Pilot reported operating an aircraft with a malfunctioning number 1 Alternator which was required by the POH for flight.

Narrative

During departure from ZZZ the ALT1 warning light came on. Cycling the ALT1 power did not clear the warning. I requested a return to ZZZ where a complete shutdown and restart also did not clear the warning light.A local Mechanic; familiar with the SR22; identified the problem as a failed ALT1 and he did not have the capability to repair the part that day.We discussed the possibility of returning to the home airport ZZZ1;70 nM away; in VFR conditions. [The Cirrus SR22 ALT2/BAT2 system is made to operate the ESSENTIAL buss (which includes the PFD and GPS1) continuously and is completely isolated from ALT1 (engine instruments are then displayed on the PFD)]. The circuit breakers for the MFD and GPS2 could be pulled to reduce the electrical load on BAT1; saving its capacity in the event it should be needed to take over from the ALT2/BAT2 system if it were to fail.This was discussed (by phone) with a second Mechanic that normally maintains the airplane and he agreed that this process would work. The POH was not reviewed.After landing; the POH was reviewed; and it was determined that ALT1 is required equipment for all flights.TAKEAWAY -- The POH governs; not the hopes of the PIC (Pilot in Command) or statements by Mechanics.