Solar panels are "good enough" for "light applications" up until about Jupiter or so. Further out the solar energies become less dense.
On Earth solar panels are typically good for about thirty years, after which the solar exposure basically kills it. Loss is comonly quantified as 1%/yr but it's likely a lot higher. In space, lacking atmospheric protections, that can drop as low as 15yrs. The closer to Sol you get, the more energy the same panel will produce - but the quicker it will also burn out. The most effective current mitigation techniques currently adding about five years at best, in earth-orbit locations. These are reliable, in the right conditions, but only considerable for short term use at best. Anything that will be servicing long term habitation needs to be viable for multiple generations ideally. Can't be doing with shutting everything down every 45 years to install a new reactor or w/e.
Generating energy isn't really much of an issue, even in space. The most common issue is dissipating excess thermal energy - the only real option available being through InfraRed radiation - as there is no matter to either conduct or convect. Dissipating thermal energy through devices leveraging the "seerback effect" should allow to convert some of the excess thermal energies directly into electricity. Other cunning techniques can dissipate some through metamaterials converting heat into light - reducing the requirement to generate/use electricity. Some have proposed striling engines to deal with some of the heat - converting it into kinetic energy, which could then be translated back into electrical energy. I've even caught mention of a dyson-harrop loop, beaming the energy back with IR.