Misplaced Pages

#369630

93-655: The REF's primary activity is commissioning and writing reports to provide information on energy issues. Since 2006, the REF has published a comprehensive set of statistics, describing in detail the performance of renewable energy generators in the UK that are registered under the Renewables Obligation . On 2 February 2011, the REF released a report critical of wind power, saying it would lead to higher prices for consumers. The REF also publishes constraint payments made by

186-570: A decade or so, and nitrous oxides last about 100 years. The graph gives some indication of which regions have contributed most to human-induced climate change. When these numbers are calculated per capita cumulative emissions based on then-current population the situation is shown even more clearly. The ratio in per capita emissions between industrialized countries and developing countries was estimated at more than 10 to 1. Non- OECD countries accounted for 42% of cumulative energy-related CO 2 emissions between 1890 and 2007. Over this time period,

279-463: A faster rate than they are consumed". Solar power , wind power , hydroelectricity , geothermal energy, and biomass are widely agreed to be the main types of renewable energy. Renewable energy often displaces conventional fuels in four areas: electricity generation , hot water / space heating , transportation , and rural (off-grid) energy services. Although almost all forms of renewable energy cause much fewer carbon emissions than fossil fuels,

372-437: A given time. Solar energy can only be captured during the day, and ideally in cloudless conditions. Wind power generation can vary significantly not only day-to-day, but even month-to-month. This poses a challenge when transitioning away from fossil fuels: energy demand will often be higher or lower than what renewables can provide. Both scenarios can cause electricity grids to become overloaded, leading to power outages . In

465-517: A lack of comparability, which is problematic when monitoring progress towards targets. There are arguments for the adoption of a common measurement tool, or at least the development of communication between different tools. Emissions may be tracked over long time periods, known as historical or cumulative emissions measurements. Cumulative emissions provide some indicators of what is responsible for greenhouse gas atmospheric concentration build-up. The national accounts balance tracks emissions based on

558-952: A large portion of the total, such as Kenya (43%) and Indonesia (5%). Technical advances may eventually make geothermal power more widely available. For example, enhanced geothermal systems involve drilling around 10 kilometres (6.2 mi) into the Earth, breaking apart hot rocks and extracting the heat using water. In theory, this type of geothermal energy extraction could be done anywhere on Earth. There are also other renewable energy technologies that are still under development, including enhanced geothermal systems , concentrated solar power , cellulosic ethanol , and marine energy . These technologies are not yet widely demonstrated or have limited commercialization. Some may have potential comparable to other renewable energy technologies, but still depend on further breakthroughs from research, development and engineering. Enhanced geothermal systems (EGS) are

651-638: A more energy-dense biofuel like ethanol. Wood is the most significant biomass energy source as of 2012 and is usually sourced from a trees cleared for silvicultural reasons or fire prevention . Municipal wood waste – for instance, construction materials or sawdust – is also often burned for energy. The biggest per-capita producers of wood-based bioenergy are heavily forested countries like Finland, Sweden, Estonia, Austria, and Denmark. Bioenergy can be environmentally destructive if old-growth forests are cleared to make way for crop production. In particular, demand for palm oil to produce biodiesel has contributed to

744-506: A new type of geothermal power which does not require natural hot water reservoirs or steam to generate power. Most of the underground heat within drilling reach is trapped in solid rocks, not in water. EGS technologies use hydraulic fracturing to break apart these rocks and release the heat they contain, which is then harvested by pumping water into the ground. The process is sometimes known as "hot dry rock" (HDR). Unlike conventional geothermal energy extraction, EGS may be feasible anywhere in

837-814: A particular base year. Choosing between base years of 1750, 1900, 1950, and 1990 has a significant effect for most countries. Within the G8 group of countries, it is most significant for the UK, France and Germany. These countries have a long history of CO 2 emissions (see the section on Cumulative and historical emissions ). The Global Carbon Project continuously releases data about CO 2 emissions, budget and concentration. and industry (excluding cement carbonation) Gt C change Gt C Gt C Gt CO 2 (projection) Distribution of global greenhouse gas emissions based on type of greenhouse gas, without land-use change, using 100 year global warming potential (data from 2020). Total: 49.8 GtCO 2 e Carbon dioxide (CO 2 )

930-409: A range of construction strategies and technologies that aim to optimize the distribution of solar heat in a building. Examples include solar chimneys , orienting a building to the sun, using construction materials that can store heat , and designing spaces that naturally circulate air . From 2020 to 2022, solar technology investments almost doubled from USD 162 billion to USD 308 billion, driven by

1023-483: A significant contributor to warming. Although CFCs are greenhouse gases, they are regulated by the Montreal Protocol which was motivated by CFCs' contribution to ozone depletion rather than by their contribution to global warming. Ozone depletion has only a minor role in greenhouse warming, though the two processes are sometimes confused in the media. In 2016, negotiators from over 170 nations meeting at

