I'll tell you about my experience, how I spent 3 months traveling in an old Chevy Suburban in Florida, USA from September to November 2023. I lived in a car. I also worked there. Work remotely. I am a computer programmer.
I equipped my car with four 100-watt panels with a total power of 400 watts. As an energy storage device, I used a battery with the most modern 100 Amp hour lithium phosphate cells (LiFePO4, LFP). It was a separate battery from the car's on-board network. I put together a custom station with a battery, controller, fuses, car sockets and USB ports. The solar panels generated electricity, which charged my station through the solar controller.
The main consumers were:
- Laptop;
- Two cell phones;
- 5G modem;
- Video surveillance system;
- Air purifier;
- Household tile that I used as a cabin heater;
- Heated blanket.
I also occasionally powered from the battery:
- Car tire inflator;
- Power tools charger;
- Small vacuum cleaner.
Charging the laptop at peak power consumed up to 9 amperes. The laptop charges in an hour. Charging one of the phones consumed about 6 amperes, the second 2 amperes. Their charging time is also about an hour. The 5G modem also had its own battery, but was constantly being charged and the consumption was approximately 1 ampere. The surveillance recording system was running constantly and consumed half an amp. The cameras simply ran on batteries and I don't take them into account. The air purifier used between half an amp and one and a half amps. Most often it worked in minimum mode, but sometimes I turned it on at full power. It mainly worked at night. The household tile had a resistance of 13 ohms and at 13 volts it essentially drew 1 amp. I turned it on only at night to heat the interior, so as not to heat it up with the engine running.
The engine on the Suburban is large and eats a lot, so I tried not to start it when there is no particular need. Heated blanket, one of the big consumers. It needed 10 amps. I used it not as a blanket, but as a sheet, folded it into a pie of other blankets, which created a kind of heating sandwich that kept me warm. So I turned it on literally, for a minute, sometimes for 5 minutes. It heated the bed and I could stay warm. Happened only a few times in the last week of November. I was in north Florida. There were very cold nights around 40 F (~5°C).
| Case | Consumption (A) | Duration |
|---|---|---|
| Laptop | 9 | ~1 hour |
| Phone #1 | 6 | ~1 hour |
| Phone #2 | 2 | ~1 hour |
| 5G Modem | 1 | Continuous |
| Video Recorder | 0.5 | Continuous |
| Air Purifier | 0.5 — 1.5 | Mostly night |
| Heated Blanket | 10 | Short bursts (minutes) |
Firstly, it should be noted that the panel power values indicated in the specifications are calculated under ideal conditions. The fact is that the efficiency of the panel drops very much when the panel itself heats up in the sun. And the efficiency is about 60% after the panel is heated. Therefore, you will never get 400 watts of power from 400 watt rated panels. Expect power to be around 50%. The panels simply become dirty, and their efficiency is really lower. There are also losses in the wires. Even though my wires were quite short, about 10 feet, there were still losses. On the sunniest days, on the display of the solar controller, I observed battery charging currents of 11 amperes and a voltage of 21 volts. It's only 230 watts. That's 58% of 400 watts. For simplicity, I assumed that it is easy to count half. Because the sun is not always at its zenith.
This is where we come to the second point. Secondly, the time of a sunny day is not that long. And this is not because it is September, October, or November. I mean the effective time of daylight when the sun is high enough. My panels are located horizontally relative to the ground, they are mounted on the roof of the car. When the sun rises or sets, the battery charging currents are half or three times less. Essentially the effective charging time is 4 hours. From 11 am to 3 pm. Provided there are no clouds, no rain.
Thirdly, if the sky is overcast or raining, do not wait to charge. I had a week when the whole sky was overcast. It rained periodically. I followed the forecast, but it was disappointing. I began to refuse any loads on my station. I connected only the essentials. A 100 Amp battery was enough for me. But I discharged it to 40%. And this is in special saving mode! Perhaps in such a case it would not be superfluous to have a station with a battery of 200 Ah or more capacious, so as not to deny yourself anything.
Of course, I did not have heavy artillery in my arsenal, such as car refrigerators or heating kettles for boiling water. But despite this, the system coped with the task that I assigned to it. It provided me with autonomy, communication, security and even warmth.
A sudden transmission failure, and then the onset of night frosts, forced me to end the trip in the city of Gainesville. I could still get around the city, but I couldn't travel far to move further south to Miami, where the temperatures were warmer.
It was a wonderful three months. I've traveled halfway through amazing Florida. I visited big and small cities, countryside, and national parks. Met many interesting people. Gained practical experience in using solar energy. Solar energy is a cool thing. But we must understand that it also has its own limits. And it will not replace everything for you. We must treat this technology as a good addition to existing sources.
