Electrical demand implied by each network’s hash rate, plotted against COINS ISSUED rather than date. At the same calendar moment Bitcoin is 16 years into its schedule and Zcash 10, so a date axis compares two different stages of maturity.
Aligning on supply asks a fairer question: what was Bitcoin’s network drawing when it had mined as many coins as Zcash has now? Both chains cap at 21M, which is what makes the alignment mean anything.
Bitcoin’s hash rate comes from blockchain.info in TH/s; Zcash’s is derived from block difficulty. Both are converted using CURRENT-generation ASIC efficiency — 17.5 J/TH for SHA-256 (Antminer S21) and 1.96 mJ/Sol for Equihash 200,9 (Antminer Z15 Pro).
That means these figures answer "what would this hash rate draw on TODAY’s hardware", not what the network actually drew at the time. Early Bitcoin ran on machines orders of magnitude worse, so its real historical draw was far higher.
Modelling the efficiency curve of a fleet nobody has an inventory of would stack a large unverifiable estimate on top, and one stated basis is easier to reason about than a fitted one. Log y-axis; the same figures feed the Mining energy @ equal issuance line on the Activity-Implied Market Cap chart.
Nobody meters the Zcash network. This is hash rate converted to electrical demand by assuming every miner runs current-generation hardware at its rated efficiency — which no network does, because old machines stay switched on while they pay for themselves. So read this as a lower bound on a lower bound: the efficiency assumption understates draw, and hash rate itself only counts the work that found blocks.
The x-axis is coins issued, not the date. At the same calendar moment Bitcoin is sixteen years into its schedule and Zcash ten, so a date axis would compare two different stages of maturity. Aligning on supply asks what Bitcoin’s network was drawing when it had mined as many coins as Zcash has now — a question that only means something because both chains cap at 21M.
It is not an environmental claim in either direction. Energy drawn says nothing about where it came from, and this chart cannot distinguish a hydro-powered network from a coal-powered one of the same size. For the input it is built from, see hash rate.