Renewable Energy Ppt Free Download
Sebrina Trottier
The National Renewable Energy Laboratory (NREL) is transforming energy through research, development, commercialization, and deployment of renewable energy and energy efficiency technologies.
Renewable energy is energy from renewable resources that are naturally replenished on a human timescale. Renewable resources include sunlight, wind, the movement of water, and geothermal heat.[2][3] Although most renewable energy sources are sustainable, some are not. For example, some biomass sources are considered unsustainable at current rates of exploitation.[4][5] Renewable energy is often used for electricity generation, heating and cooling. Renewable energy projects are typically large-scale, but they are also suited to rural and remote areas and developing countries, where energy is often crucial in human development.[6][7]
Renewable energy is often deployed together with further electrification, which has several benefits: electricity can move heat or objects efficiently, and is clean at the point of consumption.[8][9] From 2011 to 2021, renewable energy grew from 20% to 28% of global electricity supply. Use of fossil energy shrank from 68% to 62%, and nuclear from 12% to 10%. The share of hydropower decreased from 16% to 15% while power from sun and wind increased from 2% to 10%. Biomass and geothermal energy grew from 2% to 3%. There are 3,146 gigawatts installed in 135 countries, while 156 countries have laws regulating the renewable energy sector.[10] [11] In 2021, China accounted for almost half of the global increase in renewable electricity.[12]
Globally there are over 10 million jobs associated with the renewable energy industries, with solar photovoltaics being the largest renewable employer.[13] Renewable energy systems are rapidly becoming more efficient and cheaper and their share of total energy consumption is increasing,[14] with a large majority of worldwide newly installed electricity capacity being renewable.[15] In most countries, photovoltaic solar or onshore wind are the cheapest new-build electricity.[16]
Renewable energy resources exist over wide geographical areas, in contrast to fossil fuels, which are concentrated in a limited number of countries. Deployment of renewable energy and energy efficiency technologies is resulting in significant energy security, climate change mitigation, and economic benefits.[24] However renewables are being hindered by hundreds of billions of dollars of fossil fuel subsidies.[25] In international public opinion surveys there is strong support for renewables such as solar power and wind power.[26][27] In 2022 the International Energy Agency asked countries to solve policy, regulatory, permitting and financing obstacles to adding more renewables, to have a better chance of reaching net zero carbon emissions by 2050.[28]
Renewable energy is derived from natural processes that are replenished constantly. In its various forms, it derives directly from the sun, or from heat generated deep within the earth. Included in the definition is electricity and heat generated from solar, wind, ocean, hydropower, biomass, geothermal resources, and biofuels and hydrogen derived from renewable resources.
Renewable energy stands in contrast to fossil fuels, which are being used far more quickly than they are being replenished. Renewable energy resources and significant opportunities for energy efficiency exist over wide geographical areas, in contrast to other energy sources, which are concentrated in a limited number of countries. Rapid deployment of renewable energy and energy efficiency, and technological diversification of energy sources, would result in significant energy security and economic benefits.[24] Solar and wind power have got much cheaper.[31] In some cases it will be cheaper to transition to these sources as opposed to continuing to use the current, inefficient, fossil fuels. In addition, electrification with renewable energy is more efficient and therefore leads to significant reductions in primary energy requirements.[32][clarification needed]It would also reduce environmental pollution such as air pollution caused by the burning of fossil fuels, and improve public health, reduce premature mortalities due to pollution and save associated health costs that could amount to trillions of dollars annually.[33][34] Multiple analyses of decarbonization strategies have found that quantified health benefits can significantly offset the costs of implementing these strategies.[35][36]
Climate change concerns, coupled with the continuing fall in the costs of some renewable energy equipment, such as wind turbines and solar panels, are driving increased use of renewables.[26] New government spending, regulation and policies helped the industry weather the global financial crisis better than many other sectors.[37] As of 2019[update], however, according to the International Renewable Energy Agency, renewables overall share in the energy mix (including power, heat and transport) needs to grow six times faster, in order to keep the rise in average global temperatures "well below" 2.0 C (3.6 F) during the present century, compared to pre-industrial levels.[38]
