California just passed legislation that mandates solar power for all new homes. The legislation would require home builders to either make individual homes available with solar panels or construct a shared solar power system for a group of homes. The requirement is expected to increase the cost of a home by $8,000 to $12,000.
This could mean a boom for CdTe and CIGS panel makers if they make the overall cost including installation competitive. CIGS makers who produce building-integrated photovoltaic panels (BIPV) may see an especially big business boost in California, because the overall cost including installation is greatly reduced when the panels are part of the building itself.
Other solar materials such as Perovskites hold some promise for low cost, but so far their reliability outdoors lags behind that of CIGS and CdTe solar. Unless some major breakthroughs are made with Perovskite reliability, makers of Perovskite-based solar will not be able to capitalize on the California law.
Multi-junction and gallium arsenide and tandem solar cells may gain some traction in the high-end home market in California, but will not get as much of a boost as CIGS. The cost for GaAs and especially for multi-junction solar is still too high per Watt produced. Concentrator solar configurations are not mentioned in the legislation and are not likely allowed for individual homes, but may be allowed for collective (shared) solar generating systems. (let me know if this is the case).