The exploding global population and climate change are fueling a renewable energy revolution. Renewables offer a way to decrease dependence on fossil fuels and sustainably support economic development.
Learn about solar, wind, hydroelectric, biomass, biofuels, geothermal and tidal energy. Also, consider incorporating energy efficiency measures into your home design to reduce electricity use.
What is Renewable Energy?
Frequently referred to as green or clean energy, renewables utilize fuel sources that replenish themselves within a human timescale. These sources encompass sunlight, wind, moving water, organic plant and waste material (recognized as eligible biomass), and the Earth’s heat (geothermal). The generation of electricity from these sources occurs without emitting harmful substances. Nevertheless, certain renewables involve environmental trade-offs, such as clearing natural habitats for hydroelectric dams and extracting fossil fuels.
Solar and wind energy, on the contrary, present no such trade-offs. They can be harnessed freely to generate power, and if integrated with a home battery storage system, they can operate even without wind or sunlight. In addition to their environmental benefits, renewables are crucial in diminishing our reliance on nonrenewable fossil fuels, contributing to environmental damage and global warming.
Regarding the query “what are renewable energy systems,” these systems harness naturally replenishing resources like sunlight, wind, water, organic matter, and the Earth’s heat to generate electricity without harmful emissions.
Radiant light and heat from the Sun are known as solar energy, and they can be used to generate electricity or heat water (like solar water heating). Unlike fossil resources like coal, oil, and natural gas, which take millions of years to replenish, solar energy is an endless resource.
Sunlight hitting silicon solar cells knocks electrons loose to create an electric current. This current flows through wires and is transformed into alternating current, which powers homes, businesses, and the national electric grid. Solar power can also be stored in a battery or sold back to the electric grid for credits on your bill.
Learn how to harness the power of the Sun, discover cutting-edge wind energy technology, and discover innovative ocean and geothermal energy sources in this book that paints a picture of a future powered by renewables. With expert contributors, fascinating narratives, and stunning visuals, this is a must-have for anyone interested in the clean energy revolution.
The wind is a powerful and natural energy source constantly replenishing, unlike fossil fuels, which require millions of years to be replaced. Its power can be harnessed by wind turbine technology to produce electricity without the emissions and pollution associated with burning fossil fuels.
Wind-powered electricity is becoming increasingly popular in homes, businesses, and power plants nationwide. Wind and solar energy can stand alone or be connected to the grid, which allows homeowners who produce more power than they use to sell the surplus back to their utility providers.
People have been harnessing the power of the wind for thousands of years. From Egyptians using sails to propel boats along the Nile River to the Dutch draining wetlands and grinding grain with vertical-axis windmills to farmers pumping water for crops and cutting wood at sawmills today. The basic principle of wind energy is simple: Wind turbine blades catch the kinetic energy of air currents and turn that energy into mechanical energy, which then powers a generator to create electricity. Either utilize the energy immediately or store it in a battery for later.
Biofuels are fuels made from plants and other renewable materials that can be produced over time. They act similarly to fossil fuels, such as oil and coal, but produce significantly fewer greenhouse gas emissions when burned.
The most commonly used liquid biofuels are fuel ethanol and vegetable oil-based biodiesel. The former is produced from corn, wheat, soybeans, and other oil-producing plants. The latter is frequently mixed in different ratios with petroleum diesel fuel and is produced from recycled animal fat and other greasy waste materials. Research is ongoing for third-generation biofuels derived from algae and other plants with high natural oil content.
When produced and used as intended, biofuels have low lifecycle greenhouse gas (GHG) emissions and can significantly reduce GHG emissions over current fuel mixes. However, producing some biofuels requires large amounts of land and water, which can have unintended environmental impacts, including biodiversity loss and deforestation. EERE supports the development of policies that increase renewable energy use and reduce GHG emissions. These include requiring a percentage of renewable energy, encouraging vehicles that run on alternative fuels, and promoting strategies like public transportation, carpooling, and telecommuting.
Geothermal energy produces electricity by harnessing heat from the Earth’s core. It is constantly available and combines the thermal energy from the planet’s original formation and radioactive decay.
The hot molten rock (magma) deep within the Earth heats underground layers of water and rocks, and some of this warmth rises to the surface as lava or steam. This is the source of many geothermal power plants, especially in the Ring of Fire, where volcanic eruptions and earthquakes occur regularly.
Power plants tap into the Earth’s geothermal energy by drilling deep wells to extract heated water or steam. They then run that fluid through turbines to generate electricity.
Some countries, like Iceland, use geothermal energy for nearly all their electricity needs. Geothermal energy is also used in direct-use applications, such as heating public buildings and keeping ice-covered sidewalks clear in cold climates.