According to the research, a nation must reach a certain point in its growth before it can take use of more renewable energy. In our words, its addition changed how crucial input factors (labor and capital) connect to one another, lowering their overall elasticity and increasing the apparent economies of scale.[41] United Nations' eighth Secretary-General Ban Ki-moon has said that renewable energy has the ability to lift the poorest nations to new levels of prosperity.[42] At the national level, at least 30 nations around the world already have renewable energy contributing more than 20% of energy supply.[43] Although many countries have various policy targets for longer-term shares of renewable energy these tend to be only for the power sector,[44] including a 40% target of all electricity generated for the European Union by 2030.[45]
More than a quarter of electricity is generated from renewables as of 2021.[47] One of the efforts to decarbonize transportation is the increased use of electric vehicles (EVs).[48] Despite that and the use of biofuels, such as biojet, less than 4% of transport energy is from renewables.[49] Occasionally hydrogen fuel cells are used for heavy transport.[50]
Heat pumps provide both heating and cooling, and also flatten the electric demand curve and are thus an increasing priority.[52] Renewable thermal energy is also growing rapidly.[53] About 10% of heating and cooling energy is from renewables.[47]
Solar energy, radiant light and heat from the sun, is harnessed using a range of ever-evolving technologies such as solar heating, photovoltaics, concentrated solar power (CSP), concentrator photovoltaics (CPV), solar architecture and artificial photosynthesis.[59][60] Most new renewable energy is solar.[61] Solar technologies are broadly characterized as either passive solar or active solar depending on the way they capture, convert, and distribute solar energy. Passive solar techniques include orienting a building to the Sun, selecting materials with favorable thermal mass or light dispersing properties, and designing spaces that naturally circulate air. Active solar technologies encompass solar thermal energy, using solar collectors for heating, and solar power, converting sunlight into electricity either directly using photovoltaics (PV), or indirectly using concentrated solar power (CSP).
A photovoltaic system converts light into electrical direct current (DC) by taking advantage of the photoelectric effect.[62] Solar PV has turned into a multi-billion, fast-growing industry, continues to improve its cost-effectiveness, and has the most potential of any renewable technologies together with CSP.[63][64] Concentrated solar power (CSP) systems use lenses or mirrors and tracking systems to focus a large area of sunlight into a small beam. Commercial concentrated solar power plants were first developed in the 1980s. CSP-Stirling has by far the highest efficiency among all solar energy technologies.
In 2011, the International Energy Agency said that "the development of affordable, inexhaustible and clean solar energy technologies will have huge longer-term benefits. It will increase countries' energy security through reliance on an indigenous, inexhaustible and mostly import-independent resource, enhance sustainability, reduce pollution, lower the costs of mitigating climate change, and keep fossil fuel prices lower than otherwise. These advantages are global. Hence the additional costs of the incentives for early deployment should be considered learning investments; they must be wisely spent and need to be widely shared".[59] Solar power accounts for 505 GW annually, which is about 2% of the world's electricity. Solar energy can be harnessed anywhere that receives sunlight; however, the amount of solar energy that can be harnessed for electricity generation is influenced by weather conditions, geographic location and time of day.[65]
According to chapter 6 of the IPCC 2022 climate mitigation report, the global potential of direct solar energy far exceeds that of any other renewable energy resource. It is well beyond the total amount of energy needed in order to support mitigation over the current century.[48] Australia has the largest proportion of solar electricity in the world, supplying 9.9% of the country's electrical demand in 2020.[66] More than 30 per cent of Australian households now have rooftop solar PV, with a combined capacity exceeding 11 GW.[67]
There are, however, environmental implications of scaling up solar energy. In particular, the demand for raw materials such as aluminum poses concerns over the carbon footprint that will result from harvesting raw materials needed to implement solar energy.[68]
PV uses solar cells assembled into solar panels to convert sunlight into electricity. PV systems range from small, residential and commercial rooftop or building integrated installations, to large utility-scale photovoltaic power station. The predominant PV technology is crystalline silicon, while thin-film solar cell technology accounts for about 10 percent of global photovoltaic deployment. In recent years, PV technology has improved its electricity generating efficiency, reduced the installation cost per watt as well as its energy payback time, and reached grid parity.[72]
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