Energy saving for working from home

Safe Distancing

To flatten Coronavirus Disease COVID-19 pandemic curve, work from home has become a new norm for many companies. Except for medical and essential workers, most of us need to either work from home or simply stay home. Since more people are using home appliances for longer hours, it’s inevitable that our monthly electricity bill will rise.

There’re many ways to optimize our home energy usage. One of the most visible improvements is to minimize energy wastage for heating and cooling due to poor home insulation. Unfortunately, the renovation cost to improve the insulation is expensive. Or we can also change our habits to minimize energy wastage. This behavioral change is free. We just need to do it consciously and consistently and help to reduce our personal carbon footprint at the same time.

1. Choose Electricity Retailer that Provides the Best Rate on Kilowatt-Hour (kWh)

Smart Energy with Best kWh Rate

In most countries, the energy markets are managed by local authorities only. If this is your case, then this step is not applicable to you.

For those countries like Singapore whose energy market is liberated, we can choose energy retailers that best fit our needs. Instinctively, we’re attracted to retailers that offer the best rate on kilowatt-hour (kWh). Obviously, the lower the energy rate the more money we can save on our monthly electricity bill. Other factors to consider are the duration of new contract and the discount on bundled packages.

Regardless of which energy retailers we choose, the goal is to achieve cost saving instantly with the same energy usage. This is the easiest and quickest way to save energy cost without any change of our behaviors. Although it seems that we’re not doing any favor to mother earth here, it’s a great start for energy saving. If we move on to the next step, we’ll be able to unlock additional saving with sustainable good practices.

2. Identify Home Appliances That Contribute 80% of Total Electricity Bill

Smart Energy on Air Conditioner

Before we begin saving, we need to identify the home appliances that consume more than 10% of monthly total energy usage. For instance, if the total monthly energy usage is 100 kWh, then we’ll identify appliances that consume at least 10 kWh per month.

From our experience, home appliances that we use regularly for heating and cooling consume the most energy. Examples are room heaters, air-conditioners, water heaters, irons, airpots and so on.  Power consumption is available on the appliance specification label. If not, check the power consumption in the user manual or Internet.

For instance, assume that our latest monthly energy usage as shown on electricity bill is 450 kWh. And the power consumption of air-conditioner is 0.77 kW. We enjoy it for 8 hours a day, 30 days a month. The calculation is as shown below:

Air-Conditioner Energy Usage = (0.77 kW x 8 h x 30 ) / 450 kWh x 100% = 41.1%

As expected, heating and cooling appliances consume the most energy every month. Note that the actual usage is usually lower than the calculated value. In practice, we’re not using the maximum power because we’re not having the lowest temperature setting for the air-conditioner.

Use this method to calculate the rest of the home appliances. Soon, we can identify a list of home appliances that consume more than 10% of total monthly energy usage. Adding up the power consumption of these appliances and we’ll find that they contribute around 80% of our monthly electricity bills.

3. Focus Energy Saving on Home Appliances With Top Energy Consumption

Smart Energy on Ironing

Based on the calculation method above, we notice that there’re only a handful of home appliances that fall into the 10% category. Yet the total monthly energy that they consume is around 80% or even more!

Indeed, we can save more than 10% of energy usage in total rather easily by focusing on reducing energy usage on these appliances. More so if we optimize the energy usage at the same time.

For instance, by reducing the air-conditioner operation from 8 hours per day to 6 hours per day due to lunch hours or breaks, we can reduce a quarter of the energy usage, i.e.

Air-Conditioner Energy Saving = (8-6) h /8 h x 41.1% = 10.3%

We can save even more by setting the temperature to 1ºC higher at the same time. It’s amazing that by focusing on air-conditioner alone, we’ve achieved more than 10% of energy saving! Want to save more? How about replacing the air-conditioner with a powerful fan (90W)?

