I was merely pointing out that CSP efficiency likely doesn't increase with increasing ambient temperature, it's just inherently more tolerant. As an aside, you

I was merely pointing out that CSP efficiency likely doesn't increase with increasing ambient temperature, it's just inherently more tolerant. As an aside, your calculations are improper, even though results are close enough. 0℃ is merely 273.15K and the temperature at which water tends to freeze. E.g. PV efficiency is usually quoted at 25℃ (or 300K), so at -20℃ they could generate cca 120% of "max" (rated) capacity.