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Questions and Answers
What is the annual heating demand if direct electric heating is utilized with a thermal efficiency of 98%?
What is the annual heating demand if direct electric heating is utilized with a thermal efficiency of 98%?
What is the primary heating technology used in the residential sector in Norway?
What is the primary heating technology used in the residential sector in Norway?
Which fossil fuel is considered highly polluting?
Which fossil fuel is considered highly polluting?
If you switch to a heat pump with a COP of 3, how is your annual energy saving calculated from the heating demand of 15 MWh?
If you switch to a heat pump with a COP of 3, how is your annual energy saving calculated from the heating demand of 15 MWh?
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What unit represents energy in the equation E=∫pdt where p is in kJ/s and t is in s?
What unit represents energy in the equation E=∫pdt where p is in kJ/s and t is in s?
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What is an effective way to reduce GHG emissions?
What is an effective way to reduce GHG emissions?
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Which statement is true regarding the conservation of energy?
Which statement is true regarding the conservation of energy?
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What is ocean thermal energy primarily derived from?
What is ocean thermal energy primarily derived from?
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How much power was used to charge the battery if it increased from 20% to 80% over 6 hours with a total capacity of 60 kWh?
How much power was used to charge the battery if it increased from 20% to 80% over 6 hours with a total capacity of 60 kWh?
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What is the equivalent of 1 kWh in megajoules?
What is the equivalent of 1 kWh in megajoules?
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Which statement about renewable energy sources is true?
Which statement about renewable energy sources is true?
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What is the correct equivalent of 2000 MWh?
What is the correct equivalent of 2000 MWh?
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What does efficacy demonstrate in lighting?
What does efficacy demonstrate in lighting?
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Which energy source is characterized as a 'use it or lose it' type?
Which energy source is characterized as a 'use it or lose it' type?
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If your annual heating demand is 15 MWh with a thermal efficiency of 98%, what is your annual electric energy consumption?
If your annual heating demand is 15 MWh with a thermal efficiency of 98%, what is your annual electric energy consumption?
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If your annual heating demand is 15 MWh and the efficiency of fuel oil is 85%, how much fuel energy is actually needed?
If your annual heating demand is 15 MWh and the efficiency of fuel oil is 85%, how much fuel energy is actually needed?
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Which component in a hydropower plant is responsible for preventing unwanted material from entering the turbine?
Which component in a hydropower plant is responsible for preventing unwanted material from entering the turbine?
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What does net head in a hydropower plant refer to?
What does net head in a hydropower plant refer to?
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Why is a tunnel referred to as a 'pressure tunnel' in a hydropower plant?
Why is a tunnel referred to as a 'pressure tunnel' in a hydropower plant?
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What is the primary concern when trying to balance demand and supply in a grid system?
What is the primary concern when trying to balance demand and supply in a grid system?
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What is one significant benefit of having a large reservoir in a hydropower plant aside from power generation?
What is one significant benefit of having a large reservoir in a hydropower plant aside from power generation?
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If the grid frequency rises to 50.5 Hz, which action would help in balancing the demand and supply?
If the grid frequency rises to 50.5 Hz, which action would help in balancing the demand and supply?
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What percentage of the total hydropower capacity in Norway is flexible?
What percentage of the total hydropower capacity in Norway is flexible?
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Which statement about the hydropower industry in Norway is accurate?
Which statement about the hydropower industry in Norway is accurate?
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Which action is most appropriate when the grid frequency is recorded at 49.5 Hz?
Which action is most appropriate when the grid frequency is recorded at 49.5 Hz?
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What geographical features make underground tunnels preferable for hydropower in Norway?
What geographical features make underground tunnels preferable for hydropower in Norway?
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How can you effectively manage a scenario where your installed 100 kW wind turbine's supply fluctuates while your demand varies highly?
How can you effectively manage a scenario where your installed 100 kW wind turbine's supply fluctuates while your demand varies highly?
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In response to an unexpected surge in grid frequency, which method might not be effective for balancing?
In response to an unexpected surge in grid frequency, which method might not be effective for balancing?
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What challenges does the construction of surface mounted penstocks face in Norway?
What challenges does the construction of surface mounted penstocks face in Norway?
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When grid frequency is stable but demand exceeds supply, what is the best strategy?
When grid frequency is stable but demand exceeds supply, what is the best strategy?
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If you do not have storage and your wind turbine supplies 100 kW while demand is at 20 kW, what action can you take?
If you do not have storage and your wind turbine supplies 100 kW while demand is at 20 kW, what action can you take?
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What should be done when demand is significantly low, and the grid frequency increases as a result?
What should be done when demand is significantly low, and the grid frequency increases as a result?
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What action should be taken to balance a demand of 6 MW and a wind turbine production of 7.5 MW if the storage is fully charged?
What action should be taken to balance a demand of 6 MW and a wind turbine production of 7.5 MW if the storage is fully charged?
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What is the relationship between the availability factor and the capacity factor of a wind turbine?
