Blog Frank Boerman

Flowbased: an update on export restrictions of France

Wed, 11 Mar 2026 00:00:00 +0000

Last year I wrote about fluctuations in the market and the effects on grid constraints. In summary due to increased exports from France to Italy North, the French TSO RTE introduced new Flowbased constraints. These then limit the French export possibilities towards the Core region. These limits follow from forecasted flows from France to Italy North, the so called Fuaf.

We are now a year further and the question is, is this still true? Please note I will not repeat all concept explanations in this post, for more details on this please consult the original post!

Using my new datalake in practise: a case study

Mon, 12 Jan 2026 00:00:00 +0000

I have received many requests over the years for people wanting to use my private databases. I have always wanted to open it up but, until recently, never got around to setting up proper security and organisation. Now I have and my new Amun Analytics Datalake is live in beta mode!
You can register and login through the new Amun Single Sign On. After this you need to contact me through email or LinkedIn chat to ask to activate your account (this is still a manual action for now).

Flowbased Tutorial: CNECs and Active Constraints and how to analyse them

Tue, 18 Nov 2025 00:00:00 +0000

The flowbased capacity calculation system as a whole, and the domain specifically, can be pretty daunting to people who are just learning about it. Today I wanted to give a short introduction on some key concepts. Next to that I will present some analysis methods of the active constraints. Please note that I will assume some basic linear algebra optimization knowledge throughout this post.
This post is partly based on the great work by my Hungarian collegues of MAVIR in their eCIGRE paper, reference 11358-2024. MAVIR has very knowledgeable flowbased experts and are quite well known in the small flowbased community, especially through the huge amount of work moved by Ferenc Nagy.

Flowbased IDCC: parallel run of IDCC(c)

Tue, 24 Jun 2025 00:00:00 +0000

On the 25th of June, the new Core IDCC(c) capacity calculation will go live. This is the third of a total of five planned Core capacity calculations in the intraday timeframe. For each of these updates, the capacities will be recalculated with updated forecasts and will take into account the trades up until the point of (re)calculation.
In this post, I present an overview of the intraday process for the Core region. After that, I discuss the results of the parallel run of the new (c) calculation.
These results of the parallel run show a “reflow” effect ocurring. The available capacities are redistributed around the current market clearing point. This effect opens isolated zones and borders, in exchange for a lower average positive capacity.

Flowbased: how the markets can fluctuate, 2025 Q1 vs 2024 Q1

Mon, 31 Mar 2025 00:00:00 +0000

Summary

One of the (many) things that keeps my work interesting is that the system I work on is very dynamic. Today I want to highlight one such dynamic situation by comparing the first quarter of 2025 with the first quarter of 2024. Here we will see that the grid constraints that limit the market have shifted from one TSO to another due to changing grid situation.

RTE (TSO of France) in particular shows up a lot more in list of constraints that have actively limited the market, so called active constraints. It also has a lot more forecasted flows from outside the Core capacity calculation region, thus strongly limiting the capacity it can provide inside Core. The source of these flows is probably due to higher west-east export flows towards Italy and Switzerland. These increased flows then map onto newly added network elements in the Flowbased domain, located close to these countries.
These are legitimate process steps to take, but show the impact of southern European flows on the Core region. The upcoming Italy North integration into the new Flowbased Central capacity calculation region will possibly help with better integration and managing these flows.

Year in review 2023: Day-Ahead market results

Sun, 14 Apr 2024 00:00:00 +0000

A while ago, I wrote the first part of my “year in review” series of 2023. In this series, I take a look back at some key indicators of 2023. This series looks at indicators that I find most interesting. Those are also the ones I have the most knowledge about.

Today, we are going to look at the Day Ahead market results in the CORE region (AT, BE, CZ, DE_LU, FR, HR, HU, NL, RO, SI, SK, PL), with a focus on prices.
Please note that this is not an exhaustive list of all indicators that you can frame a year in. For a more exhaustive look, wait for the TenneT Annual Market Update, to which I also contribute. I will also publish more parts in this series soon.
If you are a frequent reader of my blog you will recognize some of the ones used in this post, as I reused some ideas from earlier blogs.
Please note that due to the aggresive polish allocation constraint, which regularly closes the borders for import and export, Poland has been excluded from all CORE indicators.

