Reducing the energy consumed by datacenters becomes of major importance due to the current climate changes and the increasing success of cloud computing. Studies to optimize the energy consumption of cloud systems exist but do not take into account the end-user. The goal of this paper is to understand and quantify the link between the PaaS parameters a user can configure and the application energy consumption. In this work we summarize the parameters available at the PaaS layer and measure their influence on the energy consumed by RUBiS, a web application benchmark. Different database technologies and programming languages are compared as well as their software versions. Experimentation results show that by themselves the existing PaaS parameters can variate the application energy consumption. Although it shows that different programming languages do not consume the same, we discovered that a wider energy difference exists between database technologies which means higher energy savings is possible when the less consuming technology is used. Thus, users could optimize the energy impact of their applications by carefully configuring on-hand PaaS parameters.