net present value, page-8

"Earnings are in US$, costs US$, debt US$....exchange rate is irrelevant unless.."

No incorrect - they have (or had) some assets in $AUD so in $US terms their nett debt rose because of exchange rate loss - however there earnings outweighed the exchange rate loss

NPV is more important that the SP (especially when looking at covering debt) Their Market Cap is low is another way of saying they are cheap

Most think energy prices are at unsustainably low levels now

PSA is in an excellent position to whether this and come out on top - they are a producer & are making good profits.

They don't need to sell off assets in the current market

My prediction is that by the end of the year they will have paid off a lot of their debt & energy prices will have rebounded.