Environmental technologies Flashcards
What is the purpose of permitted development in the context of building regulations?
To allow certain building work without needing planning permission.
Which act brought microgeneration under the requirements of the Building Regulations in the UK?
The Climate Change and Sustainable Energy Act 2006.
Who is responsible for ensuring that Building Regulations have been met during the installation of microrenewable technologies?
The installer.
What are the key components of a solar thermal hot-water system?
A solar thermal collector, a differential temperature controller, and a hot-water storage cylinder.
Which part of the Building Regulations in England focuses on ventilation in buildings?
Part F
What is the primary source of energy for a solar thermal hot-water system?
Solar radiation
Which term refers to the small-scale generation of heat or electric power by individuals, small businesses, and communities?
Microgeneration
What is the purpose of a differential temperature controller in a solar thermal hot-water system?
To regulate the temperature of the hot water
Which part of the Building Regulations in England deals with the conservation of fuel and power?
Part L
What is the role of Local Authority Building Control (LABC) in the context of Building Regulations?
Checking for compliance with Building Regulations.
What is the primary purpose of Permitted Development in the context of building regulations?
To streamline the planning application process.
Which organization is responsible for checking compliance with Building Regulations in the UK?
Local Authority Building Control (LABC)
What is the purpose of an Approved Document in relation to Building Regulations in England?
To serve as a non-statutory guideline on how to comply with statutory requirements.
In England, which part of the Building Regulations focuses on drainage and waste disposal in buildings?
Part H
Which term describes the small-scale generation of electric power or heat for self-use, as an alternative to grid-connected power?
Microgeneration
Which technology uses solar radiation to produce heat directly or indirectly?
Solar thermal (hot-water) systems
In the UK, which Part of the Building Regulations deals with electrical safety in buildings?
Part P
What is the primary purpose of a circulating pump in a solar thermal hot-water system?
To transport solar radiation from the collector to the storage cylinder
Which Act in the UK brought microgeneration under the purview of the Building Regulations?
The Climate Change and Sustainable Energy Act 2006
Which Building Regulations in England focus on the structure of buildings?
Part A
What is the primary function of a solar thermal collector?
To absorb heat radiation from the Sun
Which of the following statements is true about flat-plate collectors compared to evacuated-tube collectors?
Flat-plate collectors are less efficient but cheaper.
What is the primary purpose of insulation in a flat-plate solar thermal collector?
To prevent heat from escaping
: In an evacuated-tube collector, what is the role of the heat tube containing methanol?
To transfer heat to the heat-transfer fluid
What happens to the methanol vapor in the heat tubes of an evacuated-tube collector when it is heated?
It condenses and flows down the tubes.
In which type of cylinder does the lower coil represent the solar heating circuit?
Twin-coil cylinder
What distinguishes a direct system from an indirect system in solar thermal hot-water systems?
In a direct system, the hot water for taps circulates through the solar collector.
What serves as the auxiliary heat source when there is insufficient solar energy available for hot water?
Electric immersion heaters
What is the ideal orientation for solar collectors to maximize efficiency?
Due south
What percentage of sunlight blockage can significantly reduce a solar collector’s efficiency?
35%
Which Part of the Building Regulations in the UK deals with energy efficiency and fuel conservation?
Part L
What type of solar thermal collector is generally considered more efficient but also more expensive?
Evacuated-tube collector
Which component of a solar thermal system is responsible for circulating the heat-transfer fluid in the solar hot-water circuit?
Circulating pump
In a twin-coil cylinder, which coil represents the auxiliary heating circuit?
Upper coil
What is the ideal angle for solar collectors in the UK to maximize their efficiency?
35 degrees
What is the primary purpose of a differential temperature controller (DTC) in a solar thermal system?
To control the temperature difference between the collector and hot-water storage
What type of water is typically used as the heat-transfer fluid in solar thermal systems?
Water mixed with antifreeze (glycol)
In a direct system, what circulates through the solar collector and is drawn off at the taps?
The same water used for taps
Which regulatory document outlines the wiring regulations for solar thermal systems?
BS 7671: 2018 (2022) The IET Wiring Regulations
What is one of the advantages of solar thermal hot-water systems?
Reduced CO2 emissions
What is the primary purpose of a heat pump?
To extract and transfer heat energy
At what temperature does heat energy cease to exist in a system?
-273°C
What is the primary role of the compressor in a heat pump?
To compress the refrigerant and raise its temperature
How does heat move according to the basic rule of heat transfer?
