Megajoule.org, a structured searchable database of estimates of key energy-related quantities, makes this whole process much easier!
Megajoule.org stores estimates of industry-defining quantities, such as the average efficiency of PV cells, or the pack cost of lithium-ion batteries for electric vehicles. The data is highly structured, allowing users to search estimates by technology (e.g. amorphous silicon PV), or a subclass of technologies (e.g. solar), and/or by metric (e.g. efficiency).
Each estimate is fully documented with source information, units, uncertainty (if applicable), and a space to state assumptions. This estimate structure ensures that estimates added by the many different users will fit fairly neatly in the same structured database.
Figure 2 shows a detailed view of an individual estimates.