I am not sure if solar panel are worth using in places where the sky is clear only several months a year. A desert (for example, in Africa or Emirates) would be a better place for them.

Wouldn't it be better to have thousands of traditional natural gas, coal or diesel-powered generators to replace large centralized plants? They are compact (easier to hide). A 2 MW generator is a size of a truck. And portable 24 MW generator is a size of several trucks. Before the war, they had ~44 GW of generation (~1 kW per person), so one needs thousands of mobile generators to replace the system, and I doubt anyone provided them.

I wish there was a comparison of installation costs and generation costs for traditional and renewable energy. Without comparison, it might be that renewables are simply not worth investing yet.

One company advertises solar panels [1] and claims that 1 MW scale array requires 3000 panels and costs over $1M. While used diesel-powered 2MW generator costs several hundreds thousands USD. Why would someone buy one array when for that price several diesel generators can be bought?

Traditional energy is cheap. For example, Russia has 240 GW of generation, almost no solar and wind, and electricity costs 8 cents per kWh and in the West the energy is super expensive despite using solar and wind power. Also, diesel costs 65 RUB/liter, or 2.94 USD/US gallon (if 1 US gallon = 3.78 L) and again in the West for some reason it is overpriced. Maybe the renewables are only profitable with overpriced natural resources and government subsidies, without a comparison it is difficult to say.

[1] https://solartechonline.com/blog/what-is-a-solar-array/

Why is fuel so costly in Russia? In Libya and Venezuela, prices are around $0.02 to $0.03 per liter.

Natural gas& co need infrastructure to be carried around, stored, processed etc.. you have just traded a single target power plant for a single target gas pipeline.