**9. Conclusion**

**R(t)**

**R(t-1)**

**Figure 15.** Solar radiation predicted by NARX.

**Figure 16.** Solar radiation prediction error with NARX model.

**Figure 14.** Optimal neural architecture for the NARX model.

**R(t-2)**

**T(t-2)**

**T(t-1)**

262 Advanced Applications for Artificial Neural Networks

In this chapter, the solar radiation is predicted using two different neural networks, the static one and the NARX model. Simulations results are presented and are proven the effectiveness of NARX model to predict the solar radiation compared to the static neural network. The efficiency of NARX model is proven especially for the low solar radiation fluctuations. The NARX model is characterized by the presence of a direct feedback of the output which has given it an additional predictive power.
