\newcommand{\thistitle}{Lecture 1: Organisation \& Introduction}

\input{title.tex}


\section{Administration}




\begin{frame}
  \frametitle{Team Details}

  Prof. Dr. Tom Brown

  Department of `Digital Transformation in Energy Systems', Institute of Energy Technology

  I specialise in the modelling of energy systems to meet strict
  greenhouse gas emission targets. I work at the intersection of
  engineering, economics, informatics, mathematics \& meteorology.

  \vspace{.4cm}

  Philipp Glaum is a research assistant in our group and will lead the tutorials; he can also answer any organisational questions (\hrefc{mailto:p.glaum@tu-berlin.de}{p.glaum@tu-berlin.de}). Please do not email me.

  \vspace{.4cm}

  Group website: \urlc{https://www.tu.berlin/ensys}

  Personal website: \urlc{https://nworbmot.org/}


\end{frame}


\begin{frame}
  \frametitle{Course ISIS Website}

  You can find links to lecture notes, exercise sheets and all other information on ISIS:

  \urlc{https://isis.tu-berlin.de/course/view.php?id=47916}

  Course abbreviation: [SoSe 2026] Energy Systems

  Annoucements will also be made there, and you can ask questions in the discussion forum.

  All lecture slides will be available there as PDFs shortly before each lecture.

\end{frame}


\begin{frame}
  \frametitle{Course Registration: 6 ECTS}

  \hrefc{https://moseskonto.tu-berlin.de/moses/modultransfersystem/bolognamodule/beschreibung/anzeigen.html?nummer=30685&version=3&sprache=2}{MTS: Energy Systems (6 LP)}

  Registration:
  \begin{itemize}
    \item via MTS (up to one week before the exam)
    \item Erasmus: try via MTS, if that fails, register via ISIS (exam registration)
  \end{itemize}

\end{frame}


\begin{frame}
  \frametitle{Written Exam}

  \begin{itemize}
  \item Written exam in presence
  \item 90-minute exam
  \item Dates: 04.08.2026 1030-1200,  24.09.2026 1330-1500
  \item Sample exams in last weeks of lectures
  \item Content: as in lecture and tutorials
  \item Voluntary group project (six unsupervised study periods in June) can boost grade by 5 points
  \item No programming is needed in the exam (students only need to know programming for the group project)
  \end{itemize}

\end{frame}


%% \begin{frame}
%%   \frametitle{Seminar 1 `New Developments in Energy Markets'}

%%   Available as stand-alone (3 ECTS) or as module in Energy Systems (9 ECTS)

%%   \begin{itemize}
%%   \item Students analyse a current topic in energy markets, prepare a 20-minute presentation and present it for discussion
%%   \item Presentations as a block at the end of the lecture-free period
%%   \item Supervision and discussion led by Prof. Erdmann, Prof. Grübel and scientific employees of the department
%%   \item Students work on topic with a supervisor during semester (2-3 meetings)
%%   \item Topics will be presented during a lecture in May 2024, presentations in September 2024
%%   \item Example topics: smart meter rollout, gas crisis, market reform, EEG, European Green Deal, e-mobility, hydrogen economy, industrial decarbonisation, flexibility markets, etc.
%%   \end{itemize}

%%   The seminar has \hrefc{https://isis.tu-berlin.de/course/view.php?id=39098}{its own ISIS page}.

%% \end{frame}



\begin{frame}
  \frametitle{SoSe-26: Seminar `New Research in Energy System Modelling'}

  3 ECTS seminar together with Prof. Gunnar Luderer's group at PIK (Potsdam Institut für Klimafolgenforschung)
  
  \begin{itemize}
  \item Students analyse a recent research paper on energy system modelling looking at transformation of energy system over next decades
  \item Students prepare a 20-minute presentation and present it for discussion
  \item Presentations as a block at the end of the lecture-free period
  \item Students work on topic with a supervisor during semester (2-3 meetings)
  \item Topics will be presented during a lecture in May 2026, presentations in September 2026
  \item Example topics: integration of renewable energy, hydrogen trade, storage modelling, endogenous learning, role of carbon capture
  \end{itemize}

  \hrefc{https://isis.tu-berlin.de/course/view.php?id=48182}{Seminar ISIS page}

\end{frame}


\begin{frame}
  \frametitle{SoSe-26: Course `Data Science for Energy System Modelling'}

  6 ECTS course led by Dr. Fabian Neumann

  \begin{itemize}
  \item Students get hands-on experience modelling and analysing future energy systems
  \item All coursework in programming language Python plus associated libraries
  \item Focus on renewable energy resources, storage and network infrastructures
  \item Working with real data on weather, land use, power plants, grids and demand
  \item Learn about the challenges and solutions for a successful transition towards climate-neutral energy systems across the globe
  \end{itemize}


  \hrefc{https://isis.tu-berlin.de/course/view.php?id=48364}{Course ISIS page}

  First lecture: Tue 14th April 2026 1415 in BIB 014.
\end{frame}


\begin{frame}
  \frametitle{SoSe-26: Excursion to Verbio Biogas Plant}

  3 ECTS excursion on Friday 3rd July 2026 to Verbio Biogas Plant near
  Schwedt (2 hours by bus).

  The biogas plant uses exclusively straw as a feedstock, making it a
  pioneer in sustainable biomass.

  Students have to give a 7-minute presentation and write up a report
  afterwards.

