Key term
CCEA AS-Level Environmental Technology 3930
Fossil Fuels
Global Action on Energy Conservation and Climate Change
Macrogeneration
Microgeneration
Energy From Wind
Topic overviewHorizontal and vertical axis wind turbinesKinetic energy, wind power and the Betz limitPower curves, rated output and energy lossesSwept area, blade length and turbine massAir density, hub height and turbine sitingPower control, yawing and survival speedChoosing a location for a commercial wind farm
Energy From the Sun
Topic overviewSolar radiation, tracking and concentrating solar powerFlat plate and evacuated tube collectorsSizing a domestic solar thermal systemPhotovoltaic cells and semiconductor wafersTypes of photovoltaic module comparedPlanning regulations and solar incentivesPassive solar design in new and existing buildings
Energy From Biomass
Energy Storage
Plastics for the Future
Topic overviewCrude oil as a fuel and a feedstockRefinery gases and the making of polymersPersistent plastic waste and the Great Pacific Garbage PatchToxic gases from incinerating plasticsBiodegradable, photodegradable and compostable plasticsTesting photodegradable plastic against polytheneBio-derived polyethylene and a sustainable plastics future
Renewable Energy Investigations
Microgeneration
- 4 subtopics
- 12 things to know
- AS 1
What Microgeneration covers
Microgeneration is examined in Unit AS 1, The Earth's Capacity to Support Human Activity, a written examination. It covers microgeneration technologies, benefits of home and community microgeneration, the heat pump cycle and coefficient of performance and air source and ground source heat pumps.
Where it is assessed
AS 1
The Earth's Capacity to Support Human Activity — a written examination.
Check the CCEA specification ↗The 4 subtopics
Each one has its own page. CCEA AS Environmental Technology students sit this topic in the first year.
- Microgeneration technologiesWhat microgeneration is and its legal size limit, microelectricity and microheat technologies, reduced transmission losses, the Microgeneration Certification Scheme, grid-connected and off-grid systems, and the Isle of Eigg.Open →
- Benefits of home and community microgenerationLower bills and payback calculations, carbon savings, security of supply, the Feed-in Tariff and Smart Export Guarantee, the Boiler Upgrade Scheme, the Renewable Heat Incentive lesson and community ownership.Open →
- The heat pump cycle and coefficient of performanceThe refrigerant, evaporator, compressor, condenser and expansion valve, one full cycle, the refrigerator as a heat pump, coefficient of performance and its calculations, and why COP falls with a larger temperature lift.Open →
- Air source and ground source heat pumpsHow air source and ground source pumps work and compare, closed and open loops, horizontal, vertical and pond loops, slinky coils, emitters, a running-cost comparison with oil, and matching a pump to a home.Open →
What you need to know
Answer each one before you reveal it.
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Key term
Demonstrate how a heat pump works by describing one full cycle of the refrigerant.
Key term
Define microgeneration.
Key term
Identify the main benefits of home and community microgeneration.
Process
How does an air source heat pump work?
Numbers
How does UK law define the upper size limit of microgeneration?
Key term
How does microgeneration reduce a household's energy costs?
Process
How does a ground source heat pump work?
Key term
How does microgeneration differ from macrogeneration?
Numbers
A household microgeneration system costs £9,000 and saves £750 a year. Calculate its simple payback period.
Key term
What is a heat pump?
Key term
Why does a ground source heat pump usually achieve a higher COP than an air source heat pump?
Take Microgeneration further
The same content, four other ways.
Commonly confused
Pairs that lose marks when they are blurred together.
Macrogeneration vs Microgeneration
Macrogeneration: large-scale electricity production at centralised power stations. Microgeneration: small-scale production of heat or electricity close to where it is used.
Evaporator vs Condenser
Evaporator: the heat exchanger where cold refrigerant absorbs heat and boils. Condenser: the heat exchanger where hot refrigerant gives out heat and liquefies.
Compressor vs Expansion valve
Compressor: the electrically driven part that raises refrigerant pressure and temperature. Expansion valve: the restriction that lowers refrigerant pressure so that it cools.
Questions from this topic
Each one with the model answer underneath.
- 1
Define microgeneration.
Model answer
Microgeneration means producing heat or electricity on a small scale. Households, communities and small businesses generate the energy close to where it is used.
- 2
How does UK law define the upper size limit of microgeneration?
Model answer
The Energy Act 2004 defines microgeneration as up to 50 kW of electrical capacity or 45 kW of thermal capacity.
- 3
How does microgeneration differ from macrogeneration?
Model answer
Macrogeneration produces electricity in large, centralised power stations and sends it through the grid. Microgeneration produces small amounts of heat or electricity at or near the point of use.
- 4
List the main microelectricity technologies.
Model answer
The main microelectricity technologies are solar photovoltaic panels and small wind turbines.
- 5
List the main microheat technologies.
Model answer
The main microheat technologies are solar thermal collectors, ground source heat pumps and biomass boilers.
- 6
Why is a ground source heat pump classed as a microheat technology even though it runs on electricity?
Model answer
A ground source heat pump collects heat stored in the ground, which is renewed by the Sun. The pump delivers several times more heat than the electrical energy it uses.
What is inside Levo
Six ways to work the same material.
Microgeneration revision questions
- Is Microgeneration examined at AS in CCEA Environmental Technology?
- Yes. It sits in AS 1, which you take in the first year, so it is on the AS paper as well as counting towards the full A level.
- What does Microgeneration cover in CCEA AS-Level Environmental Technology?
- 4 subtopics: microgeneration technologies, benefits of home and community microgeneration, the heat pump cycle and coefficient of performance and air source and ground source heat pumps. Each one has its own page with questions and model answers.
- How is Microgeneration organised?
- By the CCEA 3930 specification, subtopic by subtopic, so it matches the order you are taught it in.
Every question in Microgeneration, on a schedule.
Attempt a question from memory, write the correct version, then attempt it again. Levo records the jump between your first attempt and your last, and brings each question back on the day you are due to forget it.
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