TM

incorportingSOLAR 4 BOATS™ SOLAR 4 INDUSTRY ™

TM

TM

Examples

Calculation:   Appliance Watts × Hours used per day = daily watt hours consumption

Appliance/DeviceMinMax
Air conditioner
 1000 1300
Alarm Clock12
Blender300
Coffee Maker3001500
Electric Blanket (double)100200 
Electric Kettle
10002000
Electric Shaver
1520
Fridge Freezer
80100
Hair dryer
10002000
Hair curler or straightener
90100
Iron
10001800
Laptop Computer
2060


Appliance/DeviceMinMax
Microwave
6001500
Mobile Phone charger
24
​Portable electric fan
1050
Portable electric heater
 1500
Radio
70
Satellite dish
2030
Toaster
8001800
TV
70100
Washing machine
230500
Water Pressure Pump (shower)
120180
Water Pressure Pump (sink only)
3040
LED light
8


Typical watts of appliances used in caravans/RVs:

How do I calculate watt hours (Wh)?

When we are calculating what size solar power system to install in a caravan/RV we consider how many watts your appliances use and how long you use them for.

If you have already read our
power v energy pageyou will know that a watt (W) is a measure of how much electrical energy is being used. 1000W equals one kilowatt (kW).

​A Watt hour (Wh) represent the estimated amount of energy an electrical appliance consumes in one hour.
To work out the Wh take the watts (W) of the appliance and multiply this with the hours used on the average day. 
​This will give you the Wh consumed in your caravan/RV per day.  

How many watts do appliances use?

An appliance usually has the wattage it uses written on the label.  This label is often at the back or bottom of the appliance. The list below shows some common appliances used in caravans and RVs and the typical watts they use.  

What's Watt?

How much electricity do the appliances in your caravan/RV use?

Red circle indicates watts displayed on label underneath toaster

Example 2

Kettle

Some items are used only for a fraction of an hour or minute per day, for example a kettle.  The calculation for this scenario is:

Watts × minutes used per day ÷ 60 minutes = daily watt hours (Wh)

 A 1100 watt kettle used for 10 minute per day will therefore only consume 183 watt hours per day or 0.18 kWh:
1100W x 10 ÷ 60 = 183.3 Wh


Example 3

Fridge

This is relevant if you have a compressor fridge in your caravan/RV (rather than a 3way fridge)

Even though a fridge is “turned on" all the time, the actually cycle goes on and off as needed to maintain its temperature. This is dependent on how hot a day it is.  Nevertheless, to estimate the number of hours that a refrigerator actually operates at its maximum wattage you can divide the total time the refrigerator is plugged in by three to give you an average estimate. 

For a typical caravan/RV fridge let’s do the calculation:

80 watts ÷ 3 = 27 watts

27 watts x 24 hours = 648 Wh


Example 1

Portable fan

If you use a portable fan that uses 20 watts for 4 hours per day then the calculation is:

​​20W x 4 hours = 80 daily watt hours (Wh) consumption


multi-award winning family company

providing engineered solutions