New renewables (small hydro, modern biomass, wind, solar, geothermal, and biofuels) account for another 3% and are growing very rapidly. The share of renewables in electricity generation is around 19%, with 16% of global electricity coming from hydroelectricity, and 3% from new renewable sources.

ATP can be immediately replenished by creatine phosphate, another high-energy molecule in the muscle cells. But creatine phosphate is also in limited supply and can only support muscle contraction for an additional 3–4 seconds.

The energy is derived from adenosine triphosphate (ATP) present in muscles. Muscles tend to contain only limited quantities of ATP. When depleted, ATP needs to be resynthesized from other sources, namely creatine phosphate (CP) and muscle glycogen.

Energy is stored in the bonds between the phosphate groups (PO4-) of the ATP molecule. When ATP is broken down into ADP (adenosine diphosphate) and inorganic phosphate, energy is released. When ADP and inorganic phosphate are joined to form ATP, energy is stored.

By 2050, the research estimates that coal will be down to just 16 percent of global power generation (from 41 percent now) and fossil fuels to 38 percent (from 66 percent now). Overall, though, coal, oil, and, gas will continue to be 74 percent of primary energy demand, down from 82 percent now.

nuclear energy

coal

Primary energy sources take many forms, including nuclear energy, fossil energy — like oil, coal and natural gas — and renewable sources like wind, solar, geothermal and hydropower.

Carbohydrates

The different types of energy include thermal energy, radiant energy, chemical energy, nuclear energy, electrical energy, motion energy, sound energy, elastic energy and gravitational energy.

These are the top 10 energy sources:

• Biomass Biomass or bio-energy, the energy from organic matter for thousands of years, ever since people started burning wood to cook food.
• Biogas.
• Tidal Energy.
• Wind Energy.
• Geothermal Energy.
• Radiant Energy.
• Hydro Electricity.
• Compressed Natural Gas.

Energy resources can be roughly classified in three categories: renewable, fossil, and nuclear.

What are some examples of renewable resources?

• On this page: What are renewable resources?
• Solar energy. Going solar is the most practical renewable energy option for homeowners.
• Wind energy.
• Geothermal energy.
• Hydropower.
• Bioenergy.
• Natural gas.
• Oil.

Renewable resources include biomass energy (such as ethanol), hydropower, geothermal power, wind energy, and solar energy. Biomass refers to organic material from plants or animals.