Unit 8 - Energy and Transport Flashcards
Direct CC impacts on the energy sector
- temperature changes affect energy demand and consumption
2. secondary CC impacts (flooding, storms etc) affect energy production and distribution.
Four main determinants of CO2 or GHG emissions as set out in the kaya identity
- Population
- GDP per capita
- Energy intensity (energy used per $ of GDP)
- Carbon (or GHG) intensity (CO2/GHG released per unit of Energy
Calculating Energy Requirements for heating and cooling
HDD = O (B - Ti) CDD = O (Ti - B)
HDD= heating degree days CDD= cooling degree days B= comfort temperature Ti= daily temperature O= cumulation calculated using the sine method
Converting this into energy consumption is difficult because energy use will depend on the technology used to generate heat or cooling as well as building structures and insulation.
energy demand for heating and cooling changes depending on:
- temp changes (both scale and location)
- temp variation between seasons + predictability
- population distribution
- wealth
- building design and construction + passive building measures
- balance of power sources used
Leapfrogging (like China in the energy sector)
when developing countries can advance rapidly by adopting modern, more efficient technologies and systems without first using elss efficient older technologies and systems which may still be in use in depeveloped countries
Impacts of CC on energy production
- Oil/Gas - infrastructure is vulnerable - especially when off shore. Disadvantages of dependence on fossil fuels 1) peak oil 2) cc 3) high vulnerability to extreme weather events.
- Nuclear power - vulnerable for droughts + health/safety issues due to extreme weather events
- Hydropower - vulnerable for droughts
- wind energy - initially positive effect, but strong winds could be harmfull
- bioenergy - variable (negative effect on energy crops)
- solar - minimal effect
Two ways to achieve lower GHG emissions
- improve energy intensity (EE)
2. improve carbon intensity (RE)
move to lower emission or carbon-free electricity through:
- Low GHG emission fossil fuel
- RE
- CCS
- Nuclear
When evaluating low carbon solutions take into account:
costs scale lifetime capacity reliability flexibility location lifecycle emissions environmental and social concern
Solar facts
- Concentrating solar power (CSP) - heat to boiler
- Photovoltaic (PV) solar cells
PV efficiencies between 10-20% - low power output
DC load - potential inverter necessary to go to AC
DC vs AC
DC = Direct Current = flat line - the flow goes in one single direction
AC = Alternating Current = like sinus/cosinus (Hertz) - more efficient to travel and can be distributed at a low voltage. The frequency is so high we can not notice the appliances to go on/off 50 or 60x per second. All grids are AC.
Nuclear energy
1) costs
2) health risks
Nuclear fusion vs nuclear fission
Hydrogen vs uranium
transport sector’s share of global anthropogenic GHG emissions
13%
and 24% of all GHG emissions from fossil fuel sources (39% for e+heat)
economic growth leads to increased energy demand for transport
- integral part of development (even a goal)
- urbanisation (transport of food, trade etc)
- increasing size of cities and home/work traffic
- increased income > cars & moterized transport
- larger less fuel efficient cars
- increased freight transport
Improved energy intensity in the transport sector
- Reduced demand for transport services
- changes in lifestyles
- changes in systems (less travel same lifestyle)
- Increased transport efficiency to meet demand
- Increased energy efficiency to delivery transport services
- different modes of transport
- improved technology / fuels
