I think the ones around here being installed are 10 KW. Heard of the shingles before also.
Here is a quote form this site:
http://news.energysage.com/how-much-does-the-average-solar-panel-installation-cost-in-the-u-s/

Knowing the average cost per watt is helpful, but what does $3.57/watt actually mean for you? The cost of installing solar on your home or business depends on how much electricity you want to generate – a bigger system will cost more, because you’ll need to buy more equipment and more labor will be needed to install it.

The average solar energy system size in the U.S is approximately 5 kilowatts (kW). Based on the average price of $3.57/watt, a 5kW system would cost $12,500 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
•10kW solar energy system cost: $25,000

These prices reflect the cost of a solar energy system after deducting the federal solar tax credit, which reduces your solar system cost by 30 percent.