It is referenced in the article itself.
http://arxiv.org/abs/1305.3913
564degC, 511degC, 495degC, etc. throughout the report. This report was aiming for energy density, not necessarily just output in degrees, etc.
Ah I got it now. Thanks for the link.
Wow, that is really some usable heat then. You could build a steam engine for electrical power and then the excess heat to provide hot water / heating for the house, possibly even heating a green house. I could see this being viable for a farm or small business if the price is right.