Silverstone Nightjar 520 W @ techPowerUp
 

Silverstone has been offering fanless PSUs for quite some time; however, they hadn't released a relevant product for some years now, which changed recently as their Nightjar fanless series now includes the NJ520 with Platinum efficiency, a fully modular cabling design, and a promise of total silence.

http://www.techpowerup.com/reviews/Silverstone/NJ520/