Category: Alternative Energy
Fossil Fuels: What They Are and Why They’re Running Out
Fossil fuels (oil, coal and natural gas) are energy sources formed over millions of years from the remains of living organisms. They are non-renewable resources because they are consumed much faster than nature can replenish them. In 2025 they supplied about 86% of the world’s total energy supply (Energy Institute, 2026), and their CO2 emissions…
Natural Gas: What It Is, How It Forms and Its Uses
Natural gas is a fossil fuel made up mainly of methane (CH4) that formed over millions of years from buried organic remains. In 2024 it supplied about 22% of the world’s electricity, according to Ember, and demand for it grew 2.7% that year (IEA 2025). What exactly is natural gas, how does it form, and…
Coal: What It Is, Types, Uses and Environmental Impact
Coal is a combustible, carbon-rich sedimentary rock formed over millions of years from buried plant remains. It was the world’s largest source of electricity in 2024 (about 34%, according to Ember) and remains the largest single source of energy-related CO2 emissions (about 15 gigatonnes in 2021, according to the IEA). What types of coal are…
What Is Petroleum? How It Forms, Its Uses and Environmental Impact
Petroleum is a liquid fossil fuel formed over millions of years from the remains of marine organisms. It is a non-renewable natural resource and the world’s largest source of energy: although its share fell below 30% of global energy demand for the first time in 2024, it remains the mainstay of transportation and petrochemicals (IEA…
Home Solar Energy: A Practical Guide to Self-Consumption
Home solar energy means installing photovoltaic panels on your roof to produce your own electricity and use it right where it is generated (self-consumption). The price of solar modules fell from $6.50 per watt in 2000 to just $0.27 per watt in 2024 (in 2025 dollars), which has made the technology cost-effective for households (Our…
Sustainable Development Projects: What They Are and Examples
Sustainable development projects are ideas that pursue economic prosperity, environmental integrity and social equity at the same time. What examples of sustainable development projects are there? The Shams 1 solar plant in the United Arab Emirates reaches 100 megawatts with 258,048 mirrors, and in 2011 Japan set out to build a 1-gigawatt floating wind farm…
Emerging Energy Sources: Airborne Wind, Algae Fuel and Waste-to-Energy
Emerging energy sources rely heavily on renewable resources such as the sun, wind and water, and involve new methods and technologies to harness them more effectively. Notable innovations include the airborne wind farms studied by NASA, algae for biofuels and generating energy from waste. What are the new emerging energy technologies? In 1954, Lewis Strauss,…
Types of Renewable Energy: What They Are and Examples
The six main types of renewable energy are solar, wind, hydropower, geothermal, biomass and marine (tidal and wave). All of them generate electricity from natural sources that are continuously replenished. At the end of 2025 the world had 5,149 GW of installed renewable capacity, and solar was already the largest source, with 2,392 GW (IRENA…
Biomass Energy: What It Is, How It Works and Advantages
Biomass energy is energy obtained from organic matter (wood, agricultural and forestry residues, biogas and biofuels) by burning, gasifying or fermenting it. Modern bioenergy is the world’s largest source of renewable energy: it accounted for more than 50% of global renewable energy use and 6.5% of total energy supply in 2023 (IEA 2024). Is it…
Tidal and Wave Energy: What It Is and How It Works
Tidal energy harnesses the rise and fall of the tides, while wave energy captures the motion of ocean waves. Both are renewable and predictable, but still marginal: at the end of 2024, the world had about 500 MW of installed ocean energy capacity, almost all of it from just two large barrage plants (IRENA 2024).…