Step 1: Combining the Individual Models into a single Project
The combined parametric model should be an introduction into how the future Renewable Energy Park should look like and what energy outputs are expected. For this, the models and computations need to be brought into the same project context. To achieve a fast and simple solution it was tried to use Speckle and share the models and high performance outputs. This collided with the already established project stage because Speckle cannot be used for Solids (Speckle Docs). A conversion into a different data type, like the MeshToolKit.mesh, did not solve this issue. Instead, the three projects are combined into one single Dynamo file. This comes with a number of disadvantages. First, future changes can only be done in the new, combined model. For a project that should be a collaborative work, this can be an obstacle as with Speckle it would be possible for the users of each individual projects to change their building without touching the combined model. Second, the model gets bigger and the computation takes longer. As this is the case here, a single Updraft Tower Collector has, for example, a diameter of 500 to 7000 m. The creation of separate objects for every collector panel results in a high number of objects and with that a longer compilation time. By not using Speckle, a good tool for a group-workflow is missed out but in avoidance of a backward step in the development stage of the different models.
In order to combine different Dynamo files, one have to open the files in an editor and copy the data by hand into a new file. This of course is a very tedious process and can lead to an incomplete combination. Afterwards, it is necessary to check the model for missing nodes or connections. In most cases, a simple run of the model should indicate if the copy process was successful or not.
Step 2: Defining the Input Parameters
The three models need a new set of input parameters. The integration context already gives a first idea of the input parameters. This Energy Park should be able to fully supply a city with energy. The size of the city is given by a number of people. The energy consumption per capita varies greatly between less than 200 kWh per year in lesser developed countries, like e. g. in Africa, and over 10 000 kWh per year in more developed countries, like e. g. in Northern Europe or the Middle East. The global average comes down to 4250 kWh per year, which is considered as a good starting point and set as another input parameter. The needed energy output should be mainly provided by a number of Solar Tower Power Plants . The Solar Updraft Towers should be able to generate only a minimum proportion of the electrical power as a backup. On one side, this minimum output should be used for the maintenance of the Solar Power Towers so that downtime can be reduced to a minimum. On the other side, the Solar Updraft Tower should be able to keep infrastructure and important buildings in the town like hospitals running.
Fig.1: Input Parameters of the Renewable Energy Park [taken from Dynamo Sandbox]
Using these input parameters to generate an useful and efficient Energy Park, consisting of a varying number of Solar Power Tower and Solar Updraft Tower plants, can be achieved in a several ways. When a project requires a certain output, but a number of parameters functions as input, a high number of different combinations of input parameters can fulfill the requirements. The number of people, that need to be satisfied with the generated energy, is in this case an input parameter but is an output parameter in the individual model, where the size of the plant dictates the energy output. This change in the combined project goal means, that the former output is now an input parameter and the energy input has to be converted into the dimensions and number of towers.
The required output can be either achieved by building a number of small plants or by building less, but bigger plants. In order to generate the best solution for a given energy demand with the performance criteria costs and CO2 emission, an iterating process would be necessary to balance the size and number of the plants. This iterating process is not achievable in the very demanding Dynamo model. For this, a purely mathematical model would outperform the whole object creation and visualization in the existing Dynamo project. Thus, some parameters of the plants have to be limited to a fixed input parameter. Within this combined model, the size, and by this the energy output, is set to a desired number. With this the number of required plants, the output parameters can be calculated. This way of creating the Energy Park leads to a higher number of generated energy than needed, because the number of plants are rounded up. If 2.5 Solar Power Towers would be required, the model would create three plants and thus, generate more energy than consumed by the inhabitants of the city. This surplus of energy output can be used on one hand as buffer for a higher future energy demand and on the other hand feed the national power grid. The calculated energy output does not consider changes in the energy output throughout the day, month or even year due to a reduced solar radiation, but with the additional performance of the Energy Park the energy demand of the city might still be fulfilled.
Step 3: Creating of Output Parameters
To get the fixed input parameters for the size of a single energy-generating structure the parametric models of each individual system should be calculated beforehand. The optimal size for a given power output can be easily found for a single plant. With this existing knowledge a well-founded input parameter can be set. The combined parametric model calculates the necessary Solar Towers as well as Transmission Towers and visualizes them. Output parameters are the already mentioned material cost and CO2 emissions, whereby material cost are considered without any construction, transportation or labour cost. For these solar towers the construction cost will grow with the height. Furthermore, for all individual system only a limited number of construction elements are included in the calculation. For example, the Solar Updraft Tower only takes into account the volume of the central tower and the volume of the columns holding up the collector elements. But they scale the tower height as well as collector area and should give a first insight into how the input parameters alter the output performance.
See also:
Results of the parametric model
Introduction to Parametric Model
Or main topics:
Integration Context and Individual Systems