I need to find out information on 'pay back times'- home insulation?

Question

Does anyone know what 'pay back times' could mean? I am learning about energy heat transfer if that helps. I'm not lazy in that I can't be bothered to search for it myself, but I was unsure as whether 'pay back times' was intended to be a figure of speech (hence quotation marks)... my teacher used them when she wrote it herself so I don't know what I am supposed to be looking for.

Thanks in advance to anyone who helps.

(I don't really want to ask her before the lesson, she might think I'm a bit of a fool...)

Answer 1

Pay back time for something like this is only an estimate at first.

Pay back is what it cost, and what it saves you over time with the savings.

When you have saved enough on your heating or cooling bill that equals what you paid to start with. That's pay back time.

Like an A/C unit with a big SEER rating. It cost more the higher the SEER rating is. But in turn it saves more each month.

They will tell you it will pay for itself in 5 years.

That's 5 years pay back time.

Answer 2

Its a way to justify the cost of an investment by working out how long it will take to recoup the money spent.  One example - I get my house insulated.  The cost will be £210, but I expect that by installing the insulation my heating bills will reduce by £70 each year.  Because 210 divided by 70 is 3, the payback period is 3 years.