Wiggly amps

There have been many suggestions over the past few
months to fit equipment to gliders of all flavours,
most of them requiring electrical power.

The list is long, transponders, strobe lights, anti
collision warnings and thermal predictors.
We already have electric varios, turn and slip, artificial
horizon, gps, palm top, bug wipers and loggers and
I probably have not mentioned them all.

My question: Where is the power coming from to run
all these devices?