Demand Flashcards
Why is understanding and knowing electrical load important?
- To build adequate network and generation capacity
- operate networks efficiently
- meet electricity demand
- optimize energy costs
What factors affect the total electrical load of an area?
Population, living standards, economics, climate and other factors
What is domestic load?
The total energy consumed by household electrical appliances such as lights fans refrigerators air conditioners and heaters
What appliances are included in commercial loads?
Appliances in shops offices markets restaurants and advertisements including fans air conditioning and heating systems
What constitutes industrial load?
Electrical demand from small, medium and large-scale industries, with induction motors forming a major component of the load. dependent on frequency and voltage
What is a resistive load and how does it work?
A resistive load obstructs electrical energy flow converting it into thermal energy with current and voltage in sync
What are common examples of resistive loads?
Toasters ovens and space heaters
How does an inductive load function?
It uses wire coils to create inductive fields with current peaking after voltage
What are common examples of inductive loads?
Dishwashers, washing machines, refrigerators, air conditioners and electric motors
What is a capacitive load?
A load where current peaks before voltage commonly used to support inductive loads
What are examples of capacitive loads?
Capacitor banks and three-phase induction motor starting circuits
What is a load profile?
The variation of load concerning time plotted as power versus time
What factors affect domestic load profiles?
House income, number of bedrooms, number of inhabitants, education level, house type and weather
What challenges exist in commercial and industrial load profiles?
High demand uncertainties causing significant challenges in network planning and operation
What is load factor in power systems?
It is the ratio of actual kilowatt-hours (kWh) delivered to the total possible kWh that could be delivered over a specific period
What is a load duration curve (LDC)?
shows how power demand varies over time, helping to determine the generating capacity needed to meet peak demand and assess how efficiently the electricity is used.
How is a load duration curve obtained?
By plotting load profiles in descending order of load magnitudes with respect to time
What is the practical use of a load duration curve?
It helps design baseload and peak load power plants by indicating how long specific load levels are required
What is an electricity tariff?
It is the price at which electricity is sold to consumers varying by country and city
What are the main objectives of electricity tariffs?
- To recover electricity generation cost.
- To recover cost due to electricity lost during
transmission and distribution. - To recover network investment and maintenance cost.
- To earn a reasonable profit on the total investment.
What are important features of electricity tariffs?
Return, fairness, simplicity and attractiveness
What is a simple tariff?
A fixed rate per unit of energy consumed regardless of usage amount
What are the advantages of a simple tariff?
It is easy to understand apply and ensures consumers pay according to their energy usage
What are the disadvantages of a simple tariff?
No consumer type discrimination, no incentives and no charges if electricity is not used
What is a flat rate tariff?
A fixed cost per unit of energy consumed regardless of the time of use with charges based on total units consumed
What are the advantages of a flat rate tariff?
It is fairer to different consumers and involves simple calculations
What are the disadvantages of a flat rate tariff?
No consumer incentives and a need for separate meters for different loads
What is a two-part tariff?
A tariff with two components: fixed charges and running charges
What is an example of a two-part tariff system?
Paying to join a tennis club (fixed charge) and paying to play (running charge)
What is a three-part tariff?
A tariff divided into fixed, semi-fixed and running charges typically applied to large consumers
What is a time-of-use tariff?
A tariff with different prices based on the time of electricity use encouraging off-peak consumption
What are the benefits of time-of-use tariffs?
They help customers reduce bills and relieve pressure on the power system by balancing demand
What is a real-time pricing tariff?
A dynamic pricing system where the per-kWh charge varies hourly based on real-time production costs
What are the advantages of real-time pricing tariffs?
Greater profit control, consumer incentives for energy use adjustments and improved cost efficiency through market-based pricing adjustments
What is price elasticity of demand?
It measures how the quantity demanded changes in response to a price change calculated as the percentage change in demand divided by the percentage change in price
What is perfectly elastic demand?
Demand where any price change leads to an infinite change in quantity demanded though rarely found in practice
What is relatively elastic demand?
When the percentage change in quantity demanded is greater than the percentage change in price
What is unitary elastic demand?
When the percentage change in quantity demanded equals the percentage change in price resulting in an elasticity of 1
What is relatively inelastic demand?
When the percentage change in price is greater than the percentage change in quantity demanded
What is perfectly inelastic demand?
When quantity demanded remains constant regardless of price changes
What factors affect the elasticity of demand?
Availability of substitutes, necessity of the product, income and educational background
What is demand side response (DSR)?
A method to modify consumer energy demand using financial incentives and education to reduce costs emissions and increase renewable energy usage
