Continuing the development of the planning tool for micro grids

Photo by Moritz Kindler on Unsplash

In this interview, Paul David Bohn from Cologne University of Applied Sciences talks about his role in the EnerSHelF project. He continues the work of Silvan Rummeny on an advisor and planning tool for Photovoltaic-diesel-hybrid systems.

In autumn 2021, you took over the role of Silvan Rummeny, who was working in work package 3.3. Can you tell us what his – and now your – work entails?

The main subject of work package 3.3. is the development of an advisor and planning tool for micro grids. The acronym for this tool is Micro Grid User Energy Planning TooL (MiGUEL). MiGUEL is used to design, simulate and evaluate Photovoltaic (PV)-diesel-hybrid systems for Ghanaian health facilities. The goal is to provide users with suitable solutions on how to design a cost-effective micro grid, contributing to fulfil the sustainable development goals and affiliated roadmaps. The target groups are project developers, engineering companies, and private as well as public grid operators who want to implement micro or mini grids. Silvan Rummeny started designing MiGUEL and I took over the development since he left EnerSHelF.

In addition to work package 3.3, I am also working in work package 3.1. The aim of work package 3.1. is to create a data basis for electrical consumption in the Ghanaian health sector. Therefore, load measurements are carried out. This data is reused to simulate the energy side of everyday hospital life in MiGUEL.

Prior to your position at EnerSHelF, did you work on sustainable energy systems before?

During and even before my studies, I worked in different industries and positions. 2015, I finished my training as an Industrial Mechanic at Dürr Dental AG. Since beginning my studies at the University of Applied Science Cologne, I was working in the automotive sector at Porsche AG, Energy Economy for EuPD Research, and in the engineering sector for FERCHAU GmbH before eventually joining EnerSHelF.

Due to my course of studies in ‘Renewable Energies’, working on sustainable energy systems has been a substantial priority for me over the past years. I had the possibility working on existing energy systems as well as designing new ones. This included the development of a measurement concept for electrical and thermal energy consumption in a brewhouse of a medium-sized brewery or the calculation of thermal losses of a former shopping centre for the dimensioning of the heating system.

At what stage of the development of MiGUEL did you take over your new position?

Silvan Rummeny started designing MiGUEL from scratch. Before taking over Silvan Rummeny’s position in October 2021, I had already worked on a simulation tool as part of a university project. The result of the project is the tool Hospital Energy Design Utility named under the following acronym: HEyDU. HEyDU will be implemented in MiGUEL to model the electric loads of the hospital.

MiGUEL is able to generate the onsite components of the energy system. This includes diesel generators, photovoltaic systems, and electric storage. One task is to merge HEyDU and MiGUEL. The energy system is evaluated through the levelized costs of energy (LCOE) and the carbon dioxide emissions. These reference variables are used for the optimization of the energy system. The optimization algorithm is yet to be finalized.

How does your work contribute to the overall project’s goal to improve and disseminate marketable PV-based energy solutions for health facilities in Ghana?

The work packages 3.1. and 3.3. go hand in hand. Work package 3.1. delivers a much-needed database of the energy consumption for health facilities in Ghana. The data will be used to create a database for electrical hospital equipment used in many African countries. This data is essential for a more adequate energy system planning process.

MiGUEL offers an opportunity to simulate various types of energy systems. These systems can be simulated with different operating strategies to get the best component combination, helping to decrease the vulnerability for blackouts as well as the overall system costs and carbon dioxide emissions.

In doing so, EnerSHelF can demonstrate how the implementation of a PV-diesel hybrid system optimizes the security of energy supply in the healthcare sector and thus enables an improved daily hospital routine.

What are the next steps for your work?

One of the main tasks will be processing the gathered data. The data needs to be evaluated and prepared so it can be used in MiGUEL. This includes building a database of electric hospital equipment. In parallel, MiGUEL needs to be developed further in order to be able to carry out the first test runs.


Paul Bohn is a master student in Renewable Energies (M.Sc.) at the University of Applied Sciences Cologne (TH Köln). Prior to his masters, he obtained a B.Eng. in Renewable Energies at TH Köln in 2020. He is a trained industrial mechanic and completed his vocational training from 2012-2015 at the Dürr Dental AG in Bietigheim-Bissingen. Since October 2021, he is working as a research associate in the EnerSHelF project.