108-668: Llyn Celyn ( Welsh pronunciation: [ɬɨ̞n ˈkɛlɨ̞n] ) is a reservoir constructed between 1960 and 1965 including the highly controversial Tryweryn flooding in the valley of the River Tryweryn in Gwynedd , Wales . This included the forcible removal of the Capel Celyn village residents despite protest and opposition of Welsh MPs. With an area of 320 hectares (1.2 sq mi), it measures roughly 2.5 miles (4.0 km) long by 1 mile (1.6 km) wide, and has
216-577: A private bill in January 1957; by obtaining authority through an Act of Parliament, Liverpool City Council avoided having to gain consent from the Welsh planning authorities. The legislation enabling the development was ultimately passed, despite mass protests in Wales, marches through Liverpool by Capel Celyn residents and their supporters, and the opposition of 35 out of 36 Welsh Members of Parliament , with
324-688: A rebound effect in which consumers use the money they save to buy more energy-intensive goods and services. For example, recent technical efficiency improvements in transport and buildings have been largely offset by trends in consumer behaviour , such as selecting larger vehicles and homes. Renewable energy sources are essential to sustainable energy, as they generally strengthen energy security and emit far fewer greenhouse gases than fossil fuels. Renewable energy projects sometimes raise significant sustainability concerns, such as risks to biodiversity when areas of high ecological value are converted to bioenergy production or wind or solar farms. Hydropower
432-537: A block for migrating fish, trapping them in one area, producing food and a habitat for various water-birds. They can also flood various ecosystems on land and may cause extinctions. Creating reservoirs can alter the natural biogeochemical cycle of mercury . After a reservoir's initial formation, there is a large increase in the production of toxic methylmercury (MeHg) via microbial methylation in flooded soils and peat. MeHg levels have also been found to increase in zooplankton and in fish. Dams can severely reduce
540-815: A chain up the valley. Coastal reservoirs are fresh water storage reservoirs located on the sea coast near a river mouth to store the flood water of a river. As the land-based reservoir construction is fraught with substantial land submergence, coastal reservoirs are preferred economically and technically since they do not use scarce land area. Many coastal reservoirs were constructed in Asia and Europe. Saemanguem in South Korea, Marina Barrage in Singapore, Qingcaosha in China, and Plover Cove in Hong Kong are
648-658: A conventional oil-fired thermal generation plant. For instance, In 1990, the impoundment behind the Balbina Dam in Brazil (inaugurated in 1987) had over 20 times the impact on global warming than would generating the same power from fossil fuels, due to the large area flooded per unit of electricity generated. Another study published in the Global Biogeochemical Cycles also found that newly flooded reservoirs released more carbon dioxide and methane than
756-533: A drop of water seep into the ocean without benefiting mankind." He created the reservoir named Parakrama Samudra ("sea of King Parakrama"). Vast artificial reservoirs were also built by various ancient kingdoms in Bengal, Assam, and Cambodia. Many dammed river reservoirs and most bank-side reservoirs are used to provide the raw water feed to a water treatment plant which delivers drinking water through water mains. The reservoir does not merely hold water until it
864-525: A few such coastal reservoirs. Where water is pumped or siphoned from a river of variable quality or size, bank-side reservoirs may be built to store the water. Such reservoirs are usually formed partly by excavation and partly by building a complete encircling bund or embankment , which may exceed 6 km (4 miles) in circumference. Both the floor of the reservoir and the bund must have an impermeable lining or core: initially these were often made of puddled clay , but this has generally been superseded by
972-437: A given unit of energy produced, the life-cycle greenhouse-gas emissions of natural gas are around 40 times the emissions of wind or nuclear energy but are much less than coal. Burning natural gas produces around half the emissions of coal when used to generate electricity and around two-thirds the emissions of coal when used to produce heat. Natural gas combustion also produces less air pollution than coal. However, natural gas
1080-455: A high-level reservoir is filled with water using high-performance electric pumps at times when electricity demand is low, and then uses this stored water to generate electricity by releasing the stored water into a low-level reservoir when electricity demand is high. Such systems are called pump-storage schemes. Reservoirs can be used in a number of ways to control how water flows through downstream waterways: Reservoirs can be used to balance
1188-570: A loss in both quantity and quality of water necessary for maintaining ecological balance and pose a risk of increasing severity and duration of droughts due to climate change. In summary, they consider it a misadaptation to climate change. Proponents of reservoirs or substitution reserves, on the other hand, see them as a solution for sustainable agriculture while waiting for a truly durable agricultural model. Without such reserves, they fear that unsustainable imported irrigation will be inevitable. They believe that these reservoirs should be accompanied by
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#17327901777341296-575: A maximum depth of 140 ft (43 m). It has the capacity to hold 71,200,000 cubic metres (93,100,000 cu yd) of water. It was originally to be named Llyn Tryweryn Mawr (meaning "great Tryweryn lake"), but in September 1964 Liverpool Corporation agreed to the name change following a letter from the Tryweryn Defence Committee. Construction of the reservoir for Liverpool Corporation Waterworks involved flooding
1404-419: A narrow valley or canyon may cover relatively little vegetation, while one situated on a plain may flood a great deal of vegetation. The site may be cleared of vegetation first or simply flooded. Tropical flooding can produce far more greenhouse gases than in temperate regions. The following table indicates reservoir emissions in milligrams per square meter per day for different bodies of water. Depending upon
