tbh, the energy accounting of the Matrix never made sense to me
if you take an average energy intake of about 2000 kcal per day, that comes down to about 100W of power (it'll be a lot less depending on how you plan to convert that to electricity)
there are far more potent ways of getting energy, even if you remove direct sunlight
and they never explained why the highly advanced machines, who do not need to maintain an atmosphere inside a spacecraft, would not be able to deploy orbital solar panels - there's no reason for them to deploy the majority of their activities on the planet's surface