The levy is 500 bucks for EVs and 250 bucks for hybrids every two years. Given the premium cost for these vehicles, the provincial government takes in additional tax revenue when they are bought... and the loss in fuel tax revenue is nowhere near these numbers. We've contacted our MLA Tim Halman (who is also Environment Minister for NS) to ask how he decided on the numbers and he literally won't say. He was happy to lie and say Ontario and Quebec do the same (they don't). 

The average a motorist drives in NS per year is 16k km.Let's say that takes 1300 litres of gasoline. A hybrid might save 320 litres of gasoline for this.

A benefit of living in Ontario is that the electricity I use is produced almost entirely by hydro (thanks Niagara Falls) or nuclear, rather than how certain American states produce electricity through the burning of fossil fuels.

Edited to add: for further context, after eight years and a reasonable amount of battery degradation, my Tesla Model 3 can probably get around 250 miles of highway driving on a full charge, or possibly 20-25 miles more than that, though whenever I've driven it on long trips I tend to stop to charge once along the way at a time when it's convenient to get a bite to eat or whatever. In that case, charging the car back up to 80%+ generally takes 15-20 minutes, or enough time for me to eat and go to the bathroom.