1512-406: A path to net-zero emissions . Developing natural gas infrastructure risks carbon lock-in and stranded assets , where new fossil infrastructure either commits to decades of carbon emissions, or has to be written off before it makes a profit. The greenhouse gas emissions of fossil fuel and biomass power plants can be significantly reduced through carbon capture and storage (CCS). Most studies use
1620-428: A quarter of all low-carbon energy , making it the second largest source after hydropower. Nuclear power's lifecycle greenhouse gas emissions—including the mining and processing of uranium —are similar to the emissions from renewable energy sources. Nuclear power uses little land per unit of energy produced, compared to the major renewables. Additionally, Nuclear power does not create local air pollution. Although
1728-611: A reservoir is called the "conservation pool". In the United Kingdom, "top water level" describes the reservoir full state, while "fully drawn down" describes the minimum retained volume. There is a wide variety of software for modelling reservoirs, from the specialist Dam Safety Program Management Tools (DSPMT) to the relatively simple WAFLEX , to integrated models like the Water Evaluation And Planning system (WEAP) that place reservoir operations in
1836-611: A risk of inducing earthquakes, needs effective protection to avoid water pollution, and releases toxic emissions which can be captured. Biomass is renewable organic material that comes from plants and animals. It can either be burned to produce heat and electricity or be converted into biofuels such as biodiesel and ethanol, which can be used to power vehicles. The climate impact of bioenergy varies considerably depending on where biomass feedstocks come from and how they are grown. For example, burning wood for energy releases carbon dioxide; those emissions can be significantly offset if
1944-740: A river valley, with the potential to wash away towns and villages and cause considerable loss of life, such as the devastation following the failure of containment at Llyn Eigiau which killed 17 people. (see also List of dam failures ) A notable case of reservoirs being used as an instrument of war involved the British Royal Air Force Dambusters raid on Germany in World War II (codenamed " Operation Chastise " ), in which three German reservoir dams were selected to be breached in order to damage German infrastructure and manufacturing and power capabilities deriving from
2052-627: A small fraction of the energy in sunlight, producing a given amount of bioenergy requires a large amount of land compared to other renewable energy sources. Second-generation biofuels which are produced from non-food plants or waste reduce competition with food production, but may have other negative effects including trade-offs with conservation areas and local air pollution. Relatively sustainable sources of biomass include algae , waste, and crops grown on soil unsuitable for food production. Carbon capture and storage technology can be used to capture emissions from bioenergy power plants. This process
2160-401: A solar panel to produce as much energy as was used for its production. Less energy is needed if materials are recycled rather than mined. In concentrated solar power , solar rays are concentrated by a field of mirrors, heating a fluid. Electricity is produced from the resulting steam with a heat engine . Concentrated solar power can support dispatchable power generation , as some of the heat
2268-599: A stilling basin and then down the narrow and rocky valley of the River Tryweryn. This section of the river provides facilities for international level white-water canoeing , and rafting at the Canolfan Tryweryn National White-water Centre. Some water in the reservoir is held in reserve to be released down the river for specific whitewater events. Because the reservoir's principal purpose is to support low river flows in
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#17327901777342376-487: A sustainable way is a critical challenge for the global goal of limiting climate change while maintaining economic growth and enabling living standards to rise. Reliable and affordable energy, particularly electricity, is essential for health care, education, and economic development. As of 2020, 790 million people in developing countries do not have access to electricity, and around 2.6 billion rely on burning polluting fuels for cooking. Improving energy access in
2484-582: A territorial project that unites all water stakeholders with the goal of preserving and enhancing natural environments. Two main types of reservoirs can be distinguished based on their mode of supply. Circa 3000 BC, the craters of extinct volcanoes in Arabia were used as reservoirs by farmers for their irrigation water. Dry climate and water scarcity in India led to early development of stepwells and other water resource management techniques, including
2592-423: A working assumption that CCS can capture 85–90% of the carbon dioxide (CO 2 ) emissions from a power plant. Even if 90% of emitted CO 2 is captured from a coal-fired power plant, its uncaptured emissions are still many times greater than the emissions of nuclear, solar or wind energy per unit of electricity produced. Since coal plants using CCS are less efficient, they require more coal and thus increase
2700-569: Is Earth's primary source of energy, a clean and abundantly available resource in many regions. In 2019, solar power provided around 3% of global electricity, mostly through solar panels based on photovoltaic cells (PV). Solar PV is expected to be the electricity source with the largest installed capacity worldwide by 2027. The panels are mounted on top of buildings or installed in utility-scale solar parks . Costs of solar photovoltaic cells have dropped rapidly, driving strong growth in worldwide capacity. The cost of electricity from new solar farms
2808-407: Is a key component, in its 1987 report Our Common Future . It defined sustainable development as meeting "the needs of the present without compromising the ability of future generations to meet their own needs". This description of sustainable development has since been referenced in many definitions and explanations of sustainable energy. There is no universally accepted interpretation of how
