Energy Sources

1. Energy Sources Group 14 – Nikita Arora, Himanshu Gupta, TayyabPirzada, Bhumika Singh & Cathy Zeng

2. Introduction • This presentation covers Concentrated solar power (CSP) technology • Concept of focusing large amounts of solar energy on a small area • Lenses/mirrors used to track the sun and concentrate it onto one place • Includes many different thermal concentration technologies, of which parabolic trough was found to be the best • This presentation compares CSP to other renewable sources of energy in terms of ability to generate electricity in a 50 MW plant • Solar panels • Hydro power • Wind • Bio Fuels

3. Concentrated Solar power Parabolic Trough

4. General information • Curved trough: reflects solar radiation to an absorber pipe in the centre • Heat transfer fluid passes through absorber (e.g. molten salt or synthetic oil) • Heat transferred to steam through heat exchangers • Steam powers a turbine which generates electricity • 500 troughs needed to generate 50 MW • Plant size: 10 km2

5. Advantages • Temperatures can go as high as 700-800°C • Concentration allows for heat storage via molten salt, meaning that CSP plants can generate electricity after sunset • Back-up system can be used in case sun’s heat unreliable (mostly reliable in deserts) • Creates thousands of jobs for construction & maintenance • Completely environmentally clean • Except for petrol required for maintenance and driving around plant • Systems easy to operate • Single-axis tracking system: • Machinery is not as complex; when tracking the sun, they only have to move one way, because they are curved • When the sun is perpendicular to trough, it tilts to maintain focus • When the sun is parallel, it doesn’t have to move

6. Disadvantages • Extremely high start-up costs • A lot of space needed to make large-scale plants: 10 km2 • Won’t function in northern areas • Needs a temperature of at least 25°C to work

7. efficiency • Can attain 76% + thermal efficiency • Concentrate solar energy equivalent to 600 suns

8. Start-up costs

9. Maintenance costs

10. Ultimate price = $0.06/kWh

11. Concentrated Solar power (CSP) Power Tower

12. General Information • High-temperature collectors (heliostats) concentrate heat onto a central tower with a receiver on it • Heat exchangers change the heat to steam, which powers a turbine that generates electricity • Plant size: 15 km2

13. Advantages • Higher concentration than parabolic trough, since the energy is only concentrated onto one thing, as opposed to many absorbers • Back-up system can be used in case sun’s heat is unreliable (mostly reliable in deserts) • Creates thousands of jobs for construction & maintenance • Completely environmentally clean • Except for petrol required for maintenance and driving around plant • Heliostats are flat which makes them easier to install and manufacture

14. Disadvantages • Dual-axis tracking system: • Has to move two ways to track the sun, which is more expensive to construct and maintain as well as difficult to program • Requires more monitoring by humans • More materials required due to the involvement of a tower and receiver • Takes up even more space than parabolic trough plant: 15 km2

15. efficiency • 50 % efficiency

16. Start-up costs

17. Maintenance costs

18. Ultimate price • $0.07 cents/kWh

19. Solar panels

20. General Information • Converts the Sun’s light energy into electrical energy using the photovoltaic effect • The ‘photovoltaic effect’ • 2 layers of semi-conducting material (i.e. silicon) • When exposed to light, photons are absorbed by the material and excites the electrons • Electrons then ‘jump’ from one layer to another • This ‘jumping’ generates electricity • Conductive metal strips are attached to the cells to take the electrical current and power an electrical load

21. Advantages • Renewable energy source • Environmentally friendly as it does not release any emissions (i.e. CO2, SO2) • After initial investment in equipment, there is a very low ongoing maintenance cost • Since there are no moving parts in the solar cell, it is virtually impossible to damage it • No noise is made by the solar cells • Can harness energy in remote locations • Minimizes the need for wires which have to be maintained, and also the cost of transmission • Electrical companies find it dangerous and costly to construct an electrical grid extending to mountainous areas • Governments offer tax incentives for taking the initiative to become environmentally-friendly

22. Disadvantages • Initial capital investment may be too much • Solar power cannot be harnessed during a storm or on a cloudy day • Solar panels are ineffective at nightbecause there is no sunlight • A backup supply or energy storage system is needed since solar power is not reliably available at all times of the day • A large area of land is generally used to improve efficiency, thus land resources for humans are reduced • Can’t concentrate large amounts of energy • Generates electricity which cannot easily be stored • It is easier to store heat energy than electricity

23. efficiency • Dust can reduce the efficiency of a solar panel system • 4 grams of dust per 0.34 square meters can reduce the efficiency by 40% • A large area is required for the solar panels to be truly efficient • The efficiency relies on the location of the panels • Obstructions such as buildings will not allow much sunlight to reach the solar panels • Typical photovaltaic cells convert 15% of sunlight into electricity

24. costs • AVA Solar Inc. produces solar panels using glass coating with a cadmium telluride thin film • Half of the cost is for solar panels. • At Fort Collins, Colorado, USA. • In Ontario, Canada, California’s OptiSolar will construct a 365-hectare solar plant near Sarnia • Can power 10000-15000 homes on sunny days • 40-megawatts • Estimated to be $300 million • China’s Suntech Power is going to build a plant in Arizona, USA • The actual solar cells will be manufactured in China and imported into USA where they will be assembled by factory workers into grids • An initial budget of $10 million, but increases over time • Maintenance costs, assuming some government subsidy: • $ 4.38 million

