Hi - my name is XXXXX XXXXX I'm a Real Estate litigation attorney. Thanks for your question.
If the electric company has a utility easement across your property, then it would have the right to cut trees, limbs, etc. to run utility lines to customers. However, if there is no easement, then you could refuse access to your property.
However, if there is no utility easement in place, and if you refuse to agree to provide such an easement, the utility company has a right to file an eminent domain lawsuit against you to secure a utility easement. Generally, all the utility has to show is that the easement is needed to provide utility services to a citizen/customer and the court will grant the request. At that juncture, the only question is the amount of compensation you should be paid for the use of your property.
Compensation is usually determined by an appraisal that shows the impact the easement has on the value of your property. Generally, you are entitled to the difference between the value of your property before and after the easement is taken. For instance, if your property is worth $150,000 now, and if the easement will impact the marketability or the value of your property and makes it worth $135,000, then you would be entitled to that dimunition of value - $15,000.