You know how much they spent, and they also, say, because they had to contract with the local government to get the power provided, you might know what they made a deal to buy, so you know how much power it takes.
まず支出額です さらに電力供給を受けるには 地元自治体と 契約を結ぶ必要があるため 購入の内容がわかり その結果 — 電力の消費量がわかるのです