Open main menu

Portal:Renewable energy

Introduction

Wind, solar, and hydroelectricity[how?] are three emerging renewable sources of energy.

Renewable energy is energy that is collected from renewable resources, which are naturally replenished on a human timescale, such as sunlight, wind, rain, tides, waves, and geothermal heat. Renewable energy often provides energy in four important areas: electricity generation, air and water heating/cooling, transportation, and rural (off-grid) energy services.

Based on REN21's 2017 report, renewables contributed 19.3% to humans' global energy consumption and 24.5% to their generation of electricity in 2015 and 2016, respectively. This energy consumption is divided as 8.9% coming from traditional biomass, 4.2% as heat energy (modern biomass, geothermal and solar heat), 3.9% hydro electricity and 2.2% is electricity from wind, solar, geothermal, and biomass. Worldwide investments in renewable technologies amounted to more than US$286 billion in 2015, with countries such as China and the United States heavily investing in wind, hydro, solar and biofuels. Globally, there are an estimated 7.7 million jobs associated with the renewable energy industries, with solar photovoltaics being the largest renewable employer. As of 2015 worldwide, more than half of all new electricity capacity installed was renewable.

Renewable energy resources 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 is resulting in significant energy security, climate change mitigation, and economic benefits. The results of a recent review of the literature concluded that as greenhouse gas (GHG) emitters begin to be held liable for damages resulting from GHG emissions resulting in climate change, a high value for liability mitigation would provide powerful incentives for deployment of renewable energy technologies. In international public opinion surveys there is strong support for promoting renewable sources such as solar power and wind power.

At the national level, at least 30 nations around the world already have renewable energy contributing more than 20 percent of energy supply. National renewable energy markets are projected to continue to grow strongly in the coming decade and beyond. Some places and at least two countries, Iceland and Norway generate all their electricity using renewable energy already, and many other countries have the set a goal to reach 100% renewable energy in the future. For example, in Denmark the government decided to switch the total energy supply (electricity, mobility and heating/cooling) to 100% renewable energy by 2050. At least 47 nations around the world already have over 50 percent of electricity from renewable resources, with Iceland generating all its electrical power from renewable energy though this does not include non-electrical energy (e.g. transport and heating).

While many renewable energy projects are large-scale, renewable technologies are also suited to rural and remote areas and developing countries, where energy is often crucial in human development. Former United Nations Secretary-General Ban Ki-moon has said that renewable energy has the ability to lift the poorest nations to new levels of prosperity. As most of renewables provide electricity, renewable energy deployment is often applied in conjunction with further electrification, which has several benefits: Electricity can be converted to heat (where necessary generating higher temperatures than fossil fuels), can be converted into mechanical energy with high efficiency and is clean at the point of consumption. In addition to that electrification with renewable energy is much more efficient and therefore leads to a significant reduction in primary energy requirements, because most renewables do not have a steam cycle with high losses (fossil power plants usually have losses of 40 to 65%).

Renewable energy systems are rapidly becoming more efficient and cheaper and their share of total energy consumption is increasing. Global installed electricity generating capacity in 2017 was 2.2 TW. Growth in consumption of coal and oil could end by 2020 due to increased uptake of renewables and natural gas.

Selected article

A mandatory renewable energy target is a government legislated requirement on electricity retailers to source specific proportions of total electricity sales from renewable energy sources according to a fixed timeframe. The additional cost is distributed across most customers by increases in other tariffs. The cost of this measure is therefore not funded by government budgets, except for costs of establishing and monitoring the scheme and any audit and enforcement actions.

At least 66 countries, including 27 EU countries have renewable energy policy targets of some type. The EU baseline target is 20% by 2020. While the USA does not have a national RET, 29 of its states do. Similarly Canada has 9 state RETs but no national target. Targets are typically for shares of electricity production, but some are defined as by primary energy supply, installed capacity or otherwise. While some targets are based on 2010-12, many are now for 2020 which ties in with the IPCC suggested greenhouse gas emission cuts of 25 to 40% by Annex I countries by 2020, although some are for 2025.

Read more...

Selected image

View of the solar energy dish at the Ben-Gurion National Solar Energy Center in Israel.
The world's largest solar energy dish at the Ben-Gurion National Solar Energy Center in Sde Boker, Israel.

Selected biography

Ben-122.JPG

Benjamin K. Sovacool is Director of the Danish Center for Energy Technology at AU Herning and a Professor of Social Sciences at Aarhus University in Denmark. He is also Associate Professor at Vermont Law School and Director of the Energy Security and Justice Program at their Institute for Energy and the Environment. Sovacool's research interests include energy policy, environmental issues, and science and technology policy, and his research has taken him to 50 countries. He is the author or editor of sixteen books and 250 peer reviewed academic articles. Sovacool's work has been referred to in academic publications such as Science, Nature, and Scientific American. He has written opinion editorials for the Wall Street Journal and the San Francisco Chronicle. Sovacool is a Intergovernmental Panel on Climate Change Contributing Author.

Read More...

Did you know?

... that Selling Solar: The Diffusion of Renewable Energy in Emerging Markets, a 2009 Earthscan book by Damian Miller, argues that in order to solve the climate crisis, the world must immediately and dramatically accelerate the commercialization of renewable energy technology ? This needs to happen in the industrialized world, as well as in the emerging markets of the developing world where most future GHG emissions will occur.

WikiProjects

News

Quotations

  • "The sun provides more energy in one hour than all humanity uses, in all forms, in a single year. Sunlight can provide us with its own resolution to our energy problems. The only transformation required is for humanity to reduce, or end, consumption of stored solar (as fossil fuels) and, in its place, use freely available 'fresh' solar". – David S. Findley (2010). Solar power for your home, p.12.

Related portals


Associated Wikimedia

The following Wikimedia Foundation sister projects provide more on this subject:

Wikibooks
Books

Commons
Media

Wikinews 
News

Wikiquote 
Quotations

Wikisource 
Texts

Wikiversity
Learning resources

Wiktionary 
Definitions

Wikidata 
Database

Wikispecies 
Species