\end{frame}

\begin{frame}
  \frametitle{Schedule for Lectures and Tutorials}


  \begin{tabular}{@{} llll @{}}
    \toprule
    Day & Time & Location & Event \\
    \midrule
    Tuesday  & 1000-1200  & H 0111 & Lecture \\
    Wednesday  & 1000-1200  & HFT-TA 101 & Tutorial \\
    Thursday & 1600-1800  & HFT-TA 131 & Lecture \\
 \bottomrule
  \end{tabular}

  \vspace{.2cm}
  First lecture: Tuesday 14th April 2026, last lecture: Thursday 16th July 2026

  \vspace{.2cm}
  First tutorial: Wednesday 22nd April 2026
  \vspace{.2cm}

  Some of the exercises will require you to program in \alert{Python}, so please do an online tutorial in Python if you don't know it. We will help you to install Python and the
  requisite libraries.

  \alert{Mathematics requirements}: linear algebra, Fourier analysis, basic calculus, basic statistics.


\end{frame}



\begin{frame}
  \frametitle{Literature}


  There is no book which covers all aspects of this course. In particular there is no good source for the combination of data analysis, complex network theory, optimisation and energy systems. But there are lots of online lecture notes. The world of renewables also changes fast...

  The following are concise:
  \begin{itemize}
    \item Joshua Adam Taylor, ``Convex Optimization of Power Systems'', Cambridge University Press, 2018
  \item Volker Quashning, ``Regenerative Energiesysteme'', Carl Hanser Verlag München, 2015
      \item      Leon Freris, David Infield, ``Renewable Energy in Power Systems'', Wiley, 2006
      \item Göran Andersson Skript, ``Elektrische Energiesysteme: Vorlesungsteil Energieübertragung,'' online
          \item D.R.~Biggar, M.R.~Hesamzadeh, ``The Economics of Electricity
  Markets,'' Wiley, 2014
  \end{itemize}

\end{frame}


\section{Course Structure}


\begin{frame}[fragile]
  \frametitle{Inter-Disciplinary Methods Required!}

  Energy System Modelling requires methods and skills from several disciplines:
  \begin{itemize}
  \item \alert{Engineering:} Technical description of energy system components and interactions
  \item \alert{Economics:} Efficient allocation of resources and infrastructure to meet consumer preferences
  \item \alert{Informatics:} Large datasets, complex interactions
  \item \alert{Meteorology:} Influence of weather and climate on demand and variable renewables
  \item \alert{Geology:} Underground storage, geothermal power
  \item \alert{Biology:} Biomass-Food-Water nexus
  \item \alert{Sociology:} Impacts of consumer behaviour and preferences on energy system
  \item \alert{Politics:} What policies are feasible and can be enabled in time
  \end{itemize}
\end{frame}





\begin{frame}
  \frametitle{Course outline}

  \begin{itemize}
  \item Measuring energy
  \item Time series analysis for demand and renewables
    \item Backup generation, curtailment
  \item Network modelling in power systems
  \item Storage modelling
  \item Optimization theory
  \item Energy system economics
  \item Learning curves and long-term dynamics
  \item Reducing emissions in transport, heat and industry
  \item Current research topics
  \end{itemize}


\end{frame}


\begin{frame}
  \frametitle{Different time scales}

  We will focus on the righthand side (hours to decades):

  \vspace{1cm}

  \centering
  \includegraphics[width=13cm]{Time-scales-in-electric-grid-operation_W640.jpg}

  \source{\hrefc{https://doi.org/10.1109/EPQU.2011.6128888}{doi:10.1109/EPQU.2011.6128888}}
\end{frame}


\section{What is Energy System Modelling?}




\begin{frame}
  \frametitle{What is Energy System Modelling?}

  \alert{Energy System Modelling} is about the overall \alert{design} and \alert{operation} of the energy system.


\begin{columns}[T]
  \begin{column}{8cm}

    \vspace{.1cm}
    \begin{itemize}
      \item What are our \alert{energy needs}?
  \item What \alert{infrastructure} do they
    require?
  \item \alert{Where} should it go?
  \item How much will it \alert{cost}?
  \end{itemize}

  \hspace{0.2cm}

  The answers to these questions affect \alert{hundreds of billions}
  of euros of spending per year in Europe.

  \hspace{0.3cm}

  Researchers deal with these questions by \alert{building computer models}
  of the energy system and then, for example, \alert{optimizing}
  its design and operation.

  \end{column}
  \begin{column}{5.5cm}
    \vspace{.2cm}
  \includegraphics[width=5.7cm]{goat-clean}
  \end{column}
\end{columns}
\end{frame}


\begin{frame}
  \frametitle{Energy System Modelling: Who is it for?}

  Broadly speaking, we model energy systems to help \alert{society} make decisions. Examples:


\begin{columns}[T]
  \begin{column}{6.5cm}
    Government agencies commission studies to look at possible future
    scenarios:

    \vspace{.2cm}

    \includegraphics[width=6cm]{bmwi-langfrist}

  \end{column}
  \begin{column}{6.5cm}

      But also companies and non-governmental organisations:

    \vspace{.2cm}

  \includegraphics[width=6cm]{transnet-stromnetz2050}

    \vspace{.5cm}

  \includegraphics[width=6cm]{pac-scenarios}

  \end{column}
\end{columns}

\end{frame}




\begin{frame}
  \frametitle{Guildelines: Energy Trilemma}

  Optimization - but with respect to what? We design with respect to three goals:

\begin{columns}[T]

  \begin{column}{5.5cm}


  \vspace{1cm}

    \begin{tikzpicture}[thick,scale=1.3]

      \coordinate (O) at (0,0);
      \coordinate (A) at (2.5,0);
      \coordinate (B) at (1.25,2);
      \draw (O)--(A)--(B)--cycle;
      \draw (1.25,2.2) node[green]{sustainability};
      \draw (-0.2,-0.2) node[red]{reliability};
      \draw (2.5,-0.2) node[blue]{affordability};
  \end{tikzpicture}

  \end{column}


  \begin{column}{8cm}
\begin{itemize}
  \item \alert{Sustainability}: Respect environmental constraints (greenhouse gases, air quality, preservation of wildlife), social and political constraints (geopolitics, public acceptance of transmission lines, onshore wind, nuclear power)
  \item \alert{Reliability}: Ensure energy services are delivered whenever needed, even when the wind isn't blowing and the sun isn't shining, and even when components fail
  \item \alert{Affordability}: Deliver energy at a reasonable cost
  \end{itemize}

  \end{column}
\end{columns}


  \vspace{.3cm}

  Some of these policy targets can come into \alert{conflict} - an \alert{energy trilemma}.

