Tutorial 4 – Power-to-gas

Sympheny V1.1



This tutorial will show you how to implement the following features in your energy model:

> Multiple solar energy carrier: Solar roof and façade
> Virtual Energy conversion
> P2G technology constellation: Electrolyzation + Methanation 
> H2 storage
> Complex energy pricing structures: Capacity based pricing









The energy hub diagram of this tutorial will look like the following:



Step 0 – Getting started

The procedure here is the same as for Tutorial 1. You can name the project, Analysis and the scenario, Tutorial 4, power2gas and Baseline respectively.


Step 1 - Hubs

The hub section allows you to create different energy hubs that will contain multiple energy conversion, storage and/or network technologies. This tutorial contains a single hub.

> Select Add New, name it (e.g. Campus) and press Add.

> Press Next on the lower right corner to move to the Energy Carriers (EC) section.



Step 2 – Energy carriers

> select Add New to define the energy carriers.

> Assign a Type, a Subtype, and a Name to each energy carrier that you create and Add it.

Find below the list of energy carriers used here.





Heating Energy

Heat 50-60°C

Heat 50-60°C

Electrical Energy



Electrical Energy

Electricity Renewable

Electricity Renewable

Solar Irradiance

Solar Roof

Solar Roof

Solar Irradiance

Solar Facade

Solar Facade

Fuel (Gaseous)



Fuel (Gaseous)

Hydrogen Pressurized

Hydrogen Pressurized

Fuel (Gaseous)




> Select Next to move to the Energy Demands section.



Step 3 – Energy Demands

> Press Add New Energy Demand to add an electricity or heat demand.

> Select the hub that requires the energy (only one hub here to choose from). Then select the energy carrier related to the demand and name this energy demand.

> Press Generate Profile and select the following Demand Type – Building Use – Building Age combinations from the Database:

·        Electricity:  Electricity – Multi-family House – Minergie-Renovation

·        Heat 50°C-60°C: Space Heating – Multi-family House – Minergie-Renovation


> Give them an Energy Reference Area of 10’000 [m2] and select Next. This models the demand profiles for 100 multi-family housings with the hypothesis of 100 [m2] per housing.




Step 4 – Solar Resources

Since we have two solar energy carriers on for the roofs and one for the façades, we will need two solar irradiance profile. Indeed, the irradiance profiles are different depending on the mounting options.

> Select Add New to add the solar irradiance available. Select the energy carrier Solar Roof and the energy hub created before. Then, as for the Energy Demands, you need an excel file giving the Energy Profile of the irradiance for a year given in [kWh/m2].

> Select and press Generate Profile and select the following Location – Type – Slope & Orientation combination:  Lugano – Roof – 0°, (Flat), which corresponds to a horizontal mounting. Press Next.

> Give the available solar collector area of 10 000 [m2] for example and select Add.

> Repeat the procedure for Solar Façade but this time select following Location – Type – Slope & Orientation combination:  Lugano – Façade – 90° Slope Azimuth 0°, which corresponds to a vertical mounting facing South and give an available solar collector area of 2000 [m2].

> Select Next to move to the Imports & Exports section.



Step 5 – Import & Exports

> Select Add New to add the price & CO2 emissions of imported electricity and gas:

Energy carrier

Price (CHF/kWh)

Capacity Price (CHF/kW/Year)

CO2 (kg-CO2/kWh)










Sometimes electricity can have a yearly price per kW. In this tutorial this is the case for the imported electricity. To consider capacity-based pricing, add the Capacity Price (as depicted in the picture above).


> Select Add New to consider export of electricity and the derived revenues per kWh:

Energy carrier

Energy Price (CHF/kWh)




> Select Next to move to the Supply Technologies section.



Step 6 – Supply Technologies

Like mentioned in Tutorial 1, the conversion technologies Rooftop PV and Gas CHP will be used again in this tutorial.

> Select Add from Database and select the My User database button to add them from your saved technologies.

>  Select the correct Electricity Generation technology category and select the Rooftop PV technology. Scroll down, and press Select. Fill in the Name and Hubs box. For simplification, the output from Rooftop PV was set to Electricity in Tutorial 1. In this tutorial, we want to separate electricity from renewable electricity. Therefore, change the output of Rooftop PV to renewable electricity. Then press Add.

> Execute the same procedure and select Gas CHP instead of Rooftop PV. For the Gas CHP supply technology, the output temperature will have to be changed to 50-60°C as this is the temperature required for the demand.


Step 6.1 – Multiple Solar Energy carrier

Solar irradiance can be absorbed through different means. So, additionally to just creating Rooftop PV (which, if saved from tutorial 1, we can add by pressing Add From Database and looking through my User Database), we will create Façade PV.

> Select Create Custom and add the following technology:



Step 6.2 – Virtual Technology: Renewable electricity to Electricity converter

To be able to use the produced electricity by the PV on-site, a virtual technology is needed to merge Renewable electricity with conventional electricity.

> Select Create Custom and tick the virtual technology box. Give it the function that takes as input Electricity Renewable (coming from the PV) and as output Electricity.


Step 6.3 - P2G technology constellation

P2G can be modelled by using an electrolyser and a methanation conversion technology.

> Model the Electrolyser as follows:


> For the Methanation conversion, press Create Custom and fill in the boxes:


> The hydrogen produced can also be used to power a Fuel Cell:


Step 6.4 – H2 storage

To be able to store hydrogen it has to be pressurized.

> Create the hydrogen pressurization unit as a conversion technology:

The pressurized hydrogen can then be stored into a H2 storage unit.

> Select Create Custom under the Storage Technology Candidates tab and fill in the boxes like given below:

Finally, to use the stored hydrogen it has to be depressurized.

> Select Create Custom on the Conversion Technology Candidates tab and give the modelling parameters of a H2 depressurization unit:



Step 7 – Network Technologies and Links

Network technologies and links are used to model the pipes used to share an energy carrier between different hubs. This tutorial has only one hub and won’t need any links. See Tutorial 3 for an example with multiple hubs.

> Select Next to move to Other.


Step 8 – Other

This section allows to include the current interest rate in [%] to the model.

> Set it to 2%.


Step 9 – Review

The review section allows to have an overview over the entire scenario specification and edit a section if it is needed.

> Select Finish Specification & Prepare for Execution to get to the execution of the model.


Step 10 – Execution & Results

Next to the Setup section you can find the Execution section where you select the scenario to be optimized, the two objectives the optimization should be based on and finally the number of points wanted in the pareto front.

> Select the scenario(s) for which you want to execute the analysis (otherwise the execute button will stay grey and cannot be selected)  

> Select Execute to start the optimization.

> Once you receive an email that the optimization is completed, Go to the Results section and Select Download to go through the results of the optimization.

> Click on View results to open the dashboard of your optimal design