Transparency, predictability and longevity of government programmes are necessary if investors are to initiate a project in green technologies. For instance, the degree of high uncertainty in American Production Tax Credits (PTC) was a contributing factor to investor exit from the wind power sector, in particular - illustrating the importance for governments of ensuring that programmes are not subject to excessive policy uncertainty (see Figure 2). Retroactive policy changes regarding solar power projects in Spain have also been concerning investors. 18 Meanwhile, a survey conducted by the Institutional Investors Group on Climate Change (IIGCC) found that less than 10%.
