How the 75 marks of AS Environmental Technology split between Section A and the 15-mark essay, why the Betz limit and swept area calculations need the formula shown, and the named merits that beat generic praise.
閱讀時間 3 分鐘更新於: 2026年9月3日
試卷概覽
卷數
1
總分
75
考試時間
1小時 30分鐘
題型
11
試卷
時間
分數
題數
比重
題型
AS 1: The Earth's Capacity to Support Human Activity
1小時 30分鐘
75
7
50%
Short recall / identification, Multi-step process description, Structured discussion (3 points x 2 marks), Diagram and component explanation, Graphical analysis and comparison, Extended response essay (乙部)
評級
ABCDEU
計算機規定
Calculators are permitted and needed for this paper's wind energy, Betz limit and solar calculations. The standard JCQ rule applies: no retrievable information stored in the calculator, including saved formulae, notes or programs. Clear your calculator's memory before the exam, write the formula on the page before you calculate, and switch on exam mode if your calculator has one.
AO1: AO1: knowledge and understanding of environmental technology (36%)
AO2: AO2: the application of skills, knowledge and understanding through different contexts associated with environmental technology (36%)
AO3: AO3: the ability to investigate, analyse, evaluate, make reasoned judgements and communicate findings about issues in environmental technology (28%)
Live wind kinetic energy and Betz limit calculation
用途: Get the total wind power available and the maximum power a turbine could theoretically extract under the Betz limit, from air density, swept area and wind speed.
使用時機: For wind energy questions that ask for total wind power or the Betz limit maximum extractable power.
步驟
Calculate total wind power as one live sequence: 0.5, times, air density, times, swept area, times, wind speed cubed, equals. Then multiply that result by 0.593 to find the maximum power a turbine could theoretically extract under the Betz limit.
考試提示: Perform this live from the figures given in the question, with your formula written on the page. CCEA and JCQ rules do not allow any formula, note or program to be stored in the calculator beforehand. Clear the memory before the exam and use exam mode if your calculator has one.
Live swept area from radius, not diameter
用途: Get a turbine's swept area correctly from a given blade diameter, without missing the step of halving it to reach the radius.
使用時機: For wind turbine questions that give a blade diameter and ask for the swept area.
步驟
If the question gives a blade diameter, halve it first and write down the radius as a labelled step. Then key the swept area as one sequence: radius, times, radius, times, pi, equals.
考試提示: This is a live calculation from data printed in the exam. No figures or formulae may be pre-stored in the calculator, which is not permitted under JCQ rules.
Live solar module count, rounded up
用途: Get the number of solar modules needed to meet a required annual energy output, correctly rounded up to a whole module.
使用時機: For solar energy questions that give a required annual energy figure and an output per module, and ask how many modules are needed.
步驟
Divide the required annual energy by the output of a single module, as one live sequence: required energy, divide, output per module, equals. Round the result up to the next whole module, since a fraction of a module cannot be installed.
考試提示: Carry out this division live from the figures given, and apply the rounding rule by hand. No formula or prior result may be stored in the calculator ahead of the exam.
常見錯誤
1high涉及分數: 2Energy from wind
Carrying out a coefficient of performance or wind kinetic energy calculation without writing the formula out first.
如何避免: Write the formula as its own line before you substitute any figures into it. Method marks are awarded for the formula as well as the final answer.
2high涉及分數: 2Macrogeneration and microgeneration
Giving generic advantages for a renewable energy system, such as "clean energy", instead of a specific technical or economic merit.
如何避免: Replace adjectives with named mechanisms: say the technology mitigates price volatility or provides off-grid independence, not that it is simply clean or green.
3medium涉及分數: 2Energy from the sun
Confusing flat-plate solar collectors, which use direct thermal conduction, with evacuated tube collectors, which use a phase-change heat exchanger.
如何避免: When comparing the two, state the mechanism for each by name and link it to the performance difference the question asks about.
4high涉及分數: 2Energy from wind
Using a given diameter directly in the swept area formula, \(\pi r^2\), instead of converting it to a radius first.
如何避免: Halve the diameter as a written first step, labelled radius, before you square it and multiply by pi.
5medium涉及分數: 2Energy from biomass
Confusing aerobic and anaerobic processes when explaining how biogas is generated from biomass.
如何避免: State explicitly that biogas comes from anaerobic digestion, in the absence of oxygen, before describing the stages that follow.
6medium涉及分數: 2Energy from wind
Quoting the Betz limit as 59.3 percent without explaining the physical principle, that extracting all of a wind's kinetic energy would stop the air completely and prevent further flow.
如何避免: Add one sentence on why the limit exists, then show the calculation, total wind power multiplied by 0.593, rather than quoting the figure alone.
7medium涉及分數: 2Energy from wind
Assuming doubling a turbine blade's length simply doubles its mass, rather than mass scaling with the cube of length.
如何避免: Apply the cubic relationship directly: doubling blade length multiplies mass by roughly eight, not two.
8high涉及分數: 1Energy from the sun
Rounding a solar module calculation down to the nearest whole module instead of up to the minimum number needed to meet the required energy threshold.
如何避免: Always round module calculations up. A system that falls short of the target because you rounded down has not met the brief.