All the models mentioned in the previous sections can be used for daily plan­ning of electricity production. As a simple example, a simulation experiment is shown in this section on applying the hierarchical daily production planning struc­ture shown in Fig. 8.2. This application can use real data from the installation or a model of direct […]

The energy needed to start up the plant depends on the time elapsed since it was in operation and the required energy is between 200 and 1200 kWh;. The start-up phase includes the following steps: 1. Increase the pressure to 25 bar. 2. Preheat the pipes and turbine. 3. Start the turbine and reach the […]

Table 8.1 shows efficiency data of the elements: solar collector field, storage tanks and power conversion part. The yearly efficiency coefficients have been obtained from the monthly efficiency data. This type of information is useful to evaluate the best and worst cases for making decisions taking risks into account. The steam turbine can be operated […]

Losses are important when designing a plant-wide control scheme. Overall losses can be computed as the difference between the input and the output power. The input power to the PCS is the thermal power of the hot oil (Phtf), which depends on the inlet oil temperature (Ti„Tur), outlet oil temperature (ToutTur), and flow (qT) as […]

There are different methods for modeling the power conversion systems. The model presented in this section has been obtained from data taken from the power conver­sion system of the DCS project [190]. The PCS is composed of the steam generator, preheater, steam turbine, and refrigeration tower. The steam generator is fed by ther­mal hot oil […]

In other cases, hot oil is directly stored in a tank (thermocline). Thermal stratification of the oil in the tank allows energy to be stored at different temperatures. As an example, in the ACUREX field, the storage tank is connected to the solar field and to the PCS by means of two pipe circuits placed […]

Molten Salt Accumulators Different thermal energy storage systems are used in solar plants. In some cases molten salt tanks are used. The basic idea is to use the heat from salt fusion; that is, the amount of heat required to melt a solid salt at its melting point into a liquid without increasing its temperature. […]

This section analyzes some prediction models needed for scheduling production and optimal control of solar power plants. The most important variable in a solar plant is solar radiation. Different models for solar radiation prediction and forecasting have been explained and developed in Chap. 2, both for short and long term forecasting. Different models of solar […]