From warmer spaces to colder spaces
What is the efficiency of a heat pump typically measured with?
Coefficient of Performance (COP)
Which type of heat pump is more efficient in milder weather conditions?
Air-source heat pump (ASHP)
What is the purpose of a buffer tank in a heat pump system?
To allow continuous operation and store excess heat
What is the primary advantage of using under-floor heating with a ground-source heat pump (GSHP)?
Higher heat output
Which component of a heat pump system can provide cooling during the summer by reversing the refrigeration process?
Compressor
What is the primary source of heat energy that heat pumps extract and transfer?
Air or ground
What role does the refrigerant play in a heat pump system?
Absorbing and releasing heat
What does COP stand for in the context of heat pump efficiency?
Coefficient of Performance
In what situation does a heat pump work most efficiently?
In mild weather
What is the primary function of a buffer tank in a heat pump system?
To maintain continuous operation
Which type of heat pump is suitable for both heating and cooling applications?
Air-source heat pump (ASHP)
What is the primary advantage of using low-temperature radiators with a ground-source heat pump (GSHP)?
Reduced maintenance costs
Which component of a heat pump system is responsible for extracting heat from the ground?
Heat-collection loops and a pump
In a ground-source heat pump (GSHP) system, how are the heat-collection loops typically installed?
In horizontal trenches
What temperature does the heat output from a ground-source heat pump (GSHP) typically reach?
40°C
What is the primary source of heat energy that air-source heat pumps extract and release?
Low-temperature air
What are the key components of an air-source heat pump (ASHP)?
A heat exchanger, a compressor, and an expansion valve
How does an air-source heat pump (ASHP) work in relation to a refrigerator?
ASHP releases heat to the outside like a refrigerator
What type of heating system is ideally suited to be coupled with an air-source heat pump (ASHP)?
Under-floor heating or warm-air heating
In what type of premises are air-source heat pumps (ASHPs) an ideal solution?
New-build properties with high insulation levels and under-floor heating
Under what conditions is planning permission typically required for the installation of an air-source heat pump (ASHP)?
Only for listed buildings or buildings in conservation areas
What is the primary disadvantage of air-source heat pumps (ASHPs) compared to ground-source heat pumps (GSHPs)?
Lower efficiency in mild weather
Why do air-source heat pumps (ASHPs) generate noise?
Due to the fans
What does COP stand for in the context of air-source heat pump efficiency?
Coefficient of Performance
What is the primary advantage of air-source heat pumps (ASHPs) compared to ground-source heat pumps (GSHPs)?
Lower installation costs
Which of the following is NOT a key component of an air-source heat pump (ASHP)?
Buffer tank
What is the primary disadvantage of air-source heat pumps (ASHPs) during the winter?
Reduced efficiency
Which type of heat emitters (heating devices) is most suitable for use with an air-source heat pump (ASHP)?
Under-floor heating
Why is an ASHP more efficient in mild weather compared to cold weather?
The heat source is colder in mild weather
In which type of building are air-source heat pumps (ASHPs) typically NOT recommended?
Buildings in conservation areas
What is the purpose of the expansion valve in an air-source heat pump (ASHP)?
To lower the refrigerant’s pressure and temperature
What does the acronym MCS stand for in the context of ASHP planning standards?
Microgeneration Certification Scheme
What type of heating system is NOT suitable for coupling with an air-source heat pump (ASHP)?
Gas-fired boiler
Which of the following is a disadvantage of air-source heat pumps (ASHPs) compared to ground-source heat pumps (GSHPs)?
Incompatibility with existing heating systems
What is the purpose of a defrost cycle in an air-source heat pump (ASHP)?
To keep the evaporator from freezing
What is the primary advantage of air-source heat pumps (ASHPs) over traditional gas or oil boilers in terms of environmental impact?
Reduced carbon dioxide (CO2) emissions
What is the major difference between biomass and fossil fuels?
Biomass is carbon-neutral, while fossil fuels are not.
Why is biomass considered a renewable energy technology?
It can be replenished as long as demand does not exceed replacement time.
What is a disadvantage of biomass compared to fossil fuels regarding heat output?
Biomass requires a greater quantity to achieve the same heat output.
Which of the following is NOT a class of biomass raw material that can be turned into biomass fuels?
Natural gas
What is the primary factor affecting the calorific value of woody biomass?
The moisture content of the wood
How do woody biomass boilers transfer heat to the central heating system?
