Racing for the sun
Let the sun help you up those hills.
There are a number of bike designs which incorporate a solar powered motor – see links below.
Another option is the pedal-charged battery, which powers the motor which powers the bike.
Check out these sites:
https://solar-bike.blogspot.com/
https://www.solartrike.com/
https://www.kk.org/streetuse/archives/2006/11/solarpowered_trike.php
https://www.solarnavigator.net/electric_trike_rickshaw.htm
https://www.rhoadescar.com/jumpshow.htm