In modern manufacturing environments, new technologies are introduced that bring machines, analytics and people closer together. As a consequence, a rise in productivity, flexibility and efficiency is expected. However, these technologies raise new privacy concerns as well. We look at AssiEff, a tool to reduce the energy consumption of production systems, analyse its privacy issues and requirements regarding authentication and propose two approaches in order to address these issues. The first approach is based on anonymous credentials; the second follows an organisational approach. Both approaches are evaluated in regards to security-, privacy- and economic-aspects. In the end, we draw the conclusion that although anonymous credentials fulfil all security and privacy requirements, the organisational approach is the more appropriate solution in most scenarios. Costs are low and the privacy of the employees is protected sufficiently.