SECTION 10

#1732780968370

1116-461: A significant margin, Asia's and the world's largest emitter: it emits nearly 10 billion tonnes each year, more than one-quarter of global emissions. Other countries with fast growing emissions are South Korea , Iran, and Australia (which apart from the oil rich Persian Gulf states, now has the highest per capita emission rate in the world). On the other hand, annual per capita emissions of the EU-15 and

1209-702: A variety of environmental conditions and perform more efficiently allowing a greater proportion of photon energy to end up in the storage compounds, i.e., carbohydrates (rather than building and sustaining living cells). However, prominent research faces hurdles, Sun Catalytix a MIT spin-off stopped scaling up their prototype fuel-cell in 2012 because it offers few savings over other ways to make hydrogen from sunlight. Most new renewables are solar, followed by wind then hydro then bioenergy. Investment in renewables, especially solar, tends to be more effective in creating jobs than coal, gas or oil. Worldwide, renewables employ about 12 million people as of 2020, with solar PV being

1302-472: Is energy from renewable natural resources that are replenished on a human timescale . The most widely used renewable energy types are solar energy , wind power , and hydropower . Bioenergy and geothermal power are also significant in some countries. Some also consider nuclear power a renewable power source , although this is controversial. Renewable energy installations can be large or small and are suited for both urban and rural areas. Renewable energy

1395-456: Is thermal energy (heat) extracted from the Earth's crust . It originates from several different sources , of which the most significant is slow radioactive decay of minerals contained in the Earth's interior , as well as some leftover heat from the formation of the Earth . Some of the heat is generated near the Earth's surface in the crust, but some also flows from deep within the Earth from

1488-450: Is a framework of methods to measure and track how much greenhouse gas an organization emits. Cumulative anthropogenic (i.e., human-emitted) emissions of CO 2 from fossil fuel use are a major cause of global warming , and give some indication of which countries have contributed most to human-induced climate change. In particular, CO 2 stays in the atmosphere for at least 150 years and up to 1000 years, whilst methane disappears within

1581-471: Is a more economical means of long-term renewable energy storage, in terms of capital expenditures compared to pumped hydroelectric or batteries. Solar power produced around 1.3 terrawatt-hours (TWh) worldwide in 2022, representing 4.6% of the world's electricity. Almost all of this growth has happened since 2010. Solar energy can be harnessed anywhere that receives sunlight; however, the amount of solar energy that can be harnessed for electricity generation

1674-537: Is a technology for generating electricity by mixing fresh water and salty sea water in large power cells. Most marine energy harvesting technologies are still at low technology readiness levels and not used at large scales. Tidal energy is generally considered the most mature, but has not seen wide deployment. The world's largest tidal power station is on Sihwa Lake , South Korea, which produces around 550 gigawatt-hours of electricity per year. Earth emits roughly 10 W of infrared thermal radiation that flows toward

1767-419: Is about 800 times denser than air , even a slow flowing stream of water, or moderate sea swell , can yield considerable amounts of energy. Water can generate electricity with a conversion efficiency of about 90%, which is the highest rate in renewable energy. There are many forms of water energy: Much hydropower is flexible, thus complementing wind and solar. In 2021, the world renewable hydropower capacity

1860-525: Is common in Iceland, or to generate electricity. At smaller scales, geothermal power can be generated with geothermal heat pumps , which can extract heat from ground temperatures of under 30 °C (86 °F), allowing them to be used at relatively shallow depths of a few meters. Electricity generation requires large plants and ground temperatures of at least 150 °C (302 °F). In some countries, electricity produced from geothermal energy accounts for

1953-656: Is diametrically opposed to the interests of the wind energy industry. "It is an anti-wind lobbying organisation," she told BusinessGreen. "I'd like to know where the renewable energy part of their remit is. They don't foster or promote or develop, they just try to undermine the case for wind energy all the time." In 2011 it was revealed that it had been in discussion in April 2008 with the Charities Commission about its possibly overly political nature. Renewable energy Renewable energy (or green energy )

SECTION 20

#1732780968370

2046-401: Is enough fuel for breeder reactors to satisfy the world's energy needs for 5 billion years at 1983's total energy consumption rate, thus making nuclear energy effectively a renewable energy. In addition to seawater the average crustal granite rocks contain significant quantities of uranium and thorium with which breeder reactors can supply abundant energy for the remaining lifespan of the sun on

2139-421: Is exported. In comparison, methane has not increased appreciably, and N 2 O by 0.25% y . Using different base years for measuring emissions has an effect on estimates of national contributions to global warming. This can be calculated by dividing a country's highest contribution to global warming starting from a particular base year, by that country's minimum contribution to global warming starting from