Through a heat exchanger
In what circumstances would planning permission be required for the installation of a biomass boiler?
Only if the installation involves external work
What is an “exempt appliance” in the context of biomass heating?
An appliance designed to burn specific fuels without emitting smoke
What are the advantages of biomass fuels?
Carbon neutrality, sustainability, low greenhouse gas emissions
Which of the following is NOT an electricity-producing micro-renewable energy technology discussed in the section?
Geothermal
What is the main environmental concern associated with the use of biomass fuels?
Greenhouse gas emissions
How does the calorific value of woody biomass change with moisture content?
It decreases with higher moisture content.
What is the purpose of an inverter in an off-grid electricity-producing micro-renewable energy system?
To convert DC electricity to AC electricity
What is the significance of deep-cycle batteries in off-grid electricity-producing micro-renewable energy systems?
They can efficiently store and release electricity.
In on-grid electricity-producing micro-renewable energy systems, what happens to excess electricity generated?
It is exported back to the grid.
What type of connection exists in an off-grid electricity-producing micro-renewable energy system?
Off-grid connection
Why was the Clean Air Act of 1956 introduced in the United Kingdom?
To address poor air quality caused by smog from coal burning
What is the primary advantage of electricity-producing micro-renewable energy technologies over traditional fossil fuel-based electricity generation?
They produce no carbon emissions.
What is the lifespan of typical deep-cycle batteries used in off-grid renewable energy systems?
5 years
Which of the following is a potential disadvantage of using biomass for heat production compared to using a gas boiler?
Biomass is not carbon-neutral.
What is the primary function of a solar photovoltaic (PV) cell?
To convert light into electricity
Which semiconductor material is most commonly used in the production of PV cells?
Silicon
What type of semiconductor material is created by adding an impurity to silicon through the process of “doping”?
n-type semiconductor
How is the voltage generated in a photovoltaic cell when exposed to photons?
Photons allow electrons to overcome their bonds and generate voltage.
What is the primary purpose of connecting PV modules in series to create “strings”?
To increase the voltage output
In which type of PV system are PV modules used to charge batteries?
Off-grid systems
What is the key function of an inverter in a PV system?
To convert DC electricity to AC electricity
What is the primary purpose of a generation meter in a PV system?
To record the number of units generated
Which direction is considered optimum for the solar collectors (PV modules) to face in the UK?
Due south
What factor is responsible for reducing the efficiency of a PV system that does not face due south?
Shade
In which direction should PV modules ideally face to maximize energy generation throughout the day?
Due south
What is the maximum theoretical efficiency that can be obtained with a single junction silicon cell?
34%
Which type of PV module has the advantage of flexibility and is ideal for non-flat surfaces?
Amorphous film
What component of a PV system converts the DC input to a 230 V AC output?
Inverter
What type of connection is typically used to connect a PV system to the grid supply within domestic premises?
Grid-tied connection
What is the purpose of an isolator in a PV system?
To allow isolation for maintenance
Under what circumstances might planning permission not be required for the installation of a PV system on a dwelling house?
If specific criteria are met
In which case is planning permission typically required for a PV system installation?
On a dwelling house in a conservation area
What is the maximum allowable height for a stand-alone PV array in the UK?
4 meters
What direction should a PV array face to achieve the most efficient energy generation in the UK?
South
In an on-grid PV system, what is the primary purpose of AC cabling?
To synchronize with the mains supply frequency
What is the main function of tracking systems in PV mounting systems?
To change both azimuth and tilt to track the Sun’s position
Why are on-roof PV systems commonly used for retrofit installations?
They do not require additional mounting systems.
What is the function of DC isolators in a PV system?
To allow isolation for maintenance or emergencies
Which PV system type is ideal for locations with no mains supply and relatively small power demand?
Off-grid system
What is the primary purpose of deep-discharge batteries in an off-grid PV system?
To store excess electricity
In a PV system, what does “wind uplift” refer to?
The force exerted by the wind on the module and mounting system
Which type of PV module is known for its higher efficiency but is generally more expensive to purchase?
Monocrystalline modules
What is the primary purpose of the isolator at the intake position in a PV system connected to the grid?
To isolate the PV system from the grid for safety or maintenance
In a PV system, what determines the suitability of a location for installation?
Factors such as orientation, shading, and location within the UK
What is one advantage of solar PV systems?
They use zero-carbon technology.
What is a disadvantage of solar PV systems?
They give variable output dependent on sunshine.
Which of the following is NOT a disadvantage of solar PV systems?
