The objective of this paper is to present a model for electricity spot prices and the corresponding forward contracts, which relies on the underlying fuels markets, thus avoiding the electricity non-storability restriction. The structural aspect of our model comes from the fact that the electricity spot prices depend on the dynamic of the electricity demand at the maturity $T$, and on the random available capacity of each production means. Our model allows to explain, in a stylized fact, how the different fuels prices together with the demand combine to produce electricity prices. This modeling methodology allows to transfer to electricity prices the risk-neutral probabilities of the fuels market and under the hypothesis of independence between demand, outages filtrations on one hand, and fuels prices filtration on the other hand, it provides a regression-type relation between electricity forward prices and fuels forward prices. Moreover, the model produces, by nature, the well-known peaks observed on electricity market data. In our model, spikes occur when the producer has to switch from one technology to the lowest cost available one. Numerical tests performed on a very crude approximation of the French electricity market using only two fuels (gas and oil) provide an illustration of the potential interest of this model.