Topic 1 - Energy Generation Flashcards
1 kwh = ? J/s
1000 J/s
name 3 types of hydropower
Run of River, Pump & Store, Large scale store
Why is SOx reduction seen but less so in NOx?
SOx is related to energy production whilst NOx is related to transport
Challenges of Wind Power
Very variable supply
ideal location on high carbon peatlands
dissolved carbon in waterways mobilises other metals
Impacts on carbon from Wind Power
Peatland locations are ideal
Construction dries Peatlands
Increase oxygen and thus aerobic decomp
wet & cold slows decomp rate
Strategies to mitigate impacts of Wind Power
Use floating rods for foundations
Reuse the peat if stored well
special licence needed to store peat
issues with reliability of storage centres
Discuss Three Gorges Power Plant
Equivalent to 15 nuclear pp
World largest Hydro power plant
submerged much of the surrounding vegetation
displaced population
methane and CO2 production from submerged vegetation
Negative impacts of Hydro Power
Reservoirs are big contributors to mehtane emission (6-7%)
Emit 20% of global CO2
Benefits of Geothermal Energy
operates 24/7
constant fuel supply
consistent base load
Shallow Geothermal
~500m depth
Low grade heart
from solar radiation
distributed via meteoric water, GW and water from old coal mines
Deep Geothermal
> 500 m depth
primordial heat from earths formation
heat from radioactive decay
inject water to extract heat
UK - need to fracture rocks to extract
Binary Cycle Geothermal Plant
water pumped in loop into and out of ground
heat transferred to external water loop that generates steam and powers a turbine
closed loop => no pollutant release
How do Geothermal Plant work?
Flash Steam
- rapid depressurisation
- used to power turbine
Dry steam
- steam drawn directly through turbine
- condenser turns back into water
- no mineral laden brines
Name 4 types of energy storage
Physical - pumped hydro
Chemical - battery
Mechanical
Hydrogen - still hypothetical
Advantages of Li-Ion batteries (list 7)
Charge and discharge quickly
stable voltage
high E density
low maintenance
80% usable capacity
Long life
cheaper per kWh
Disadvantages of Li-Ion batteries (list 6)
More expensive upfront
Lithium brine deposits
relies on other elements for anode and cathode
phosphate needed but also needed for food
Phosphate in geopolitically unstable regions
titanium needed
Performance decreases as temp increases and as used more
Environmental Concerns of Lithium Brine
Extraction of lithium brine needed lots of land
large water use
CO2 emissions
depletes geothermal waters
fish deaths
End of Life process for Lithium Ion Batteries
5% recycling rate
pyrometallurgy - melt in furnace
hydro metallurgy - use acidic/basic solution
direct metallurgy - reuse and seperate
bio metallurgy - custom organisms
Minimising fires in disposal of Li-Ion batteries
discharge before disposal
remove flammable electrolyte
store in clay
Advantages of Vanadium Batteries
Non-flammable electrode
Longlasting
Scalable - no addition metal required just more liquid
Disadvantages of Vanadium Batteries (fuel, health etc.)
cost more per kWh (newer tech)
extracted from ground
not recycled
mined in Amazon
toxic and hazardous metal
interferes with haemoglobin
interferes with sodium and neuron
cross placenta
lung cancer
Advantages of Nuclear
Low land use
stable baseload
low life time emissions
high energy to fuel ratio
Disadvantages of Nuclear
nucealr waste
water use
high cost
highly regulated
Process of nuclear power production
Uranium powered
step 1 - open cast mining
step 2 - refine ores
step 3 - use centrifuge to seperate isotopes