2232-518: Is influenced by weather conditions , geographic location and time of day. There are two mainstream ways of harnessing solar energy: solar thermal , which converts solar energy into heat; and photovoltaics (PV), which converts it into electricity. PV is far more widespread, accounting for around two thirds of the global solar energy capacity as of 2022. It is also growing at a much faster rate, with 170 GW newly installed capacity in 2021, compared to 25 GW of solar thermal. Passive solar refers to

2325-460: Is more valuable than VRE countries with large hydroelectric developments such as Canada and Norway are spending billions to expand their grids to trade with neighboring countries having limited hydro. Biomass is biological material derived from living, or recently living organisms. Most commonly, it refers to plants or plant-derived materials. As an energy source, biomass can either be used directly via combustion to produce heat, or converted to

2418-596: Is not possible to use or store excess electricity. Electrical energy storage is a collection of methods used to store electrical energy. Electrical energy is stored during times when production (especially from intermittent sources such as wind power , tidal power , solar power ) exceeds consumption, and returned to the grid when production falls below consumption. Pumped-storage hydroelectricity accounts for more than 85% of all grid power storage . Batteries are increasingly being deployed for storage and grid ancillary services and for domestic storage. Green hydrogen

2511-520: Is often associated with unsustainable deforestation . As part of the global effort to limit climate change , most countries have committed to net zero greenhouse gas emissions . In practice, this means phasing out fossil fuels and replacing them with low-emissions energy sources. This much needed process, coined as "low-carbon substitutions" in contrast to other transition processes including energy additions, needs to be accelerated multiple times in order to successfully mitigating climate change. At

2604-501: Is often deployed together with further electrification . This has several benefits: electricity can move heat and vehicles efficiently and is clean at the point of consumption. Variable renewable energy sources are those that have a fluctuating nature, such as wind power and solar power. In contrast, controllable renewable energy sources include dammed hydroelectricity , bioenergy , or geothermal power . Renewable energy systems have rapidly become more efficient and cheaper over

2697-633: Is responsible for around 73% of emissions. Deforestation and other changes in land use also emit carbon dioxide and methane . The largest source of anthropogenic methane emissions is agriculture , closely followed by gas venting and fugitive emissions from the fossil-fuel industry . The largest agricultural methane source is livestock . Agricultural soils emit nitrous oxide partly due to fertilizers . Similarly, fluorinated gases from refrigerants play an outsized role in total human emissions. The current CO 2 -equivalent emission rates averaging 6.6 tonnes per person per year, are well over twice

2790-477: Is that the heated water can be stored until it is needed, eliminating the need for a separate energy storage system. Solar thermal power can also be converted to electricity by using the steam generated from the heated water to drive a turbine connected to a generator. However, because generating electricity this way is much more expensive than photovoltaic power plants, there are very few in use today. Humans have harnessed wind energy since at least 3500 BC. Until

2883-454: Is the dominant emitted greenhouse gas, while methane ( CH 4 ) emissions almost have the same short-term impact. Nitrous oxide (N 2 O) and fluorinated gases (F-gases) play a lesser role in comparison. Greenhouse gas emissions are measured in CO 2 equivalents determined by their global warming potential (GWP), which depends on their lifetime in the atmosphere. Estimations largely depend on

Renewable Energy Foundation - Misplaced Pages Continue

2976-563: Is the first major source of greenhouse gas emissions from transportation, followed by aircraft and maritime. Waterborne transportation is still the least carbon-intensive mode of transportation on average, and it is an essential link in sustainable multimodal freight supply chains . Buildings, like industry, are directly responsible for around one-fifth of greenhouse gas emissions, primarily from space heating and hot water consumption. When combined with power consumption within buildings, this figure climbs to more than one-third. Within

3069-449: Is the main greenhouse gas resulting from human activities. It accounts for more than half of warming. Methane (CH 4 ) emissions have almost the same short-term impact. Nitrous oxide (N 2 O) and fluorinated gases (F-gases) play a lesser role in comparison. Emissions of carbon dioxide, methane and nitrous oxide in 2023 were all higher than ever before. Electricity generation , heat and transport are major emitters; overall energy

3162-662: Is to slow and eventually stop climate change , which is widely agreed to be caused mostly by greenhouse gas emissions . In general, renewable energy sources cause much lower emissions than fossil fuels. The International Energy Agency estimates that to achieve net zero emissions by 2050, 90% of global electricity generation will need to be produced from renewable sources. Renewables also cause much less air pollution than fossil fuels, improving public health, and are less noisy . The deployment of renewable energy still faces obstacles, especially fossil fuel subsidies , lobbying by incumbent power providers, and local opposition to