2916-444: Is a major source of air pollution, which causes an estimated 7 million deaths each year, with the greatest attributable disease burden seen in low and middle-income countries. Fossil-fuel burning in power plants, vehicles, and factories is the main source of emissions that combine with oxygen in the atmosphere to cause acid rain . Air pollution is the second-leading cause of death from non-infectious disease. An estimated 99% of
3024-476: Is a natural lake whose level was raised by a low dam and into which the River Dee flows or discharges depending upon flow conditions, as part of the River Dee regulation system . This mode of operation is a form of hydraulic capacitance in the river system. Many reservoirs often allow some recreational uses, such as fishing and boating . Special rules may apply for the safety of the public and to protect
3132-402: Is a potent greenhouse gas in itself, and leaks during extraction and transportation can negate the advantages of switching away from coal. The technology to curb methane leaks is widely available but it is not always used. Switching from coal to natural gas reduces emissions in the short term and thus contributes to climate change mitigation . However, in the long term it does not provide
3240-484: Is a water reservoir for agricultural use. They are filled using pumped groundwater , pumped river water or water runoff and are typically used during the local dry season. This type of infrastructure has sparked an opposition movement in France, with numerous disputes and, for some projects, protests, especially in the former Poitou-Charentes region where violent demonstrations took place in 2022 and 2023. In Spain, there
3348-437: Is also used technically to refer to certain forms of liquid storage, such the "coolant reservoir" that captures overflow of coolant in an automobile's cooling system. Dammed reservoirs are artificial lakes created and controlled by a dam constructed across a valley and rely on the natural topography to provide most of the basin of the reservoir. These reservoirs can either be on-stream reservoirs , which are located on
Llyn Celyn - Misplaced Pages Continue
3456-399: Is an enlarged lake behind a dam , usually built to store fresh water , often doubling for hydroelectric power generation . Reservoirs are created by controlling a watercourse that drains an existing body of water, interrupting a watercourse to form an embayment within it, excavating, or building any number of retaining walls or levees to enclose any area to store water. The term
3564-472: Is competitive with, or in many places, cheaper than electricity from existing coal plants. Various projections of future energy use identify solar PV as one of the main sources of energy generation in a sustainable mix. Most components of solar panels can be easily recycled, but this is not always done in the absence of regulation. Panels typically contain heavy metals , so they pose environmental risks if put in landfills . It takes fewer than two years for
3672-594: Is contained behind a rock gravity dam and, at its upper end, it is bounded between Arenig Fawr and Arenig Fach , two of the mountains of south Snowdonia . Water is released from the reservoir into the River Tryweryn which flows into the River Dee. Most of the water passes through a small hydro-electric plant to supply green electricity to the National Grid . The released water first flows into
3780-504: Is controversial. Nuclear power does not produce carbon pollution or air pollution, but has drawbacks that include radioactive waste , the risk of nuclear proliferation , and the risk of 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 (CO 2 ) emissions, but this technology
3888-439: Is controversy over whether nuclear power is sustainable, in part due to concerns around nuclear waste , nuclear weapon proliferation , and accidents . Radioactive nuclear waste must be managed for thousands of years and nuclear power plants create fissile material that can be used for weapons. For each unit of energy produced, nuclear energy has caused far fewer accidental and pollution-related deaths than fossil fuels, and
3996-661: Is expensive and has rarely been implemented. Fossil fuels provide 85% of the world's energy consumption, and the energy system is responsible for 76% of global greenhouse gas emissions. Around 790 million people in developing countries lack access to electricity , and 2.6 billion rely on polluting fuels such as wood or charcoal to cook. Cooking with biomass plus fossil fuel pollution causes an estimated 7 million deaths each year. Limiting global warming to 2 °C (3.6 °F) will require transforming energy production , distribution, storage, and consumption. Universal access to clean electricity can have major benefits to
4104-501: Is greater acceptance because all beneficiary users are involved in the implementation of the system. The specific debate about substitution reservoirs is part of a broader discussion related to reservoirs used for agricultural irrigation, regardless of their type, and a certain model of intensive agriculture. Opponents view these reservoirs as a monopolization of resources benefiting only a few, representing an outdated model of productive agriculture. They argue that these reservoirs lead to
4212-466: Is harvested unsustainably. Bioenergy feedstocks typically require significant amounts of energy to harvest, dry, and transport; the energy usage for these processes may emit greenhouse gases. In some cases, the impacts of land-use change , cultivation, and processing can result in higher overall carbon emissions for bioenergy compared to using fossil fuels. Use of farmland for growing biomass can result in less land being available for growing food . In
4320-420: Is known as bioenergy with carbon capture and storage (BECCS) and can result in net carbon dioxide removal from the atmosphere. However, BECCS can also result in net positive emissions depending on how the biomass material is grown, harvested, and transported. Deployment of BECCS at scales described in some climate change mitigation pathways would require converting large amounts of cropland. Marine energy has
4428-466: Is needed: it can also be the first part of the water treatment process. The time the water is held before it is released is known as the retention time . This is a design feature that allows particles and silts to settle out, as well as time for natural biological treatment using algae , bacteria and zooplankton that naturally live in the water. However natural limnological processes in temperate climate lakes produce temperature stratification in
