Frequently Asked Questions
1) How green is it?
How green is the 500W solar kit? Compared to a 500W Honda Gas Backup Generator that fire up all over the US when power outages occur – yes. You will be emitting zero (and your fuel cost will be zero!).
Does it have an impact on your CO2 footprint, though? Let’s calculate:
Production footprint mono-cristalline PV: 4200kWhee/kW  * 0.1kW = 420kWh embodied energy Production footprint li-ion 18650 battery: 321kWhee/kWh  * 0.5kWh = 161kWh embodied energy Total Footprint: 581kWh Annual energy production system: 155kWh/y Payback period: 581kWh / 155kWh/y = 3.7 year CO2 footprint payback
It’ll take 3+ years of usage until this system is CO2 net-positive.
2) Will this system save me a money?
What’s the payback period for our solar battery system? Will it save me money?
Payback period for 100W, 540Wh system System cost: $499 Yearly energy creation: 365d * 4.26hsun/d * 100W = 155kWh/y Yearly value creation: 155kWh/y * 15c/kWh = $24/y energy created 100W system payback period: $499 / $24 = 21 years until payback
In San Francisco, the payback is 10 years. The further south you are, or the more expensive energy is in your area, the shorter it’ll be. This system will not save you money until after that, and even then is definitely not a “money-saver”. It will however be more valuable in the event of backup generator needs, at camping/outdoors, and of course it’s just generally cool to be independent from the grid and make your own renewable energy.
3) How much electricity will it make?
Short answer It can charge all your laptops and phones and run your speakers and power your lights. It’s a powerful solar system with a powerful battery and inverter attached. It cannot run your iron or laundry, but it is enough to back up a full-size, family fridge for a 4 hours a day in summer if the power goes out, or easily power a mini-fridge at the beach for 24 hours. Have fun! :)
Longer answer is in SF it’ll make on average 4.26 * 100W = 426Wh (0.426kWh) per day. Of course in winter it’ll make less (around 300Wh), in summer more (around 800Wh). Of that 540Wh will be stored. And if you’re further north, maybe you will want a second panel for winters. And if you’re further south, even in winter your batteries will always be full even when you’re using energy all day from the system.
Any questions? Get in contact above.
4) Where can I put the panel?
Here are our main suggestions but you can get creative! Let the sunlight inspire you!
- Off-Grid Apartments
- Backup during blackouts, hurricanes, earthquakes, etc
- Backyard experiments
- Tiny houses
5) Can I charge the battery off my car?
Yes you can! 12V DC in is supported, and an adapter is included in the box.