Energy History, Modelling and Transition Flashcards
(21 cards)
What is an energy system and what effects it?
The production, use and storage of energy by local, national or global society.
Effected by:
* Societal pressures
*Population
*Policy
*New technology
*Finance
List is not exhaustive
Why do we model energy systems?
Modelling is key to planning.
Planning is key to dealing with threats such as climate change.
What is Entropy? (in the context of thermodynamics)
A measure of energy which is unavaiable for doing work.
What is Exergy?
The maximum amount of work that can be done by a system as it approaches equilibrium.
Define the Kaya Identity (or IPAT)
What conclusion can be drawn from it?
Emissions = Population·Economy·Technology
or
Impact = Population·Affulance·Technology
Only technology (emission impact of/per energy) can feasibly be reduced. The was to do this is transition to less emission intense energy production.
Why are renewables preferable to fossil fuels?
Renewables offer much better lifetime emissions. Often 1/50th or 1/100th compared to coal.
Since renewable’s emissions come from their production, the emission impact will improve as the global network transitions.
Summarise the key differences in the lifetime energy investment/return graphs of generic renewable and fossil fuel production methods.
The initial energy investment for renewables is far greater but the production requires no fuel making the lifetime emissions per energy much lower (up to 1/100th).
Historically fossil fuels EROEI has increased or decreased to a plateau?
Decreased.
Over time deposites of resources become harder to access. Occasionally technological improvements cause small increases (eg fracking).
The EROEI of renewables is predicted to increase or decrease?
Increase to a plateau.
Technology improves efficiency but is capped by the availability of high quality sites.
Define Capacity Factor
The proportion of an energy generating systems capacity that is actually utilised.
Define Base Load
The minimum demand on a grid over a span of time (eg a day or week).
How dispatchable and cost effective is Nuclear Power?
Not very dispatchable, it can take days to turn on/off.
It is very cost effective.
List the four considerations a grid opperator must weigh up when deciding how to meet demand.
- Availability
- Price
- Environmental Impact
- Dispatchability
In the UK renewable energy MUST be used before fossil fuels regardless of price.
What is the most dispatchable electricty generating source?
Hydro
Summarise the two main viewpoints in the debate in allocating the global transition budget fairly.
- Allocate based on; Population, Resources, GDP, History.
- Ignore the above and focus solely on EROEI. Produce energy where its most efficient and trade/distribute it.
Moral fairness vs lowest impact
What is the approximate efficency loss from power to liquid?
~50%
What is the Jevons Paradox?
Give three reasons for it.
As technological advancements make use of a resource more efficiently, demand increases.
1) Subsitution effect - everyone wants to use the now cheaper energy service.
2) Direct Income Effect - Users can afford more so the use more.
3) Increased Income - Affluance increases demand for all goods and the production demand increases energy demands.
Explain the statement “the current UK policy regarding energy transition is not synchronised “
Elements that effect the grid such as the switch to renewable and electric cars have little policy relation. This makes planning harder, leads to confusion and potentially failure to meet goals.
Population globally is forecast to…?
Increase over the next 50 years and then plateau around 10 B
Affluence globally is forecast to…?
Generally increase
Levelled Cost of Energy (£/kwh) is what?
The average cost of generating electricity froma source over its life time (ie the total cost / the total production)
For a given source the graph follows roughly the inverse of the EROEI.
