This article is based on some incredibly bad estimates, and reaches an outrageously large conclusion. Let us assume that 100% of all mining rewards go to electricity (and none to buying mining equipment, paying employees, servers, or networking), and let us further assume the electricity costs $0.01 / KWhr, which is cheaper than one can buy basically anywhere. From flippening.watch, BTC paid miners $20,797,200 yester…
My calculator and Google (search for "2079720000 kWh per 24 hours to MW") says it's more than 86,000 MW (so ~86 GW).
edit: corrected units from TW to GW, as pointed out by philipkglass