Fan Energy Usage = (0.09 kW x 8 h x 30 ) / 450 kWh x 100% = 4.8%

Energy Saving by Using Fan = 41.1% – 4.8% = 36.3%

It’s a whopping 36.3% of energy saving for a month and every month thereafter! In reality, we can’t really replace air-conditioner entirely with fan even though we can save like crazy. That will defeat the purpose of having air-conditioner in the first place. However, it gives us a very good idea on how we can save energy substantially by using fan as a substitute where applicable.

Do the same exercise for the remaining appliances in this category. We should be able to save around 20% of energy without too much trouble.

4. Improve Energy Saving of the Remaining Home Appliances

Smart Energy on Fan

Although it’s rather easy to achieve 20% of energy saving initially, it’s not so easy to extend the saving further. The other option is to sacrifice our comfort for more saving, like replacing air-conditioner with fan. This’s not a desirable option especially during hot summer nights, haze season or air pollution.

Of course, we could’ve stopped here since we’ve accomplished our goal of saving energy, cost and mother earth. But we can do even more simply by putting in additional effort.

For instance, assume that we’ve 3 fans (90W each) running for about 8 hours each every day. And they’re not replacing air-conditioners:

Fans Energy Usage = (0.09 kW x 8 h x 30 x 3) / 450 kWh x 100% = 14.4%

Switch the fans off when we leave the room, and switch them on only when we’re back to the laptop. We should be able to save 2 hours each fan every day:

Fan Energy Saving = (8-6) h / 8 h x 14.4% = 3.6%

We may be spending greater amount of effort for these appliances but the saving is substantially smaller. Collectively, we may be able to save around 5 – 10% of energy. It may not seem like it’s worth our effort at first. However, if we look at a longer term, like a year, then we could be saving around $100 after 12 months assuming monthly electricity bill is $100. That’s about 1 month of free electricity for every 12 months!

5. Optimize Energy Saving of Home Appliances with Smart Home Devices

Smart Energy with App Control

So far, we need to remind ourselves constantly to minimize energy usage while reducing unnecessary wastage. When we cool the room with air-conditioner, we need to raise the temperature higher and set the duration shorter consciously. Every time we leave the work-from-home room for a break, we need to remember to switch off light, fan, air-conditioner and so on.

Wouldn’t it be nice if we can have some smart devices to take care of these boring and repetitive tasks for us?

Smart Air-Conditioners

Unfortunately, smart air-conditioners are too expensive while smart air-conditioner controllers support limited models only. It seems that the good old remote controllers for the air-conditioners are here to stay.

However, if we’ve a centralized HVAC (Heating, Ventilation and Air Conditioning) system, then we can upgrade the mechanical or digital thermostat to a smart thermostat. Saving energy with smart thermostat app will be a breeze.

Smart Appliances

For other home appliances, we may consider smart power plugs for energy saving. For instance, we can limit fan running to 6 hours with mechanical timers. Or we can use smart power plugs with remote control, flexible scheduling features and energy monitoring.

Note that smart plugs provide accurate energy readings but they can’t measure appliances connected to power directly, e.g. wall switches or water heater which draws power from circuit breaker directly. Since smart power plugs are a lot more expensive than mechanical timers, they are not cost effective for all home appliances.

Smart Lighting

For energy saving on home lighting, we may also consider smart LED light bulbs. During work-from-home hours, we can leave the room for a break and the smart light will switch off automatically either by sensing our absence or by coffee-break schedule. Meanwhile, we can make use of the built-in or user-defined scenes to create the right atmosphere for working, relaxing and more.

In fact, smart lighting is also a very effective method for smart home security.

The Most Important Energy Saving Tip

There’re tens, if not hundreds, of energy saving tips that we can find from Internet. We’ve seen posts with hundreds of energy saving tips although some of them are not related to electricity. Nevertheless, not all of these tips will produce substantial energy saving. By now, you understand that some home appliances consume more energy than others.

Based on the above results, we conclude that the best tip is to focus our energy saving efforts on the heating and cooling appliances. Now that we’re spending longer hours due to work from home, it’s even more important to manage the usage of these appliances. Meanwhile, make use of smart devices to save energy automatically. Ask Alexa for advice on steps on reducing the electricity usage or utility bill.

Stay safe and be socially responsible.

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