When I briefly moved to US end 1990s I put the motherboard and hard drives in hand luggage so I only had to buy the chassis and power supply there. This earned me a wipedown for explosive traces at the control. Asking “this is because of Lockerby, isn’t it?” did not help things.

Supercapacitors are for stabilizing the grid, the batteries are for flattening the peaks/load-levelling at diurnal scale.

The trick is to buy dead tree and also download the same book from the usual online libraries.