> Solar panels require an accompanying energy storage system, hydro or gas turbines.
That is not exactly true. For example Europen super grid is an alternative solution. The idea is that you generate electricity in one country and then transfer it to another. For example "midday" lasts about 7 hours in Europe, so at least one country. You will have pretty good generation between 8:00 - 16:00, so that is 15 hours of good electricity generation. During night time the demand is lower. When you combine this with wind, you get pretty good summer/winter coverage.
You will still need for example hydro and gas turbines, but those don't need to be in your country as you can buy it from other countries. For example Eastern countries can buy nuclear from France during their evening time when it is already night in France. And hydro in Sweden and Norway can cover multiple countries around them.