The recent Spinks and Bonhams auctions showed the strong demand for similar notes with many Promotional Notes selling for triple the book price. Incredible prices for notes that are rare, and utterly superb in quality. Here is a wonderful collection of the four notes in the original folder which outlines the printing designs and security features. Geothermal (New Zealand), Tidal (N Ireland), Solar (Australia), Wind (Scotland). Rare and almost unique as thus. They come in the original folder of which around 500 were printed.