3255-665: Is very complex, and is affected by how carbon sinks are allocated between regions and the dynamics of the climate system . The graphic shows the logarithm of 1850–2019 fossil fuel CO 2 emissions; natural log on left, actual value of Gigatons per year on right. Although emissions increased during the 170-year period by about 3% per year overall, intervals of distinctly different growth rates (broken at 1913, 1945, and 1973) can be detected. The regression lines suggest that emissions can rapidly shift from one growth regime to another and then persist for long periods of time. The most recent drop in emissions growth – by almost 3 percentage points –

3348-463: The 2023 United Nations Climate Change Conference , around three-quarters of the world's countries set a goal of tripling renewable energy capacity by 2030. The European Union aims to generate 40% of its electricity from renewables by the same year. Renewable energy is more evenly distributed around the world than fossil fuels, which are concentrated in a limited number of countries. It also brings health benefits by reducing air pollution caused by

3441-494: The NASA Office of Science and Technology Policy examined the concept and concluded that with current and near-future technologies it would be economically uncompetitive. Collection of static electricity charges from water droplets on metal surfaces is an experimental technology that would be especially useful in low-income countries with relative air humidity over 60%. Breeder reactors could, in principle, depending on

3534-523: The National Grid Electricity System Operator to wind farms to reduce output. These payments are made when excess electricity is being generated in a particular region and a grid bottleneck prevents that electricity being exported to a region where the electricity could be used. Wind farm constraint payments reached a record £125 million in 2018, with Scottish wind farms receiving £115 million of this total. In 2023,

3627-719: The greenhouse effect . This contributes to climate change . Carbon dioxide (CO 2 ), from burning fossil fuels such as coal , oil , and natural gas , is one of the most important factors in causing climate change. The largest emitters are China followed by the United States. The United States has higher emissions per capita . The main producers fueling the emissions globally are large oil and gas companies . Emissions from human activities have increased atmospheric carbon dioxide by about 50% over pre-industrial levels. The growing levels of emissions have varied, but have been consistent among all greenhouse gases . Emissions in

3720-511: The mantle and core . Geothermal energy extraction is viable mostly in countries located on tectonic plate edges, where the Earth's hot mantle is more exposed. As of 2023, the United States has by far the most geothermal capacity (2.7 GW, or less than 0.2% of the country's total energy capacity ), followed by Indonesia and the Philippines. Global capacity in 2022 was 15 GW. Geothermal energy can be either used directly to heat homes, as

3813-473: The 2010s averaged 56 billion tons a year, higher than any decade before. Total cumulative emissions from 1870 to 2022 were 703 GtC (2575 GtCO 2 ), of which 484±20 GtC (1773±73 GtCO 2 ) from fossil fuels and industry, and 219±60 GtC (802±220 GtCO 2 ) from land use change . Land-use change , such as deforestation , caused about 31% of cumulative emissions over 1870–2022, coal 32%, oil 24%, and gas 10%. Carbon dioxide (CO 2 )

Renewable Energy Foundation - Misplaced Pages Continue

3906-520: The 2030 Paris Agreement increase of 1.5 °C (2.7 °F) over pre-industrial levels. While cities are sometimes considered to be disproportionate contributors to emissions, per-capita emissions tend to be lower for cities than the averages in their countries. A 2017 survey of corporations responsible for global emissions found that 100 companies were responsible for 71% of global direct and indirect emissions , and that state-owned companies were responsible for 59% of their emissions. China is, by

3999-400: The 20th century, it was primarily used to power ships, windmills and water pumps. Today, the vast majority of wind power is used to generate electricity using wind turbines. Modern utility-scale wind turbines range from around 600 kW to 9 MW of rated power. The power available from the wind is a function of the cube of the wind speed, so as wind speed increases, power output increases up to

4092-498: The EU, the agricultural sector presently accounts for roughly 10% of total greenhouse gas emissions, with methane from livestock accounting for slightly more than half of 10%. Estimates of total CO 2 emissions do include biotic carbon emissions, mainly from deforestation. Including biotic emissions brings about the same controversy mentioned earlier regarding carbon sinks and land-use change. The actual calculation of net emissions

4185-474: The Earth can cool off. The major anthropogenic (human origin) sources of greenhouse gases are carbon dioxide (CO 2 ), nitrous oxide ( N 2 O ), methane and three groups of fluorinated gases ( sulfur hexafluoride ( SF 6 ), hydrofluorocarbons (HFCs) and perfluorocarbons (PFCs, sulphur hexafluoride (SF 6 ), and nitrogen trifluoride (NF 3 )). Though the greenhouse effect is heavily driven by water vapor , human emissions of water vapor are not

4278-482: The REF published a paper titled "The Economics of Utility-Scale Solar Generation". The REF has frequently argued against wind farm expansion, and the organization has frequently been accused of in fact being anti-wind, rather than pro-renewable energy. Critics such as Maria McCaffery, chief executive of RenewableUK , a pro-wind trade body , says the Renewable Energy Foundation's true purpose