Reduction in electricity imported
What is an advantage of micro-wind systems?
They produce no CO2 emissions.
Which of the following is a disadvantage of micro-wind systems?
They have high initial costs.
What is an important consideration when installing a micro-wind turbine?
Turbine vibration should be addressed.
When can permitted development apply to building-mounted wind turbines?
Only for detached premises
What is NOT a condition for permitted development of wind turbines?
Minimum distance of 2 m from the boundary
Which of the following is an advantage of solar PV systems related to electricity generation?
They generate electricity even on cloudy days.
What is a primary disadvantage of solar PV systems in terms of aesthetics?
They can detract from the building’s visual appeal.
Which aspect of solar PV systems contributes to reducing electricity bills?
Selling excess electricity to the grid
Why can micro-wind systems be particularly effective in the UK?
The UK experiences strong Atlantic winds.
What is a common drawback of micro-wind systems related to their performance?
Dependence on wind availability
Why might micro-wind turbines cause shadow flicker?
Because their blades obstruct sunlight
In which season do micro-wind systems tend to produce the most energy?
Winter
What is an essential consideration when installing a micro-wind turbine in terms of noise?
Turbine noise can affect nearby buildings.
Which of the following is NOT a factor considered for permitted development of wind turbines?
Location within a national park
What is the main advantage of micro-wind systems in areas without access to mains electricity?
They can provide an independent source of electricity.
What is the primary benefit of selling excess electricity generated by solar PV systems back to the grid?
It reduces the amount of electricity imported.
Why is it important to consider the average wind speed when determining the suitability of a location for a micro-wind turbine?
Wind turbines work best at higher wind speeds.
What is the primary source of kinetic energy harnessed by micro-hydro-electric generation?
Water flow from higher to lower levels
In micro-hydro systems, what is the purpose of the forebay?
To ensure the penstock remains pressurized and handle surges in demand
What is “gross head” when determining the suitability of a water source for hydro-electric generation?
The vertical height difference between the inlet and outlet positions
Which of the following is a classification of head height typically used when assessing water sources for micro-hydro systems?
Medium head, 10–50 m
What is “net head” used for in micro-hydro calculations?
It calculates potential power generation, accounting for losses due to friction.
Which type of turbine is typically used with high-head water sources?
Pelton turbine
What is the primary advantage of the reverse Archimedes’ screw turbine?
It is suitable for fish migration.
Why is planning permission required for micro-hydro schemes?
To consider environmental impacts and measures to minimize them
Which of the following is NOT one of the regulatory requirements to consider for micro-hydro systems?
Traffic regulations
What is a significant advantage of micro-hydro systems over some other microgeneration technologies?
They are not affected by weather conditions.
What role does the penstock play in a micro-hydro system?
It connects the intake to the forebay.
What is the primary purpose of an environmental statement in the context of a micro-hydro scheme?
To describe environmental impacts and mitigation measures.
Which type of turbine is most suitable for low-head water sources?
Archimedes’ screw turbine
Why is an impoundment licence required in micro-hydro systems?
To control the water flow within the main stream of water.
What is a significant advantage of micro-hydro systems over other renewable energy sources like solar and wind?
They produce electricity year-round.
What is the primary function of the tailrace in a micro-hydro system?
To return water exiting the turbines to the main stream or river
Which type of turbine operates with water jets driving the runner and is typically used with high-head water sources?
Pelton turbine
What is the main reason why planning permission is required for micro-hydro schemes?
To consider environmental impacts and minimize them
What does “net head” take into account when calculating potential power generation in a micro-hydro system?
Losses due to friction in the penstock
In a micro-hydro system, which type of turbine is most suitable for low-head water sources and is designed to be “fish-friendly”?
Archimedes’ screw turbine
What is the primary function of an mCHP unit?
To generate heat as the primary function, with electricity generation as a secondary function.
Which fuel sources are commonly used to power domestic mCHP units?
Natural gas and liquid propane gas (LPG)
What is the main advantage of locally generated power by mCHP units?
It reduces transmission losses.
What type of engine is typically used in domestic mCHP units to produce electricity?
Stirling engine
In what type of building is an mCHP system most viable in terms of carbon savings?
Buildings with a high demand for space heating
What is the primary function of the supplementary burner in an mCHP unit?
To provide backup heating when there is a high demand for heat
What type of gas is typically used within a Stirling engine in an mCHP unit?
Helium
Why is an mCHP system considered a carbon-reduction technology rather than a carbon-free technology?
