They run on methanol (next best thing to hydrogen…seeing as you can easily purchase these now) which is produced naturally in plants like cotton
The easily portable 2200 provides 90W (enough for a laptop) and i think the m28 cartridge could charge one’s laptop continuously for 2500 hours (and that’s without attaching solar/wind into the mix). It’s a little less than $10,000 and available through Amazon

and here is an even more baddass/efficient hydrogen charger but on a smaller scale (Horizon is helping the hydrogen market bigtime and does have larger scale products)