There are demanding informational requirements related to the DG sector associated with carrying out detailed macroeconomic analyses of its impact. One important requirement in estimating the macroeconomic impacts of DG is reliable and realistic estimates of the extent of DG generation. Government targets for the uptake of renewable energy provide some indication of the potential penetration of DG. Furthermore, there are government and other organisations' forecasts/projections at a national level of the likely system-wide uptake of DG technologies. However, in practice, it is likely that one or two DG technologies become dominant, and such projections do not provide information on how the overall level of penetration is shared across technologies. Due to the heterogeneous nature of distributed energy technologies – each technology differs greatly in terms of their financial costs (thereby influencing overall expenditures, for example, and corresponding macroeconomic impacts), as well as their emissions performance, for example – more detail is required not only on the likely overall DG capacity, but also on its likely composition.