I need to run electrical in 3/4" Grey PVC conduit 1000' to operate a gate opener which is just a 24V A/C adapter 40VA and two lights (maybe 60Watts/ea). Can I get away with running #10, or do I need #8? Thanks for the help.

If I calculated it correctly, you would need to use XHHW type cable.

A 120 V / 20 amps feed would require a 2/0 - 2 wire plus ground cable.

That would give you 113.6 AC volts at the end of the run with 20 amps.

I'm sure TK will check my clacks for accuracy so please wait for his response.

Wow, that will cost a fortune to run two lines. I can run 1000' low voltage wire, and install low voltage lights on columns as well. I thought some THHN #8 would at least power a couple of light bulbs. Can I run low voltage wire next to THHN stranded wire in 3/4" Grey PVC? Thanks for your help.

Assuming 2 amps , two, of load at 120 volts 1000 feet, you would need # 8 copper wire.

120 watts of lighting is 1 amp, and allow 1 amp for the opener is how I arrive at 2 amps of load.

I would deliver 120 volts to the opener, and have the 24 volt at the end of the circuit. Do not try to deliver the 24 volts 1000 feet.