How to use RESYSproDESAL on the Web?

Important: If you are using Microsoft Internet Explorer, you need to adjust the options of Internet Explorer in order to display the configurations correctly. Click here for additional information.

Selecting a Configuration

At the left side of this page, you find a menu that contains all available reference configurations. To get a short description of each of the configurations, click on the button in the Available Configurations line. Select any of the configurations by clicking on its name.

Page Layout

When you select a configuration, your browser displays a page with three sections:

Among the command buttons the one for will switch your view to the flowsheet for the example selected. The scale of the graph depends on the settings of your browser. Clicking once in the graph will enlarge scale and scroll bars will help you to move through flowsheets which now are larger than your window. Clicking again in the graph will cause the return to the inital scale.

First appearance of the flowsheet before you run is without results in the data frames distributed over the graph. After running you may switch back and forth between and to check both, the results in data frames in the flowsheet and in the result tables.

Entering Data

The page contains fields for entering data in one or more input Tables. You select an input Table by clicking on the respective tab.

Usually, you enter the data in edit fields. Occasionally you will also be able to select options from a selection field. Make sure that you do not exceed the given limits.

When you open a configuration, it already contains default values for each of the fields. 

You find a description of the available fields in the description of the individual projects (To access the description, click on the button next to the name of the configuration.). 


Once you have modified the values according to your requirements, click on the button. This sends your modified data to the website, runs the calculation and displays the results. It may take up to one minute, depending on the load on the internet and on the web server. During this time, all input in the page is disabled.

When the calculation is finished, the results are displayed in the lower part of the window. The results are organized in output tables. You select an output table by clicking on the respective tab.


For each projects, two datasets are available:

When you open a configuration, the page always displays the Design dataset.

Technical performance

After opening one of the projects you first may the default Design. You may then introduce your own input values and selections into the upper Tables. Be aware that not all combinations of input values within the given limits will automatically be physically reasonable. It may happen that you choose values which result in failure of the iteration process run by .

To prevent you from getting lost with not compatible inputs we suggest that you always begin your study from the default Design introducing small deviations only. In some cases (e.g. RO membrane characteristics for nominal operation) we included such default values as constants in output tables, which you may look up to recall from where you started. As particularly the mathematical modelling of the RO-process is sensitive to unlucky choice of start values, we advice you to return to default values when is answered by an error message.

When you are satisfied with the results from Design, you select Dataset LifeCycle and this first. You may then do further changes in the input Tables for LifeCycle. E.g. you may adjust climatic data for the operation modes in table Site or specify new local prices for fuel, water and electricity in table Cost. You maye ven change some of your earlier Design settings in the Tables of LifeCycle. E.g. in table Energy you may recognise that a PV generator is contributing a low annual solar fraction of the electricity supplied to the process. Increasing the setting for peak capacity of PV in table Power you will see changes in the annual performance and in the cost results after of this new situation.

Economic Analysis

Cost analysis is integrated with the system performance calculation. By setting project life, interest rate and prices for water, fuel and electricity on site in table Cost of Dataset LifeCycle you allow for the evaluation of annual costs and revenues, present worth of life cycle costs including O&M and replacements. The evaluation is separately done for the subsystems for desalination, power generation and -if applicable- heat supply. This allows for the individual determination of levelised costs for water, electricity and heat. For the total system the net present worth and the payback period for the initial investment are calculated from the discounted net cash flow assuming that revenues and operation costs are evenly distributed over the life cycle of the project. 

For all system components the parameters required for correlation of cost with size and number of units are set within the modelling equations. But for selected key components the input Tables of Dataset Design offer adjustment of reference capacity and reference investment to the user, who may know more realistic values from the local market. As the calculation of all cost items - investment, replacement, fixed and variable O&M - is based on reference capacity and investment such adjustment will have impact on the entire cost analysis.

Civil Work and Staff are important cost items particularly for small de-central systems. Usually they cannot be allocated to individual system components. Therefore the configurations are equipped with extra units without stream or power connections to the rest of the process. The user himself may specify the investment into civil work for desalination, power generation and heat supply in table Cost of Dataset Design. As staff costs depend on life cycle they are specified in table Cost of Dataset LifeCycle.


As a new user of RESYSproDESAL_WEB you may first look into the Pump_240_PV_LG example. This is kept technically very simple and may help you to get acquainted with using the tool.