^Ah, I think that was shown over two weeks over here.
It was shown as one "two hour" episode here but, strictly speaking, House is a 1-hour program and aloting so much money each year to make so-many episodes. The season-premiere, for my purposes, counts as two episodes.
That said, the story Thirteen began to tell had to do with wind turbines.
IIRC he has invested in, owned or operated wind turbines but the expense of their upkeep, the fall of the economy and perhaps other issues essentialy caused him to go out of business forcing him to dip into savings/cash in the 401(k) in order to keep paying the bills.