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4536-536: Is now used by the Aquarius Golf Club. Service reservoirs perform several functions, including ensuring sufficient head of water in the water distribution system and providing water capacity to even-out peak demand from consumers, enabling the treatment plant to run at optimum efficiency. Large service reservoirs can also be managed to reduce the cost of pumping by refilling the reservoir at times of day when energy costs are low. An irrigation reservoir
4644-558: Is often cheaper than existing coal plants and competitive with natural gas and nuclear. Wind turbines can also be placed offshore, where winds are steadier and stronger than on land but construction and maintenance costs are higher. Onshore wind farms, often built in wild or rural areas, have a visual impact on the landscape. While collisions with wind turbines kill both bats and to a lesser extent birds, these impacts are lower than from other infrastructure such as windows and transmission lines . The noise and flickering light created by
4752-955: Is ongoing. Hydroelectric plants convert the energy of moving water into electricity. In 2020, hydropower supplied 17% of the world's electricity, down from a high of nearly 20% in the mid-to-late 20th century. In conventional hydropower, a reservoir is created behind a dam. Conventional hydropower plants provide a highly flexible, dispatchable electricity supply. They can be combined with wind and solar power to meet peaks in demand and to compensate when wind and sun are less available. Compared to reservoir-based facilities, run-of-the-river hydroelectricity generally has less environmental impact. However, its ability to generate power depends on river flow, which can vary with daily and seasonal weather. Reservoirs provide water quantity controls that are used for flood control and flexible electricity output while also providing security during drought for drinking water supply and irrigation. Hydropower ranks among
4860-482: Is produced from the steam created in underground reservoirs. Geothermal energy provided less than 1% of global energy consumption in 2020. Geothermal energy is a renewable resource because thermal energy is constantly replenished from neighbouring hotter regions and the radioactive decay of naturally occurring isotopes . On average, the greenhouse gas emissions of geothermal-based electricity are less than 5% that of coal-based electricity. Geothermal energy carries
4968-419: Is stored in the reservoir. Any excess water can be spilled via a specifically designed spillway. Stored water may be piped by gravity for use as drinking water , to generate hydro-electricity or to maintain river flows to support downstream uses. Occasionally reservoirs can be managed to retain water during high rainfall events to prevent or reduce downstream flooding. Some reservoirs support several uses, and
5076-401: Is the golden thread that connects economic growth, increased social equity, and an environment that allows the world to thrive. Development is not possible without energy, and sustainable development is not possible without sustainable energy." UN Secretary-General Ban Ki-moon The United Nations Brundtland Commission described the concept of sustainable development , for which energy
5184-491: Is the largest source of renewable electricity while solar and wind energy are growing rapidly. Photovoltaic solar and onshore wind are the cheapest forms of new power generation capacity in most countries. For more than half of the 770 million people who currently lack access to electricity, decentralised renewable energy such as solar-powered mini-grids is likely the cheapest method of providing it by 2030. United Nations targets for 2030 include substantially increasing
5292-473: Is the portion of the reservoir that can be used for flood control, power production, navigation , and downstream releases. In addition, a reservoir's "flood control capacity" is the amount of water it can regulate during flooding. The "surcharge capacity" is the capacity of the reservoir above the spillway crest that cannot be regulated. In the United States, the water below the normal maximum level of
5400-448: Is to use fewer materials whose production requires a lot of energy, for example through better building design and recycling. Behavioural changes such as using videoconferencing rather than business flights, or making urban trips by cycling, walking or public transport rather than by car, are another way to conserve energy. Government policies to improve efficiency can include building codes , performance standards , carbon pricing , and
5508-567: Is typically stored to enable electricity to be generated when needed. In addition to electricity production, solar energy is used more directly; solar thermal heating systems are used for hot water production, heating buildings, drying, and desalination. Wind has been an important driver of development over millennia, providing mechanical energy for industrial processes, water pumps, and sailing ships. Modern wind turbines are used to generate electricity and provided approximately 6% of global electricity in 2019. Electricity from onshore wind farms
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#17327901777345616-452: The Ruhr and Eder rivers. The economic and social impact was derived from the enormous volumes of previously stored water that swept down the valleys, wreaking destruction. This raid later became the basis for several films. All reservoirs will have a monetary cost/benefit assessment made before construction to see if the project is worth proceeding with. However, such analysis can often omit
5724-533: The least-developed countries and making energy cleaner are key to achieving most of the United Nations 2030 Sustainable Development Goals , which cover issues ranging from climate action to gender equality . Sustainable Development Goal 7 calls for "access to affordable, reliable, sustainable and modern energy for all", including universal access to electricity and to clean cooking facilities by 2030. Energy efficiency—using less energy to deliver
5832-477: The uranium ore used to fuel nuclear fission plants is a non-renewable resource, enough exists to provide a supply for hundreds to thousands of years. However, uranium resources that can be accessed in an economically feasible manner, at the present state, are limited and uranium production could hardly keep up during the expansion phase. Climate change mitigation pathways consistent with ambitious goals typically see an increase in power supply from nuclear. There
