The average solar energy system size in the U.S is approximately 5 kilowatts (kW). Based on the average price of $3.36/watt, a 5kW system would cost $11,760 after tax credits. Below are some average 2015 quotes for other solar energy systems by size: 6kW solar energy system cost: $15,000. 8kW solar energy system cost: $20,000.
Pros: 1  Economical option. Homeowners appreciate the sleek appearance of an asphalt-paved driveway at a lower cost than concrete or paver surfaces. 2  Flexible in extreme climate conditions. Asphalt driveways typically cost $2 - $5 per sq foot to install - more than gravel, but much less than many other options. 3  Long lifespan.
How much a driveway should cost. Average costs and comments from CostHelper's team of professional journalists and community of users. A gravel driveway starts at roughly $0.75-$3 or more a square foot, or $300-$1,000 for a 12'x25' single-car driveway. Costs can double for a roadway-quality driveway.