How Much RV Solar Power Do You Need?
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How Much RV Solar Power Do You Need?

July 15, 2024

Adding solar power to your RV not only helps the environment by cutting fossil fuel use but also extends your ability to be off grid. Since it can be tricky to figure out how much power you need for when the sun is shining and when it’s not, here are some tips to help.

Step 1: Understand the Basics of a RV Solar Setup

The four main pieces of equipment that are needed to create a solar system:

  1. Solar panel: Generates energy from sunlight
  2. Inverter: Converts the solar energy into electricity, which can then be utilized by the RV’s appliances or the RV’s electric engine (if it has one)
  3. Charge Controller: Prevents battery damage from overcharging and over-discharging by controlling the flow of electrical current from and to the batteries; this device determines how quickly the battery can be charged
  4. Battery: Stores the electricity

Note: Inverters and charge controllers can be found in an integrated, single piece of equipment

Step 2: Calculate Energy Consumption

The RV's energy consumption varies depending on the appliances used and for how long. Daily assumptions based on usage are below:

  • Low Usage (the average RVer): 3-5 kWh or 250-420 Amp Hrs using a 12V battery
    Basic lighting, ventilation, and occasional phone charging
  • Moderate Usage: 7-10 kWh or 580-830 Amp Hrs using a 12V battery
    Running a refrigerator, lights, and using a microwave occasionally, with occasional air conditioning
  • High Usage: 15+ kWh daily or 1250 Amp Hrs using a 12V battery.
    Frequent air conditioning, TV, and intensive appliance use

We like this appliance consumption calculator to estimate usage for your specific needs.

Step 3: Determine RV Battery Size Required

Based on the energy consumption demand, pick a battery that will allow running the appliances. Battery capacity is measured in Amp Hours (Ah), not watts like for appliances, with a higher Ah rating meaning a larger capacity for storing energy.

As an example, a 100Ah battery can theoretically provide 100 Amps of current for 1 hour, or a lower current for a longer duration. So if a small RV fridge uses 20 Ah over the course of the day, the 100Ah battery would be able to run the fridge for 5 days (100Ah ÷ 20 = 5 days).

Step 4: Select Solar Panels

The three main types of solar panels for RVs are:

  • Traditional solar panels attached to the RV roof
  • Rigid or rollable hybrid solar awnings
  • Mobile solar panels

Based on your estimated energy consumption and battery size required, any of the above solar panel options or a combination of them could work, provided there’s enough space on the RV’s exterior (roof panels, solar awning) or interior (mobile solar panels). Our XpanseTM solar awning is a great option because its compact design takes up little RV space while generating 1200 watts of power. It can also be paired with a second XpanseTM or large rooftop solar to create enough capacity that meets even high electricity demands.

To help determine how many panels are needed, multiply the solar panel’s stated kW rating by both the number of hours of sunlight per day (6 hours of sunlight per day as a rule of thumb) and 80% of the panel’s Imp rating to allow for system inefficiencies. In this example, an average 1.2kW solar panel would generate 1.2kW x 6 hours x .8 = 5.76kWh daily production. Keep in mind too that products with the same kW rating can generate different amounts of power based on how the panel’s system is designed. For instance, through independent 3rd party testing, our flagship XpanseTM 1.2kW solar awning has shown to consistently generate 7kWh (580 Amp Hrs on a 12V battery) during summer day testing in California.

Parting Thoughts

Adding solar to your RV can be an exciting, practical, and environmentally friendly way to ditch crowded RV parks and explore more of the world especially with an XpanseTM solar awning to power your trip. If you’re planning on running a lot of appliances, then with one or more XpanseTM solar awnings from Xponent Power and a rooftop solar system working together, even more wilderness awaits – powered by the sun!

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