Earth Platform > Energy

What is energy?

energyThere are two types of energy: Potential energy (stored energy) and kinetic energy (moving energy). All forms of energy are stored in different ways in the energy sources that we use every day. These sources are divided into two groups, renewable energy and non-renewable energy. Renewable and non-renewable energy can be converted into secondary energy sources like electricity and hydrogen. Secondary sources of energy are used to store, move, and deliver energy in easily usable form. We have to use another energy source to make electricity or hydrogen, e.g. coals.

Energy is measured in joules (J). The work done, or energy used, during a certain time is called power. Power is measured in watts (W). A watt is the use of one joule of energy for one second. A watt is a small amount of energy, thus we measure power in units of 1000 watts for one hour, kilowatts for one hour. 


What is non-renewable energy?

non-renewable energyNon-renewable energy is an energy source that we are using up and cannot recreate in a short period of time. We get most of our energy from non-renewable energy sources, which includes the fossil fuels (oil, natural gas and coal). They are called fossil fuels, because they were formed over millions of years by the action of heat from the earth's core and pressure from rock and soil on the remains (or ‘fossils’ ) of dead plants and animals.  Examples of non-renewable energy sources are coal, petroleum, natural gas, propane, oil and uranium.


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There are different types of renewable energy. Some are biomass energy, wind energy or water energy.
Types of non-renewable energy are gas, coal or nuclear energy.

What is renewable energy?

renewable energyRenewable energy is an energy source that can be replenished in a short period of time. Renewable energy sources are solar energy (sun), wind energy, geothermal energy (from inside the earth), biomass (from plants) and hydropower (water). We use renewable energy sources mainly to make electricity. Also referred to as sustainable energy, which means the sources of energy should be replenishable within a lifetime and should not cause any longterm pollution or damage to the environment.

News about energy

New Scientist - Earth

CO2 emissions from energy remain flat for third year running - Carbon dioxide emissions from the energy sector have not increased for three years in a row even as the global economy grew
Deep cuts to environmental research in Trump’s budget proposal - US agencies doing climate research see concerning budget proposal that would eliminate funding for government science on air, energy and water within EPA, and slash satellite and coastal research at NOAA
There’s no such thing as ‘clean coal’ – it’s dirty and expensive - Australia and the US want to revive an uneconomical and polluting technology, and, worse, Australia plans to take money from a clean energy fund to do it
The EU’s renewable energy policy is making global warming worse - Independent report concludes the massive subsidies for wood energy are increasing greenhouse emissions, and are a waste of public money

What is the most promising source of renewable energy?