Electricity generated from solar power is cheap. The cost has come down by ninety percent over the past ten years and is continuing to fall. A 300-watt (DC rating) PV module of the type used in large solar systems currently costs less than $120 in quantity. This module will produce over 10,000 kWh of electricity over its 25-year life, which works out to about 1.1 cents per kWh. Of course, an AC off-grid solar power system requires a battery, charge controller, and an inverter, which will make it substantially more expensive.
Most designers do not realize that a utility-scale (72 cell / 300+ Wp) module may actually be cheaper than a 100 Wp or even 60 Wp module because the large modules are made in highly automated factories for big projects, while the smaller modules are typically made with lots of manual labor.