Year in review 2023: Flowbased CORE Individual Validations

Tue, 06 Feb 2024 00:00:00 +0000

Another year is over, and I wanted to write a ‘year in review’ series about the electricy system in 2023! First up is a look at how different TSOs adjust the Flowbased Domain for grid security reasons, the Individual Validations or IVA for short.

But first, a quick shout out to the sponsor of my database server: Code Yellow! Code Yellow has provided the server that supports my flowbased domain database. Without them the analysis in this post would be a lot more work. Many thanks!

Flowbased: update 2 about the the Nordic Flowbased parallel run results

Mon, 16 Oct 2023 00:00:00 +0000

Recently, it was announced that the Nordic Flowbased go-live was delayed due to IT issues. While this is obviously a pity to hear, other positive things have been announced.
The evaluation report from NRAs was published. It was evaluated and found sufficient by the NRAs, although with some extra remarks.
A very interesting summary containing issues found and lessons learned, was published alongside the report. In there a point-by-point analysis is done for specific issues that were encountered during the parallel run. A very interesting read for experts!

DA market: the benefits of the Day-Ahead market design for NL

Mon, 24 Jul 2023 00:00:00 +0000

Recently a well known participant in the dutch energy debate, lector Martien Visser, wrote tweets and a column setting out his view that the current day ahead market design is not a good business case for NL anymore. He is not the only one, this sentiment is widespread on social media. While I do agree that in a RES dominated system it could be possible to have a better tweaked market mechanism, I disagree that the current one is a very bad one, especially for NL. In this post I present some figures to support that.

Flowbased: One year of CORE: A look at the price convergence since go live

Thu, 08 Jun 2023 00:00:00 +0000

A full year ago the Flowbased capacity calculation methodology went live in the CORE region. To mark this milestone and celebrate the anniversary, this post will look at the process stability and price convergence of Flowbased.
Minimizing the price spread, or in other words maximizing the price convergence, is one of the goals of a more efficient capacity calculation in the region. At the time that full price convergence (e.g. a price spread of zero) is achieved, the market did not hit any constraint in the capacity domain.
The go live of FB CORE at business day 2022-06-09 coincided with an ongoing energy crisis in Europe, one of the worst in recent memory. I thought it would be interesting to take a look at how the price spread in the region held up in those times.

Aten: pausing a wind park for bird migrations, a worlds first in the Netherlands

Mon, 15 May 2023 00:00:00 +0000

On the 11th of May a new kind of operational message was published on the TenneT NL feed. Normally this feed is quite boring, announcing transport restrictions or grid status for example. But on Friday it announced a special type of restriction for offshore windparks. To help large scale bird migrations the offshore windparks were restricted to very slow turning of turbines.
The discussion whether (sea)birds get killed en masse by (offshore) wind turbines is a long one. As far as I know there is no hard scientific evidence either way, but out of extra caution the Netherlands has implemented a process to help birds anyway.
It tries to detect and predict large bird migrations in the spring and fall over the north sea and then schdules a stop of the turbines in a controlled manner for a period of time. That way everybody involved, including TenneT for grid stability, can prepare for it.

Day Ahead Market adventures: capacity restrictions and huge negative prices for business day 2023-04-19

Sun, 23 Apr 2023 00:00:00 +0000

The day ahead market has fascinated me since the very first day that I started working in the sector. Many components working together to form a safe and efficient market for electricy trading. On the 18th of April this year in some of these components rare events happened. In this post, I will offer an explaination on what happened.

The Day Ahead market: a description and some definitions

In the Day Ahead market every day electricity is traded. The traded energy is then delivered the day after trading. This explains the name, you trade one day ahead. We call this first day the trading day and the second day the business day. For the case with the extreme negative prices in this post 2023-04-18 is thus the trading day and 2023-04-19 is the business day.
In the EU trading is optimized over a large area called the Single Day-ahead Coupling or SDAC, more info on this can be found on the entsoe website. The market algorithm which determines the prices looks at this whole region to optimize trades. Prices from the Day Ahead (DA) market are generally refered to as the dynamic wholesale prices and differ per hour. Normally household consumers are not exposed directly to these prices, but instead are insulated through various financial instruments. However recently having a dynamic tarrif in your contract based on DA prices has become more popular. Whether that is a good idea is situation dependant, my colleague Jesse van Elteren has written about this recently.
The SDAC area is divided in bidding zones, usually one per country, in which eletricity can be freely traded. So the interactions that are determined by the algorithm are the import/exports from zone to zone, since within the zone there are no trading restrictions.

