Unfortunately the blog didn't link to the SFP+ module they're using, but everyone should know there's effectively 2 different generations of 10gbit sfp+ to ethernet^H10BASE-T modules. The old gen, labeled as 30 meters, draws ~3 W, and gets extremely hot (to the point it'll usually cause link flaps), and the newer gen, usually labeled as 100m or 80m, draws ~1.5 W, and runs much, much cooler.
Example of the new gen: https://www.amazon.com/Wiitek-Transceiver-Compatible-UF-RJ45...
Old gen: https://www.amazon.com/10Gtek-SFP-10G-T-S-Compatible-10GBase...
Typically the old gen uses a Marvell AQR113C, and the new gen uses a Broadcom chip that I forget the number of off hand.