25. Ultimate price • In Colorado, USA, AVA Solar Inc., the price is $2/watt for the consumer • In Sarnia, Ontario, the price for the 40 MW plant is $0.42/kilowatt hour

26. Hydro Power

27. General Information • Energy that is taken from the force of moving water • E.g. Niagara Falls

28. Advantages • More reliable than other renewable energy sources in that water never stops flowing/falling • Long lifespan • Electricity generation can be stopped and started according to level of demand • Lake’s water can be used for irrigation • Completely clean electricity generation after dam is built • No environmental implications

29. Disadvantages • Dams are very expensive to build • High start-up costs • Natural ecosystems in the body of water are destroyed • Can cause geological damage • Hoover dam in the USA caused numerous earthquakes • Dams might break down under the water pressure of the flow of water • Consequence: human & animal deaths, flooding

30. efficiency • 80% efficiency for an average plant • However, efficiency varies from 60-90% depending on water flow and structure

31. Start-up costs • $150 million • Inclusive of investments & land purchase

32. Maintenance costs • $1 011 000/year

33. Ultimate price • $0.85/kWh

34. Wind power

35. General Information • Wind is converted into reusable energy • Wind Turbines – A machine in which kinetic energy is converted into mechanical energy which is usually further converted into electrical energy • Wind Mills – Devices in which wind energy is converted by vanes on the windmill which move in a circular motion (called sails) into kinetic energy which allows for the grinding of a substance • Wind Pumps – Devices used to pump out water using kinetic energy from the wind to power the pumping out of water from bodies of fresh water such as lakes, streams or wells • Sails – Apparatus used to create thrust (Reaction force described by Newton’s 2nd and 3rd laws in which a system accelerates mass in one direction and a proportional, opposite force will go against the same system) while in wind • 80 countries around the world are using wind power commercially • 2009: Global wind power increased 27,051 MW • 42% of new US fuel generators used wind power

36. Advantages • Clean Energy Source – No pollution or radioactive waste produced by wind power  • Self-Sufficient Energy – No need for third party materials or fuel • Electricity will not be cut off if external power lines are cut off  • Large Amount of Power – Large wind turbines may be connected to a power grid, resulting in a large amount of people to benefit from the electricity produced.  • No Non-Renewable Fuels – Wind power does not consume any non-renewable fuels such as coal, oil, or natural gas. • Plentiful Wind – Wind itself is very bountiful in the earth. • Non-Dispatchable– All output of wind turbines are taken when available as opposed to other sources of energy such as hydropower in which load management techniques must be employed to keep an equilibrium for supply with demand • Wind turbines may be dispatched on and off upon demand, without any wait time.

37. Disadvantages • Undesirable Appearance – Very tall apparatuses that some people regard as unsightly • Easily Damaged in Thunder-Storms – Wind turbines are easily damaged in thunder storms due to their overall tall, slim shape • Damaging to Birds – The blades of a wind turbine may hit birds flying in the general vicinity • Noise – Make a lot of noise: can be harmful to epileptics  • Cost – The overall cost for building and maintaining wind turbines is much more than other energy sources, second only to solar power

38. efficiency • Wind power is generally very efficient as they usually function at a medium voltage • 34.5 kV • Result: surplus energy • Endless supply of wind and it is completely free • 20% efficiency

39. Start-up costs • $65 393 400 for 50 MW plant: • Levelized cost: $149.3 per MWh • *8760 h/yr • $1 307 868 per MW/yr • *50 MW • $ 65 393 400

40. Maintenance costs • 10% of levelized costs: especially for new turbines • $ 6 539 340/yr

41. Ultimate price • $0.06/kWh

42. biofuels

43. General Information • Sugar & starch crops are fermented • Enzymes & microorganisms are used to break down the energy stored in these plants • Corn is most common source of biofuel

44. Advantages • Reduce dependence on foreign oils • Much more environmentally friendly that fossil fuels • Contributes to global warming much less • Bio-degradable • The carbon dioxide they release when burnt is equal to the amount that the plants absorbed out of the atmosphere • Does not require radical changes to machinery or new technology to accommodate this energy source • Bio-fuels can be used in cars or in replacement for anything fossil fuels were used for

45. Disadvantages • Extremely land-consuming • More farming land will have to be developed to produce bio-fuels • Food prices would rise • Bio fuels are currently not readily available which reduces their appeal • Production uses massive amounts of water which could strain local water reserves $

46. efficiency • Not very efficient because: • Diesel fuel used in the tractors for cultivation and harvest • Massive energy consumption of a typical ethanol production plant (much of which comes from coal-fired power plants) • Fertilizers used are largely synthesized from petroleum • Overall yield: 10% greater than the amount of fossil fuel used in production • Fossil fuel plants typically have a 50% efficiency, meaning biofuels have 60% efficiency

47. Start-up costs • $719 million

48. Maintenance costs • The total costs to the consumer in subsidizing ethanol and corn production: $8.4 million/yr • Producing the required corn feedstock increases corn prices • Ethanol production adds more than $1 billion to the cost of beef production/yr • Overall: market cost of biofuels are similar if not somewhat higher due to the increased food prices

49. Ultimate price • Total ethanol subsidies = $0.79/ litre • Ethanol = 66% as much energy per litre as gasoline • Corn ethanol costs $1.88/kWh • Gasoline costs $ 0.33/kWh

50. Conclusion