4371-718: The US accounted for 28% of emissions; the EU, 23%; Japan, 4%; other OECD countries 5%; Russia, 11%; China, 9%; India, 3%; and the rest of the world, 18%. The European Commission adopted a set of legislative proposals targeting a reduction of the CO 2 emissions by 55% by 2030. Overall, developed countries accounted for 83.8% of industrial CO 2 emissions over this time period, and 67.8% of total CO 2 emissions. Developing countries accounted for industrial CO 2 emissions of 16.2% over this time period, and 32.2% of total CO 2 emissions. However, what becomes clear when we look at emissions across

4464-552: The US are gradually decreasing over time. Emissions in Russia and Ukraine have decreased fastest since 1990 due to economic restructuring in these countries. 2015 was the first year to see both total global economic growth and a reduction of carbon emissions. Annual per capita emissions in the industrialized countries are typically as much as ten times the average in developing countries. Due to China's fast economic development, its annual per capita emissions are quickly approaching

4557-419: The ability of oceans and land sinks to absorb these gases. Short-lived climate pollutants (SLCPs) including methane, hydrofluorocarbons (HFCs) , tropospheric ozone and black carbon persist in the atmosphere for a period ranging from days to 15 years; whereas carbon dioxide can remain in the atmosphere for millennia. Reducing SLCP emissions can cut the ongoing rate of global warming by almost half and reduce

4650-446: The burning of fossil fuels. The potential worldwide savings in health care costs have been estimated at trillions of dollars annually. The two most important forms of renewable energy, solar and wind, are intermittent energy sources : they are not available constantly, resulting in lower capacity factors . In contrast, fossil fuel power plants are usually able to produce precisely the amount of energy an electricity grid requires at

4743-465: The case of Jupiter , or from its host star as in the case of the Earth . In the case of Earth, the Sun emits shortwave radiation ( sunlight ) that passes through greenhouse gases to heat the Earth's surface. In response, the Earth's surface emits longwave radiation that is mostly absorbed by greenhouse gases. The absorption of longwave radiation prevents it from reaching space, reducing the rate at which

SECTION 50

#1732780968370

4836-778: The cold outer space. Solar energy hits the surface and atmosphere of the earth and produces heat. Using various theorized devices like emissive energy harvester (EEH) or thermoradiative diode, this energy flow can be converted into electricity. In theory, this technology can be used during nighttime. Producing liquid fuels from oil-rich (fat-rich) varieties of algae is an ongoing research topic. Various microalgae grown in open or closed systems are being tried including some systems that can be set up in brownfield and desert lands. There have been numerous proposals for space-based solar power , in which very large satellites with photovoltaic panels would be equipped with microwave transmitters to beam power back to terrestrial receivers. A 2024 study by

4929-667: The concentration of carbon dioxide and other greenhouse gases. Emissions have grown rapidly since about 1950 with ongoing expansions in global population and economic activity following World War II. As of 2021, measured atmospheric concentrations of carbon dioxide were almost 50% higher than pre-industrial levels. The main sources of greenhouse gases due to human activity (also called carbon sources ) are: Global greenhouse gas emissions are about 50 Gt per year and for 2019 have been estimated at 57 Gt CO 2 eq including 5 Gt due to land use change. In 2019, approximately 34% [20 GtCO 2 -eq] of total net anthropogenic GHG emissions came from

5022-554: The crops used to produce bioethanol and biodiesel are grown specifically for this purpose, although used cooking oil accounted for 14% of the oil used to produce biodiesel as of 2015. The biomass used to produce biofuels varies by region. Maize is the major feedstock in the United States, while sugarcane dominates in Brazil. In the European Union, where biodiesel is more common than bioethanol, rapeseed oil and palm oil are

5115-412: The deforestation of tropical rainforests in Brazil and Indonesia. In addition, burning biomass still produces carbon emissions, although much less than fossil fuels (39 grams of CO 2 per megajoule of energy, compared to 75 g/MJ for fossil fuels). Some biomass sources are unsustainable at current rates of exploitation (as of 2017). Biofuels are primarily used in transportation, providing 3.5% of

5208-413: The difference between a country's exports and imports. For many richer nations, the balance is negative because more goods are imported than they are exported. This result is mostly due to the fact that it is cheaper to produce goods outside of developed countries, leading developed countries to become increasingly dependent on services and not goods. A positive account balance would mean that more production

