If I lease my site and Greenbug installs an Archimedes screw generator, will my property taxes go up?

No your property taxes will not go up. In Ontario, Any water power installation does not affect property taxes.

Hydro-electric generating stations are not subject to property tax. In its place, they are subject to a provincial Gross Revenue Charge (GRC), based on the gross revenue (regulated rate) and actual generation of the facility.

For further information, you can check out the following links:
The Ontario Waterpower Association also has information if you click on this link http://www.owa.ca/home/policy-initiatives/ and scroll down to “Taxation and Resource Valuation”.