>> >> >(7) Adding an inverter and peak power matching hardware to solar
>> >panels cost $2 per peak watt.
>>
>> That sounds exhorbitant. I can buy small PF-corrected switching
>> supplies for 25 cents a watt,
>
>Their efficiencies are far less than unity, and this is but one step
>in the inversion peak power matching process and then synchronizing
>with the AC grid in such a way as to contribute that power
>efficiently.
There are around 7 manufacturers who now sell peak power matching solar panel inverters approved for grid connection, per a system installer I know. Full power efficiencies are all well over 90%, and the prices all run around 50 cents a watt for the sizes which are most commonly used (4 or 5 kW).
A big piece of the higher than 25 cent/watt cost is probably the rated line disconnect means, which must of course disconnect reliably under overload, short circuit or reverse power (line to inverter) conditions, and that capability tested by an approved rating agency. The rest (mabey most) of the cost difference is due to still relatively low volumes. Automatic paralleling with the line is of course trivial, adding almost nothing to the cost - a bit of extra code to synchronize, voltage match and issue the close contactor command.
BTW, typical costs for installed 4 of 5 kW (at 25 deg C ambient) grid connected home solar systems in CA are now running between $9.00 and $9.50 per peak watt. Basic panel ratings are at 25 deg C junction temperature, and since black panels in full sun get quite hot they need to be derated for operating temp, somewhere around 15% IIRC, exact value to be found in the fine print on the data sheet of course. A bit more panel is also added for inverter loss, so the customer gets the rated peak power actually delivered to the grid.
These costs do not need to come down very much to be economical when standard economic analysis of the present value of future payments is done for the 30 year life expectancy of the system, considering that increases in the cost of electricity are not likely to lag inflation. $7.00 per installed peak watt is probably attainable in the near future. $.07 per peak watt is a misplaced decimal point.