5940-673: The 1800s, most of which are lined with brick. A good example is the Honor Oak Reservoir in London, constructed between 1901 and 1909. When it was completed it was said to be the largest brick built underground reservoir in the world and it is still one of the largest in Europe. This reservoir now forms part of the southern extension of the Thames Water Ring Main . The top of the reservoir has been grassed over and
6048-459: The 36th ( David Llywelyn , Conservative MP for Cardiff North) abstaining. This led to an increase in support for the Welsh nationalist party, Plaid Cymru , in the late 1950s and gave fresh impetus to Welsh devolution. The official opening was held on 28 October 1965. Representatives came from Liverpool City Council, and invitations were sent to all those with family links to the valley. In view of
6156-546: The City. They have, in so many ways, enriched the life of the City. We know that Liverpool, especially in the fields of medicine and education, has been of real service to the people of Wales. We realise the hurt of forty years ago when the Tryweryn Valley was transformed into a reservoir to help meet the water needs of Liverpool. For any insensitivity by our predecessor Council at that time, we apologise and hope that
6264-731: The Meroitic town of Butana . The Hafirs catch the water during rainy seasons in order to ensure water is available for several months during dry seasons to supply drinking water, irrigate fields and water cattle. The Great Reservoir near the Lion Temple in Musawwarat es-Sufra is a notable hafir in Kush. In Sri Lanka , large reservoirs were created by ancient Sinhalese kings in order to store water for irrigation. The famous Sri Lankan king Parākramabāhu I of Sri Lanka said "Do not let
6372-488: The US. The capacity, volume, or storage of a reservoir is usually divided into distinguishable areas. Dead or inactive storage refers to water in a reservoir that cannot be drained by gravity through a dam's outlet works , spillway, or power plant intake and can only be pumped out. Dead storage allows sediments to settle, which improves water quality and also creates an area for fish during low levels. Active or live storage
6480-403: The United States, around 10% of motor gasoline has been replaced by corn-based ethanol , which requires a significant proportion of the harvest. In Malaysia and Indonesia, clearing forests to produce palm oil for biodiesel has led to serious social and environmental effects , as these forests are critical carbon sinks and habitats for diverse species. Since photosynthesis captures only
6588-513: The amount of water reaching countries downstream of them, causing water stress between the countries, e.g. the Sudan and Egypt , which damages farming businesses in the downstream countries, and reduces drinking water. Green Energy Energy is sustainable if it "meets the needs of the present without compromising the ability of future generations to meet their own needs." Definitions of sustainable energy usually look at its effects on
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#17327901777346696-406: The anticipated protest, there was a strong police presence. The ceremony lasted less than three minutes, as protesters had cut the microphone wires, and the chants of the hundreds of protesters made the speeches inaudible. In October 2005, Liverpool City Council issued a public apology, which read: The Council acknowledges its debt to the many thousands of Welsh people who have made their homes in
6804-535: The area flooded versus power produced, a reservoir built for hydro- electricity generation can either reduce or increase the net production of greenhouse gases when compared to other sources of power. A study for the National Institute for Research in the Amazon found that hydroelectric reservoirs release a large pulse of carbon dioxide from decay of trees left standing in the reservoirs, especially during
6912-428: The base of the dam or some distance away. In a flat river valley a reservoir needs to be deep enough to create a head of water at the turbines; and if there are periods of drought the reservoir needs to hold enough water to average out the river's flow throughout the year(s). Run-of-the-river hydro in a steep valley with constant flow needs no reservoir. Some reservoirs generating hydroelectricity use pumped recharge:
7020-556: The building of a reservoir at Girnar in 3000 BC. Artificial lakes dating to the 5th century BC have been found in ancient Greece. The artificial Bhojsagar lake in present-day Madhya Pradesh state of India, constructed in the 11th century, covered 650 square kilometres (250 sq mi). The Kingdom of Kush invented the Hafir , a type of reservoir, during the Meroitic period . 800 ancient and modern hafirs have been registered in
7128-579: The by-products of combustion. Oil spills at sea harm marine life and may cause fires which release toxic emissions. Around 10% of global water use goes to energy production, mainly for cooling in thermal energy plants. In dry regions, this contributes to water scarcity . Bioenergy production, coal mining and processing, and oil extraction also require large amounts of water. Excessive harvesting of wood and other combustible material for burning can cause serious local environmental damage, including desertification . Meeting existing and future energy demands in
7236-487: The climate, human health, and the economies of developing countries. Climate change mitigation pathways have been proposed to limit global warming to 2 °C (3.6 °F). These include phasing out coal-fired power plants, conserving energy , producing more electricity from clean sources such as wind and solar , and switching from fossil fuels to electricity for transport and heating buildings. Power output from some renewable energy sources varies depending on when
