The author himself seems to have no idea what he's talking about when he writes:
Last year, solar energy met 2.8% of demand out a total of 12.9% for all renewables.
The author puts the figure or CSP at just over 400 MW, whereas Spain has around 3,400 MW of photovoltaics installed. Obviously, we are getting more electricity from photovoltaics than from CSP in Spain.
And in case you are thinking that the 50 MW Spanish CSP plant the British author refers to as the largest in the world is a far bigger than anything that could be done with photovoltaics, take a look at this list, which shows that Spain already has 60 MW photovoltaic plant.
A recent press release from Germany is more insightful. This week, Germany was producing up to eight gigawatts of electricity from photovoltaics, compared to 14.5 gigawatts from nuclear plants. Germany has 17 nuclear power plants, but four of them are currently off-line for scheduled and unscheduled repairs; furthermore, they are currently slightly being throttled because the waste heat would otherwise heat up rivers too much.
It is possible that photovoltaic electricity production will peak at levels above nuclear power production as soon as next year in Germany. And if you are focusing on large systems, keep in mind that Germany is mainly doing this with small rooftops.