Development of New Energy Resources (Cambridge (CIE) IGCSE Environmental Management): Revision Note

Hydrogen as an energy source

Why hydrogen can be used as an energy source

• Hydrogen is a fuel that burns easily, releasing large amounts of energy

• When hydrogen burns, it produces water vapour instead of carbon dioxide, so it can be a low-carbon energy source

Blue hydrogen fuel

• Blue hydrogen—hydrogen fuel made from natural gas

• Natural gas is reacted with steam in a process called steam methane reforming

  • This produces hydrogen gas and carbon dioxide

• Carbon dioxide is captured and stored using carbon capture and storage (CCS)

• Hydrogen can then be used as a clean fuel for vehicles, heating or electricity generation

Green hydrogen fuel

• Green hydrogen—hydrogen fuel made using renewable energy

• Electricity from solar, wind or hydropower is used for electrolysis

  • Electrolysis is the splitting of water into hydrogen and oxygen using electricity

• Produces no carbon emissions during production

• Hydrogen can be stored and used when needed, helping balance renewable energy supply

Ground source heat pumps

Ground source heat pumps: transfer of heat from the ground for heating

• Pipes are buried underground, where the temperature stays fairly constant

• A liquid (water mixed with antifreeze) flows through the pipes

  • The liquid absorbs heat from the ground

• The pump transfers this heat into a building’s heating system

• Provides low-carbon heating for homes, schools and offices

• Works well in places with enough outdoor space for underground pipes

Insert image: Ground source heat pump
How a ground source heat pump works

Air source heat pumps

Air source heat pumps: transfer of heat from the air for heating

• A fan draws in outside air, even on cold days

• A refrigerant fluid absorbs heat from the air

• A compressor then compresses the air, increasing its temperature

• The heat is then transferred indoors

  • Can heat radiators, underfloor heating, or hot water

• Easier to install than ground source systems because they stay above ground

• More effective in mild climates where air temperatures stay higher