New testing conducted at France’s oldest PV system have shown that its solar modules can still provide performance values in line with what the manufacturers promised.
Those are way more interesting than this single installation with -0.66%:
“Another more recent study carried out by the US Department of Energy’s National Renewable Energy Laboratory (NREL) on 1,700 American sites totaling 7.2 GW of power, showed a median degradation of around -0.75%/year. Moveover, another research focused on 4,300 residential installations in operation in Europe and used different data processing methodologies. Depending on the methods, a median loss of -0.36% to -0.67%/year was obtained.”
Also the article doesn’t mention standard deviation or IQR of the drop, or what efficiency they originally had. Which is the minimum of information I would expect.
You are totally right. Median and average alone mean shit without each other and without deviation, and such article like this is considered by me a manipulation without further correctness check. The same shit is with journalists confuckulating percentages with percentage points.
In over 10 years I was made aware by my university professor of these practices I haven’t found a single article which got that right.
