Energy Generation
• How many forms of energy generation can you think of?
• What fuel do you think generates the most power in the country?
• What fuels do you think are high carbon?
High Carbon
• The term High carbon relates to energy generated using fossil fuels.
• Fossil fuels are burned generating heat, the heat is used to super heat water.
• The steam is used to turn a turbine that is connected to a generator.
• The steam is condensed back into water and returned into the system for re-boiling the hot water reduces the amount of energy required to boil the water the subsequent times.
• Why are energy companies trying to reduce their dependency of fossil fuels?
• The energy industry is trying to reduce its dependency of fossil fuels because:– They are limited; fossil fuels are finite, once
they are gone they are gone. – Cost; as the fuels start to run out the cost
rises, fossil fuels will only get more expensive.– Pollution; all fossil fuels release CO2 and
other greenhouse gasses when burned these are environmentally damaging and have been linked to global warming.
High Carbon
• The reason fossil fuels are so polluting is they are releasing carbon that has been stored in the planet for millions of years in the form of coal, oil & gas.
• Burning these fuels releases the carbon into the atmosphere.
High Carbon
Coal
Coal
• Coal used to account for the majority of energy production, both in this country and the world.
• It is the ‘dirtiest’ form of energy releasing the most amount of CO2 per kw of energy generated.
• Coal powered stations are being phased out in Europe due to concerns over emissions, but are on the rise in developing countries who have an increased demand for power and an abundant supply of coal and labour to mine it!
Coal
Oil
Oil
• Oil has become a minor contributor to power generation because of its use in other types of industry are more important; fuel for vehicles, use in plastic industry, use in pharmaceutical industry, etc.
• With the cost of oil going up all of the time its use to generate electricity can not be justified.
Gas
Gas
• Gas fired power stations are the ‘cleanest’ of the fossil fuels releasing less than half the CO2 per Kw than coal.
• Gas is transported via pipe lines across countries / continents or liquefied and shipped across the oceans in bulk transporters.
• Gas makes up the majority of energy generation in the UK but as the cost of gas goes up so does the price of electricity.
Gas Transport
• What fuels do you think are medium carbon?
Low Carbon
• Low carbon energy is a subjective term; it usually relates to energy generated either by a fuel that releases less carbon or by a process that is more efficient, e.g. utilizing what would have traditionally been waste heat to heat water as in the CHiP (combined heat and power) system.
• Other systems whilst on the face of it are carbon intensive e.g. biomass the CO2 emissions are offset by burning quick growing plant mass creating a mini carbon cycle so you are not adding any additional carbon to the system.
Biomass
• Biomass is considered to be carbon neutral; this is because the carbon in the fuel being burned has been captured in the bio-material from the atmosphere. When you consider transport and processing the process in not quite carbon neutral.
• There are two main types of biomass boilers;– Direct burn– Gasifier
CO² is released into the
atmosphere by burning
CO² is absorbed by the leaves by the process of photosynthesis
The CO² is broken down by the leaves
into carbon and oxygen, the carbon is used by the tree
to grow and the oxygen is released
back into the atmosphere
Waste wood from the
manufacturing industry is
processed into pellets
A small amount of CO² is
released during the processing and transport of the wood waste
Stored energy is released by
burning the pellets
Biomass Direct burning
• With the direct burn as the name suggests the biomass fuel is burned in a power plant like any other fuel.
• The biomass is processed in to pellets and dried. When it is in this form it can easily be stored, transported and used.
• Can you think of fuels that can be used in a biomass power plant?
Biomass
Rubbish
Bio-mass Pellets for ease of
transport and supply to the
boiler Animal Waste
Rice Husks
Sugar Cane Waste
Elephant Grass
Wood Waste
Biomass Gasifier
• In the biomass Gasifier the biomass is heated / partially burned to release gas, the gas is burned in a traditional gas powered power station or any other gas appliance.
Biomass Gasifier
Hydrogen Fuel Cell
• Hydrogen fuel cells combine oxygen and hydrogen together with the help of catalyst to form water; this reaction gives of electricity.
• The process is the reverse of electrolysis where an electrical current is passed through water, splitting it into its component parts hydrogen & oxygen.
Hydrogen Fuel Cell
CHiP
CCH&P
• http://www.youtube.com/watch?v=uXLUoqzlT2k&feature=youtu.be
Heat Pumps
• A heat pump uses the principal of tacking a small amount of heat in a large body of water or air and converting it a large amount of heat in a small amount of water or air.
Heat Pumps
Compressor
• The compressor moves & compresses the refrigerant through the system. As the refrigerant is compressed (changed from a gas to a liquid) it changes from a gas to a liquid. This process is an exothermic reaction
Evaporator
• The evaporator uses the small amount of energy collected from the underground coil to evaporate the refrigerant (the refrigerant absorbs energy making the molecules more energetic this allows them to break free from each other and change from a liquid to a gas). The evaporation process is an endothermic reaction.
Condenser
• The condenser cools the gas until it turns back into liquid; as it turns back into liquid form it gives up energy in the form of heat, this heat is exchanged to the water of the heating system and is used to augment the heating system of the house.
Expansion Valve
• The expansion valve is used to reduce the pressure of the liquid refrigerant. This allows the liquid to boil / evaporate more easily when it enters the evaporator.
Pump
• The pump circulates the water through the underground coil / heat sink and the evaporator.
Underground Coil
• The underground coil absorbs latent heat from the ground and transports it via the liquid to the evaporator.
Heating circuit in the house
• The house hold heating circuit is augmented by the heat pump, it is typically used in conjunction with another more traditional system.
Solar Thermal
Solar collector
Hot water to taps
Cold water feed
Hot water tank
Boiler
Controller&
pump
Cold water feed
Hot water tank
Controller&
pump
Boiler
Solar collector
• What do you think are low carbon methods of energy generation?
Low Carbon
Solar Photo-voltaic
Solar Photo-voltaic
Photo-Voltaic panels convert the energy of the sun (light) into a DC
voltage
DC Isolator is a switch that allows
the power from the solar panels to flow
to the DC/AC inverter
DC/AC Inverter converts the low
DC voltage to high AC voltage
(230V)
The AC isolator isolates the AC
power generated by the solar panels
from the rest of the dwelling
The PV Generation Meter measures how much electricity has been generated by the solar panels
Fuse Board or to give it its proper name consumer unit,
this holds the circuit protection devices and
distributes the electricity around the various circuits in
the house
Import / export meter this is a special meter that
measures the amount of electricity the dwelling
uses from the distributor and how much electricity
the dwelling has ‘sold’ back to the supplier.
Wind
Wind
Blades
Rotor
Generator
Gear Box
Low Speed Shaft
Brake
Pitch Control
High Speed Shaft
Nacelle
Wind Vane
AnemometerController
Tower
Yaw Motor
Yaw Drive
Hydroelectric
Hydroelectric
• http://www.youtube.com/watch?v=S4B2gODY3Mk
Tidal
Tidal
• http://www.youtube.com/watch?v=F0mzrbfzUpM
Nuclear
Nuclear
Glossary
• Augmented– To make bigger, larger, to add to.
• Latent– Potential but not obvious.
• Endothermic – A chemical or mechanical process that absorbs
heat.
• Exothermic – A chemical or mechanical process that gives off
heat.
Top Related