It reduces carbon emissions compared to conventional power generation.
What is the primary benefit of connecting an mCHP unit to the supply via a dedicated circuit?
It facilitates easy isolation of the generator from the incoming supply.
In which type of building is an mCHP system least likely to be suitable?
Small, well-insulated buildings
What is the primary advantage of using gas in an mCHP system for electricity generation?
Gas is cheaper than electricity, resulting in cost savings.
What is the primary disadvantage of mCHP systems in terms of electricity generation capacity?
They have limited capacity for the generation of electricity.
What is the primary purpose of an environmental statement in the context of mCHP system installation?
To describe environmental impacts and mitigation measures.
In what type of location is a micro-CHP system typically powered by biomass fuels?
Rural areas
What is the efficiency of an mCHP unit in terms of electricity generation compared to a modern condensing boiler?
Same efficiency
What is the key component responsible for generating electricity in an mCHP unit?
Stirling engine generator
Which type of engine is used in a Stirling engine generator in an mCHP unit?
None of the above (Stirling engines are distinct from internal combustion engines)
What is the primary function of the engine burner in an mCHP unit when there is demand for heat?
To preheat the heating-system return water
In terms of cost savings, why is locally generated power by mCHP units advantageous compared to using electricity from the grid?
Locally generated power reduces transmission losses.
What is the main reason for using a Stirling engine in mCHP units?
Stirling engines are quieter.
In which type of building is mCHP most likely to result in greater carbon savings?
Buildings with a high demand for space heating
Why is planning permission not typically required for the installation of an mCHP unit inside a domestic dwelling?
The installation is considered a permitted development.
What is one common perception about the climate of the UK mentioned in the text?
The UK has a lot of rain, especially in the west.
Why are hose-pipe bans common in many parts of the UK during the summer months?
Because water supply systems are overwhelmed by increased demand.
What are the two methods of water conservation discussed in the text?
Rainwater harvesting and reuse of greywater.
What does a water bill typically consist of?
Charges for fresh water supplied and charges for sewage or waste water taken away.
How can water conservation reduce the cost of water bills?
By reducing the demand for water.
What percentage of an average household’s consumption is used for flushing toilets?
28.1%
Why is rainwater considered a valuable resource for conservation?
Rainwater can replace wholesome water for various non-drinking purposes.
What is the primary limitation of using rainwater for drinking purposes?
Rainwater is classified as ‘fluid category 5’ risk.
What is the first step in the process of rainwater harvesting?
Collection
What factors determine the amount of rainwater that can be collected during rainfall?
The size of the storage tank and the number of downpipes.
What is the purpose of filtration in the rainwater harvesting process?
To remove debris and contaminants.
what is the primary purpose of storage tanks in rainwater harvesting?
To protect rainwater from direct sunlight.
How is the size of a rainwater storage tank typically determined?
Based on 5% of the annual rainwater supply or anticipated demand.
What type of pump is used to transport rainwater from the storage tank to the point of demand?
Submersible pump
What is the purpose of an overflow pipe in a rainwater storage tank?
To connect to the drainage system of the property.
Which type of water is considered suitable for direct consumption in the UK?
Wholesome water
What is the primary purpose of an indirect distribution system in greywater reuse?
To prevent cross-contamination with wholesome water.
What is the primary method of treating greywater in a short-retention system?
Filtration
Which system uses biological and physical methods to treat greywater?
Biomechanical system
Why is an air gap maintained between wholesome water and greywater in greywater reuse systems?
To provide backflow prevention and avoid cross-contamination.
What is the primary purpose of rainwater harvesting?
To reuse rainwater for various non-drinking purposes.
What can rainwater harvested from hard standings, such as driveways, be contaminated with?
Organic matter and bacteria.
Why is it essential to protect rainwater storage tanks from direct sunlight?
To prevent algae growth.
Which of the following is NOT a suitable use for harvested rainwater?
Washing dishes
What is the primary purpose of the short-retention system in greywater reuse?
To reduce water usage in toilets.
In a biomechanical system for greywater reuse, which substances are filtered out during the treatment process?
Soap, detergents, and cosmetic products.
Why is it essential to label outlets supplied with treated greywater and indicate that the water is not suitable for drinking?
To prevent cross-contamination with wholesome water.
: What type of pump is typically used in a direct distribution system for greywater reuse?
Centrifugal pump
Why are there long payback periods associated with greywater reuse systems?
Because of the initial high installation costs.