\end{frame}

\begin{frame}
  \frametitle{Why it's hard: many components and interactions}

  Need to model: (at least) all of Europe for market integration; enough spatial and temporal detail to capture all important effects;
  all interactions between energy sectors; correct physics.

  \vspace{.3cm}

\begin{columns}[T]
  \begin{column}{6cm}

    \vspace{.2cm}
    \centering
    \includegraphics[width=6.5cm]{pypsa-eur-grid.pdf}
  \end{column}

    \begin{column}{5.5cm}

  \centering
  \includegraphics[width=6cm]{20200223_multisector_figure.pdf}
  \end{column}
\end{columns}

\end{frame}


\begin{frame}
  \frametitle{Why it's hard: non-linearities and social effects}

\begin{columns}[T]
  \begin{column}{7.5cm}

    \vspace{.2cm}
    \centering
    \includegraphics[width=8.5cm]{BNEF-Figure-1-Global-levelized-cost-of-electricity-benchmarks-2009-2022-cropped.png}
  \end{column}
  \begin{column}{6cm}

\centering
\includegraphics[width=5cm]{nein_zur_monstertrasse}
  \end{column}
\end{columns}

  \source{\hrefc{https://about.bnef.com/blog/cost-of-new-renewables-temporarily-rises-as-inflation-starts-to-bite/}{BloombergNEF, 2022}}
\end{frame}



\begin{frame}
  \frametitle{Not everyone gets it right...}
\begin{columns}[T]
  \begin{column}{7.5cm}

    \vspace{.2cm}
    \centering
    \includegraphics[width=7cm]{2019-01-10-IEEFA-EIA-coal-all-consumption-forecasts-470-x-395-v2-768x646}
  \end{column}
  \begin{column}{7.5cm}

    \vspace{.2cm}
    \centering
    \includegraphics[width=7cm]{auke.jpg}
  \end{column}
\end{columns}
\end{frame}

\begin{frame}
  \frametitle{...and it's not always uncontroversial}

  \begin{columns}[T]
\begin{column}{6cm}
  \includegraphics[trim=0 0cm 0 0cm,width=6cm,clip=true]{sinn-atomkraft}

    {\small Sinn's study was \hrefc{https://doi.org/10.1016/j.euroecorev.2018.07.004}{debunked}
       using an
      open model (he exaggerated storage requirements by `up to
      \alert{two orders of magnitude}')}

\end{column}
\begin{column}{6cm}

  \includegraphics[trim=0 0cm 0 0cm,width=5.4cm,clip=true]{sinn-eautos}

  {\small Sinn's study was \hrefc{https://doi.org/10.1016/j.joule.2019.06.002}{debunked}, shown to use cherry-picked assumptions}
\end{column}
\end{columns}

\end{frame}







\section{The Greenhouse Gas Challenge \& The Energy System}


\begin{frame}
  \frametitle{2015 Paris Agreement}

  The 2015 Paris Agreement pledged its signatories to
 `pursue efforts to limit [global warming above pre-industrial levels] to \alert{1.5$^\circ$C}' and
   hold `the increase...to \alert{well below 2$^\circ$C}'.
  These targets were chosen to avoid potentially irreversible \alert{tipping points} in the Earth's systems.


  \begin{columns}[T]
\begin{column}{9.5cm}

  \includegraphics[width=10cm]{nclimate3013-f1.jpg}
\end{column}
\begin{column}{4.5cm}

  \vspace{.3cm}

  WAIS: West Antarctic Ice Sheet ($\Rightarrow$ 5m sea level rise)

  \vspace{.2cm}

  Greenland (7m)

  \vspace{.2cm}

  THC: thermohaline circulation (warms Europe)

  \vspace{.2cm}

  ENSO: El Niño–Southern Oscillation (extreme weather)

  \vspace{.2cm}

  EAIS: East Antarctic Ice Sheet ($>50$ m)

\end{column}
  \end{columns}

\source{\hrefc{https://www.nature.com/articles/nclimate3013}{`Why the right climate target was agreed in Paris'}, Nature Climate Change, 2016}
\end{frame}


\begin{frame}
  \frametitle{The Global Carbon Dioxide Challenge: Net-Zero Emissions by 2050}

  \begin{columns}[T]
\begin{column}{7.5cm}

  \includegraphics[width=8cm]{ipcc-sr15}


\end{column}
\begin{column}{6cm}
  \begin{itemize}
\item Scenarios for global CO$_2$ emissions that limit warming to 1.5$^\circ$C about industrial levels (\alert{Paris agreement})
\item Today emissions \alert{still rising}
\item Level of use of negative emission technologies (NET) depends on rate of progress
\item 2$^\circ$C target without NET also needs
  rapid fall by 2050
\item Common theme: \alert{net-zero by 2050}
\end{itemize}
\end{column}
  \end{columns}

    \source{\hrefc{http://ipcc.ch/report/sr15/}{IPCC SR15 on 1.5C, 2018}}
\end{frame}

\begin{frame}
  \frametitle{The Greenhouse Gas Challenge: Net-Zero Emissions by 2050}

  Paris-compliant 1.5$^\circ$~C scenarios from European Commission for \alert{net-zero GHG in EU by 2050}. This target has been adopted by the EU and enshrined in the \alert{European Green Deal}.

