joeyh at

For perspective, the old panels here generated 32 amp-hours on this sunny winter day. At noon, 70 watts were being produced. (These panels were originally rated at 256 watts; they might have generated 128 watts 15 years ago.)

The 32 amp-hrs is ample for my laptop for a day. I could stretch this windfall for a week if I needed to. As it is, tomorrow should be fairly sunny too, and the charge controller has nearly topped off the batteries full, so I am running some hard drives on the inverter and blasting hundreds of GB of data around., Greg Grossmeier likes this.