secondary fuels

Question 1

what is a secondary fuel

Answer 1

fuel which has been converted into another energy

Question 2

give some examples of secondary fuels

Answer 2

1) electricity

2) hydrogen

Question 3

outline how electricity is a secondary fuel

Answer 3

involves the conversion of energy from a range of original primary fuels such as kinetic energy, chemical energy or light.

Question 4

outline how electricity is converted from kinetic energy

Answer 4

1) spinning of an electrical conductor within a magnetic field in a generator
2) spinning could be obtained from wind power or water power

Question 5

outline how electricity can be converted from light energy

Answer 5

photons of light strike the surface of photovoltaic cells and displace electrons which make the surface layer negatively charged

the now free electrons flow along a conductor to the lower layer which is relatively positively charged

the movement of electrons generates power

Question 6

how is electricity transported

Answer 6

• using a grid of electrical cables
• underground cables are expensive as they need to be cooled which requires energy
• overhead cables can cause aesthic problems in scenic areas and bird may be killed if they collide with them

Question 7

how is hydrogen a secondary fuel

Answer 7

a reactive gas produced by the electrolysis of water using electricity from surplus primary energy sources

Question 8

what are the uses of hydrogen

Answer 8

1) combustion to produce heat- heat is then used to heat buildings, water, and industrial processes, boil water, produce steam to drive turbines, and generate electricity
2) fuel cells- an electrochemical process which combines oxygen and hydrogen to produce water and thereby release energy

Question 9

what is hydrogen economy

Answer 9

the storing of hydrogen to help address the disadvantages of energy resources such as intermittency

Question 10

how can compressed gas be a technique to store hydrogen

Answer 10

1) compressor holds up to 700 times the normal volume of storage tanks
2) however energy is required to run the compressor

Question 11

outline liquid stored hydrogen

Answer 11

1) liquified under high pressure at low temps

2) energy is used for refrigeration and the running of compressors

Question 12

outline metal hydride systems as a way in storing hydrogen

Answer 12

1) it is absorbed to the surface of metal matric enabling low pressure storage