A common easement is from NB Power. It is written into the deed that NB Power can have power lines or an anchor on your property. It is transferrable to all future owners.
A dusk to dawn light is a large bright light (usually mounted on an NB power pole) that automatically comes on at night and turns off in the morning. It provides light at night if you don't have street lights. The light can be rented from NB power for about $13/month or purchased. You pay for the power it consumes as well.