Flowbased: an update about the the Nordic Flowbased parallel run results

Fri, 31 Mar 2023 00:00:00 +0000

The Nordic Flowbased external parallel run is still going strong and its two months since my first look so time for an update!

If you missed it, please see the first part for a general introduction and some data remarks.

Flowbased Domain Results

Lets start with looking at the capacity calcuation process and domain. The flowbased process output seems to be still quite stable. From business day 2022-09-01 until the last business day possible, at time of writing 2023-03-31, all 5088 hours have a domain. All FB domain data in this post is for this time range.
According to the FB domain backup page only for two business days, 2023-03-16 and 17 a fallback or backup was applied. Thats only a failure rate of 0.94%. Thats pretty good for a parallel run.

Flowbased: a quick look at first results of the Nordic Flowbased parallel run

Mon, 23 Jan 2023 00:00:00 +0000

The Flowbased capacity calculation methodology that I have written about earlier is not meant only for continental Europe. In the Nordics (NO, SE, DK and FI) the TSO’s and market parties have been working on an implementation in their region as well. In the recent months they have started to publish results from their external parallel run. This is a process in which you run the new methodology in parallel to the old one still in production to be able to compare results.

Aten: Market Cap Reached Incident Baltics 2022

Mon, 29 Aug 2022 00:00:00 +0000

This post is part of a series written to celebrate the launch of Amun Analytics. This company will serve as the business umbrella for all my data analytics projects. If you have some interesting data analysis and visualization projects in which you need some help, shoot me an email! Now lets dive into the topic of today.

High Prices in the Baltics

On Wednesday 17th August 2022, the Day Ahead (DA) market price in the Baltic region hit the price cap of €4000 per Mwh. Between 17:00 and 18:00, the price for Estonia, Latvia and Lithuania hit simultaneously the then active price cap (depicted in figure 1 below).

Aten: negative prices and wind curtailment

Tue, 03 May 2022 00:00:00 +0000

In the weekend of 23th and 24th of April 2022 the day ahead prices in the Netherlands reached record lows. On Saturday it reached €-222.36 at 12:00 and on Sunday €-117.21 at 13:00. Now there are many discussion to be had about the place of negative prices in the current market design, which I will not get into now here. However the cause is quite clear: a huge ammount of renewable energy sources. With the growth of these sources negative prices will happen more and more in the future.
Yet many units keep running during times with very low prices. This can have many reasons, for example because shutting down and starting up again is too expensive. Or because units are active on the balancing market instead. Only when none of these are true units shutdown.

Aten: non-intuitive flows in flowbased capacity calculation: NL -> BE

Wed, 16 Mar 2022 00:00:00 +0000

Intuitive and non intuitive flows

The recent market developments put the spot light on all kinds of interesting behaviour of the way European electricity market works. One of those is non intuitive flows. At 4th November 2020 the electricity day ahead market value broke a fundamental rule: allocation of cross border flows was no longer restricted to go from a low price zone to a high price zone. Flows from a low to a high price zone are called intuitive, since it is intuitive that exporting from a low price to high price will average out the final price between the zones and maximize global welfare.
However this is not always the best optimization. Sometimes the optimal approach is to allocate a flow from a high to a low price zone (also known as non intuitive flows). For example if it makes capacity available for a flow from a low price zone to a high price zone on a different border.
Another example is when a flow goes from a high price zone to a low price zone to an even higher price zone. Non intuitive optimization was enabled for the first time to optimize the integration process within the European electricity market at the 4th of november 2020.

Aten: electricity generation sources in NL 2021

Tue, 11 Jan 2022 00:00:00 +0000

When I talk to friends and family about the electricitymarket, they often do not realise the large reliance of the electricity market on gas. This inspired me to look at 2021 electricity production sources.
The plot below shows largest electricity source per hour in the Netherlands (sources are color coded over time; days at the x-axis and hours at the y-axis).
This plot makes evident the market’s reliance on gas (i.e. yellow = gas). It also highlights the market’s shift towards renewables sources (i.e dark green = wind; dark blue = solar).
Time of the day and seasons also seem to influence the usage of energy sources. It is evident that day time electricity generation in summer time is largely powered by Solar energy. That can be seen by the nice block of blue for Solar energy at the middle of the day.
The effect of increased coal usage (light blue) due to high market prices in the second half of the year during is also visible, with it being the dominating power sources at night.
What do you think, how long will we keep being reliant on gas?

