topic 9 Flashcards
solar
intermittency
E.D.
new tchnology
high intermittency
cant be predicted-cloud cover etc
low E.D. large area needed
photovoltaic solar power-provides electrical currents by dislodging electrons which flows a long a electrical conductor from negative layer to pos. lower layer-appliances
multi junction PV cells-more light wavelength absorbed
HEP
newtech
e.i.
location
needs a high total rainfall throughout year
low seismic activty
large embodied energy
reduced turbidity downstream
micro hydro damn-no barrier across whole of the river
helical turbines-turned by water flowing down them-high efficiency
wind power
HAWTS+VAWTS
locational constraints
environmental impacts
hawts-more efficient+more establilshed than vawts
vawts-wind any direction-lower wind velocities
location-coatsal areas
nimbies dont like them
located away from high bat populations
bat deaths -turbines stopped at lower wind velocity
bird strikes-migrating birds-careful placement of HAWTS
blade tip fins-reduces wind resistance-increasing efficiency
helical VAWT blades-rotate more smoothly than straight bladed+facturing
wave power
location
harnessing wave power
design problems
e.i
long fetch
point absorber
surface attenuators-moves pistons ‘push and pulls
difficult to anchor in deep water
withstan-storms+corosion
sea bed damage
biofuels
advantages
disadvantages
locational factors
e.i
new tech
can be stored until need
carbon neutral-sequest the same amount they release
large areas of farmland lost
lower energy density than f.f.
fertile soil+topography
habitat loss-encoureages deforestation
hydrogen from alage-if they are deprived of sulfur -used as fuel
geothermal power
technology
low/high temp
location
E.I.
new tech
geothermal springs -hot water heated by rocks used in district heating
gepthermal steam systems
groundwater a v high temps to surface via borhole-steam
150 degrees-volcanic actovoytty
waste water-heavy metals
gaseous emissions-c02
low temp fluids-boil at lower temperatures -uk
tidal power
predicatble moon and sun positioning
few suitable sites
in stream turbines-absorb kinetic energy of natural
tidal flow-no sig impact on environment
tidal barrage-damn across estuary maximum use of tidal flow -large embodied energy -lots of material+transportaition
sedimentation-redueced current build up of sediment
tidal reef-wtaer can flow over the top-allowing fish to pass overtop
secondary fuel electricity -
pv panels+
rechargeable batteries
how does the energy form
electricity from solar energy-displacemnt of electrons-free electrons go to lower layers which are more pos.
chemical energy-rechargeable batteries use electricity to reform chemicals that produce electricity-lead acid
hydrogen-high energy density
uses
stores
hydrogen economy
fuels cells-oxygen+hydriegn=water releasing water
liquid-high pressure+cool temps-needs energy for refigeration
hydrogen is stored like biofuels as energy surpluses in case of shortage-used in vehicles
why is energy storage important
nergy production ates can be kept constant
larger quantity of fuel if trasportation is economic
causes of energy fluctuations+demand
intermittent energy resources-solar
seasonal fluxes
demand may drop off too fast before power stations can reduce the output
lost through heat in cables
factors affecting rechargeable batteries
safety-toxic-lead acid
+recharging speed -
compressed gas
surplus energy drives an air compessing pump-compressing air produces a lot of air-90% recovery raet
types of storage systems
high volume storage-s.a;v
high thermal mass building materials-high specific heat capacity-concrete-reduces need of air con
transport of energy conservation
bulk transport-rapid transport for perishable goods
fuel tax
vehicle design
aerodynamics -less friction
reduced mass-carbon fibre high strength: weight
vehicle design fo rend if life
recyclable materials
smart motorways-reduce chance of congestion -speed changes
building house type
building surface area-terraces etc low s.a:v
choice of materialsin conserving energy
earth sheltered buildings-warmer ground colder than air
low embodied energy materials-rammed earth over concrete
window conservation
newtech
multiple layers of glass reduces energy loss -gap should be large enough without convection current starting-low emissivity glass-reflects long wavelengths back
ventilation
heat recovery ventillation-heat leaving building passes cold air coming in -causes a counter current air flow
energy managementin household-tehcnology
programmable thermostats-room temps can vary between different rooms-easier to manage heat in different rooms
human behaviour in savong energy
truning lights off when not required turning thermostsats down to prevent unecsssary heatingn
