What are the most important greenhouse gases?
water vapor
Carbon dioxide
Methane
Nitrous oxide
Ozone
What is the greenhouse effect?
The retention of the sun ́s heat on the earth by a layer of gases in the atmosphere.
What are major possible effects of Global Warming?
Hotter temperatures
Increase of extreme weather events
Droughts
Melting of glaciers (rising of sea levels)
Poverty, displacement, mass migration
Loss of species
Is the utilization of biomass carbon neutral?
Yes, the utilization of biomass is carbon neutral since the crops that are the source of biomass energy capture almost all the CO2 (with photosynthesis) that is released because of the utilization.
Describe the differences between sustainable and non-sustainable biomass use and the implications on the environment.
Every step of production chain from the growing of feedstock to final energy has different sustainability challenges that need to be managed:
sustainable: clean energy, climate action, restoring of degraded land
Non-sustainable: food security, land use & change, biodiversity
Explain the well-to-wheel approach in environmental assessments.
Method to evaluate efficiency & emissions of an energy source by considering its entire life cycle
Accurate method to measure energy consumption and GHG emissions
Combination of well-to-tank and tank-to-wheel method
Explain why energy indicators are important and name one key energy indicator, including its equation.
Energy indicators relate the energy demand to economic and human activities. They help to extract key trends from a large amount of data. We can assess past changes in energy use and estimate future impacts of policies and other components.
Key indicator: energy intensity per capita (EIpop = E/POP)
Name three countries with high overall CO2 emissions and three countries with high CO2 emissions per capita. Why are there differences?
Overall CO2 emissions: China, United States, India
CO2 emissions per capita: Qatar, Kuwait, UAE
Countries such as China or India have a very large population and therefore a high number of total emissions but relatively low per capita emissions. In rich countries like Qatar on the other hand, people have very high per capita emissions due to their more luxurious lifestyle (big houses, travelling, etc.).
Developing countries often also don’t use clean energy sources and are much more focused on their economical growth which also leads to higher emissions
What are the major challenges related to the use of electric vehicles?
costs
Driving range
Charging time
Charging infrastructure
Source of energy (e.g. nuclear power not carbon neutral)
Which types of electric vehicles are in use? What are their major characteristics?
Types:
HEV (Hybrid Electric Vehicles): use both ICE and electric motor, but battery is charged by the engine or regenerative braking, not an external source
PHEV (Plug-in Hybrid Electrical Vehicles): use both ICE and electrical motor, require external charging for battery
REX (Range-Extended Vehicles): Subcategory of PHEV (smaller tank, bigger battery)
BEV (Battery Electric Vehicles): fully electrical with no ICE, powered by recharcheable batteries
FCV (Fuel Cell Vehicles): Powered by hydrogen fuel cells, emit only water vapor and heat as byproducts
—> Increasing electrification, lower use of fossil fuel
What are the major challenges related to the use of biofuels?
food and fuel competition
Sustainability
Risks of degradation of land/ forests/ water resources
What are the perspectives of biofuels for their future use?
Future perspective:
• 1/3 of global fuel supply in 2050 -> optimistic
• Strong dependency on government policy
• Incentives for development of 2nd gen. biofuels (waste & residues)
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