7344-1194: The concept of sustainability applies to energy on a global scale. Working definitions of sustainable energy encompass multiple dimensions of sustainability such as environmental, economic, and social dimensions. Historically, the concept of sustainable energy development has focused on emissions and on energy security . Since the early 1990s, the concept has broadened to encompass wider social and economic issues. The environmental dimension of sustainability includes greenhouse gas emissions , impacts on biodiversity and ecosystems, hazardous waste and toxic emissions, water consumption, and depletion of non-renewable resources. Energy sources with low environmental impact are sometimes called green energy or clean energy . The economic dimension of sustainability covers economic development, efficient use of energy, and energy security to ensure that each country has constant access to sufficient energy. Social issues include access to affordable and reliable energy for all people, workers' rights , and land rights. The current energy system contributes to many environmental problems, including climate change , air pollution, biodiversity loss ,
7452-442: The context of system-wide demands and supplies. In many countries large reservoirs are closely regulated to try to prevent or minimize failures of containment. While much of the effort is directed at the dam and its associated structures as the weakest part of the overall structure, the aim of such controls is to prevent an uncontrolled release of water from the reservoir. Reservoir failures can generate huge increases in flow down
7560-561: The dam located at the narrowest practical point to provide strength and the lowest cost of construction. In many reservoir construction projects, people have to be moved and re-housed, historical artifacts moved or rare environments relocated. Examples include the temples of Abu Simbel (which were moved before the construction of the Aswan Dam to create Lake Nasser from the Nile in Egypt ),
7668-460: The developed world Naturally occurring lakes receive organic sediments which decay in an anaerobic environment releasing methane and carbon dioxide . The methane released is approximately 8 times more potent as a greenhouse gas than carbon dioxide. As a human-made reservoir fills, existing plants are submerged and during the years it takes for this matter to decay, will give off considerably more greenhouse gases than lakes do. A reservoir in
7776-642: The development of energy-efficient infrastructure to encourage changes in transport modes . The energy intensity of the global economy (the amount of energy consumed per unit of gross domestic product (GDP)) is a rough indicator of the energy efficiency of economic production. In 2010, global energy intensity was 5.6 megajoules (1.6 kWh ) per US dollar of GDP. United Nations goals call for energy intensity to decrease by 2.6% each year between 2010 and 2030. In recent years this target has not been met. For instance, between 2017 and 2018, energy intensity decreased by only 1.1%. Efficiency improvements often lead to
7884-507: The downstream river to maintain river quality, support fisheries, to maintain downstream industrial and recreational uses or for a range of other purposes. Such releases are known as compensation water . The units used for measuring reservoir areas and volumes vary from country to country. In most of the world, reservoir areas are expressed in square kilometers; in the United States, acres are commonly used. For volume, either cubic meters or cubic kilometers are widely used, with acre-feet used in
7992-623: The energy sources with the lowest levels of greenhouse gas emissions per unit of energy produced, but levels of emissions vary enormously between projects. The highest emissions tend to occur with large dams in tropical regions. These emissions are produced when the biological matter that becomes submerged in the reservoir's flooding decomposes and releases carbon dioxide and methane. Deforestation and climate change can reduce energy generation from hydroelectric dams. Depending on location, large dams can displace residents and cause significant local environmental damage; potential dam failure could place
8100-553: The energy system each year between 2016 and 2035 to limit global warming to 1.5 °C (2.7 °F). Governments can fund the research, development, and demonstration of new clean energy technologies. They can also build infrastructure for electrification and sustainable transport. Finally, governments can encourage clean energy deployment with policies such as carbon pricing , renewable portfolio standards , and phase-outs of fossil fuel subsidies . These policies may also increase energy security . Energy
8208-399: The environment, the economy, and society. These impacts range from greenhouse gas emissions and air pollution to energy poverty and toxic waste . Renewable energy sources such as wind , hydro , solar , and geothermal energy can cause environmental damage but are generally far more sustainable than fossil fuel sources. The role of non-renewable energy sources in sustainable energy
8316-440: The environmental impacts of dams and the reservoirs that they contain. Some impacts, such as the greenhouse gas production associated with concrete manufacture, are relatively easy to estimate. Other impacts on the natural environment and social and cultural effects can be more difficult to assess and to weigh in the balance but identification and quantification of these issues is now commonly required in major construction projects in
8424-499: The first decade after flooding. This elevates the global warming impact of the dams to levels much higher than would occur by generating the same power from fossil fuels . According to the World Commission on Dams report (Dams And Development), when the reservoir is relatively large and no prior clearing of forest in the flooded area was undertaken, greenhouse gas emissions from the reservoir could be higher than those of
8532-413: The flow in highly managed systems, taking in water during high flows and releasing it again during low flows. In order for this to work without pumping requires careful control of water levels using spillways . When a major storm approaches, the dam operators calculate the volume of water that the storm will add to the reservoir. If forecast storm water will overfill the reservoir, water is slowly let out of
8640-569: The historic and sound relationship between Liverpool and Wales can be completely restored. The reservoir was built to help maintain the flow in the River Dee , so that drinking water could be abstracted further downstream as part of the Dee Regulation Scheme . These abstractions include one at Huntington water treatment works in Chester , operated by United Utilities , which supplies water to Liverpool and Wirral . The reservoir
