multi-award winning family company

providing engineered solutions





Our What's Watt pagelists the watts of common Caravan/RV appliances and shows how watt hours can be calculated.
Our Solar4 RVs Solar Power Estimate Calculator (SPEC)automatically calculates watt hours and suggests what size solar power system you need.

How do I work out the watt hours (Wh) for appliances/devices in my RV?

To determine what solar system will meet your needs you will need to know how much power you will use at any point in time in your Caravan/RV and how much energy you consume on a regular basis.  Power and energy are sometimes confused.  

An electrical load (e.g. a lamp, kettle, hairdryer, etc.) has a rated "size" in watts. This is the power level and is the instantaneous rate at which energy is consumed to run the appliance/device. How much energy is consumed at that rate depends on how long the device is running. Usually the power level remains constant while the appliance or device is running however the amount of energy used increases over time. Both power and energy are important components to consider as the solar power system you choose for your Caravan/RV must be able to cater for:

  • your power needs (how many appliances/devices you are using at any one point in time).  In other words the energy you are drawing down at once; and​

  • your energy needs (how long you use the appliance in a day. In other words how much energy are you using up each day which would drain your battery reserve.

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.

​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.

What is the difference between Power and Energy?