We investigate the problem of finding the local analogue of the ergotropy, that is the maximum work that can be extracted from a system if we can only apply local unitary transformation acting on a given subsystem. This is a model for extracting work from a quantum system coupled with an environment. Previous work on the problem on local work extraction has been focused on determining the maximum energy which can be obtained with any local CPTP map (Frey et al. 2014, Alhambra et al. 2019), and on finding the local analogue of the non-equilibrium free energy (Mukherjee et al., 2016). Differently from the problems mentioned above, the local ergotropy can not be written as the solution of a Semidefinite Program Optimization (in fact, it can be seen as a quantum generalization of the assignment problem, hence we know that no closed formula may exist for its solution the general case). Our study is, to our knowledge, the first analysis of the problem of local ergotropy in the case in which the system and the environment are coupled by a non-trivial interaction. Our main result is an exact closed formula for the local ergotropy in the special case in which the local system has only two levels. We also provide upper and lower bound for the general case. As non-trivial examples of application, we compute the local ergotropy for an atom interacting with an electromagnetic cavity with Jaynes-Cummings coupling, and the local ergotropy for a spin site in an XXZ Heisenberg chain. In both systems, we find regimes in which the local ergotropy is bigger than the ergotropy of the decoupled local system. This indicates that the environment may be a resource, and not only a nuisance, for work extraction.