Secondary fuels and energy storage | AQA A-Level Environmental Science Revision | Primrose Kitten

Primary fuel

Comes from a natural resource like coal, wind, etc.

Secondary fuel

When a primary fuel is converted into another energy type.

Electricity

One of the examples of secondary fuels; can be fed directly into the National Grid for use in homes and industry.

Hydrogen

Another example of a secondary fuel obtained from the electrolysis of water; a reactive gas.

Energy conversion efficiency

The efficiency decreases with more conversions; not all energy is converted, some is lost in the process.

Advantages of using electricity as a secondary fuel

Infrastructure for transportation is present, wide range of uses, no pollution upon use, can be converted into other energy forms.

Disadvantages of using electricity as a secondary fuel

Overhead cables are unsightly, low efficiency in converting from primary fuels, difficult to store long-term.

Hydrogen properties as a fuel

Renewable, easily stored, high energy density, non-depletable, high theoretical abundance, low intermittency, high predictability.

Hydrogen fuel cell

Consists of an anode and a cathode; hydrogen gas is split into protons and electrons to generate electrical current.

Hydrogen economy

A proposed model for energy generation where renewables generate electricity and surplus is used to produce hydrogen for storage and peak shaving.

Methods of storing hydrogen

Can be stored as compressed gas in tanks or as liquid hydrogen at low temperatures and high pressures.