5301-440: The energy supply sector, 24% [14 GtCO 2 -eq] from industry, 22% [13 GtCO 2 -eq]from agriculture, forestry and other land use (AFOLU), 15% [8.7 GtCO 2 -eq] from transport and 6% [3.3 GtCO 2 -eq] from buildings. Global carbon dioxide emissions by country in 2023: The current CO 2 -equivalent emission rates averaging 6.6 tonnes per person per year, are well over twice the estimated rate 2.3 tons required to stay within

5394-489: The entire life cycle from the production of a good or service along the supply chain to its final consumption. Carbon accounting (or greenhouse gas accounting) is a framework of methods to measure and track how much greenhouse gas an organization emits. The greenhouse effect occurs when greenhouse gases in a planet's atmosphere insulate the planet from losing heat to space, raising its surface temperature. Surface heating can happen from an internal heat source as in

5487-414: The estimated rate 2.3 tons required to stay within the 2030 Paris Agreement increase of 1.5 °C (2.7 °F) over pre-industrial levels. Annual per capita emissions in the industrialized countries are typically as much as ten times the average in developing countries. The carbon footprint (or greenhouse gas footprint ) serves as an indicator to compare the amount of greenhouse gases emitted over

5580-585: The fastest-growing renewable energy technology. It is cheap, low-maintenance and scalable; adding to an existing PV installation as demanded arises is simple. Its main disadvantage is its poor performance in cloudy weather. PV systems range from small, residential and commercial rooftop or building integrated installations, to large utility-scale photovoltaic power station . A household's solar panels can either be used for just that household or, if connected to an electrical grid, can be aggregated with millions of others. The first utility-scale solar power plant

5673-548: The fuel cycle employed, extract almost all of the energy contained in uranium or thorium , decreasing fuel requirements by a factor of 100 compared to widely used once-through light water reactors , which extract less than 1% of the energy in the actinide metal (uranium or thorium) mined from the earth. The high fuel-efficiency of breeder reactors could greatly reduce concerns about fuel supply, energy used in mining, and storage of radioactive waste . With seawater uranium extraction (currently too expensive to be economical), there

SECTION 60

#1732780968370

5766-744: The horizontal axis units currently in use. As offshore wind speeds average ~90% greater than that of land, offshore resources can contribute substantially more energy than land-stationed turbines. Investments in wind technologies reached USD 161 billion in 2020, with onshore wind dominating at 80% of total investments from 2013 to 2022. Offshore wind investments nearly doubled to USD 41 billion between 2019 and 2020, primarily due to policy incentives in China and expansion in Europe. Global wind capacity increased by 557 GW between 2013 and 2021, with capacity additions increasing by an average of 19% each year. Since water

5859-824: The importing country, rather than the exporting, country. A substantial proportion of CO 2 emissions is traded internationally. The net effect of trade was to export emissions from China and other emerging markets to consumers in the US, Japan, and Western Europe. Emission intensity is a ratio between greenhouse gas emissions and another metric, e.g., gross domestic product (GDP) or energy use. The terms "carbon intensity" and " emissions intensity " are also sometimes used. Emission intensities may be calculated using market exchange rates (MER) or purchasing power parity (PPP). Calculations based on MER show large differences in intensities between developed and developing countries, whereas calculations based on PPP show smaller differences. Carbon accounting (or greenhouse gas accounting)

5952-474: The lapse of formerly declining trends in carbon intensity of both developing and developed nations. China was responsible for most of global growth in emissions during this period. Localised plummeting emissions associated with the collapse of the Soviet Union have been followed by slow emissions growth in this region due to more efficient energy use , made necessary by the increasing proportion of it that

6045-721: The levels of those in the Annex I group of the Kyoto Protocol (i.e., the developed countries excluding the US). Africa and South America are both fairly small emitters, accounting for 3-4% of global emissions each. Both have emissions almost equal to international aviation and shipping. There are several ways of measuring greenhouse gas emissions. Some variables that have been reported include: These measures are sometimes used by countries to assert various policy/ethical positions on climate change. The use of different measures leads to

6138-408: The main feedstocks. China, although it produces comparatively much less biofuel, uses mostly corn and wheat. In many countries, biofuels are either subsidized or mandated to be included in fuel mixtures . There are many other sources of bioenergy that are more niche, or not yet viable at large scales. For instance, bioethanol could be produced from the cellulosic parts of crops, rather than only

6231-500: The main international treaty on climate change (the UNFCCC ), countries report on emissions produced within their borders, e.g., the emissions produced from burning fossil fuels. Under a production-based accounting of emissions, embedded emissions on imported goods are attributed to the exporting, rather than the importing, country. Under a consumption-based accounting of emissions, embedded emissions on imported goods are attributed to

6324-504: The main sequence of stellar evolution. Artificial photosynthesis uses techniques including nanotechnology to store solar electromagnetic energy in chemical bonds by splitting water to produce hydrogen and then using carbon dioxide to make methanol. Researchers in this field strived to design molecular mimics of photosynthesis that use a wider region of the solar spectrum, employ catalytic systems made from abundant, inexpensive materials that are robust, readily repaired, non-toxic, stable in

