Journalists discovered a shabby, nearly-forgotten, 40 year old solar panel in New Hampshire. And it was still producing electricity. Perhaps not as much as in the beginning, but “on a partly cloudy midafternoon” it could still cough up 24 Watt of the original 42 nameplate peak-Watt. This shows that the standard 20-year economic lifetime/warranty of solar parks is very conservative.
[concordmonitor.com] – A solar panel in the New Hampshire woods is old enough to run for president
Even more spectacular and accurately German-academically established are the results from a 35 year old solar array at the University of Oldenburg:
[uol.de] – 30 Years at the Service of Renewable Energies
Spectacular! Conversion efficiency decreased only mildly from 8.55% to 8.2%! The panels survived the companies AEG and Telefunken that build the installation.
[source] The 35 year old solar modules at Oldenburg University
Some calculations. A standard 300 Watt panel of 160 x 100 cm at a price of 250 euro (without installation cost) will produce in Oldenburg something like 285 kWh per year. Multiply that with 50 years = 14.250 kWh lifetime total. One liter of gasoline contains 12 kWh energy in the form of heat. Note that electricity from a solar panel is “higher grade” than heat. You can power your fridge on electricity but not on heat. Conversion of heat into electricity comes with a loss of perhaps 50%.
So this 30 kilo solar panel will produce the thermal equivalent of 1188 liter of gasoline over 50 years or 2375 liter of gasoline if required for electricity generation. Note that these 2375 liter gasoline weigh 1710 kilo. An amount that needs to be transported from Siberia or Saudi-Arabia to Germany first, where the Good Lawd deliverers all these photons at location in Oldenburg, free of charge.
Current consumer price gasoline in Oldenburg: 1.35 euro/liter.
1188 liter would cost 1604 euro.
2375 liter would cost 3208 euro.
The panel would cost ca. 500 euro, including installation and grid connection.
From this it becomes obvious that once a society is able to store renewable electricity efficiently, and all the signs are that this is going to work (battery 98%, pumped hydro 80%, power-to-gas 70%, CAES 60%), the shocking result is that renewable energy will be much cheaper than fossil fuel. Note that the figures here relate to Oldenburg in Northern Germany. In North-Africa, Australia or elsewhere, solar conditions are up to twice as good and renewable electricity prices can be slashed accordingly, giving poor but sunny countries the excellent opportunity to make money with the export of hydrogen-based stored energy (H2, NH3, CH4, NaBH4), generated by huge solar arrays at a cost of 2 cent/kWh.
P.S. criticasters might bring forward that the gasoline prices contain a considerable chunk of taxes, which is true. The counterargument is that that argument applies to the solar panels as well. We are comparing end-consumer prices for both gasoline and solar panels. Add to that that gasoline prices are unlikely to fall, but could very well increase, certainly if a carbon tax is applied, hand-in-hand with increasing signs of disastrous climate change:
[omroepbrabant.nl] – February 15, 2019, warmest 15-2 day in recorded history in the South of the Netherlands.
It is safe to predict in contrast that prices for solar voltaics will further come down considerably:
[newenergyupdate.com] – Solar costs forecast to drop 40% by 2020
Massive further reduction of cost of solar arrays is possible if one abandons the concept of heavy and expensive solar modules and corresponding all-weather mounting racks and replace them with thin solar film, mounted on lightweight plastic and rails, much like a curtain. A bit like this:
They can be installed in a desert with low air circulation, with the possibility of closing “the curtains” in case of rare strong winds.
More examples of solar panels/cells with remarkable longevity:
[dailymail.co.uk] – Britain’s first solar panel uncovered after 60 years… and it still works
[solarpowerrocks.com] – How long do solar panels last?