmosphere, such as CO2 Removal Certificates (CORCs).
Coal pollution mitigation, sometimes called clean coal, is a series of systems and technologies that seek to mitigate the health and environmental impact of coal; in particular air pollution from coal-fired power stations, and from coal burnt by heavy industry.
Supercritical carbon dioxide is a fluid state of carbon dioxide where it is held at or above its critical temperature and critical pressure.
Carbon capture and storage (CCS) or carbon capture and sequestration is the process of capturing carbon dioxide (CO2) before it enters the atmosphere, transporting it, and storing it (carbon sequestration) for centuries or millennia. Usually the CO2 is captured from large point sources, such as coal-fired power plant, a chemical plant or biomass power plant, and then stored in an underground geological formation. The aim is to prevent the release of CO2 from heavy industry with the intent of mitigating the effects of climate change. Although CO2 has been injected into geological formations for several decades for various purposes, including enhanced oil recovery, the long-term storage of CO2 is a relatively new concept. Carbon capture and utilization (CCU) and CCS are sometimes discussed collectively as carbon capture, utilization, and sequestration (CCUS). This is because CCS is a relatively expensive process yielding a product with an intrinsic low value (i.e. CO2). Hence, carbon capture makes economically more sense when being combined with a utilization process where the cheap CO2 can be used to produce high-value chemicals to offset the high costs of capture operations.
An integrated gasification combined cycle (IGCC) is a technology using a high pressure gasifier to turn coal and other carbon based fuels into pressurized gas—synthesis gas (syngas). It can then remove impurities from the syngas prior to the electricity generation cycle. Some of these pollutants, such as sulfur, can be turned into re-usable byproducts through the Claus process. This results in lower emissions of sulfur dioxide, particulates, mercury, and in some cases carbon dioxide. With additional process equipment, a water-gas shift reaction can increase gasification efficiency and reduce carbon monoxide emissions by converting it to carbon dioxide. The resulting carbon dioxide from the shift reaction can be separated, compressed, and stored through sequestration. Excess heat from the primary combustion and syngas fired generation is then passed to a steam cycle, similar to a combined cycle gas turbine. This process results in improved thermodynamic efficiency compared to conventional pulverized coal combustion.
A low-carbon economy (LCE) or decarbonised economy is an economy based on energy sources that produce low levels of greenhouse gas (GHG) emissions. GHG emissions due to anthropogenic (human) activity are the dominant cause of observed climate change since the mid-20th century. Continued emission of greenhouse gases may cause long-lasting changes around the world, increasing the likelihood of severe, pervasive, and irreversible effects for people and ecosystems.
Greenhouse gas emissions from human activities strengthen the greenhouse effect, causing climate change. Most is carbon dioxide from burning fossil fuels: coal, oil, and natural gas. The largest emitters include coal in China and large oil and gas companies, many state-owned by OPEC and Russia. Human-caused emissions have increased atmospheric carbon dioxide by about 50% over pre-industrial levels.
Low-carbon power is electricity produced with substantially lower greenhouse gas emissions than conventional fossil fuel power generation. The energy transition to low-carbon power is one of the most important actions required to limit climate change. Power sector emissions may have peaked in 2018. During the first six months of 2020, scientists observed an 8.8% decrease in global CO2 emissions relative to 2019 due to COVID-19 lockdown measures. The two main sources of the decrease in emissions included ground transportation (40%) and the power sector (22%). This event is the largest absolute decrease in CO2 emissions in history, but emphasizes that low-carbon power "must be based on structural and transformational changes in energy-production systems".
Carbon dioxide removal (CDR), also known as negative CO2 emissions, is a process in which carbon dioxide gas is removed from the atmosphere and sequestered for long periods of time. Similarly, greenhouse gas removal (GGR) or negative greenhouse gas emissions is the removal of greenhouse gases (GHGs) from the atmosphere by deliberate human activities, i.e., in addition to the removal that would occur via natural carbon cycle or atmospheric chemistry processes. In the context of net zero greenhouse gas emissions targets, CDR is increasingly integrated into climate policy, as a new element of mitigation strategies. CDR and GGR methods are also known as negative emissions technologies, (NET) and may be cheaper than preventing some agricultural greenhouse gas emissions.
