When people think of home solar, they imagine spending $15,000–25,000 for panels — another $10,000+ on a Tesla Powerwall or the like.
For $100, my iPhone, iPad, Chromebook, and Quest 2 all charge for free.
A foldable 21W solar panel sits in my driveway right now, charging two 25,000 mAh batteries. In two days, both batteries will be full.
- The 21W panel (about the size of an sheet of paper, folded) was $40.
- The Li-ion batteries (each about the size of an iPhone) were $30 each.
Both are from Amazon. Both use USB-C for input and output.
In two days, I’ll conservatively net 50,000 mAh (about 250 Wh of power at 5V). That’s 25,000 mAh/day.
Consider the battery capacities of personal electronics:
- iPhone 12: 2,815 mAh
- 7th-Gen iPad Pro: 9,720 mAh
- Asus C302C Chromebook Flip: 5,270 mAh
- Meta Quest 2: 3,640 mAh
Combined, these gadgets store 21,445 mAh.
One 21W solar cell adds more power every day than all of my devices combined can store.
Portable batteries rapidly charge from USB-C output. I don’t have to worry about plugging anything into a wall. I don’t worry about whether my devices are charged, and I don’t feel guilty about charging them.
It’s one of the best $100 I ever spent.