Renewable energy
Chapter 2 - Society
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Welcome to the Renewable energy page
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'Renewable energy' is a somewhat misleading phrase. Energy generated by solar panels etc. cannot be reused once it has been used. 'Renewable energy' is energy that comes from a source that won’t run out. They are natural and self-replenishing, and most important, have a low entropy level. The bottom line is: the closer the primary energy is captured to our primary energy source, the sun, the better.
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Core ideas
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Sources of low entropy energy
Intermittent (solar, wind, tidal, wave) electricity
Intermittent electricity is electrical energy that is not continuously available due to external factors that cannot be controlled, produced by electricity generating sources that vary in their conditions on a fairly short time scale. Sources of intermittent electricity include solar power, wind power, tidal power, and wave power. Although solar and tidal power are fairly predictable (length of days, weather patterns, tidal cycles), they are still intermittent because the time period that electricity can be created is limited. Because of this varying electrical generation these sources are considered non-dispatchable, meaning that their electrical output cannot be used at any given time to meet societies fluctuating electricity demands.
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Hydropower
Hydropower extracts mechanical energy from water, transforming it into electrical energy to generate electricity. Water in the environment often has both gravitational potential energy and kinetic energy, which can generate electricity using a generator. Note that traditionally this does not refer to the energy obtained from flowing water in the form of tides. In the case of obtaining energy from the tides, the term tidal power is used. The amount of potential energy stored in a body of water at a hydroelectric dam is measured using the height difference between the head race and tail race, known as the elevation head (part of the hydraulic head).
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Geothermal energy
Geothermal energy is energy that is extracted from thermal sources that originate deep underground. Geothermal energy is a form of primary energy. It can be used directly for heat or to create electricity. Deep underground, the Earth will remain hot for billions of years, so geothermal energy can be used for a long time (as a renewable energy source), but if the resource is not treated carefully, it will not be sustainable.
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Energy sources with low CO2 emissions
Bioenergy
Electricity can be generated when organic matter is burned as a fuel source. These fuels are known as biomass and include anything from plants to timber to food waste. Carbon dioxide (CO2) is emitted when bioenergy is made, but these fuel sources are considered renewable because they can be regrown and absorb as much carbon as they emit across their lifespans.
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Nuclear energy
First, almost all forms of primary energy come from nuclear reactions. Fossil fuels and biofuels got their energy from sunlight. Geothermal energy comes from radioactive decay or thermal energy left over from when the Earth originally formed (which came from a cataclysmic nuclear explosion, a supernova). Of course, nuclear reactors ultimately get their energy from nuclei.
In power plants, nuclear power is harnessed from isotopes of large elements such as uranium, thorium, and plutonium as fuel in nuclear fission reactors. The uranium and thorium isotopes occur naturally and are mined from rock. Using uranium in a nuclear reactor can make plutonium, which can also be burned in nuclear reactors. The energy coming from the nuclei can be used to heat a liquid or gas to run turbines in a nuclear power plant, producing electricity.
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Deep dive
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| Electricity Maps |
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| Climate Impact by Area - Ranked by carbon intensity of electricity consumed (gCO₂eq/kWh) |
| https://app.electricitymaps.com/map |
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Do you want to know more?
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| Executive summary Renewable Energy | |
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| 2024 | Global renewable capacity is expected to grow by 2.7 times by 2030, surpassing countries’ current ambitions by nearly 25%, but it still falls short of tripling. Climate and energy security policies in nearly 140 countries have played a crucial role in making renewables cost-competitive with fossil-fired power plants. This is unlocking new demand from the private sector and households, while industrial policies that encourage local manufacturing of solar panels and wind turbines are fostering domestic markets. However, this is not quite sufficient to reach the goal of tripling renewable energy capacity worldwide established by nearly 200 countries at the COP28 climate summit.
Considering existing policies and market conditions, our main case sees 5 500 gigawatts (GW) of new renewable capacity becoming operational by 2030. This implies that global renewable capacity additions will continue to increase every year, reaching almost 940 GW annually by 2030 – 70% more than the record level achieved last year. Solar PV and wind together account for 95% of all renewable capacity growth through the end of this decade due their growing economic attractiveness in almost all countries. |
| https://www.iea.org/reports/renewables-2024 | |
| 2023 | Global annual renewable capacity additions increased by almost 50% to nearly 510 gigawatts (GW) in 2023, the fastest growth rate in the past two decades. This is the 22nd year in a row that renewable capacity additions set a new record. While the increases in renewable capacity in Europe, the United States and Brazil hit all-time highs, China’s acceleration was extraordinary. In 2023, China commissioned as much solar PV as the entire world did in 2022, while its wind additions also grew by 66% year-on-year. Globally, solar PV alone accounted for three-quarters of renewable capacity additions worldwide.
Under existing policies and market conditions, global renewable capacity is forecast to reach 7 300 GW by 2028. This growth trajectory would see global capacity increase to 2.5 times its current level by 2030, falling short of the tripling goal. Governments can close the gap to reach over 11 000 GW by 2030 by overcoming current challenges and implementing existing policies more quickly. These challenges fall into four main categories and differ by country: 1) policy uncertainties and delayed policy responses to the new macroeconomic environment; 2) insufficient investment in grid infrastructure preventing faster expansion of renewables; 3) cumbersome administrative barriers and permitting procedures and social acceptance issues; 4) insufficient financing in emerging and developing economies. This report’s accelerated case shows that addressing those challenges can lead to almost 21% higher growth of renewables, pushing the world towards being on track to meet the global tripling pledge. |
| https://www.iea.org/reports/renewables-2023 |
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