I recently did some carbon footprint calculations for the organization I work for. I used conversion factors I found at the Dutch CO2 emission factors website. This website lists standard emission factors for various energy sources to make it easier to calculate one's carbon footprint and so people can more easily compare carbon footprint reports.
On the site they say that for electricity generated by Dutch wind, solar or hydro-power plants you should use 0 kg/CO2. The site also remarks that this is the Well-To-Wheel (WTW) approach (a.k.a. in-use approach) and that for a Life-Cycle Analysis (LCA) approach you can use 12 grams CO2/kWH for wind, 4 grams/kWh for hydro and 70 grams/kWh for solar.
The LCA looks much more accurate to me, but all Dutch carbon footprint reports I read use the WTW approach. How come this is the standard approach here in the Netherlands? And how is this in other countries? Why would people want to use a less accurate WTW approach (other than making their impact look less bad)?