The company’s property, plant and equipment relates to the operating segments as shown in the following table: Renewable energy assets include the company’s hydroelectric generating stations, wind energy, pumped storage and natural  gas-fired co-generation facilities. Renewable energy assets are accounted for under the revaluation model and the most recent date of revaluation was  December 31, 2013. Valuations utilize significant unobservable inputs (level 3) when determining the fair value of renewable  energy assets. The significant level 3 inputs include: The company’s estimate of future renewable power pricing is based on management’s estimate of the cost of securing new  energy from renewable sources to meet future demand by 2020, which will maintain system reliability and provide adequate  levels of reserve generations. The key valuation metrics of the company’s hydro and wind generating facilities at the end of 2013 and 2012 are summarized  below.  United States Canada Brazil Dec. 31, 2013 Dec. 31, 2012 Dec. 31, 2013 Dec. 31, 2012 Dec. 31, 2013 Dec. 31, 2012 Discount rate Contracted  5.8% 5.2% 5.1% 4.7% 9.1% 8.6% Uncontracted  7.6% 7.0% 6.9% 6.5% 10.4% 9.9% Terminal capitalization rate  7.1% 7.0% 6.4% 6.5% n/a n/a Exit date  2033 2032 2033 2032 2029 2029 Carried at Fair Value Carried at Amortized Cost Total (MILLIONS) Note Dec. 31, 2013 Dec. 31, 2012 Dec. 31, 2013 Dec. 31, 2012 Dec. 31, 2013 Dec. 31, 2012 Renewable energy  (a) $ 16,611 $ 16,532 $ — $ — $ 16,611 $ 16,532 Infrastructure  (b) 8,564 8,736 — — 8,564 8,736 Property  (c) 3,042 2,968 — — 3,042 2,968 Private equity and other  (d) — — 2,802 2,912 2,802 2,912 $ 28,217 $ 28,236 $ 2,802 $ 2,912 $ 31,019 $ 31,148 The table above outlines property, plant and equipment measured at fair value, all of which are classified as level 3 in the fair  value hierarchy given the inclusion of unobservable inputs outlined below. Relationship of unobservable input(s) to fair value Significant unobservable input(s) Valuation technique(s) Discounted cash flow models • Future cash flows – primarily  driven by future electricity  price assumptions • Discount rate • Terminal capitalization rate • Increases (decreases) in terminal capitalization rate  will decrease (increase) the fair value • Increases (decreases) in discount rate will decrease  (increase) the fair value • Increases (decreases) in future cash flows will  increase (decrease) the fair value Terminal values are included in the valuation of hydroelectric assets in the United States and Canada. For the hydroelectric  assets in Brazil, cash flows have been included based on the duration of the authorization or useful life of a concession asset  without consideration of potential renewal value. The weighted-average remaining duration at December 31, 2013 is 16 years  (2012 – 17 years). Consequently, there is no terminal value attributed to the hydroelectric assets in Brazil.  a)  Renewable Energy 2013 ANNUAL REPORT 117 (MILLIONS) Dec. 31, 2013 Dec. 31, 2012 Cost  $ 8,784 $ 7,617 Accumulated fair value changes  10,058 10,712 Accumulated depreciation  (2,231) (1,797) Total  $ 16,611 $ 16,532