Graph of the Day: Contrasting outputs from a wind farm and a solar farm

This mesmerising image looks like it might be the work of a child with a crayon, but it’s actually a plot – for the whole of 2019 – of the output of a solar farm and a wind farm.

The author, Australian Renewable Energy Agency CEO Darren Miller, doesn’t say which actual facilities he has been plotting, telling RenewEconomy only that he was “messing around” with some data at home.

But he posted it on LinkedIn, with the message: “There’s something mesmerising about energy data! Here’s 5-minute data from a large solar farm and wind farm in 2019.”

As others noted, it illustrates the reliability of solar in daytime hours. Russell Harris, the head of consulting at Clean Technology Partners, noted that while solar output is often measured in “capacity factors” for a 24hr period (usually 25-32 per cent), the output from a solar farm during the hours you’d expect to get generation is more like 70 to 80 per cent.

“Secondly, the correlation between output of solar clusters (eg 1 inverter’s worth) drops off quickly with distance. Using 5s data, on a very intermittently cloudy day for a 15MW generator in Qld, the output of two inverters 1600m apart were virtually uncorrelated,” Harris noted.

Others wanted more visibility of the wind data, broken down in months or quarters, to get a better idea of output. Others simply wanted to download it on their desktop or stick it on their office wall.