The challenges for solar cell adoption are:
Cost-effective manufacturing methods
The market price of silicon
Efficiency of conversion
Storing the energy for when it's required (or moving it to where it is helpful)
The price of silicon isn't the biggest problem now. Solar cells are already at parity with coal in India, and keep getting cheaper every year.
Efficiency is generally sufficient. A house's whole roof can generally power it.
Durability also isn't generally an issue. Solar cells usually last for upwards of 20 years.
The primary challenges now are:
Electrical connection costs (i.e. an inverter)
and Storage (or grid hookup costs)