Aten: Price Convergence 2021 in CWE region

Tue, 21 Dec 2021 00:00:00 +0000

Bar chart of price convergence per day in 2021 for CWE region (click to enlarge)

What is price convergence?

The electricity market in Europe is split into so-called bidding zones. The rule is that within these zones you can trade without transport restrictions, as if the entire grid there is one big conducting plate. This also means that for the day ahead marketi, there is one price per hour per bidding zone. If neighbouring bidding zones have enough interconnection capacity available to satisfy the market direction, then the price in those zones will converge: it will be the same. So, price convergence can be seen as a measure on how much transport restriction the market has run into between bidding zones.

Aten: introduction and the first plot

Mon, 13 Dec 2021 00:00:00 +0000

As those that I have spoken with personally recently are well aware by now, I am working at TenneT at the System Operation Transport division, mainly on flowbased capacity calculation and bidding zone review topics. I have chosen TenneT because I wanted to play a part in something that both fascinates my and in which I hope to make a small difference for good: the energytransition and the energy market.
The more I work on it the more I become fascinated by all the intricate details and endless possibilities to analyse it, encouraged by my helpful co-workers. From this fascination a new hobby was born: project Aten. I like to name my projects after greek-roman, old norse or ancient egyptian mythology and this one is named after the egyptian sungod Aten.

Graduation project: My presentation

Tue, 30 Jun 2020 00:00:00 +0000

Graduated!

After long months of work, today I finished my graduation project with a 7.5! That means I am now a graduated msc Electrical Engineering. Many thanks to Kees van Berkel and Marc Geilen for their supervising work!

Due to the corona crisis the presentation was done fully online through microsoft teams. I have made a recording of the 30 min presentation, links to all material can be found below. I will finish my blog parts about my graduation project somewhere in the future, but first I am going to enjoy a holiday over the summer.

Adventures in data presenting: Covid-19

Wed, 18 Mar 2020 00:00:00 +0000

While I’m finishing the last touches on my graduation thesis (posts about that will follow soon) I wanted to take my mind off a little bit with some hobby. I have always been fascinated by presenting data in a clear and automated way and wanted to experiment a bit with that. As a subject for this I chose the big crisis of this moment: the corona virus or Covid-19. This posts serves as quick write up documenting various scripts and tools that I used to experiment a bit with data visualization. You cant visualize anything without actual data so that was the first hurdle to solve!

Graduation project part 3: FFT theory

Thu, 13 Feb 2020 00:00:00 +0000

Introduction

Welcome back to a new part in my blog series about my graduation project. As mentioned in the previous parts, the Fourier Transform will be dominant in the implementation of the Coherent De-Dispersion. This part will dive into the relevant theory behind the Fourier Transform. This includes another algorithm that is need to accomplish the implementation of the Fourier Transform: the CORDIC.

The Fourier Transform

DFT

The Fourier Transform, named after its inventor Joseph Fourier, converts a signal from the time to the frequency domain [wiki]. The Inverse Fourier Transform does the opposite, converting a signal from the frequency domain to the time domain.
In other words the Fourier Transform decomposes a signal in time into its frequency components, showing which frequencies make up the original signal. Both the time signal and the frequency signal can be complex, which in that case constitutes the phase information of the signal. In its continious form the transform it is defined as show in equation 1 below.

Graduation project part 2: De-Dispersion

Sun, 22 Dec 2019 00:00:00 +0000

Introduction

This second post of the series about my graduation project focusses on the De-Dispersion methods that are considered and their algorithms. These build on the models presented in part 1. Equation numbers are numbered through in all parts, so references can be towards part 1.

Coherent versus In-Coherent De-Dispersion

De-dispersion is the process of reversing the effects of frequency dispersion of a signal, in this case the signal of a radio pulsar transmitted through the ISM.
The two models presented in part 1 with equation (2) and (4) can each be used as the basis for a de-dispersion method.

