Punctuation with “equivalently” and “alternatively”

Question

What is the preferable punctuation when using equivalently in the middle of a sentence in order to give an equivalent interpretation of something as illustrated below?

1. It minimizes the power consumption or equivalently the energy consumption of the system.

2. It minimizes the power consumption or, equivalently, the energy consumption of the system.

3. It minimizes the power consumption, or equivalently the energy consumption, of the system.

4. …

Similarly, how is it with alternatively?

1. It can minimize the power consumption or alternatively the execution time of the system.

2. It can minimize the power consumption or, alternatively, the execution time of the system.

3. It can minimize the power consumption, or alternatively the execution time, of the system.

4. …

Answer 1

The first version,

It minimizes the power consumption or equivalently the energy consumption of the system.

sounds rushed. To avoid starting to read "equivalently" as a noun following "power consumption", it's nice to have a break. However,

It minimizes the power consumption or, equivalently, the energy consumption of the system.

has a parallelism problem because "of the system" applies to "power consumption" as well. An alternative such as

It minimizes the power consumption of the system or, equivalently, the energy consumption of the system.

is too wordy. A better rephrasing would be

It minimizes the power consumption (equivalently, the energy consumption) of the system.

or

It minimizes the power consumption—equivalently, the energy consumption—of the system.

(Even better, replace "it" with what you're actually referring to for clarity.)

The same comments apply to "alternatively".