6417-459: The major source of greenhouse gas emissions in the EU . Greenhouse gas emissions from the transportation sector continue to rise, in contrast to power generation and nearly all other sectors. Since 1990, transportation emissions have increased by 30%. The transportation sector accounts for around 70% of these emissions. The majority of these emissions are caused by passenger vehicles and vans. Road travel

6510-408: The maximum output for the particular turbine. Areas where winds are stronger and more constant, such as offshore and high-altitude sites, are preferred locations for wind farms. Wind-generated electricity met nearly 4% of global electricity demand in 2015, with nearly 63 GW of new wind power capacity installed. Wind energy was the leading source of new capacity in Europe, the US and Canada, and

6603-472: The medium-term, this variability may require keeping some gas-fired power plants or other dispatchable generation on standby until there is enough energy storage, demand response , grid improvement, and/or baseload power from non-intermittent sources. In the long-term, energy storage is an important way of dealing with intermittency. Using diversified renewable energy sources and smart grids can also help flatten supply and demand. Sector coupling of

6696-479: The past 30 years. A large majority of worldwide newly installed electricity capacity is now renewable. Renewable energy sources, such as solar and wind power, have seen significant cost reductions over the past decade, making them more competitive with traditional fossil fuels. In most countries, photovoltaic solar or onshore wind are the cheapest new-build electricity. From 2011 to 2021, renewable energy grew from 20% to 28% of global electricity supply. Power from

6789-571: The power generation sector with other sectors may increase flexibility: for example the transport sector can be coupled by charging electric vehicles and sending electricity from vehicle to grid . Similarly the industry sector can be coupled by hydrogen produced by electrolysis, and the buildings sector by thermal energy storage for space heating and cooling. Building overcapacity for wind and solar generation can help ensure sufficient electricity production even during poor weather. In optimal weather, it may be necessary to curtail energy generation if it

6882-488: The primary challenges for new developments. It is popular to repower old dams thereby increasing their efficiency and capacity as well as quicker responsiveness on the grid. Where circumstances permit existing dams such as the Russell Dam built in 1985 may be updated with "pump back" facilities for pumped-storage which is useful for peak loads or to support intermittent wind and solar power. Because dispatchable power

6975-422: The renewable energy sector. Globally in 2020 there are over 10 million jobs associated with the renewable energy industries, with solar photovoltaics being the largest renewable employer. The clean energy sectors added about 4.7 million jobs globally between 2019 and 2022, totaling 35 million jobs by 2022. Greenhouse gas emissions Greenhouse gas ( GHG ) emissions from human activities intensify

7068-585: The second largest in China. In Denmark, wind energy met more than 40% of its electricity demand while Ireland, Portugal and Spain each met nearly 20%. Globally, the long-term technical potential of wind energy is believed to be five times total current global energy production, or 40 times current electricity demand, assuming all practical barriers needed were overcome. This would require wind turbines to be installed over large areas, particularly in areas of higher wind resources, such as offshore, and likely also industrial use of new types of VAWT turbines in addition to

7161-527: The sector's increasing maturity and cost reductions, particularly in solar photovoltaic (PV), which accounted for 90% of total investments. China and the United States were the main recipients, collectively making up about half of all solar investments since 2013. Despite reductions in Japan and India due to policy changes and COVID-19 , growth in China, the United States, and a significant increase from Vietnam's feed-in tariff program offset these declines. Globally,

7254-418: The seed as is common today. Sweet sorghum may be a promising alternative source of bioethanol, due to its tolerance of a wide range of climates. Cow dung can be converted into methane. There is also a great deal of research involving algal fuel , which is attractive because algae is a non-food resource, grows around 20 times faster than most food crops, and can be grown almost anywhere. Geothermal energy

7347-451: The solar sector added 714 gigawatts (GW) of solar PV and concentrated solar power (CSP) capacity between 2013 and 2021, with a notable rise in large-scale solar heating installations in 2021, especially in China, Europe, Turkey, and Mexico. A photovoltaic system , consisting of solar cells assembled into panels , converts light into electrical direct current via the photoelectric effect . PV has several advantages that make it by far

7440-629: The summit of the United Nations Environment Programme reached a legally binding accord to phase out hydrofluorocarbons (HFCs) in the Kigali Amendment to the Montreal Protocol . The use of CFC-12 (except some essential uses) has been phased out due to its ozone depleting properties. The phasing-out of less active HCFC-compounds will be completed in 2030. Starting about 1750, industrial activity powered by fossil fuels began to significantly increase

