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Primary v. Secondary Energy Sources
Primary v. Secondary Energy Sources
Primary energy consists of unconverted or original fuels. For example, primary energy sources include petroleum, natural gas, coal, biomass, flowing water, wind, and solar radiation. Those are the fuels that can be mined, reaped, extracted, harvested, or harnessed directly.
Secondary energy includes resources that have been converted or stored. Secondary energy cannot be harnessed directly from nature; rather, secondary energy is energy that has already been converted.
Energy Sources Organized
Energy Sources Organized
Energy Source - B5 2022-24
Energy Source - B5 2022-24
Energy Sources - B7 2022-24
Energy Sources - B7 2022-24
Wind Power Calculations
Wind Power Calculations
Power extracted is P(in) -P(out)
Gary has a wind turbine on his roof. The blade radius of the turbine is 5 m. The turbine is rated to generate power within wind speeds of 3 to 15 ms-1. After passing through the wind turbine the speed of the air drops 2 ms-1. This drop in velocity causes the air to increase in density from 1.2 kg m-3 to 1.4 kg m-3.
Determine the range of power extracted by Gary's wind turbine.
Gary has 3 TESLA PowerWall blocks installed in his house that can store a total of 40.5 kWh of energy. Suppose the average wind speed at Gary's house is 9 m/s, how long (in seconds) would be required to fully charge the TESLA PowerWall?
Wind Turbine Sample Prob.pdfHydroelectric Problem Solving
Hydroelectric Problem Solving
Model v. Reality: IB models stored hydro systems with output at bottom of reservoir. This allows for a more simplified calculation of height of water. Height of water is assumed to be at mid-point of reservoir. In the example to the left the height of the water is calculated using 127 m.
Energy conservation of Gravitational Potential Energy (mg∆h) is translated into electrical energy. Mass of water is typically determined using a density ratio of density x volume. Or a flow rate measured in volume per second (m^3/s) or mass per second (kg/s). This can the be used to calculate the power (P=mgh/t) or energy output (Pt = E).
Pumped Storage Systems
Pumped Storage Systems
Pumping water (or other mass) to a reservoir (greater height) at the top of a hill (or tower) when energy is in plentiful supply, then letting it flow back down through a turbine to generate electricity when demand increases.
Typically no calculations, only conceptual.
Solar Power - Photovoltaics
Solar Power - Photovoltaics
A question of area and efficiency.
The Masdar City Solar Photovoltaic Plant covers an area of 210 000 square meters. During peak production it can produce 10 MW of power. The average solar intensity falling on the farm is 240 W m–2.
Determine the efficiency of the MCSPP.
Determine the energy produced in a 10h period of typical day. Report this value in MWh.
Outline two ways in which Abu Dhabi could store the energy any excess energy produced during the day to use during non-daylight hours.
A typical Abu Dhabi home uses 11445 kWh of energy during a typical year. Determine the number of homes the MCSPP can support during a typical day.
State and explain two assumptions you made using the calculations above.
From the Physics Data Booklet:
1 kilowatt-hour (kWh) = 3.60x106 J
Solar Power - Solar Heating
Solar Power - Solar Heating
Conceptual understanding of basic function is all that is required.
Dimensional Analysis Practice:
Dimensional Analysis Practice:
Gold chains can be purchased for $8.00 USD per inch. How much would a 50.0 cm chain cost in AED? (1AED = 0.27USD). 583.26 AED
If a runner runs 26.2 miles in 3h 20 min, how many meters does she run each second? (1 mile = 1.609 km) 3.5 m/s
Chicago uses 1.2x109 gallons of water per day. How many liters must be pumped out of Lake Michigan per second? (1 gal = 3.785 L) 52569.4 L/s
Energy Problem Solving
Energy Problem Solving
Two Key Ideas
A kilowatt hour (kWh) is a measurement of energy (1 kilowatt-hour (kWh) = 3.60x106 J). Power companies bill by the kWh (energy), instead of kW (power), they (power companies) only care about the total energy consumed v. the rate at which you consume the energy (power).
Mass - rate or volume - rate, is a way of describing power. As can be seen in the following equations:
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