electricity in portland, last i calculated it at the lightthouse, was 7 cents per kilowatt hour.

a solar panel like this one costs $4,464 per kilowatt. Every hour, the panel is creating 7 cents of value.  for the solar panel to equal the cost of electricity from the grid, the same panel would have to produce at peak output for 63,771 hours. Take 8 hours of direct sunlight in a day and thats 21 years of operation to equal the cost of grid power.

oh and that doesn't include the batteries needed to store the power to make it usable or the charge controller(s). the same website sells off-grid kits that include batters and controllers for $10,670 per kilowatt.