How To Do An RV Solar Energy Audit
Why do I need to do an RV solar energy audit?
“How much solar do I need for my RV?” is probably the most common question we get. That answer comes down to you and your specific lifestyle, which you can figure out through an RV solar energy audit.
When planning an RV solar system, we need to know enough about your expected energy usage to keep you comfortable. This means accounting for which appliances you use, how much you use them, and how much power they require to run as often as you need.
This information will determine your ideal RV solar set-up: your solar panels, battery bank, monitoring and control equipment, and more.
Step 1: Inventory every appliance going into your RV
The first step in an RV solar energy audit is to work out which appliances you have or need.
Visit our post below on conducting your appliance inventory, and download our free RV Solar Energy Audit Appliance Inventory checklist to get started.
Step 2: Find the wattage of every appliance going into your RV that will run off of solar power
Once you have your inventory of appliances, you’ll need to find the wattage of each one. Don’t be intimidated — this is actually pretty easy to figure out! Use the guidance in our post below to find the wattage of any appliance.
Step 3: Plug your appliances, wattage, and estimated use times into the RV Solar Energy Audit Calculator
Now that we know which appliances you’ll use, and their respective wattage, we can total up your estimated energy needs. The final piece of the puzzle is about how much you use each item, which we can work out as we go.
Open the RV Solar Energy Audit Calculator. The top section includes some appliances and their details to get you started, but now that you’re more prepared, you can go straight to the add-your-own section.
Tips for using the RV Solar Energy Audit Calculator
- Only include the appliances which will run off of solar power. If your heater or 3-way fridge will run off of propane, don’t worry about including it here.
- The refrigerator in your RV will cycle on and off throughout the day. This can make it a little tricky to calculate energy consumption. For refrigerators, you can use the make and model to find the “Energy Guide” label. Simply divide the estimated yearly electricity use by 365 (days).
- In that example, we would divide 594,000 kWh by 365 days and arrive at 1,627.4 kWh per day. You can use that as your wattage (and leave your hours multiplier as just 1), or divide it further to get the wattage per hour (1627.4/24 = 67.81). If you do that, be sure to then set “24” for your hours.
- If you use an appliance for less than an hour, you’ll need to convert minutes to a fraction of an hour using the calculator at the top of the page. Then, input that decimal value into the hours column for that appliance.
- For example, you may only use a coffee pot for 15 minutes per day — that should go into the calculator as 0.25 hours.
- Don’t skip appliances you use less-than-daily. We want to estimate for your highest possible watt hours, not your lowest level of energy consumption.
- Don’t forget about quantity. You might have 10+ LED lights, but if you set the quantity to “1” in the calculator, you’ll be missing a lot of important data.
- Device chargers won’t be actively in use all day long, but will be needed for a few hours at a time and should be included. To get the best time estimate, observe how long your devices take to charge and how often you do this each day.
- For example, watch the status indicator of your phone and how long it takes. to charge fully.
Saving and using your results
The calculator will total up your estimated overall watt hours per day, including accounting for an inverter inefficiency. This is the big, bold number at the bottom of the calculator page.
Once you’re finished totaling, be sure to email a copy of the entire audit to yourself — this will have every appliance you included, the values you put in, and the total estimate.
Your estimated overall watt hours per day is the most important factor in identifying the best size solar array and battery bank for your lifestyle. Once you have that number, you’re ready to start designing and building out your system.
Remember: this is all an estimate based off of the information you have gathered. Take your time and be thorough to ensure the most accurate results!
Did this guide help you? Was there anything that surprised you? How can we make it even better? Let us know in the comments!