Page 56 - Energize October 2022

VIEWS AND OPINION

output from CSP, which needs direct a six-day period of significantly lower than normal performance. The deficit in energy
sunlight to operate. Meteorologists production in this period amounts to approximately 2,5 times the daily production.
predict that climate shift or climate Assuming six peak equivalent hours (PEH) this amounts to 2,5 x 9000 MWh = 22 500
change will cause such occurrences to MWh. To make up for this deficit, one would need additional generation capacity or
be more frequent and more severe in storage capacity of 22 500 MWh, at an additional power capacity of 1100 MW.
future. The current weather cycle (La Doubling the capacity reduces the deficit to 30% of the daily capacity, and to
Niña) is also expected to persist for eliminate the deficit altogether would require an increase of 3,5 times in solar capacity.
several years, and country-wide cloud This would result in a high excess generation during normal times, assuming that demand
cover could become quite common. remains the same, but this could be absorbed by reducing the level of conventional
generation.
Solar power generation
Solar is the easiest to analyse so it The case of wind
would a good place to start. Solar PV Wind is far more difficult to analyse as it varies in a random pattern and the plain man
exhibits a periodic behaviour with a does not have access to the necessary statistical models to handle this. To simplify, we
peak at around midday, every day, the will focus on recent worst-case situations which could have plunged the country into
only variation being the level of the darkness. The concern here is not only that wind cyclically drops to low levels but that
peak. There is obviously no solar power low points of wind generation occur regularly during the evening peak period, whereas
generation outside of sunlight hours, wind is assumed to peak in this period, which it does most of the time. On three
and solar on its own does provide firm occasions in the period May/June wind remained below 500 MW (18% of capacity) for
capacity. more than 24 h.
There are two instances of low Looking at the pattern creates the impression that there is always a useable amount
solar occurring in the load shed period, of wind power available; however this visual averaging is deceptive, and while there is
and the one centred on 21 May shows some firm capacity available under normal conditions, it is only a few hundred MW.

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