  \vspace{.4cm}

  %Figure 6 from https://ec.europa.eu/clima/sites/clima/files/docs/pages/com_2018_733_en.pdf
  \includegraphics[width=14cm]{eu-lts-net-zero.png}


    \source{\hrefc{https://ec.europa.eu/clima/sites/clima/files/docs/pages/com_2018_733_en.pdf}{European Commission `Clean Planet for All', 2018}}
\end{frame}


\begin{frame}
  \frametitle{It's not just about electricity demand...}

  %GHG in 2016 are 4.291~Gt, CO2 is 3.489 ~Gt without LULUCF and without indirect
  %Global is 36.2 Gt (EU figure from carbonbrief excludes LULUCF, so assume global also)
%https://www.carbonbrief.org/analysis-global-co2-emissions-set-to-rise-2-percent-in-2017-following-three-year-plateau
  EU28 \co2{} emissions in 2016 (total 3.5~Gt \co2, 9.7\% of global):

  \centering
    % left bottom right top
  \includegraphics[trim=0 0.7cm 0 0.5cm,width=12cm]{EU28-emissions_pie-2016-CO2-190311.pdf}

%  ...\alert{but} wind and solar will dominate primary energy in all sectors, so electrification is critical.

  \source{Brown, data from \hrefc{https://www.eea.europa.eu/data-and-maps/data/national-emissions-reported-to-the-unfccc-and-to-the-eu-greenhouse-gas-monitoring-mechanism-13}{EEA}}
\end{frame}



\begin{frame}
  \frametitle{...but electrification of other sectors is critical for decarbonisation}

\alert{Electrification is essential} to decarbonise sectors such as
transport, heating and industry, since we can use low-emission
electricity from e.g. wind and solar to displace fossil-fuelled
transport with electric vehicles, and fossil-fuelled heating with
electric heat pumps.

Some scenarios show a \alert{doubling or more of electricity demand}.

  \vspace{.7cm}

  \begin{columns}[T]
\begin{column}{6cm}
  \includegraphics[trim=0 0cm 0 0cm,width=6cm,clip=true]{tesla.jpg}
\end{column}
\begin{column}{6cm}

  \includegraphics[trim=0 0cm 0 0cm,width=6cm,clip=true]{640px-Heat_Pump.jpg}
\end{column}
\end{columns}



\source{Tesla; heat pump: \hrefc{https://commons.wikimedia.org/w/index.php?curid=10795550}{Kristoferb at English Wikipedia}}

\end{frame}



\begin{frame}
  \frametitle{Many scenarios show an increase in electrification}

  Electricity as a fraction of final energy demand in 2019 versus 2050 in United States.


  \includegraphics[trim=0 0cm 0 0cm,width=6.5cm,clip=true]{nytimes-electrification-2021.png}
  \hspace{.5cm}
  \includegraphics[trim=0 0cm 0 0cm,width=6.5cm,clip=true]{nytimes-electrification-2050.png}


  \source{\hrefc{https://www.nytimes.com/interactive/2023/04/14/climate/electric-car-heater-everything.html}{New York Times, 2023}}
\end{frame}





\begin{frame}
  \frametitle{Many scenarios show increase in electrification}

  \centering
  \includegraphics[trim=0 0cm 0 0cm,height=7.5cm,clip=true]{ariadne-electrification-share.jpeg}

  \source{\hrefc{https://ariadneprojekt.de/media/2021/11/Ariadne_Kurzdossier_Wasserstoff_November2021.pdf}{ARIADNE Projekt, 2021}}
\end{frame}

\begin{frame}{Efficiency of renewables and electrification}


  \includegraphics[width=\linewidth,trim=2.7cm 20cm 3.2cm 1.8cm,clip=true]{bmwi-whitepaper-figure_18.pdf}

  \source{\hrefc{https://www.bmwi.de/Redaktion/EN/Publikationen/whitepaper-electricity-market.html}{BMWi White Paper 2015}}
\end{frame}



\begin{frame}{Electrification via heat pumps versus hydrogen boilers}

  \centering
  \includegraphics[trim=0 0cm 0 0cm,height=8cm,clip=true]{h2_versus_hp.png}

  \source{\hrefc{https://h2sciencecoalition.com/blog/hydrogen-for-heating-a-comparison-with-heat-pumps-part-1/}{Hydrogen Science Coalition}}
\end{frame}


\begin{frame}{Electric vehicles versus efuels}

  \centering
  \includegraphics[trim=0 0cm 0 0cm,height=6.5cm,clip=true]{ev-fcev-efuel.png}

  \raggedright
  Important caveat: efficiency is not cost. There are regions in the world (e.g. Patagonia) with very inexpensive wind and solar resources for efuels, where low cost could outweigh losses.
\end{frame}



\begin{frame}{Not just climate change: air pollution is a silent killer}

  Air pollution from fossil fuel burning is linked to higher mortality (deaths) and morbidity (diseases, e.g. aggravation of asthma).

