ENERGY SAVING TIP #1 (Refrigerators)

Why do some houses of similar sizes have different number of panels or different number of batteries from each other?? One of the common issues (besides usage profile) is energy saving and optimisation. Implementing energy optimisation; from the onset; will save you a lot of money; first from the cost of your solar system and on the lifespan of your system. We are going to regularly give you energy saving tips; whether you use solar and renewables or not; these tips will save a few dollars from your pocket!! Most of the tips are very inexpensive measures that are taken for granted; but end up costing us a bit at the end of the day.

If you refer to our earlier posts; you will see that the size of your solar system depends on the energy consumption of your household or building. Well one of the major consumers of energy in households is refrigeration. Refrigeration typically accounts for between 25%-40% of the energy consumption of a solar system. Savings on refrigeration could mean that your installation might need 1 or 2 panels less; and maybe a battery less :). This would be a good place to start at don’t you think? So how does one make savings on refrigeration??

1. Energy Efficiency- modern day refrigerators are typically 50% to 70% more energy efficient than older refrigerators [1] as manufacturers are now focusing more on energy consumption and efficiency as per demands and expectations of the industry and customers.. To give an illustration of this; consider a comparison below between two refrigerators of the same size: An old Energy Star Fridge is reported to consume 1700kWh of energy per year with the modern version consuming just 450kWh of energy per year [2]. This means that the older model uses about 4 times as much energy as the newer model!! This becomes significant on the cost of your system as the older fridge will need at least 300Ahs of battery capacity whilst the newer model requires just 100Ah of battery capacity (cost difference of about US$300) and about 3 x 330W panels vs just 1 panel with newer model (cost difference of about US$300)… a TOTAL cost difference of US$600!! With modern refrigerators typically costing around US$550; it means it might actually be cheaper for you to replace your old fridge with a newer model on your solar system.... not to mention that it will be getting closer to dong its time and getting replaced anyway.

BUT these modern refrigerators do come with different energy efficiencies and ratings. One of the most useful tools to use for comparison is the energy label on refrigerators. Please see below:

But what does this energy label represent? The first part gives “Energy Efficiency Classes” ; typically indicated using letters with the A+++being the most efficient; followed by A++;A+; B;C up to D. Some other models feature stars rather than letters. Look out for the arrow that points to your fridge model next to these letters. Second part shows you the energy consumption per year. This is critical as it helps you understand the approximate cost of energy of your refrigerator per annum

2. Behavioural Changes- the other major factor on your refrigerator energy consumption are simple disciplines that keep your refrigerator operating at optimum power consumption. Things like making sure you do not leave/keep the fridge doors open; you leave enough space around your fridge for it to “breathe” and ventilate heat away; not overloading your refrigerator; setting ideal temperatures (typically 2degC to 3degC for the fridge and -18degC for the freezer). These behavioural changes will save you a looooot on energy consumption of your fridge.

3. Fridge PLUS Freezer: the other question you need to ask yourself is do you really need 2 or 3 fridges; AND a freezer on your solar system?? Can you not make do with just 1 refrigerator? Do you need to have all fridges plugged on ALL the time?

For FREE tips on Energy Optimisation of your system please do get in touch with our Engineers

Sources:

1. https://www.justfridge.co.za/the-significance-of-energy-star-ratings-in-your-fridges/

2. https://www.cleanenergyresourceteams.org/your-old-refrigerator-energy-hog

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About Author:

Lovewell Chitiyo is a Mechanical Engineer with 15 years experience in the building services Engineering consultancy, renewable energy systems and sustainable design fields. He is currently studying Masters in Renewable Energy at Stellenbosch University in South Africa

Lovewell is an Accredited Professional with the Green Building Council of South Africa for Existing Buildings Performance and New Buildings; Interiors, holding several qualifications and certification in Renewable Energy and Sustainability.

Lovewell also has vast experience in design, supervision, installation and commissioning of several projects locally and regionally in the last 15 years.