Learn English – “They {don’t / didn’t} seem to have had much trouble getting work.”

To begin with, look at your sentence:

"Members of the 16th Lok Sabha worked harder in the budget session than they have in the last 10 years, parliamentary data shows.

I recommend looking at it in two parts:

1. Members of the 16th Lok Sabha worked harder in the budget session
2. than they have in the last 10 years, parliamentary data shows.

Sentence 1 tells you that members of the 16th Lok Sabha worked harder in the budget session. The "budget session" refers to the present budget session, that happened just now, or during the 16th Lok Sabha, if you will.

Sentence 2 introduces a comparison- with how much they have worked in the last 10 years. Now, the idea behind using "have" is to introduce a continuum, a matter of fact that "has been happening" regularly over the past 10 years.

If you use "had" instead, it gives the idea that something HAS happened at a certain point in time, and then that's it. It didn't happen anymore. For instance:

They studied harder this term than they had last year.

Notice how "had" is used to indicate what they did just once, that is last year.

Again, if you now use "have" in the same sentence, see how you get a different meaning:

They studied harder this term than they have in the last five years.

Here, "have" tells you about something that hasn't occurred just once, but has been occurring regularly over a course of time, that is five years.

It's interesting to note that using "had" in part 2 of your original sentence wouldn't make it incorrect, technically. There is a very fine line between using "have" and "had" to denote a continous action in the past tense. As I explained with my previous example, if you use "had" in sentence 2, it indicates that the members of the Lok Sabha had worked up until now, which doesn't fit in well with sentence 1.

And lastly, do take a look at this question on the EL&U site: How do the tenses and aspects in English correspond temporally to one another?. It should give you a clear picture about everything.

In the first case, the first statement is hypothetical (using the conditional mood), so considers a hypothetical situation where the machines would need to work, and weren't going to work without energy.
The other is a basic true statement (using the future tense) that simply states that the machines won't work without energy. I should note that this statement doesn't mean they can't work without energy, only that they won't. This is more to do with the idea of free will: consider a person who is able to work without biscuits but refuses to.

The second case is a lot more fun. Saying a machine can't (or cannot) work without energy sort of states that the machine couldn't work without energy even if it wanted to. In this case, because machines aren't sentient, it is identical to saying they won't work without energy.

However, the first sentence in the second group is either conditional or imperfect. In the case where it is conditional, it talks about a hypothetical situation like before. If, however, the tense is imperfect, it implies that the machines, in the past, weren't able to work without energy, but now supposedly can.

Note 1: Machines need energy to work. Fact of physics.

Note 2: I have no way of knowing what tense 'couldn't' is in. Normally you'd need to use the context to work it out.