# How do you install solar panels on your van?-STEP 1

### STEP 1: Calculate how much power you need for your van.

When preparing for a trip, you must think of energy usage for your trip. Solar energy is a great source. It supports off-grid, it is clean energy, and it is cost-free. There are many different sizes of solar panels. So when choosing solar panels, you need to know how much power you need.

Let's do the calculation.

• Watts to Watts Hour equation

First of all, a watt is a measure of power. Remember the equation watts multiply hours/day equals watt-hours/day, which is W * H/D = WH/D. When you calculate the watts in total, you need to know the watts per device (watts) and how long you will be using them(hour/day).

For example, if you have a laptop, it is 20 watts, and you will use it for 4 hours a day, then 20 watts * 4 hours/day = 80 watt-hour/day. Numbers may vary. You can always check how many watts the device has by reading the instructions menu or searching online. For another example, a 1000-watt microwave runs for 5 minutes equals 1000 W * 1/12 H = 83 WH.

• Amp to Watts equation

Just in case you want to know how many watts your device is, the equation is watts equals amp * volts.

Amp is short for ampere, it is a unit of electrical current.

Volt is short for voltage, which is the potential for energy to move and is analogous to water pressure. Volt is commonly 12V, 24V, 48V, 120V, and 240V.

For example, the back of the computer shows it is "100-240V ~ 2A", which means its max voltage is 240V. If we normally charge it with 110 voltage, 110V * 2A = 220W. Then we can get the watt-hour from 220W if charged for 4 hours. 220W*4hours = 880WH/day.

• How to find out how many watts of the device?

You should be able to locate all the information on the device or on its menu, you can even check details online before you purchase the item. For example, you will see the volt and amps on the back of your laptop.

You might not always find out how many watts the item is directly, but you can follow the equation above to figure it out. Just remember the equation: Watts = Amps x Volts, and Watt-hour = watts x hour/day.

Your smartphone recommends Watt is 20W, and you will need to charge it for 4 hours, 20W*4H = 80WH/day.

• Equation review

Let's do a quick review.

Watts = Amps x Volts W = V * A
Volt = Watts / Amps V = W / A
Amps = Watts / Volts A = W / V
Watt-hour = watts x hour/day WH = W*H

Now you should be able to calculate how much power you need per day. Here is a list of approximate Watts-Hours of common appliances.

 Camping appliance Approximate average running Watts Hour/day Watt-hour/day Smartphone 4 4 16 GPS 4 4 16 Radio speaker 4 4 16 Laptop 60 4 240 RV fan 36 6 216 RV fridge 10 24 240 Rechargeable camp lights 50 5 250 Water pump 40 0.5 20 ZERO BREEZE Mark 2 200 5 1000 Total 2014
(Numbers may vary.)
The next step will be choosing the right battery. The battery has to hold larger power than the total watts. For example, if your total is 2014WH, then your battery must be larger than 2014WH.
Calculating is not as hard as you think it would be. 