8748-531: The historic fatality rate of nuclear is comparable to renewable sources. Public opposition to nuclear energy often makes nuclear plants politically difficult to implement. Reducing the time and the cost of building new nuclear plants have been goals for decades but costs remain high and timescales long. Various new forms of nuclear energy are in development, hoping to address the drawbacks of conventional plants. Fast breeder reactors are capable of recycling nuclear waste and therefore can significantly reduce
8856-580: The hydroelectric reservoirs there do emit greenhouse gases, it is on a much smaller scale than thermal power plants of similar capacity. Hydropower typically emits 35 to 70 times less greenhouse gases per TWh of electricity than thermal power plants. A decrease in air pollution occurs when a dam is used in place of thermal power generation, since electricity produced from hydroelectric generation does not give rise to any flue gas emissions from fossil fuel combustion (including sulfur dioxide , nitric oxide and carbon monoxide from coal ). Dams can produce
8964-432: The landscape is relatively flat. Other service reservoirs can be storage pools, water tanks or sometimes entirely underground cisterns , especially in more hilly or mountainous country. Modern reserviors will often use geomembrane liners on their base to limit seepage and/or as floating covers to limit evaporation, particularly in arid climates. In the United Kingdom, Thames Water has many underground reservoirs built in
9072-562: The line. As a result of this, Liverpool Council decided to contribute towards the cost of the new main road (the A4212 , which was built across the pass from Bala to Trawsfynydd around the north side of the lake), and also towards the cost of a line linking the two stations in Blaenau Ffestiniog . Reservoir A reservoir ( / ˈ r ɛ z ər v w ɑːr / ; from French réservoir [ʁezɛʁvwaʁ] )
9180-509: The main River Dee, the best conditions for such events occur during long dry spells in summer when maximum releases are made. Usually the dam will release between 9 and 11 m³/s, although releases as low as 2 m³/s and as high as 16 m³/s have been known. During wet weather the releases are usually throttled back to a minimal maintenance flow unless a planned release for recreational activities has been agreed. Its four turbines are owned and run by Dŵr Cymru and generate 4.38 MW The building of
9288-470: The modern use of rolled clay. The water stored in such reservoirs may stay there for several months, during which time normal biological processes may substantially reduce many contaminants and reduce turbidity . The use of bank-side reservoirs also allows water abstraction to be stopped for some time, for instance when the river is unacceptably polluted or when flow conditions are very low due to drought . The London water supply system exhibits one example of
9396-609: The new top water level exceeds the watershed height on one or more of the feeder streams such as at Llyn Clywedog in Mid Wales . In such cases additional side dams are required to contain the reservoir. Where the topography is poorly suited to forming a single large reservoir, a number of smaller reservoirs may be constructed in a chain, as in the River Taff valley where the Llwyn-on , Cantref and Beacons Reservoirs form
9504-415: The operating rules may be complex. Most modern reservoirs have a specially designed draw-off tower that can discharge water from the reservoir at different levels, both to access water as the water level falls, and to allow water of a specific quality to be discharged into the downstream river as "compensation water": the operators of many upland or in-river reservoirs have obligations to release water into
9612-428: The original streambed of the downstream river and are filled by creeks , rivers or rainwater that runs off the surrounding forested catchments, or off-stream reservoirs , which receive diverted water from a nearby stream or aqueduct or pipeline water from other on-stream reservoirs. Dams are typically located at a narrow part of a downstream of a natural basin. The valley sides act as natural walls, with
9720-485: The pollution associated with mining and transporting coal. CCS is one of the most expensive ways of reducing emissions in the energy sector. Deployment of this technology is very limited. As of 2024, CCS is used in only 5 power plants and in 39 other facilities. Nuclear power has been used since the 1950s as a low-carbon source of baseload electricity. Nuclear power plants in over 30 countries generate about 10% of global electricity. As of 2019, nuclear generated over
9828-481: The pre-flooded landscape, noting that forest lands, wetlands, and preexisting water features all released differing amounts of carbon dioxide and methane both pre- and post-flooding. The Tucuruí Dam in Brazil (completed in 1984) had only 0.4 times the impact on global warming than would generating the same power from fossil fuels. A two-year study of carbon dioxide and methane releases in Canada concluded that while
9936-525: The proportion of renewable energy in the world's energy supply. According to the International Energy Agency, renewable energy sources like wind and solar power are now a commonplace source of electricity, making up 70% of all new investments made in the world's power generation. The Agency expects renewables to become the primary energy source for electricity generation globally in the next three years, overtaking coal. The Sun
10044-437: The quality of the water and the ecology of the surrounding area. Many reservoirs now support and encourage less formal and less structured recreation such as natural history , bird watching , landscape painting , walking and hiking , and often provide information boards and interpretation material to encourage responsible use. Water falling as rain upstream of the reservoir, together with any groundwater emerging as springs,
10152-592: The release of toxins into the environment, and water scarcity. As of 2019, 85% of the world's energy needs are met by burning fossil fuels. Energy production and consumption are responsible for 76% of annual human-caused greenhouse gas emissions as of 2018. The 2015 international Paris Agreement on climate change aims to limit global warming to well below 2 °C (3.6 °F) and preferably to 1.5 °C (2.7 °F); achieving this goal will require that emissions be reduced as soon as possible and reach net-zero by mid-century. The burning of fossil fuels and biomass
