https://bib.irb.hr/datoteka/575153.E...chnologies.pdf
"3G communication technology is the largest consumer of energy, followed by WiFi and Bluetooth communication technologies. This implies that energetically the most economical way to transfer data is when using Bluetooth communication technology.
In [6] Balasubramanian et al. showed that data transfer of 50 KB when using 3G needs 12.5 J, while when using WiFi the same data transfer consumes 7.6 J of energy indicating that WiFi communication technology is 39.2% more energy efficient than 3G communication technology. Our measure- ments showed that for data transfer of 0.5 GB when using WiFi 8% of the battery was used, while 3G for the same amount of data needs 18% of the battery. This implies that WiFi communication technology is up to 55.56% more energy efficient than 3G communication technology."