*5.1. Electricity Consumption Pinch for Each Product*

Case 1 presents the case whereby for each product, the emission limit should not be exceeded. Electricity consumption is pinched for each product, as shown in Figure 4. The source CC represents the current case, where emissions and the composition of the electricity mix for both products are fixed. The demand curve consists of two segments, one for each product. However, both segments have the same slope, since the CO2 emission benchmark is the same for both products (0.376 t CO2/MWh [5], as stated previously). For Case 1, it can be seen that both products use nuclear and fossil energy to reach the target, as presented in Table 7. Renewable energy is not selected, as it has a higher emission factor and is more expensive than nuclear.

**Figure 4.** Pinch diagram for Case 1 when electricity consumption is pinched for each product.

A sensitivity analysis was further performed by fixing the fraction of renewable energy in the electricity supply mix. It is expected that the share from renewable sources will rise in future, while the expansion of nuclear in the future is less certain. The fraction of renewable energy is increased from 0% to 100%. The results of the sensitivity analysis are shown in Figure 5 for fractions of fossil and nuclear sources (left) and cost (right).

It can be seen that the fraction of nuclear energy in the electricity mix decreases almost linearly with the increase in the renewable energy share in the electricity mix up to *w*renewable reaching about 0.7. Subsequently, nuclear energy is no longer selected because of cheaper fossil electricity, while the emission limit is satisfied. Fossil source, on the other hand, remains almost constant, between *w*renewable 0 and about 0.7. At higher values of *w*renewable, the fraction of *w*fossil starts decreasing almost linearly with the increase in *w*renewable. It should be noted that *w*renewable + *w*fossil + *w*nuclear should always be equal to 1.

The cost of the electricity supply mix is shown in Figure 5 on the right. For reasons of confidentiality, the values of cost, on the vertical axis, are hidden. The lowest cost was obtained with no renewable energy in the supply mix (as shown in Table 7). It should be noted that renewable energy is the most expensive of all the sources (see Table 1), and the cost of electricity is constantly increasing with

increasing the share of *w*renewable. The cost increases slightly for *w*renewable < 0.6, where renewable energy replaces nuclear. It begins to increase more significantly for *w*renewable > 0.6, when renewable replaces fossil energy, owing to the significant differences in price.

**Figure 5.** Composition of energy mix (**left**) and cost (**right**) while increasing the fraction of renewable energy in the electricity mix.
