Energy Ratings Explained
What are efficiency ratings?
Energy efficiency ratings, graded from A+++ (highest efficiency) to D (lowest efficiency), are an indicator of how effectively your appliance makes use of its power draw over time. This is measured in kilowatt-hours (kWh). i.e. how many thousand watts (kilowatt) are used per hour or how many hours it takes to use 1000 watts.
Energy ratings do not mean less power. An A++ dishwasher might have exactly the same power requirements as a B rated washing machine e.g. 1800W. The energy rating is a scale of the efficiency of the machine. How much power it uses per load and over time. So while a B rated dishwasher needs the same amount of power to run, an A++ rated dishwasher will wash the same number of dishes quicker (and with less water). So in the long run, the better the rating of your appliance, the more power you save over time. This is great for homes that have lithium battery systems or direct solar solutions as their power supply. Less power required over shorter periods of time.
For households utilizing solar panels and renewable energy sources, energy efficiency becomes even more crucial. Efficient appliances make the most of the electricity generated by your solar panels, maximizing your investment in clean energy. When you opt for A+++ rated appliances, they draw less power, which means your solar panels can cover a larger portion of your energy needs. This not only reduces your reliance on the grid but also cuts down on electricity costs, providing greater savings over time.
What do the efficiency labels mean?
The energy efficiency label has been designed to provide consumers with accurate and comparable information on the energy efficiency of household appliances. The information provided on the label indicates the energy efficiency class of the appliance, the manufacturer and appliance model. For some appliances, the label will also have non-energy data such as water consumption per cycle and appliance noise level.
How much better are A-grade appliances?
Higher graded appliances can make a big difference to your energy consumption. For example, let's consider two appliances with the same power rating of 1800 watts (1.8 kW) but different efficiency ratings:
1. A+ Rated clothes washer dryer (High Efficiency):
Consumes 4,76 kWh of electricity per wash cycle
Draws 1800 watts for the duration of the wash cycle, but it utilizes the energy more efficiently, so it completes the cycle with less power consumption
2. B Rated clothes washer dryer (Lower Efficiency):
Consumes 6,6 kWh of electricity per wash cycle
Draws 1800 watts for the duration of the wash cycle, but it uses the energy less efficiently, resulting in higher power consumption for the same output
An appliance's efficiency rating is a measure of how effectively it converts energy into useful work or output. Appliances with higher efficiency ratings are designed to consume less power while providing the same level of performance as less efficient models. In contrast, appliances with lower efficiency ratings tend to draw more power for the same output or performance.
How much electricity can I save?
Using the example above, we can calculate the saving per year.
Assuming each washing machine does 1 cycle per day for 365 days:
A+ Rated Washing Machine: Annual energy consumption = 4.76 kWh * 1 cycle/day * 365 days = 1,737.4 kWh/year
B Rated Washing Machine: Annual energy consumption = 6.6 kWh * 1 cycle/day * 365 days = 2,409 kWh/year
Potential savings = 671.6 kWh/year.
That’s 6 716 watts less that your batteries or solar panels need to produce. Not to mention the A+ machine will have a lower electricity draw while running.
How are efficiency ratings calculated?
1. Standard Testing Conditions
The testing process begins with setting up standard conditions in which the appliance will be evaluated. This includes factors like temperature, humidity, and voltage to ensure consistent and repeatable results across different tests.
2. Energy Consumption Measurement
The appliance is connected to a power meter, which measures the electricity consumed by the device over a specific period of time. The energy consumption is typically measured in kilowatt-hours (kWh).
3. Performance Measurement
Depending on the type of appliance, additional performance metrics may be recorded. For instance, a washing machine's efficiency might be measured by how much water it uses to wash a specific load size.
4. Reference Load Profile
For certain appliances like refrigerators or air conditioners, an average usage profile is considered to represent typical consumer behavior. This reference load profile helps in estimating the energy consumption of the appliance under real-world conditions.
5. Comparative Analysis
The recorded energy consumption and performance metrics are then compared to the baseline reference load profile or the standard set for that specific category of appliances. This comparison allows for relative assessments of energy efficiency among different models and brands.
6. Energy Rating Scale
Based on the comparison, the appliance is assigned an energy rating on a predefined scale, commonly ranging from A+++ (highest efficiency) to D (lowest efficiency). The rating scale helps consumers easily identify and compare the energy efficiency of various products.
7. Labelling and Certification
Once the energy rating is determined, the appliance is labeled with the corresponding rating, allowing consumers to make informed choices at the point of purchase. In many countries, government agencies or independent certification bodies oversee and regulate the labeling process to ensure accuracy and transparency.
What is a Kilowatt-hour?
It is a unit of measurement used to describe how much electricity is used or produced over time.
Think of electricity as the energy that powers your home, just like how gas fuels a car. When you use electricity, like turning on lights, using appliances, or charging your devices, it gets consumed, and the amount of electricity used is measured in kWh.
To understand it better, imagine a 100-watt light bulb. If you leave it on for ten hours, it will use 1 kilowatt-hour (kWh) of electricity.