10260-464: The relocation of the village of Capel Celyn during the construction of Llyn Celyn , and the relocation of Borgo San Pietro of Petrella Salto during the construction of Lake Salto . Construction of a dammed reservoir will usually require the river to be diverted during part of the build, often through a temporary tunnel or by-pass channel. In hilly regions, reservoirs are often constructed by enlarging existing lakes. Sometimes in such reservoirs,
10368-604: The reservoir also contributed to the final closure of the Great Western Railway (GWR) branch line from Bala to Blaenau Ffestiniog . Passenger trains had ceased running in 1960, and the last freight train ran in 1961. The line was subsequently flooded by the lake, and the base of the dam also crosses it. Liverpool Council had in fact planned a railway diversion, but this was never built as the British Transport Commission had decided to close
10476-638: The reservoir prior to, and during, the storm. If done with sufficient lead time, the major storm will not fill the reservoir and areas downstream will not experience damaging flows. Accurate weather forecasts are essential so that dam operators can correctly plan drawdowns prior to a high rainfall event. Dam operators blamed a faulty weather forecast on the 2010–2011 Queensland floods . Examples of highly managed reservoirs are Burrendong Dam in Australia and Bala Lake ( Llyn Tegid ) in North Wales . Bala Lake
10584-539: The same goods or services, or delivering comparable services with less goods—is a cornerstone of many sustainable energy strategies. The International Energy Agency (IEA) has estimated that increasing energy efficiency could achieve 40% of greenhouse gas emission reductions needed to fulfil the Paris Agreement's goals. Energy can be conserved by increasing the technical efficiency of appliances, vehicles, industrial processes, and buildings. Another approach
10692-462: The smallest share of the energy market. It includes OTEC , tidal power , which is approaching maturity, and wave power , which is earlier in its development. Two tidal barrage systems in France and in South Korea make up 90% of global production. While single marine energy devices pose little risk to the environment, the impacts of larger devices are less well known. Switching from coal to natural gas has advantages in terms of sustainability. For
10800-418: The surrounding population at risk. Geothermal energy is produced by tapping into deep underground heat and harnessing it to generate electricity or to heat water and buildings. The use of geothermal energy is concentrated in regions where heat extraction is economical: a combination is needed of high temperatures, heat flow, and permeability (the ability of the rock to allow fluids to pass through). Power
10908-422: The trees that were harvested are replaced by new trees in a well-managed forest, as the new trees will absorb carbon dioxide from the air as they grow. However, the establishment and cultivation of bioenergy crops can displace natural ecosystems , degrade soils , and consume water resources and synthetic fertilisers. Approximately one-third of all wood used for traditional heating and cooking in tropical areas
11016-401: The turbines can cause annoyance and constrain construction near densely populated areas. Wind power, in contrast to nuclear and fossil fuel plants, does not consume water. Little energy is needed for wind turbine construction compared to the energy produced by the wind power plant itself. Turbine blades are not fully recyclable, and research into methods of manufacturing easier-to-recycle blades
11124-499: The use of bank-side storage: here water is taken from the River Thames and River Lee into several large Thames-side reservoirs, such as Queen Mary Reservoir that can be seen along the approach to London Heathrow Airport . Service reservoirs store fully treated potable water close to the point of distribution. Many service reservoirs are constructed as water towers , often as elevated structures on concrete pillars where
11232-586: The village of Capel Celyn and adjacent farmland, a deeply controversial move. Much of the opposition was brought about because the village was a stronghold of Welsh culture and the Welsh language , whilst the reservoir was being built to supply water to Liverpool and parts of the Wirral peninsula in England, rather than Wales. Liverpool Corporation's Tryweryn Reservoir Bill was presented in Parliament as
11340-412: The water, which tends to partition some elements such as manganese and phosphorus into deep, cold anoxic water during the summer months. In the autumn and winter the lake becomes fully mixed again. During drought conditions, it is sometimes necessary to draw down the cold bottom water, and the elevated levels of manganese in particular can cause problems in water treatment plants. In 2005, about 25% of
11448-796: The wind blows and the sun shines. Switching to renewable energy can therefore require electrical grid upgrades, such as the addition of energy storage . Some processes that are difficult to electrify can use hydrogen fuel produced from low-emission energy sources. In the International Energy Agency 's proposal for achieving net zero emissions by 2050, about 35% of the reduction in emissions depends on technologies that are still in development as of 2023. Wind and solar market share grew to 8.5% of worldwide electricity in 2019, and costs continue to fall. The Intergovernmental Panel on Climate Change (IPCC) estimates that 2.5% of world gross domestic product (GDP) would need to be invested in
11556-476: The world's 33,105 large dams (over 15 metres in height) were used for hydroelectricity. The U.S. produces 3% of its electricity from 80,000 dams of all sizes. An initiative is underway to retrofit more dams as a good use of existing infrastructure to provide many smaller communities with a reliable source of energy. A reservoir generating hydroelectricity includes turbines connected to the retained water body by large-diameter pipes. These generating sets may be at
11664-614: The world's population lives with levels of air pollution that exceed the World Health Organization recommended limits. Cooking with polluting fuels such as wood, animal dung, coal, or kerosene is responsible for nearly all indoor air pollution, which causes an estimated 1.6 to 3.8 million deaths annually, and also contributes significantly to outdoor air pollution. Health effects are concentrated among women, who are likely to be responsible for cooking, and young children. Environmental impacts extend beyond
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