7533-513: The sun and wind accounted for most of this increase, growing from a combined 2% to 10%. Use of fossil energy shrank from 68% to 62%. In 2022, renewables accounted for 30% of global electricity generation and are projected to reach over 42% by 2028. Many countries already have renewables contributing more than 20% of their total energy supply, with some generating over half or even all their electricity from renewable sources. The main motivation to replace fossil fuels with renewable energy sources

7626-468: The technology employing the most at almost 4 million. However, as of February 2024, the world's supply of workforce for solar energy is lagging greatly behind demand as universities worldwide still produce more workforce for fossil fuels than for renewable energy industries. In 2021, China accounted for almost half of the global increase in renewable electricity. There are 3,146 gigawatts installed in 135 countries, while 156 countries have laws regulating

7719-407: The ten biggest solar power stations are in China, including the biggest, Golmud Solar Park in China. Unlike photovoltaic cells that convert sunlight directly into electricity, solar thermal systems convert it into heat. They use mirrors or lenses to concentrate sunlight onto a receiver, which in turn heats a water reservoir. The heated water can then be used in homes. The advantage of solar thermal

7812-501: The term is not synonymous with low-carbon energy . Some non-renewable sources of energy, such as nuclear power , generate almost no emissions, while some renewable energy sources can be very carbon-intensive, such as the burning of biomass if it is not offset by planting new plants. Renewable energy is also distinct from sustainable energy , a more abstract concept that seeks to group energy sources based on their overall permanent impact on future generations of humans. For example, biomass

7905-484: The use of land for renewable installations. Like all mining, the extraction of minerals required for many renewable energy technologies also results in environmental damage . In addition, although most renewable energy sources are sustainable , some are not. Renewable energy is usually understood as energy harnessed from continuously occurring natural phenomena. The International Energy Agency defines it as "energy derived from natural processes that are replenished at

7998-457: The world today is that the countries with the highest emissions over history are not always the biggest emitters today. For example, in 2017, the UK accounted for just 1% of global emissions. In comparison, humans have emitted more greenhouse gases than the Chicxulub meteorite impact event which caused the extinction of the dinosaurs . Transport, together with electricity generation , is

8091-484: The world's transport energy demand in 2022, up from 2.7% in 2010. Biojet is expected to be important for short-term reduction of carbon dioxide emissions from long-haul flights. Aside from wood, the major sources of bioenergy are bioethanol and biodiesel . Bioethanol is usually produced by fermenting the sugar components of crops like sugarcane and maize , while biodiesel is mostly made from oils extracted from plants, such as soybean oil and corn oil . Most of

8184-502: The world, depending on the cost of drilling. EGS projects have so far primarily been limited to demonstration plants , as the technology is capital-intensive due to the high cost of drilling. Marine energy (also sometimes referred to as ocean energy) is the energy carried by ocean waves , tides , salinity , and ocean temperature differences . Technologies to harness the energy of moving water include wave power , marine current power , and tidal power . Reverse electrodialysis (RED)

8277-582: The year 1995). A country's emissions may also be reported as a proportion of global emissions for a particular year. Another measurement is of per capita emissions. This divides a country's total annual emissions by its mid-year population. Per capita emissions may be based on historical or annual emissions. One way of attributing greenhouse gas emissions is to measure the embedded emissions (also referred to as "embodied emissions") of goods that are being consumed. Emissions are usually measured according to production, rather than consumption. For example, in

8370-455: Was 1,360 GW. Only a third of the world's estimated hydroelectric potential of 14,000 TWh/year has been developed. New hydropower projects face opposition from local communities due to their large impact, including relocation of communities and flooding of wildlife habitats and farming land. High cost and lead times from permission process, including environmental and risk assessments, with lack of environmental and social acceptance are therefore

8463-406: Was at about the time of the 1970s energy crisis . Percent changes per year were estimated by piecewise linear regression on the log data and are shown on the plot; the data are from The Integrated Carbon Observation system. The sharp acceleration in CO 2 emissions since 2000 to more than a 3% increase per year (more than 2 ppm per year) from 1.1% per year during the 1990s is attributable to

8556-522: Was built in 1982 in Hesperia, California by ARCO . The plant was not profitable and was sold eight years later. However, over the following decades, PV cells became significantly more efficient and cheaper. As a result, PV adoption has grown exponentially since 2010. Global capacity increased from 230 GW at the end of 2015 to 890 GW in 2021. PV grew fastest in China between 2016 and 2021, adding 560 GW, more than all advanced economies combined. Four of

8649-590: Was occurring within a country, so more operational factories would increase carbon emission levels. Emissions may also be measured across shorter time periods. Emissions changes may, for example, be measured against the base year of 1990. 1990 was used in the United Nations Framework Convention on Climate Change (UNFCCC) as the base year for emissions, and is also used in the Kyoto Protocol (some gases are also measured from

#369630