\includegraphics[width=6.8cm]{who-air-2.jpg}
      \includegraphics[width=6.8cm]{air-who-1.png}

  \source{\hrefc{https://www.who.int/health-topics/air-pollution}{World Health Organisation}}
\end{frame}


\begin{frame}[fragile]
  \frametitle{Why focus on wind and solar for electricity generation?}
    \begin{columns}[T]
      \begin{column}{4cm}
        \begin{itemize}
        \item construction and operation have low greenhouse gas emissions
        \item good wind and sun are available in many parts of the world
        \item worldwide potential that exceeds demand by many factors
        \item rapidly falling costs
        \end{itemize}
      \end{column}
      \begin{column}{5cm}
        \includegraphics[trim=0 0cm 0 0cm,width=4.5cm,clip=true]{SolarGIS-Solar-map-Germany-de}
      \end{column}
      \begin{column}{5cm}
        \vspace{.8cm}
        \includegraphics[trim=0 0cm 0 0cm,width=5.5cm,clip=true]{43_Mittlere_Windgeschwindigkeit_100_m_Deutschland}
      \end{column}
    \end{columns}


\end{frame}


\begin{frame}[fragile]
  \frametitle{Life Cycle Analysis (LCA) of generation technologies}
    \begin{columns}[T]
      \begin{column}{9cm}
        \includegraphics[trim=0 0cm 0 0cm,width=9.5cm,clip=true]{nrel-jisea-nicholson-box-plot.jpg}
      \end{column}

      \begin{column}{5cm}
        \begin{itemize}
        \item \alert{Life Cycle Analysis (LCA)} includes emissions and other impacts from construction, lifetime and end-of-life of generation assets (excluding land use here)
        \item Includes e.g. emissions from producing materials for generators (e.g. silicon for PV panels, concrete and steel for wind)
          \item PV, wind, geothermal and nuclear score well
        \end{itemize}
      \end{column}
    \end{columns}

    \source{\hrefc{https://www.nrel.gov/analysis/life-cycle-assessment.html}{NREL, 2021}}
\end{frame}

\begin{frame}{Worldwide potentials}


    \begin{columns}[T]
      \begin{column}{8.5cm}
  \centering
    \includegraphics[width=8.7cm]{global_potentials.png}

      \end{column}
      \begin{column}{6cm}

    \vspace{.5cm}
        \begin{itemize}
        \item Potentials for wind and solar exceed current demand by many factors (ignoring variability)
        \item Other renewable sources include wave, tidal, geothermal, biomass and hydroelectricity
        \item Uranium depends on the reactor: conventional thermal reactors can extract 50-70 times less than fast breeders
        \end{itemize}
      \end{column}
    \end{columns}

      \source{\hrefc{http://solarmarketpathways.org/wp-content/uploads/2017/08/NSC-Achieving-High-PV-Penetration-160526.pdf}{Perez et al, Applied Policy, 2016}}

\end{frame}

\begin{frame}{Low cost of wind \& solar per MWh (NB: ignores variability)}

  LCOE = \alert{Levelised Cost of Energy} = Total Costs $/$ Energy Output

  \vspace{.2cm}
  \centering
  \includegraphics[height=7cm]{BNEF-Figure-1-Global-levelized-cost-of-electricity-benchmarks-2009-2022-cropped.png}

  \source{\hrefc{https://about.bnef.com/blog/cost-of-new-renewables-temporarily-rises-as-inflation-starts-to-bite/}{BloombergNEF, 2022}}

\end{frame}




\begin{frame}
  \frametitle{Fundamental shift from scarce exhaustible to renewable energy}

\begin{columns}[T]
  \begin{column}{7.5cm}

    Fossil fuel costs rise with exploitation (can also drop with innovation)
    \vspace{.5cm}

    \centering
    \includegraphics[width=7cm]{GlobalLiquidsSupplyCostCurve.png}

    \raggedright (2019 consumption was $\sim$37 billion barrels)
  \end{column}
  \begin{column}{7.5cm}

    Solar and wind costs drop with innovation (can rise locally where land is scarce)
    \vspace{.5cm}

\centering
\includegraphics[width=7cm]{bnef-swanson-2020.png}

\raggedright (1 TW of solar generates $\sim$1200 TWh/a compared to global electricity demand of $\sim$24,000 TWh/a)

  \end{column}
\end{columns}


\source{\hrefc{https://about.bnef.com/blog/bloombergnef-2021-executive-factbook/}{BNEF 2021}}

\end{frame}


\begin{frame}
  \frametitle{4 critical technologies: wind, solar, batteries, electrolyzers}

\begin{columns}[T]
  \begin{column}{6cm}
  \centering
  \includegraphics[height=6cm]{learning-4-beasts.png}
  \end{column}
  \begin{column}{8cm}

    All the critical technologies for the energy transition share a
    small unit size, enabling fast production and installation,
    economies of scale in manufacturing and learning-by-doing.



    \begin{itemize}
    \item \alert{Low-cost electricity} from wind and solar.
    \item \alert{Batteries} for mobility and balancing applications.
    \item \alert{Electrolytic hydrogen} (splitting water) for
      everything else: long-duration storage, aviation, shipping,
      industry.
    \item \alert{Heat pumps} (missing from graphic) for building comfort and some low-temperature industry applications.
    \end{itemize}
  \end{column}
\end{columns}

  \source{\hrefc{https://www.inet.ox.ac.uk/files/energy_transition_paper-INET-working-paper.pdf}{Way et al, 2021}}

\end{frame}



\begin{frame}
  \frametitle{Hydrogen: the backstop of the energy transition}

  Clean hydrogen can do
  almost everything, but competes with direct electrification. Some
  say \alert{champagne of energy transition}; could also say
  \alert{backstop} for what efficiency and electrification don't reach.


  \includegraphics[width=14cm]{liebreich-ladder.jpg}

\end{frame}


\begin{frame}[fragile]
  \frametitle{But must take account of variability...}


  \includegraphics[width=7cm]{variability-berlin}
\hspace{.2cm}
  \includegraphics[width=6cm]{2015-11-30-0300}
\end{frame}

\begin{frame}[fragile]
  \frametitle{...and social \& political constraints}



\begin{columns}[T]

  \begin{column}{5cm}


\centering
\includegraphics[width=5cm]{nein_zur_monstertrasse}

  \end{column}


  \begin{column}{6.7cm}

    \vspace{.5cm}

    Sustainability doesn't just mean taking account of environmental constraints.

    \vspace{.5cm}

    There are also \alert{social and political constraints},
    particularly for transmission grid and onshore wind
    development.

