Solar ammonia: Its time has come?

An idea sprang up in my mind recently, that is to make ammonia with solar power.  However, as I began to research what has already been done, it turned out not to be a new idea.  Nevertheless, I think it may turn out to be a good idea that just needs somebody to take it by the horns and implement it.

My idea would not be to make ammonia with electrolysis of water.  That seems inefficient, as you have to make electricity, and the electrolysis of water is very energy intensive.  I could be wrong though.  My idea is to use concentrated sunlight in order to cause thermal decomposition of water.  With the hydrogen thus obtained, I would then use it to make ammonia.  Where I could go wrong is that the temperature required for this is 2000 degrees Celsius.   Concentrated solar can definitely reach that temperature, but would it be more efficient than electrolysis?

This is all mere speculation, though.  There's no way I would attempt this myself.

Ammonia is quite versatile, as it can be used in agriculture and energy.  As an energy source, it can be burned in an ICE engine, or a Stirling engine, or it can be used with a fuel cell.  The infrastructure to move hydrogen can be done with ammonia, and this infrastructure already exists.  Thus, solar ammonia could be used for supplying hydrogen for hydrogen fuel cell cars.