P1.2 ~ Energy And Efficiency Flashcards
What happens when devices transfer energy?
Only part of the energy is usefully transferred to where it’s wanted. The rest of the energy is “wasted”.
What is wasted energy?
Energy which is transferred to the surroundings, which becomes warmer. As energy is dissipated to the surroundings its becomes increasingly spread out and so becomes less useful.
What does replacing old technology with newer technology?
Newer technology is more efficient which means that less if the energy is wasted.
When making decisions on what technology to buy, what do we need to consider?
~how cost effective the replacement
How do we know if a device is more efficient?
The greater the proportion of energy that is usefully transferred, the more efficient we say the devices.
What a Sankey diagram is used for?
They provide a visual representation of how much energy there is a village type. They are used to illustrate energy transfers.
How do we draw Sankey diagrams?
When drawing to Sankey diagram, do you spell energy is drawn going straight through and the wasted energy branching off (curved off).
You need to be able to evaluate the effectiveness and cost effectiveness of methods used to reduce energy consumption. What are some different methods?
~Switching lights off when leaving the room
~Energy – efficient (compact fluorescent) lightbulbs
~Using electrical equipment during the night, e.g. washing machine
~More efficient tumble dryers, or letting clothes dry naturally
~Tankless water heater (Combi-boiler)
What are the advantages and disadvantages of switching lights off when leaving the room?
Advantage
~Easy and simple way to reduce energy consumption
Disadvantage
~People forget to switch the lights off or do not like being in a dark house
What are the advantages and disadvantages of energy efficient (compact fluorescent) lightbulb?
Advantage ~Use less power so cost less to run ~Less wasted energy ~Lasts longer than standard bulbs Disadvantage ~More expensive to buy
What are the advantages and disadvantages of using electrical equipment during the night E.g. washing machines?
Advantages
~Cheaper time of day for using electricity (depending on the tariff)
Disadvantages
~Can be noisy and keep people awake
What are the advantages and disadvantages of more efficient tumble dryers, or letting clothes dry naturally?
Advantages
~Driers with a sensor stop automatically when the clothes are dry, which saves energy
Disadvantages
~New driers are expensive to buy
~Cannot hang clothes out to dry if it is raining
What are the advantages and disadvantages of tankless water heater (combi boiler)?
Advantages
~Water is heated when needed so less energy is used to heat unnecessary water and keep it heated
Disadvantages
~Some units do not have enough power to supply to more than one tap at a time
