Renewable energy is energy from renewable natural resources that are replenished on a human timescale. The most widely used renewable energy types are solar energy, wind power, and hydropower. Bioenergy and geothermal power are also significant in some countries. Some also consider nuclear power a renewable power source, although this is controversial. Renewable energy installations can be large or small and are suited for both urban and rural areas. Renewable energy is often deployed together with further electrification. This has several benefits: electricity can move heat and vehicles efficiently and is clean at the point of consumption. Variable renewable energy sources are those that have a fluctuating nature, such as wind power and solar power. In contrast, controllable renewable energy sources include dammed hydroelectricity, bioenergy, or geothermal power.
Energy development is the field of activities focused on obtaining sources of energy from natural resources. These activities include the production of renewable, nuclear, and fossil fuel derived sources of energy, and for the recovery and reuse of energy that would otherwise be wasted. Energy conservation and efficiency measures reduce the demand for energy development, and can have benefits to society with improvements to environmental issues.
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 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.
Renewable energy commercialization involves the deployment of three generations of renewable energy technologies dating back more than 100 years. First-generation technologies, which are already mature and economically competitive, include biomass, hydroelectricity, geothermal power and heat. Second-generation technologies are market-ready and are being deployed at the present time; they include solar heating, photovoltaics, wind power, solar thermal power stations, and modern forms of bioenergy. Third-generation technologies require continued R&D efforts in order to make large contributions on a global scale and include advanced biomass gasification, hot-dry-rock geothermal power, and ocean energy. In 2019, nearly 75% of new installed electricity generation capacity used renewable energy and the International Energy Agency (IEA) has predicted that by 2025, renewable capacity will meet 35% of global power generation.
For solar power, South Asia has the ideal combination of both high solar insolation and a high density of potential customers.
The developing nations of Africa are popular locations for the application of renewable energy technology. Currently, many nations already have small-scale solar, wind, and geothermal devices in operation providing energy to urban and rural populations. These types of energy production are especially useful in remote locations because of the excessive cost of transporting electricity from large-scale power plants. The applications of renewable energy technology has the potential to alleviate many of the problems that face Africans every day, especially if done in a sustainable manner that prioritizes human rights.
Low-carbon electricity or low-carbon power is electricity produced with substantially lower greenhouse gas emissions over the entire lifecycle than power generation using fossil fuels. The energy transition to low-carbon power is one of the most important actions required to limit climate change.
The renewable-energy industry is the part of the energy industry focusing on new and appropriate renewable energy technologies. Investors worldwide are increasingly paying greater attention to this emerging industry. In many cases, this has translated into rapid renewable energy commercialization and considerable industry expansion. The wind power, solar power and hydroelectric power industries provide good examples of this.
Renewable energy in developing countries is an increasingly used alternative to fossil fuel energy, as these countries scale up their energy supplies and address energy poverty. Renewable energy technology was once seen as unaffordable for developing countries. However, since 2015, investment in non-hydro renewable energy has been higher in developing countries than in developed countries, and comprised 54% of global renewable energy investment in 2019. The International Energy Agency forecasts that renewable energy will provide the majority of energy supply growth through 2030 in Africa and Central and South America, and 42% of supply growth in China.
Mandatory renewable energy targets are part of government legislated schemes which require electricity merchandisers to source-specific amounts of aggregate electricity sales from renewable energy sources according to a fixed time frame. The objective of these schemes is to promote renewable energy and decrease dependency on fossil fuels. If this results in an additional expenditure of electricity, the additional cost is distributed across most customers by increases in other tariffs. The cost of this measure is therefore not funded by the government budgets, except for costs of establishing and monitoring the scheme and any audit and enforcement actions. As the cost of renewable energy has become cheaper than other sources, meeting and exceeding a renewable energy target will also reduce the expenditure of electricity to consumers.
100% renewable energy is the goal of the use renewable resources for all energy. 100% renewable energy for electricity, heating, cooling and transport is motivated by climate change, pollution and other environmental issues, as well as economic and energy security concerns. Shifting the total global primary energy supply to renewable sources requires a transition of the energy system, since most of today's energy is derived from non-renewable fossil fuels.
Policy makers often debate the constraints and opportunities of renewable energy.
Renewable energy is generally defined as energy that comes from resources which are naturally replenished on a human timescale, such as sunlight, wind, rain, tides, waves, and geothermal heat. Renewable energy replaces conventional fuels in four distinct areas: electricity generation, air and water heating/cooling, motor fuels, and rural (off-grid) energy services. Based on REN21's 2014 report, renewables contributed 19 percent to our global energy consumption and 22 percent to our electricity generation in 2012 and 2013, respectively.
Energy in Sweden is characterized by relatively high per capita production and consumption, and a reliance on imports for fossil fuel supplies.
Most of Kenya's electricity is generated by renewable energy sources. Access to reliable, affordable, and sustainable energy is one of the 17 main goals of the United Nations’ Sustainable Development Goals. Development of the energy sector is also critical to help Kenya achieve the goals in Kenya Vision 2030 to become a newly industrializing, middle-income country. With an installed power capacity of 2,819 MW, Kenya currently generates 826 MW hydroelectric power, 828 geothermal power, 749 MW thermal power, 331 MW wind power, and the rest from solar and biomass sources. Kenya is the largest geothermal energy producer in Africa and also has the largest wind farm on the continent. In March 2011, Kenya opened Africa's first carbon exchange to promote investments in renewable energy projects. Kenya has also been selected as a pilot country under the Scaling-Up Renewable Energy Programmes in Low Income Countries Programme to increase deployment of renewable energy solutions in low-income countries. Despite significant strides in renewable energy development, about a quarter of the Kenyan population still lacks access to electricity, necessitating policy changes to diversify the energy generation mix and promote public-private partnerships for financing renewable energy projects.
Ethiopia generates most of its electricity from renewable energy, mainly hydropower.
Renewable energy in Mexico contributes to 26 percent of electricity generation in Mexico. As of 2009, electricity generation from renewable energy comes from biomass, hydro power, geothermal, solar power and wind. There is a long term effort established to increase the use of renewable energy sources. The amount of geothermal energy used and harvested, places Mexico as number four in the world.
Renewables supply a quarter of energy in Turkey, including heat and electricity. Some houses have rooftop solar water heating, and hot water from underground warms many spas and greenhouses. In parts of the west hot rocks are shallow enough to generate electricity as well as heat. Wind turbines, also mainly near western cities and industry, generate a tenth of Turkey’s electricity. Hydropower, mostly from dams in the east, is the only modern renewable energy which is fully exploited. Hydropower averages about a fifth of the country's electricity, but much less in drought years. Apart from wind and hydro, other renewables; such as geothermal, solar and biogas; together generated almost a tenth of Turkey’s electricity in 2022. Over half the installed capacity for electricity generation is renewables.
Renewable energy in South Africa is energy generated in South Africa from renewable resources, those that naturally replenish themselves—such as sunlight, wind, tides, waves, rain, biomass, and geothermal heat. Renewable energy focuses on four core areas: electricity generation, air and water heating/cooling, transportation, and rural energy services. The energy sector in South Africa is an important component of global energy regimes due to the country's innovation and advances in renewable energy. South Africa's greenhouse gas (GHG) emissions is ranked as moderate and its per capita emission rate is higher than the global average. Energy demand within the country is expected to rise steadily and double by 2025.
