Renewable energy
Renewable energy is usable energy derived from renewable resources that regenerate naturally within a human timescale, including carbon-neutral sources such as sunlight, wind, rain, tides, waves, and geothermal energy. This type of energy source contrasts with fossil fuels, which are consumed much faster than they can be replenished. While most renewable energy sources are sustainable, some, such as biomass, are not.
The website you were looking for isn't displayed? We're sorry about that. We're currently revising the content.
Renewable energy sources often provide energy in four key areas: electricity generation, heating/cooling of air and water, transport, and rural (off-grid) energy services.
According to the 2017 REN21 report, renewable energy sources contributed 19.3% to global human energy consumption and 24.5% to electricity generation in 2015 and 2016. This energy consumption was broken down as follows: 8.9% from traditional biomass, 4.2% as thermal energy (modern biomass, geothermal, and solar thermal), 3.9% from hydropower, and the remaining 2.2% as electricity from wind, solar, geothermal, and other forms of biomass. In 2017, global investment in renewable energy totaled US$279.8 billion, with China accounting for 45% of global investment, and the United States and Europe each contributing approximately 15%. Globally, there were an estimated 10.5 million jobs in the renewable energy sector, with photovoltaics being the largest employer. Renewable energy systems are becoming increasingly efficient and cost-effective, and their share of total energy consumption is growing. From 2019 onwards, more than two-thirds of the world's newly installed electricity capacity was renewable. Growth in coal and oil consumption could end by 2020 due to the increasing use of renewable energies and natural gas. From 2020 onwards, photovoltaics and onshore wind power are the most cost-effective forms of constructing new power generation facilities in most countries.
At the national level, renewable energy already contributes more than 20 percent to the energy supply in at least 30 countries worldwide. National renewable energy markets are projected to continue growing strongly in the coming decade and beyond. At least two countries, Iceland and Norway, already generate all their electricity from renewable sources, and many others have set targets of using 100% renewable energy in the future. In at least 47 countries, more than 50% of electricity already comes from renewable resources. Renewable energy resources are distributed across wide geographical areas, unlike fossil fuels, which are found in only a limited number of countries. The rapid deployment of renewable energy technologies and energy efficiency measures will lead to significant energy security, climate protection, and economic benefits. International opinion polls strongly support the promotion of renewable energy sources such as solar and wind power.
While many renewable energy projects are large-scale, renewable technologies are also suitable for rural and remote areas and developing countries, where energy is often crucial for human development. Since most renewable energy technologies generate electricity, their use is often combined with further electrification, which offers several advantages: electricity can be converted into heat, can be converted into mechanical energy with high efficiency, and is clean at the point of consumption.
In 2017, global investments in renewable energy amounted to US$279.8 billion, with China accounting for US$126.6 billion, or 45% of global investment. According to researcher Dr. Cornelia Tremann, “China is now the world’s largest investor, producer, and consumer of renewable energy, manufacturing state-of-the-art solar panels, wind turbines, and hydroelectric power plants,” and is also the world’s largest producer of electric cars and buses.
Solar energy
Solar energy, that is, the light and heat radiation emitted by the sun, is harnessed using a range of constantly evolving technologies, such as solar thermal energy, photovoltaics, concentrated solar power (CSP), concentrator photovoltaics (CPV), solar architecture, and artificial photosynthesis. Solar technologies are generally referred to as passive or active solar techniques, depending on how they capture, convert, and distribute solar energy. Passive solar techniques include orienting a building towards the sun, selecting materials with favorable thermal mass or light-diffusing properties, and designing spaces with natural air circulation. Active solar technologies include solar thermal energy, which uses solar collectors for heating, and solar energy, which converts sunlight into electricity either directly through photovoltaics (PV) or indirectly through concentrated solar power (CSP).
A photovoltaic system converts light into direct current electricity by utilizing the photoelectric effect. Photovoltaics has become a rapidly growing, multi-billion-dollar industry, continuously improving its cost-efficiency and, along with concentrated solar power (CSP), holds the greatest potential among renewable energy technologies. Concentrated solar power (CSP) systems use lenses or mirrors and tracking systems to focus a large area of sunlight into a narrow beam. Commercial concentrated solar power plants were first developed in the 1980s. CSP Stirling has by far the highest efficiency of all solar energy technologies.
In 2011, the International Energy Agency stated that “the development of affordable, inexhaustible, and clean solar energy technologies will bring enormous long-term benefits. It will increase countries’ energy security by providing access to a domestic, inexhaustible, and largely import-independent resource; improve sustainability; reduce pollution; lower the costs of mitigating climate change; and keep fossil fuel prices lower than they would otherwise be. These benefits are global. Therefore, the additional costs incurred by incentivizing early adoption should be viewed as learning investments; they must be used wisely and distributed widely.” Australia has the largest share of solar power in the world; in 2020, solar energy met 9.9% of its electricity demand.
REN21
REN21 (Renewable Energy Policy Network for the 21st Century) is a think tank and multi-stakeholder governance group focused on renewable energy policy.
The goal of REN21 is to promote policy development, knowledge exchange, and joint action for a rapid global transition to renewable energy. REN21 brings together governments, non-governmental organizations, research and higher education institutions, international organizations, and industry to learn from each other and accelerate the adoption of renewable energy.
To support policy decision-making, REN21 provides information, stimulates discussions and debates, and supports the development of thematic networks. REN21 facilitates the collection of information on renewable energy. This is achieved through six products: the Global Renewable Energy Status Report (GSR), regional status reports, global futures reports (GFR), thematic reports, the REN21 Renewables Academy, and the International Renewable Energy Conference (IREC) series.
The REN21 Secretariat is based at UN Environment in Paris, France, and is a registered non-profit association under German law (e.V.). The organization has more than 65 member organizations (as of 2019).
REN21 was founded in June 2004 as a result of the International Conference on Renewable Energy in Bonn, Germany. Paul Hugo Suding was the first Executive Secretary when REN21 was founded in 2006. He was succeeded by Virginia Sonntag O'Brien (2008-2011), Christine Lins (2011-2018) and Rana Adib (2018-present).