Price
The price of solar electrical power has continued to fall so that in many countries it has become cheaper than ordinary fossil fuel electricity from the electricity grid since 2012, a phenomenon known as grid parity.[1]

Average pricing information divides in three pricing categories: those buying small quantities (modules of all sizes in the kilowatt range annually), mid-range buyers (typically up to 10 MWp annually), and large quantity buyers (self-explanatory—and with access to the lowest prices). Over the long term there is clearly a systematic reduction in the price of cells and modules. For example, in 2012 it was estimated that the quantity cost per watt was about US$0.60, which was 250 times lower than the cost in 1970 of US$150. A 2015 study shows price/kWh dropping by 10% per year since 1980, and predicts that solar could contribute 20% of total electricity consumption by 2030, whereas the International Energy Agencypredicts 16% by 2050. (1)

Advantages of Solar
The advantages of installing solar panels include the federal tax credit and state tax credit. In addition to these incentives, Arizona receives the most sun in the US. This means that less panels are needed in order to completely wipe out your electric bill. (2)

Maintenance
Solar panel conversion efficiency, typically in the 20% range, is reduced by dust, grime, pollen, and other particulates that accumulate on the solar panel. “A dirty solar panel can reduce its power capabilities by up to 30% in high dust/pollen or desert areas”, says Seamus Curran, associate professor of physics at the University of Houston and director of the Institute for NanoEnergy, which specializes in the design, engineering, and assembly of nano-structures (1)

Recycling
Most parts of a solar module can be recycled including up to 95% of certain semiconductor materials or the glass as well as large amounts of ferrous and non-ferrous metals.[1] Some private companies and non-profit organizations are currently engaged in take-back and recycling operations for end-of-life modules. (1)

Cost
The average cost of installed residential solar power systems is currently $2.64 per watt. A typical 6kW system costs $11,722 after claiming the 26% solar tax credit.

Solar panel cost is affected by many factors, such as the state you live in, solar panel brand, and total system size. This page presents data showing the impact of each of these variables on the cost of residential solar power systems. (3)

 

Sources:

(1) – https://en.wikipedia.org/wiki/Solar_panel

(2) – https://www.solar-estimate.org/residential-solar/solar-panels/arizona

(3) – https://www.solarreviews.com/solar-panel-cost