RV dry camping twelve days on solar. Great Smoky Mountain National Park. Here are the results. Did our solar work for an extended camping period in the Great Smoky Mountain National Park? Did we have to use our generator?
This is a numbers post about RV dry camping for twelve days on solar. — if you want the story about our wonderful visit to the Smoky Mountain National Park area here is the link to the articles.
The first part is the raw data followed by analysis and conclusions.
Solar Energy data points:
- Solar Array = 1800 watts, no attempt to orient the panels to the sun or track the sun path. The campsite was in full sun from 9 am (solar time) until 5 pm. (8 hours)
- Charge controller maximum amperage at 50 each — two controllers. 100 amps per hour maximum combined. Observed occasional production at 100 amps/hour. Typically energy flow into the battery at above 90 amps per hour.
- The typical voltage from the solar panel to the charge controller was 55 volts at 12.5 amps. The typical PV max voltage was 66 volts. Peak voltage observed at 70.98.
- Typically observed watts per hour at 1,300. Typical array conversion 72% of rated 1,800 ideal output.
- Peak watts per hour were observed at 1,476. Maximum array conversion 82% of rated 1,800 ideal output.
- Typical battery voltage 13.5 static no charge or discharge. Peak battery voltage when charging 14.62. The minimum battery voltage was observed at 12.91.
- Typical battery temperature 72F. Peak battery temperature 90F. Maximum outside air temperature 90F.
- Sunny days seven, cloudy days 3.
- The energy produced from solar and consumed during our eleven-night — 12-day stay. 53,210 watts full days with no partial days included, thus average solar yield was 5.32 Kwh/day (including three overcast cloudy days).
- Maximum energy gained in one day was 6.93 Kwh. The minimum energy gained on a cloudy day was 2.95 Kwh.
- The average energy produced during cloudy days, with some periods of light rain was 3.51 Kwh per day.
- Typical battery state of charge is 90%. Battery state of charge range 62 – 100%.
Appliances used from the battery power
- Air Conditioner, one day two hours
- Clothes Dryer, one day, one half hour
- Microwave, every day
- Instant pot, three days
- Computers (two) every day
- Televisions (zero) no internet or over-the-air signal
Measuring our electricity consumption
If we didn’t measure our electricity consumption and more importantly how much electricity we already drained from our battery then living on solar power for 12 days would have been folly. This one device made our electricity manageable. Here is a link to what I consider the critical component. Battery Monitor
The three cloudy days, with two in a row, was exactly the test I was hoping for and was a key design consideration of 1,800 watts of panels limited by two solar controllers. During the cloudy days, we produced almost half as much energy as during the sunny days. Had the array size been limited to thumb rules that are standard in the industry, production during cloudy days would have been cut by an additional 30%.
Analysis Battery State of Charge
Our battery bank varied between 62 and 100%. On a clear sky day, the battery state of charge was typically 100% by solar noon. (Solar noon is not the same thing as daylight savings time noon.) Battery’s low state of charge at 62% was a combination of using our air conditioner at the end of one day dropping the state of charge from 100% to 82% followed by two cloudy days. By the morning of the second cloudy day, the battery state of charge was at 62% and by the end of the second cloudy day battery state of charge was at 88%. Although the state of charge dropped to 72% overnight the next day was sunny and a full charge was achieved in the early afternoon.
Conclusions after dry camping for twelve days on solar
Our experience shows that assuming we don’t need air conditioning or the clothes dryer we should be able to operate without outside electricity all summer or winter. Not only do the results of dry camping twelve days on solar prove our solar design we have the data to prove our electrical independence — without running our generator.
Predictions after dry camping for twelve days on solar
The cloudy day data should be an accurate predictor of wintertime, limited daylight, less-than-ideal orientation, and energy production. With our current 1800-watt solar array, we may be able to operate without limitations, except for air conditioning and clothes dryer, in a mild climate, in the winter indefinitely. If this doesn’t work out, I still have more room on the roof for more solar panels.
Measuring our electricity consumption
If we didn’t measure our electricity consumption and more importantly how much electricity we already drained from our battery then living on solar power be folly. This one device made our electricity manageable. Here is a link to what I consider the critical component. Battery Monitor
This is what we used. We do not get commissions on the links and are provided only to help our friends.
Lion Energy UT1300 Lithium Iron Phosphate Batteries we also have other batteries in addition to the Lion UT1300 but I mention them specifically because they are currently on sale at Costco.
BMV-712 Victron Battery Monitor w/shunt & temp sensor
Zamp Obsidian solar panel. Zamp
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