    \vspace{.5cm}

\includegraphics[width=7cm]{Protestplakat-gegen-den-Bau-von-Windraedern-in-Hamburg-Deutschland.jpg}

  \end{column}

\end{columns}

\end{frame}


\begin{frame}
  \frametitle{Energy Transition: Several changes happening simultaneously}

  \alert{Energiewende}: The Energy Transition, consists of several parts:

  \begin{itemize}
  \item Transition to an energy system with low greenhouse gas emissions
  \item Renewables replace fossil-fuelled generation (and nuclear in some countries)
  \item Increasing integration of international electricity markets
  \item Better integration of transmission constraints in electricity markets
  \item Sector coupling: heating, transport and industry electrify
  \item More decentralised location and ownership in the power sector
  \end{itemize}

\end{frame}



\begin{frame}
  \frametitle{Renewables reached 56\% of gross electricity in Germany in 2025}

  \centering
  \includegraphics[height=7.6cm]{Fig2_Gross electricity production in Germany 1990 2025.png}

  \source{\hrefc{https://www.cleanenergywire.org/factsheets/germanys-energy-consumption-and-power-mix-charts}{Clean Energy Wire, 2026}}
\end{frame}

\begin{frame}
  \frametitle{Build-out rates for wind and solar need to increase rapidly}

  Germany has target of 80\% renewable electricity by 2030, 100\% by 2035.

  \centering
  \includegraphics[height=7cm]{eroeffnungsbilanz-vre.png}

  \source{\hrefc{https://www.bmwi.de/Redaktion/DE/Downloads/Energie/220111_eroeffnungsbilanz_klimaschutz.pdf?__blob=publicationFile}{BMWK, 2022}}

\end{frame}


\begin{frame}
  \frametitle{Electric vehicles take off, first in Norway}


  \centering
\includegraphics[height=7.5cm]{bilsalg_annual-2026.png}

  \source{\hrefc{https://robbieandrew.github.io/EV/}{Robbie Andrew, 2026}}

\end{frame}




\begin{frame}
  \frametitle{Electric vehicles: Germany catching up?}


  \centering
\includegraphics[height=7.5cm]{oet-de-evs-2026.png}

  \source{\hrefc{https://openenergytracker.org/en/docs/germany/emobility/}{Open Energy Tracker, 2026}}

\end{frame}



\section{Invitation: Balancing Variable Renewable Energy in Europe}



\begin{frame}[fragile]
  \frametitle{Goals for Energy System Modelling}

  \begin{enumerate}
  \item What \alert{infrastructure} (wind, solar, hydro generators,
    heating/cooling units, storage and networks) does a highly renewable energy system
    require and \alert{where} should it go?
  \item Given a desired \co2 emissions reduction (e.g. 95\% compared to 1990),
    what is the \alert{cost-optimal} combination of infrastructure?
  \item How do we deal with the \alert{variability} of wind and solar: balancing in space with networks or in time with storage?
  \end{enumerate}



\end{frame}


\begin{frame}
  \frametitle{Variability: Single wind site in Berlin}

  Looking at the wind output of a single wind plant over two weeks, it is highly
  variable, frequently dropping close to zero and fluctuating strongly.

  \centering
  \includegraphics[width=12cm]{variability-berlin}


\end{frame}



\begin{frame}
  \frametitle{Electricity consumption is much more regular}

  Electrical demand is much more regular over time - dealing with the
  \alert{mismatch} between locally-produced wind and the demand would
  require a lot of storage...

  \centering
  \includegraphics[width=12cm]{DE-load}


\end{frame}



\begin{frame}
  \frametitle{Variability: Different wind conditions over Germany}

  The wind does not blow the same at every site at every time: at a given time there are a variety of wind conditions across Germany. These differences \alert{balance out over time and space}.

  \centering
  \includegraphics[width=10cm]{2015-05-13-1100}

  \source{\urlc{https://earth.nullschool.net/}}

\end{frame}




\begin{frame}
  \frametitle{Variability: Single country: Germany}

  For a whole country like Germany this results in valleys and peaks that are  somewhat smoother, but the profile still frequently
  drops close to zero.

  \centering
  \includegraphics[width=12cm]{variability-de}


\end{frame}



\begin{frame}
  \frametitle{Variability: Different wind conditions over Europe}

  The scale of the weather systems are bigger than countries, so to leverage the full smoothing effects, you need to integrate wind at the \alert{continental scale}.

  \centering
  \includegraphics[width=10cm]{2015-11-30-0300}

  \source{\urlc{https://earth.nullschool.net/}}

\end{frame}



\begin{frame}
  \frametitle{Variability: A continent: Europe}


  If we can integrate the feed-in of wind turbines across the European continent, the
  feed-in is considerably smoother: we've eliminated most valleys and
  peaks.

  \centering
  \includegraphics[width=12cm]{variability-eu}


\end{frame}





\begin{frame}
  \frametitle{Variability: A continent: Wind plus Hydro}

  Flexible, renewable hydroelectricity from storage dams in Scandinavia and the Alps can fill many of the valleys; excess energy can either be curtailed (spilled) or stored.

