Increase in Electricity rate

UPDATE: Click HERE to download the file for easy calculations.

Household electricity consumption

I have covered the topic on how to measure your household electricity bill in my last article in May 2008. Since then, SP services never fail to increase electricity tariff for four consecutive quarters. Starting in April, our new rate will be 23.56 cents/kWh or an average increase of $2.47 in our monthly electricity bill in four-room HDB flats as reported by Straits Times. The latest reason cited is the increase in oil price over the past three months from US$99.38 to S$102.95 per barrel.

Ranking of power hungry household appliances

The best power saving method is NOT to switch on anything. We know it is impossible so how can you maintain or reduce your electricity bill? Identifying the most power hungry appliances and reduce its consumption is the best approach. Below is the typical list:

Ranking	Household Appliance	Power Consumption (W)
1	Bathroom Heater	2000
2	Induction Cooker	1200
3	Cloth Iron	1000
4	Water Boiler	750
5	Air Conditioner	600
6	Rice Cooker	500
7	Fridge	200
8	Desktop PC	160
9	CRT TV	135
10	Fan	60
11	Notebook	55
12	Light bulb	40

 
As a rule of thumb, appliances that heat up or cool down in the shortest time consume the most power. Bathroom heater tops the list with 2000W of power consumption while light bulb only consumes 40W. Appliances worthy of mention are Induction Cooker, Cloth Iron, Water boiler and Air Conditioner which are power hungry. To get a realistic feel of how much they are consumed, we need to know the hours of usage to get the monthly bill.

Household Appliance	Power Consumption/ unit (W)	Hours of usage/ day(Hrs)	Monthly Bill with GST (S$)	Ranking
Bathroom Heater	2000	1	15.13	3
Induction Cooker	1200	1	9.08	6
Cloth Iron	1000	0.5	3.78	8
Water Boiler	750	0.5	2.84	10
Air Conditioner	600	8	36.30	1
Rice Cooker	500	0.5	1.89	11
Fridge	200	24	36.30	1
Desktop PC	160	8	9.68	4
CRT TV	135	9	9.19	5
2 Fan	60	4	3.63	9
Notebook	55	4	1.66	12
3 Light Bulbs	40	5	4.54	7
Total Electricity Bill			134.01

 
After punching in the average consumption per day, we get a realistic power consumption of the appliances. Fridge and Air-Conditioner top the bill charges while notebook tails behind. To effectively cut down on the bill, we explore how to reduce the usage time of the appliances. Bear in mind that basic necessities such as fridge cannot be touched. Below are some suggestions:

1. Use fans instead of air conditioner;
2. Cut down on using Induction Cooker and use gas instead;
3. Reduce the frequency of using bathroom heater;
4. Iron cloth every fortnight. FYI, heating up the iron is very time consuming;
5. Refrain from using water boiler to keep warm and use vacuum flask instead;
6. Adopt standby or hibernation mode for breaks exceeding one hour; and
7. Sleep early so watch less TV programs.

Household Appliance	Power Consumption/ unit (W)	Hours of usage/ day(Hrs)	Monthly Bill with GST (S$)	Ranking
Bathroom Heater	2000	1	15.13	2
Induction Cooker	1200	0.25	2.27	8
Cloth Iron	1000	0.05	0.38	12
Water Boiler	750	0.25	1.42	11
Air Conditioner	600	3	13.61	3
Rice Cooker	500	0.5	1.89	9
Fridge	200	24	36.30	1
Desktop PC	160	6	7.26	5
CRT TV	135	6	6.13	6
2 Fans	60	12	10.89	4
Notebook	55	4	1.66	10
3 Light Bulbs	40	5	4.54	7
Total Electricity Bill			101.47

 
After changing the consumption pattern, only fans cost more due to longer period of usage. If the fridge is your top list, then you have near to your target. Revised bill is $101.47 which is a 24.28% reduction in power consumption.

Conclusions

There are some devices (S$150) sold in the market which promise to save your electricity bill. The basic operation is to optimize the inductive and capacitive powers (correcting the power factor) which exist in any power supply due to different appliances used. This is especially useful for Air conditioner, washing machine and other inductive devices. In Singapore, the effect is noticeable for 5-room flat or bigger units but less significant in smaller HDB units. Suppliers claim that the savings vary between 5-25%. If you are interested, please attend computer show as they are always participating in such shows. Watch out for mini-sun or power save booths.
Now, you can save your pocket money and environment at the same time and preserve a greener earth for our future generations. I must talk big because cutting back on what you are currently enjoying is painful. Trust me…