Are there any secret hacks to reduce electricity bills while keeping lights on for hours?

Yes... You can use the electric generator to produce electricity...

no

help that helps

You mean like legal or possible?

Use LED bulbs, 1W.

Switch your lights to LEDs.  If you have dimmable lights, dim the lights to the lowest acceptable level.

If you have the lights on for security reasons because the structure is unoccupied, then put the lights on a timer.

Use candles when safe and appropriate for your needs.

You probably will want to move your question out of the photography section into something more appropriate.