This work investigates the interaction between wind power and electricity markets. The paper is focused on balancing markets pricing policies. The proposal of a new imbalance price scheme is included and conveniently evaluated. This proposed scheme tries to minimise the use of ancillary services to compensate for deviations in searching for a more efficient market design. The effectiveness of imbalance prices as market signals is also examined, and policy recommendations regarding imbalance services are discussed. Two test cases are included that analyse the participation of a wind power producer in the Spanish electricity market using a stochastic optimisation strategy. For this purpose, the uncertainty of the variables is considered, i.e., wind power production and prediction, intraday and imbalance prices. Test cases were run with real data for 10 months, and realistic results are presented along with a hypothetical test case. The regulation of the imbalance prices may not be adequate for the Spanish electricity market because an error drop is not sufficiently encouraged. Therefore, we suggest the application of a new imbalance price scheme, which includes an additional constraint. The conclusions of this paper can be assumed to be general policy recommendations. (C) 2013 Elsevier Ltd. All rights reserved.