Variable Symbol Value Unit Source
Network Hashrate HN 296000 GH/s https://etherscan.io/chart/hashrate
GPU Hashrate HM 31.2 MH/s https://www.legitreviews.com/geforce-gtx-1070-ethereum-mining-small-tweaks-great-hashrate-low-power_195451
GPU Power PM 110.6 W https://www.reddit.com/r/ethereum/comments/7vewys/10000_tons_co2_per_day_and_climbing_eip_858/dtrswyz/

## Network Power Consumption (PN)

A baseline value for network power consumption can be found by multiplying the total network hashrate with a “best case” value for the power/hashrate ratio that a miner can achieve.

PN = HN x PM / HM

PN = 296000 (GH/s) x 110.6 (W) x 1000 (MH/GH) / ( 31.2 (MH/s) x 10^6 (W/MW) )

PN = 1049 MW

As a side note, people often confuse power (W) and energy (power x time, eg. Wh). For instance, assuming an average daily PNd of 1049 MW we can calculate that days Energy consumption by multiplying by the number of hours in a day.

ENd = PNd x Td

ENd = 1049 (MW) x 24 (h/d) / 1000 (GW/MW)

ENd = 19.7 GWh