Graduation project part 1: Pulsars Stars

Tue, 17 Dec 2019 00:00:00 +0000

Introduction

This post will be the first in a series about my graduation project. As a final deliverable I will have to write a scientific paper as well, which will be made available for download when its done. The idea behind these blog posts is that they serve as a more expanded version of this final paper for general documentation. The goal is to make it accessible for persons not directly involved with my field of study. It is highly recommended to take a look at the various links and references posted for a better understanding of the core concepts. All posts about my graduation will be in english.
The main concept that is used for designing my work is dataflow architecture [wiki], more specifically Static (or Synchronous) Data Flow [1]. More on this in later parts.
The implementation of this work is mainly done in StaccatoLab, a python library for programming dataflow graphs created by Kees van Berkel of the TU/e who is my graduation supervisor. Since the main goal is to explain my research and results I will not explain the StaccatoLab implementation part in detail. Mainly the plots of the dataflow graphs and its simulation results will be used. More on this in later parts.
These posts are subject to change while I work towards my final graduation and the end of February / beginning of march of 2020.
This first part will go into the details behind the application that this project tackles: processing the signals of pulsar stars.

De Energie Transitie en Nederland

Mon, 29 Apr 2019 00:00:00 +0000

Klimaat en de politiek

Global warming: het is een hot topic de laatste tijd. Het speelde een grote rol in de afgelopen Tweede Kamer verkiezingen (2017), met Jesse Klaver van Groenlinks als voornaamste aanjager. En met success, GroenLinks won flink. Mede hierdoor werd er vanaf 2018 een groot polder project gestart: het Nederlandse klimaat akkoord.
Ook bij de afgelopen Provinciale Staten (en dus indirect de eerste kamer) verkiezingen was het wederom een hot topic. Dit keer was het resultaat anders, de grote winnaar van deze verkiezingen (FvD) is groot tegenstander van het klimaat akkoord.

Deploying Django Channels Application

Wed, 24 Apr 2019 00:00:00 +0000

Django

For quite some time python has been one of my favourite programming language. Although its not the best choice for all use cases, the right tool for the right job after all, it has a very nice flow to it when programming. Things are easily done, the documentation quite good and there is a lot of help available through google.

One of the best examples for the excellent ecosphere of libraries that can be used with python is Django, a framework to create web application. With my company I use this exclusively. We also use the Django extension Channels, which extens django with support for things like websockets, as well as preparing it for a better codebase in the future. Channels will eventually be merged into the core Django.

Gesprekken met mijn oma: Pensioenkosten

Sun, 24 Feb 2019 00:00:00 +0000

Mijn opa en oma wonen vrij dichtbij mij in de buurt. Met mijn familie gaan we daar dan ook geregeld heen. Mijn oma is een intelligent mens en al mijn hele leven herinner ik me haar als iemand die nadenkt over de wereld om haar heen en daarover discusieert. Enige tijd geleden kwamen we op een zondag op een gevoelig onderwerp: de pensioenen. Deze zijn veel in het nieuws omdat deze alleen maar lijken te versomberen terwijl de economie wel goed draait op het moment. Ook de verhoging van de pensioen leeftijd is altijd een hot topic.

Welkom

Sun, 24 Feb 2019 00:00:00 +0000

Welkom op mijn persoonlijke blog! Hier deel ik een verzameling van gedachtes en wat data onderzoeken die ik uit hobby interesse uitgevoerd heb.

About Me

Mon, 01 Jan 0001 00:00:00 +0000

Hi my name is Frank and welcome to my blog! Something about me, I have a Msc in Electrical Engineering from the TU/e and live in Boxtel. I work at TenneT as a Flowbased capacity calculation expert and am mainly active in monitoring, reporting and helping design improvements of the CORE Flowbased processes. Sometimes I also do this for Day-ahead and Intraday markets.

As a hobby I like to run this website and read books, mainly about history. Next to that I like walking in nature and cudling my fiance and cats. I also like to help people digest complex topics through intuitive visualization.

Contact

Mon, 01 Jan 0001 00:00:00 +0000

For questions, compliments or other forms of messages you can reach me at my personal email frank@fboerman.nl.

For business inquiries you can reach me at my personal business umbrella frank@amunanalytics.eu. For registration information on my business see https://amunanalytics.eu/.

You can find me on linkedin here and my twitter (or X) here. I am also active on github here.