If you took 1billion$ today and invested it in high ROI wind farms you would have more than 1billion$ inflation adjusted by the time they broke down assuming reasonable care. However, you would have more money if you did just about any other moderate risk investment.
However opportunity cost means loans cave cost. http://en.wikipedia.org/wiki/Opportunity_cost
If you took 1billion$ today and invested it in high ROI wind farms you would have more than 1billion$ inflation adjusted by the time they broke down assuming reasonable care. However, you would have more money if you did just about any other moderate risk investment.