  \centering
  \includegraphics[width=12cm]{variability-load}


\end{frame}



\begin{frame}
  \frametitle{Daily variations: challenges and solutions}

  \begin{columns}[T]
    \begin{column}{5cm}
      \includegraphics[trim=0 0cm 0 0cm,width=5cm,clip=true]{DE-solar-day.pdf}

      \includegraphics[trim=0 0cm 0 0cm,width=5cm,clip=true]{DE-transport-day.pdf}
    \end{column}
    \begin{column}{4cm}
      \alert{Daily} variations in supply and demand can be balanced by
      \begin{itemize}
      \item \alert{short-term storage} (e.g. batteries, pumped-hydro, small thermal storage)
      \item \alert{demand-side management} (e.g. battery electric vehicles,
        industry)
      \item \alert{east-west grids over multiple time zones}
      \end{itemize}

    \end{column}
    \begin{column}{5cm}
      \includegraphics[trim=0 0cm 0 0cm,width=5cm,clip=true]{pumped-storage-diagram-best1.jpg}

      \vspace{.5cm}

      \includegraphics[trim=0 0cm 0 0cm,width=5cm,clip=true]{tesla-charging.jpg}
    \end{column}
  \end{columns}

\end{frame}




\begin{frame}
  \frametitle{Weekly variations: challenges and solutions}

  \begin{columns}[T]
    \begin{column}{5cm}
      \includegraphics[trim=0 0cm 0 0cm,width=5.3cm,clip=true]{DE-wind-month.pdf}

      \includegraphics[trim=0 0cm 0 0cm,width=5cm,clip=true]{2015-11-30-0300.png}

    \end{column}
    \begin{column}{4cm}
      \hrefc{https://www.youtube.com/watch?v=ttfuEnMz2UM}{\alert{Weekly} variations} in supply and demand can be balanced by
      \begin{itemize}
      \item \alert{medium-term storage} (e.g. chemically with hydrogen or methane storage, thermal energy storage, hydro reservoirs)
      \item \alert{continent-wide grids}
      \end{itemize}

    \end{column}
    \begin{column}{5cm}
      \includegraphics[trim=0 0cm 0 0cm,width=4.5cm,clip=true]{1024px-Gasometer_in_East_London.jpg}

      \includegraphics[trim=0 0cm 0 0cm,width=4.5cm,clip=true]{europe_map.pdf}
    \end{column}
  \end{columns}

\end{frame}




\begin{frame}
  \frametitle{Seasonal variations: challenges and solutions}

  \begin{columns}[T]
    \begin{column}{5cm}
      \includegraphics[trim=0 0cm 0 0cm,width=5cm,clip=true]{DE-wind-solar-year.pdf}

      \includegraphics[trim=0 0cm 0 0cm,width=5cm,clip=true]{DE-heat-year.pdf}
    \end{column}
    \begin{column}{4cm}
      \alert{Seasonal} variations in supply and demand can be balanced by
      \begin{itemize}
      \item \alert{long-term storage} (e.g. underground hydrogen or methane storage, long-term thermal energy storage, hydro reservoirs)
      \item \alert{north-south grids over multiple latitudes}
      \end{itemize}

    \end{column}
    \begin{column}{5cm}
      \includegraphics[trim=0 0cm 0 0cm,width=4.7cm,clip=true]{salt_caverns.jpg}

      \vspace{.2cm}

      \includegraphics[trim=0 0cm 0 0cm,width=4.7cm,clip=true]{pit-zoom.png}
    \end{column}
  \end{columns}

\end{frame}



\begin{frame}
  \frametitle{Research approach}

  Avoid too many assumptions. Fix the \alert{boundary conditions}:

  \begin{itemize}
  \item Meet demand for energy services
  \item Reduce \co2 emissions
  \item Conservative predictions for cost developments
  \item No/minimal/optimal grid expansion
  \end{itemize}

  Then \alert{let the math decide the rest}, i.e. choose the number of
  wind turbines / solar panels / storage units / transmission lines to
  minimise total costs (investment \alert{and} operation).

  \vspace{.3cm}

  Generation, storage and transmission optimised \alert{jointly}
  because they are \alert{strongly interacting}.
\end{frame}




\begin{frame}
  \frametitle{Determine optimal electricity system}


\begin{columns}[T]
\begin{column}{7cm}
  \begin{itemize}
  \item Meet all electricity demand.
  \item Reduce \co2{} by 95\% compared to 1990.
  \item \alert{Generation} (where potentials allow): onshore and offshore
    wind, solar, hydroelectricity, backup from natural gas.
  \item \alert{Storage}: batteries for short term, electrolyse hydrogen gas for long term.
  \item \alert{Grid expansion}: simulate everything from no grid expansion (like a \alert{decentralised solution}) to optimal grid expansion (with significant \alert{cross-border trade}).
  \end{itemize}
\end{column}
\begin{column}{6.5cm}


  \vspace{0.3cm}
\centering

\includegraphics[width=7cm]{europe_map}

\end{column}
\end{columns}


\source{PyPSA-Eur, based on ENTSO-E map}
\end{frame}



\begin{frame}[fragile]
  \frametitle{Linear optimisation of annual system costs}

Find the long-term cost-optimal energy system, including investments and short-term costs:
\begin{equation*}
  \textrm{Minimise} \left(\parbox{6em}{\centering\alert{Yearly\\system costs}}\right) = \sum_i \left(\parbox{6em}{\centering\alert{Annualised capital costs}}\right) + \sum_{i,t} \left(\parbox{5em}{\centering\alert{Marginal costs}}\right)
\end{equation*}
subject to
\begin{itemize}
\item meeting \alert{energy demand} at each node $i$ (e.g. region) and time $t$ (e.g. hour of year)
\item wind, solar, hydro (variable renewables) \alert{availability time series} $\forall\: i,t$
\item \alert{transmission constraints} between nodes, \alert{linearised power flow}
\item (installed capacity) $\leq$ (\alert{geographical potentials} for renewables)
\item \alert{CO${}_2$ constraint} (e.g. 95\% reduction compared to 1990)
\end{itemize}

In short: mostly-greenfield investment optimisation, multi-period with linear power flow.

