The energy market is yours for the taking in Energia, where you'll need to capture power plants owned by the city. That won't be easy, of course, because the city can and will fight back for what's theirs.

Use your hard-earned power plants to generate money and energy to upgrade your attacks, defenses and utilities and drain the city of its power.

https://ldjam.com/events/ludum-dare/39/energia-1