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.
A Select Committee of the House of Lords invited submissions on the Role of Hydrogen in Achieving Net Zero.
Here is my submission.
Topic 1) emphasises the urgency of energy transition.
Topic 2) is the main focus of the document, with the paper by Sgouridis et al, 2016.
This identifies the relationship between the remaining fossil fuel emissions cap, the transition time, and the required investment in Renewable Energy (RE) supply plant.
Topics 3) and 4) refer to the initial conditions prior to the energy transition.
Topic 5) compares the Energy Return on Investments (EROIs) of Renewable Energy (solar and wind power) supply measures with the weighted average value of 20 assumed by Sgouridis et al.
Topic 6 is concerned with the global limits of renewable power sources.
Where Topics 3) and 4) deal in UK quantities, Topic 6) deals in Global quantities. However, the UK must expect to use only a proportionate share - e.g. equal per capita.
Topics 7) and 8) consider energy demand measures as complements of the supply measures assumed by Sgouridis et al. They refer to two papers by Cullen and Allwood et al, 2010 and 2010.
Including energy demand measures will greatly ease an energy transition within the constraints, such as 2 C global warming.
Ulf Bossel, Baldur Eliasson, and Gordon Taylor
I found on the Internet an early version of this paper, authored by Ulf Bossel and Baldur Eliasson. I had been doing desk research in the same general area, and offered a number of comments and contributions over a period of some months. Eventually I became a co-author of the final version, dated 2003-04-15.