This is prompted by the Energy Hierarchy of the Institution of Mechanical Engineers.
From the most to the least sustainable,
Tier 1 is Energy Demand Reduction,
Tier 2 is Energy Efficiency,
Tier 3 is Utilisation of Renewable, Sustainable Resources,
Tier 4 is Utilisation of Other, Low-GHG-Emitting Resources, and
Tier 5 is Utilisation of Conventional Resources as we do now.
This is prompted by the Energy Hierarchy of the Institution of Mechanical Engineers.
From the most to the least sustainable,
Tier 1 is Energy Demand Reduction,
Tier 2 is Energy Efficiency,
Tier 3 is Utilisation of Renewable, Sustainable Resources,
Tier 4 is Utilisation of Other, Low-GHG-Emitting Resources, and
Tier 5 is Utilisation of Conventional Resources as we do now.