1 3-1-1 for carry-ons = 3.4 ounce (100ml) bottle or less (by volume) ; 1 quart-sized, clear, plastic, zip-top bag; 1 bag per passenger placed in screening bin. 2  One-quart bag per person limits the total liquid volume each traveler can bring. 3.4 ounce (100ml) container size is a security measure. 3  Be prepared.
Variable costs. A solar power plant is one of the cheapest to operate because there are no fuel costs involved. A solar PV (photovoltaic) power plant requires fixed expenses of $11.40 per megawatt hour, or just 1.14 cents per unit. Whatâs more, it doesnât require any variable expenses.
An array able to produce this much power must 4 kW or larger (based on 5 sun hours per day). The average cost of a solar system of this size is $17,000 and ranges from $15,000 to $20,000 installed (not taking any incentives into consideration). In This Guide. Average Cost and Factors that Affect it. Grid-Tie versus Off-Grid Installations.