A gravity field model has been estimated using energy conservation and fast spherical collocation. The energy conservation method is based on knowledge of the state vector and measurements of non-conservative forces. This is or will be provided by CHAMP, GRACE and GOCE. Here the energy conservation method is applied to calculate gravity potential values from CHAMP data measured in July 2002 – June 2003. Precise science orbits and accelerometer data are derived from GFZ Potsdam. When estimating the loss of energy due to external forces only friction is considered, calculated using the along-track acceleration. A scale-factor for the along-track accelerometer has been estimated for each half day. Fast Spherical Collocation requires data located equidistantly on parallels. It is much faster than general least squares collocation. Fast Spherical Collocation has been used to estimate a gravity field model to degree and order 90, UCPH2004 and a model UCPHcoll to degree and order 60 has been estimated with general least squares collocation using only 1% of data. Evaluation of the method is made by comparison with EIGEN-2 and TUM1s. Furthermore the gravity field is compared to data from the Arctic Gravity Project (ArGP). Good agreement has been found in the comparisons.