Norway (home to Chris!) is well-known as a producer of oil and gas. However, the landscape means that domestic electricity can be supplied entirely by hydroelectric power.
This page includes some interactive resources about three key renewable resources:
- Hydroelectric
- Wind
- Solar (both direct heating and photovoltaic cells
Key Concepts
Use quizzes to practise application of theory.
START QUIZ!
Which of the following sources of energy does not come from the sun?
tidal is from the moon the others are weather relates which is driven by the sun.
The diagram represents a mountain lake above a town.
The energy stored in the lake =
mgh
m = volume x density
h = average height
After a heavy rainfall the water flowing through a power station generating 1 MW increases from 1 m3s-1 to 3 m3s-1 . The power output will now be
power is proportional to flow rate
A hydro power station produces 1 MW when the flow rate is 1000 kgs-1.
Assuming it is 100% efficient what is the height of the water source?
mgh/t = 1000 x 10 x 100
A wind turbine produces 1 MW of power when the wind speed is 10ms-1. How much power is produced when the wind speed is 30ms-1?
power is proportional to wind speed cubed
A wind turbine is made with blades 1m long. To double the power output the blades should be changed to ones with length:
power is proportional to r2
1.4 is about √2 so increasing by this factor will double the power
The most widely use renewable source of energy (worldwide) is
they are all actually solar
Renewable sources of energy are not more widely used because
politics
Approximately what area solar cell would be needed to deliver 1kW on a sunny day? (assume 100% efficient)
Average intensity is about 350 Wm-2
A solar heating panel absorbs 1000 joules per second. Water flows through it at a rate of 100g per second.
If water flows in at 15 ℃ it will flow out at approximately
The specific heat capacity of water is 4200 Jkg-1K-1 so to heat 0.1 kg by 1℃ requires 420 J. 1000 J is about twice that so the temperature change is 2℃.
How much of Renewable sources II have you understood?
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