What is the relationship between the availability factor and the capacity factor of a wind turbine?
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Why is the capacity factor of solar PV generally lower than that of wind turbines?
Why is the capacity factor of solar PV generally lower than that of wind turbines?
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Which type of power plant is best suited for integrating with wind power?
Which type of power plant is best suited for integrating with wind power?
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What is the formula for the overall efficiency of a system with n identical components connected in series?
What is the formula for the overall efficiency of a system with n identical components connected in series?
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What might be a reason for the fluctuating demand patterns between winter and summer?
What might be a reason for the fluctuating demand patterns between winter and summer?
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Why is it important to curtail wind power production during periods of low demand?
Why is it important to curtail wind power production during periods of low demand?
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What is the likely impact of fully charged storage on energy management on a windy day?
What is the likely impact of fully charged storage on energy management on a windy day?
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Study Notes
Electric Car Charging
- An electric car battery with a capacity of 60 kWh charged for 6 hours increased its charge from 20% to 80%.
- The car used a power of 10 kW to charge the battery.
Energy Conversion
- 1 kWh is equivalent to 3.6 MJ.
Renewable Energy
- Renewable energy sources typically have lower energy density compared to fossil fuels.
Energy Units
- 2000 MWh is equivalent to 7.2 TJ.
Efficacy
- Efficacy shows the amount of light output in lumens per W of electricity consumed.
- Fluorescent lamps usually have higher efficacy than incandescent lamps.
Energy Sources
- Wind and solar energy are "use it or lose it" types of energy sources.
Heating Systems
- A house with an annual heating demand of 15 MWh and a 98% efficient electric heater will consume 15.31 MWh of electric energy annually.
- Switching from an 85% efficient fuel oil heating system to a 98% efficient electric system results in an annual energy saving of 1.86 MWh.
- Switching to a heat pump with a COP of 3 from a 98% efficient electric heating system results in an annual energy saving of 10.31 MWh.
Energy Conservation
- Energy cannot be created or destroyed, only transformed from one form to another.
Energy Calculations
- The unit of E (energy) in the equation E=∫pdt is kJ, where p is power in kJ/s and t is time in s.
Residential Heating in Norway
- The primary heating technology in Norwegian residential areas is heat pumps.
Fossil Fuels and Pollution
- Coal is a highly polluting fossil fuel.
Greenhouse Gas Emission Reduction
- Sustainable energy production and utilization, improved energy efficiency, carbon capture & storage (CCS), and carbon capture & utilization (CCU) can all help reduce greenhouse gas emissions.
Ocean Thermal Energy
- Ocean thermal energy is available in oceans, seas, and fjords.
- Water temperatures of 7-9 degrees Celsius can be found just 50-100 meters below the surface of fjords, even in winter.
Wind Turbine Integration
- Balancing supply and demand without grid connection requires storage or a diesel generator.
- If a grid frequency suddenly increases to 50.5 Hz, reducing hydropower production or starting low-priority loads can help balance the system.
- If a grid frequency suddenly reduces to 49.5 Hz, increasing hydropower production or shutting down low-priority loads help balance the system.
- Curtailing wind power production is necessary when storage is full and demand is lower than wind turbine output.
Wind Turbine Availability and Capacity Factors
- The availability factor of a wind turbine is always less than or equal to the capacity factor.
Solar PV and Wind Turbine Capacity Factors
- Wind turbines typically have higher capacity factors than solar PV because wind is available throughout the day, while solar radiation is only available during daylight hours.
Power Plant Integration with Wind Power
- Gas turbine power plants and reservoir hydropower plants are well suited for integrating wind power.
System Efficiency
- For a system with n components in series, each with the same efficiency (η), the system efficiency is η^n^.
Hydropower
- Concrete or steel-lined tunnels are used for high-pressure water transport in hydropower plants.
- Steel-lined tunnels are used for high-pressure water transport in hydropower plants.
- Unlined tunnels (shotcrete or concrete spray) are used for water transport in hydropower plants.
- The trash rack acts as a barrier to prevent unwanted materials from entering the turbine in a hydropower plant.
- Net head in a hydropower plant is the gross head minus the head loss.
- Pressure tunnels in a hydropower plant are called this because they transport water under pressure.
- Reservoir hydropower plants offer benefits beyond power production, including water supply storage, fishing, recreation, and transportation.
- Approximately 95% of Norway's total hydropower capacity is flexible.
Underground Hydropower
- The hydropower industry in Norway is primarily underground.
- Norway's topography (steep mountains) and geological conditions (hard rock) favor the use of underground tunnels for hydropower.
- Surface-mounted penstocks are difficult to install in steep mountains and are susceptible to rockfalls, slides, and avalanches.
- The decision to move hydropower operations underground was driven by factors like the shortage of steel supply and high steel prices following World War II.
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Description
Test your knowledge about electric car charging, energy conversion, and renewable energy sources. This quiz covers fundamental concepts such as energy units, efficacy, and heating systems. Challenge yourself to see how well you understand the principles of sustainable energy.
