Please please pleeeeeease start tariffing the export of electricity from Canada to America.
Tariffs affect buyers through increased cost, and sellers through reduced sales. Import tariffs affect local buyers and foreign businesses, while export tariffs affect local businesses and foreign buyers.
All of Trump's tariffs are import tariffs. They affect American buyers, who have to pay more, and foreign businesses who sell less. Generally, export tariffs are avoided, because reduced sales for local business is "a bad thing" (but fuck local consumers amirite).
With Canada's electricity exports, America needs it. They can't not have it. So a tariff here makes perfect sense: the foreign consumer has no choice but to pay, while the local business loses no sales. All the pain is felt in the foreign domain.
Electricity export tariffs are win/win for Canada as a retaliation to the US.