I installed one for my paros in shags in 2008 cost roughly Ksh 160,000. Major costs:
150 Watt Panel - 80,000
I000 Watt Inverter - 30,000
Two 100 AH Batteries - 19,800 (9,900 each)
Charge Controller - 6,000
Rest of cost goes to installation charges and accessories.
This system supports 12 energy saving bulbs and a 21 Inch colour TV you can also do some light ironing. All the lights are on AC hence consumption is a bit high. I intend to re-wire the lights to DC and install a smaller inverter for the TV. Other option is to isolate the lights from the TV and install a separate panel and battery bank for each.