The Kędzierzyn Zero-Emission Power and Chemical Complex is a proposed facility in Kędzierzyn-Koźle, Poland. It will combine power and heat generation with that of chemical products and carbon capture and storage. The project is proposed by a consortium of chemicals producer Zakłady Azotowe Kędzierzyn and electricity company Południowy Koncern Energetyczny. The plant will produce synthesis gas by gasification of hard coal. The produced gas will be used for power and heat generation or for production of chemicals. The plant will capture produced carbon dioxide (CO2), which will be stored in natural geological reservoirs or used as a raw material for production of synthesis fuels, fertilisers or plastics.
Measurement of life-cycle greenhouse gas emissions involves calculating the global-warming potential of energy sources through life-cycle assessment. These are usually sources of only electrical energy but sometimes sources of heat are evaluated. The findings are presented in units of global warming potential per unit of electrical energy generated by that source. The scale uses the global warming potential unit, the carbon dioxide equivalent, and the unit of electrical energy, the kilowatt hour (kWh). The goal of such assessments is to cover the full life of the source, from material and fuel mining through construction to operation and waste management.
Prairie State Energy Campus is a 1,600 megawatt base load, coal-fired, electrical power station and coal mine near Marissa, Illinois southeast of St. Louis, Missouri. Prairie State Energy Campus (PSEC) features low levels of regulated emissions compared to other coal-fired power stations, capturing sulfur from high-sulfur coal mined nearby instead of transporting low-sulfur coal from elsewhere.
The Allam-Fetvedt Cycle or Allam Cycle is a process for converting gaseous fuels into thermal energy, while capturing the generated carbon dioxide and water. This zero emissions cycle was validated at a 50 MWth natural gas fed test facility in La Porte, Texas in May 2018. This industrial plant is owned and operated by NET Power LLC, a privately held technology licensing company. NET Power is owned by Exelon Corporation, McDermott International Ltd, Occidental Petroleum Corporation (Oxy) Low Carbon Ventures, and 8 Rivers Capital. The key inventors behind the process are English engineer Rodney John Allam, American engineer Jeremy Eron Fetvedt, and American scientist Dr. Miles R Palmer. The Allam-Fetvedt Cycle was recognized by MIT Technology Review on the 2018 list of 10 Breakthrough Technologies.
Rodney John Allam, MBE is an English chemical engineer and fellow of the Institution of Chemical Engineers who is credited with inventions related to power generation, notably the Allam power cycle, which is a generation process for fossil fuels, with integrated carbon dioxide capture.
The Petra Nova project is a coal-energy-sector/clean-energy project designed to reduce carbon emissions from one of the boilers of a coal burning power plant in Thompsons, Texas. It is a multi-million dollar project taken up by NRG Energy and JX Nippon Oil to retrofit one of the boilers at their WA Parish Generating Station with a post-combustion carbon capture treatment system to treat a portion of the atmospheric exhaust emissions from the retrofitted boiler. The plant entered commercial service in 1977, and the new carbon emissions reduction system was first put into operation on January 10, 2017. The project is designed to annually capture approximately 33% of the carbon dioxide emissions from the plant's boiler #8.
The NET Power Test Facility, located in La Porte, Tx, is an oxy-combustion, zero-emissions 50 MWth natural gas power plant owned and operated by NET Power. NET Power is owned by Exelon Corporation, McDermott International Ltd, Occidental Petroleum Corporation (Oxy) Low Carbon Ventures, and 8 Rivers Capital. The plant is a first of its kind Allam-Fetvedt Cycle which achieved first-fire in May of 2018. The Allam-Fetvedt cycle delivers lower cost power while eliminating atmospheric emissions. The plant was featured in The Global CCS Institutes 2018 Status of CCS report. In recognition of the Allam-Fetvedt Cycle demonstration plant in La Porte, Texas, NET Power was awarded the 2018 International Excellence in Energy Breakthrough Technological Project of the Year at the Abu Dhabi International Petroleum Exhibition and Conference (ADIPEC).
Carbon storage in the North Sea, are programmes being run by several Northern European countries to capture carbon, and store it under the North Sea in either old oil and gas workings, or within saline aquifers. Whilst there have been some moves to international co-operation, most of the Carbon Capture and Storage (CCS) programmes are governed by the laws of the country that is running them. Because the governments have pledged net zero carbon emissions by 2050, they have to find ways to deal with any remaining CO2 produced, such as by heavy industry. Around 90% of the identified storage geologies for carbon dioxide in Europe, are shared between Norway and the United Kingdom; all of the designated sites for storage are located in the North Sea.
