[Smoosh]

I'm wondering if that was a constant 40 microwatts, and if that could be stored in capacitors so that every 4-5 seconds (the refresh rate of the panel) there would be enough energy accumulated to power the circuitry for an update.

[eyegor]

Yes is the answer, but it would be much slower. Assuming 1w for 6 seconds (4s refresh + 2s transfer), it would take about 42 hours for a lossless storage + regulator circuit. 40uw is an incredibly small amount of power.