Life /
Installing a solar panel in Poland [14]
Over 20 years a 200watt solar panel will produce say 200*1000*365*20=1,460,000 KwhrIf you have a full sun over some part of Poland 24 hours a day for 20 years, 200W panel would produce
0.2 kW * 24 h * 365 days* 20 years
* 0.9 = 35040 kWh
(0.9 is average based on 80% promised output in the end of 20 year life).
In a real world with average to 2.5 hours of full sun each day over the year it becomes 3650 kWh during full life cycle.
3650 * $0.05 = $182.5, compare to your $72k.
Right now we will not take conversion losses into account, but you are lucky if you'll get more than 80% of this amount into more useful form of 220V AC.
Now I look to older 100W Siemens Solar panel that is in my room now, It was removed to reinstall to another location later. Good, robust panel with 20 year warranty. There is about 2.5 kg of extruded aluminium in their frame and base.
If memory serves me correctly, producing of one ton of primary aluminium require (world's average) 15.6 Mw*h. Around 11 MW*h per ton is used to break chemical bonds in oxide, and rest is losses to heat the mixture.
So, 2.5 kg of aluminium takes around 39 kW*h just to convert oxide into metal (not counting energy expenses to mine the ore, enrich, etc).
For 100W panel will produce (based on calculations above) around 1825 kwh of energy during their 20 years life (in Poland). 91.25 kWh per year. About half year of operation just to "return" energy spent in smelters to produce raw aluminium that was used to make its frame.
With monocrystalline silicon that was used in solar cells things is even worse...
Just to note, most widely used Siemens process take about 250 kWh per kg of pure silicon that can be used for solar cells or further purified for use in electronics.
There is another, more energy-efficient processes in use, but they use rare ultra-pure minerals as feedstock.