low energy appliances
use of LED lightbulbs
colder temp washing machine cycles less energy
newer dishwashers use less water so less heating needed
industrial energy conservationwhen storing energy
insulation
insulation-use outlayer materials with a low thermal conductivity-storage tanks etc
high volume storage-reducing surface area(one large tank) than using lots of smaller tanks
intergrated manufacturing
material processes are in same site-reducing energy wasted on transport-inter dependant industries near each other
recycling-energyconserv-ation in infastructure
recyling-reduces waste and energy needed to produce new materials
mass reduction-redesign products to make them lighter-less energy used in manufacturing+transport
integrated manufacturing
elec infatsructure managemnt peak shaving storage
high voltage grid
-managemnt of peak shaving-store of surplus energy-used later to meet demand
high voltage grid-use transformers to control current and voltage of elec minimising energy lost through heat of the cables
IT management of elec supply -accurately predict and demand for electrcity and monitor electrical supplies fast-reduces energy created
per capita energy consumption and culutre how it effects
higher affluence=more energy used-less energy efficient cars-global market price of resources is low enough to afford
relative cost-large easily accessible source of energy is cheaper
environemntal awareness-historically difficulties satisfying demand–stronger energy conservation culture-sweden
type of industry
primary-agriculture
secindary-heavy manufacturing-metal smelting
tertiary-services -finance
quarternary-IT
changes in energy use
change in envoironemntal awareness-better building energy conservation
NEES -manufacturing/industrial industries energy use
features of energy resources
renewable
non/depletable-if theyre exploited unsustainably
locational constraints
intermittency
predicatbility
energy density
resource availability
ease of storage/transport
e.i.
technological development
ease of transport examples
electricity-high voltage AC-overhead cbales chea[er to maintain
coal-train-used in elec-power stations are located near coal fields-elec easier to transport to coal stations
political/economic influence on features of renewable energy
governemnts give grants-renewable energy
guaranteed price market for energy
conomic-consumer doesnt pay for secondary effects caused by the energy user like building damage
sustainability of current energy use-f.f.
economic ssutainability-
non renewable-furture-more expensive
env.influence-use of ccs reduces impact
coal-normal way to do it
where
new tech
uk and wales-once coal supplies are used
open cast mining-deep deposits unable to be accessed
loss of habitat
new technology-
coal gasification- coal is burned underground in controlled conditions releasing gases which spins a turbine
directional driling
AUVs-take seabed surveys
oil-recovery
flows through permeable rock
forced to surface by natural pressure
primary-natural press 20%
secondary-pumping water to increase pressure-40%-use ccs pumping c02 to increase pressure
tertiary-use of controlled combustion underground-increases viscosity-detergents-reduce surface tension-flow better
oil recovery-new tech
pst
primary-natural press 20%
secondary-pumping water to increase pressure-40%-use ccs pumping c02 to increase pressure
tertiary-use of controlled combustion underground-increases viscosity-detergents-reduce surface tension-flow better
oil recovery- new tech 2
directional drilling
ROVS and AUVs-conduct seabed surveys
directional drilling-may wells from single platform
underneath locations difficult to reach
fracking-new tech oil+gas environemntal imoact as well
oil+gas trapped in pores between shale-high pressure and fissures to open fissures
e.i.
natural gas may enetr aquifers-toxi metals may become mobile-
gas-where
new technology
porous rock-natural pressures-etc.
new tech
methane hydrate
emhanced gas recovery-injectionof c02 nitrogen at edge of gass fields to maintain pressure
methane hydrate-
found in polar regions-not commercially viable-yield more methane
hot water is pumped down to methane hydrate melting it releasing more methane
nuclear fission
used for base load electricity
breederreactor makes fissile fuel
high embodied energy-requires a lot of processing-urnium
high energy density-1kg of uranium=13T coal
finite resource-uranium is non renewable most of ore is found at low grade deposits
e.i. of nuclear energy
high embodied energy of materials used-health risk of ionising radiation
economic issues
use of nuclear fission
future use
large and expensive-difficult to decomission old reactors