Optimise transmission, generation and storage \alert{jointly}, since they're strongly interacting.
\end{frame}






\begin{frame}
\frametitle{Model Inputs and Outputs}

\begin{columns}
  \begin{column}{6cm}


    \begin{table}[!t]
	\centering
	\begin{tabular}{@{}p{1.15cm}p{4.54cm}@{}}
\toprule
\alert{Inputs} & Description \\
\midrule
$d_{i,t}$ & Demand (completely inelastic) \\
$G_{i,s,t}$ & Per unit availability for wind and solar \\
$\hat{G}_{i,s}$ & Generator installable potentials \\
various & Existing hydro data \\
various & Grid topology \\
$\eta_*$ & Storage efficiencies \\
$c_{i,s}$ & Generator capital costs \\
$o_{i,s,t}$ & Generator marginal costs \\
$c_\ell$ & Line costs \\
\bottomrule
	\end{tabular}
\end{table}
  \end{column}
    \begin{column}{1cm}


      \vspace{1cm}

      $\to$

    \end{column}
  \begin{column}{6cm}


    \begin{table}[!t]
	\centering
	\begin{tabular}{@{}p{1.15cm}p{4.54cm}@{}}
\toprule
\alert{Outputs} & Description \\
\midrule
$G_{i,s}$ &  Generator capacities \\
$g_{i,s,t}$ & Generator dispatch \\
$F_\ell$ & Line capacities \\
$f_{\ell,t}$ & Line flows \\
$\lambda_*,\mu_*$ & Lagrange/KKT multipliers of all constraints \\
f & Total system costs \\
\bottomrule
	\end{tabular}
\end{table}
  \end{column}

\end{columns}
\end{frame}




\begin{frame}
  \frametitle{Costs and assumptions for the electricity sector (projections for 2030)}

  \begin{table}
\centering
\begin{tabular}{@{}lrlrr@{}}
\toprule
Quantity                &Overnight  Cost [\euro]  &Unit & FOM [\%/a] & Lifetime [a] \\
\midrule
Wind onshore    &1182   &kW\el &3 & 20   \\
Wind offshore  &2506   &kW\el  &3& 20  \\
Solar PV           &600   &kW\el &4 & 20   \\
Gas             &400    &kW\el  &4& 30  \\
%Gas marginal            &75     &\euro{}/MWh$_{\textrm{e}}$    \\
Battery storage         &1275   &kW\el  & 3 & 20 \\
Hydrogen storage        &2070   &kW\el  & 1.7 &20 \\
Transmission line       &400    &MWkm & 2 & 40\\
\bottomrule
\end{tabular}
\end{table}
  Interest rate of 7\%, storage efficiency losses, only gas has \co2 emissions, gas marginal costs.

  Batteries can store for 6 hours at maximal rating (efficiency $0.9\times 0.9$), hydrogen storage for 168 hours (efficiency $0.75\times 0.58$).
\end{frame}





\begin{frame}
  \frametitle{Costs: No interconnecting transmission allowed}



\begin{columns}[T]
  \begin{column}{4.9cm}

  Technology~by~energy:
  % left bottom right top
  \begin{tabular}{cc}
    \includegraphics[trim=0 0cm 0 0cm,width=3.2cm,clip=true]{total-pie-0-0} &
  \end{tabular}


  Average~cost~\alert{\euro 86/MWh}:

  \includegraphics[width=3.6cm]{total-costs-joint-1}

  \end{column}

  \begin{column}{9cm}
    % left bottom right top
    \centering
    \includegraphics[trim=0 4cm 0 4cm,width=8cm,clip=true]{euro-pie-0-0}

    \raggedright
    Countries must be self-sufficient at all times; lots of storage and some gas to deal with fluctuations of wind and solar.
  \end{column}

\end{columns}
\end{frame}


\begin{frame}
  \frametitle{Dispatch with no interconnecting transmission}

  For Great Britain with no interconnecting transmission, excess wind is either stored as hydrogen or curtailed:

  \centering
  \includegraphics[width=13cm]{GB-0}
\end{frame}


\begin{frame}
  \frametitle{Costs: Cost-optimal expansion of interconnecting transmission}


\begin{columns}[T]
  \begin{column}{5.3cm}

  Technology~by~energy:
  % left bottom right top
    \begin{tabular}{cc}
    \includegraphics[trim=0 0cm 0 0cm,width=3.2cm,clip=true]{total-pie-0-5} &
  \end{tabular}

  Average~cost~\alert{\euro 64/MWh}:

  \includegraphics[width=4.7cm]{total-costs-joint-2}

  \end{column}

  \begin{column}{9cm}
    % left bottom right top
    \centering
    \includegraphics[trim=0 4cm 0 4cm,width=8cm,clip=true]{euro-pie-0-5}

    \raggedright
    Large transmission expansion; onshore wind dominates. This optimal solution may run into public acceptance problems.
  \end{column}


\end{columns}

\end{frame}


\begin{frame}
  \frametitle{Dispatch with cost-optimal interconnecting transmission}

  Almost all excess wind can be now be exported:

  \centering
  \includegraphics[width=13cm]{GB-1}
\end{frame}



\begin{frame}
  \frametitle{Electricity Only Costs Comparison}

\begin{columns}[T]
  \begin{column}{9cm}

    \vspace{0.5cm}
  \includegraphics[width=9cm]{opteu_paper2-elec_only-costs-curve}

  \end{column}

  \begin{column}{5cm}
    \begin{itemize}
    \item Average total system costs can be as low as \euro~64/MWh
     \item Energy is dominated by wind (64\% for the cost-optimal system), followed
       by hydro (15\%) and solar (17\%)
     \item Restricting transmission results in more storage to deal with variability, driving up the costs by up to 34\%
     \item Many benefits already locked in at a few multiples of today's grid
    \end{itemize}

  \end{column}

\end{columns}
\end{frame}



\begin{frame}
  \frametitle{Different flexibility options have difference temporal scales}

\begin{columns}[T]
  \begin{column}{10.5cm}

    \vspace{0.5cm}
  \includegraphics[width=11cm]{soc_series_LV0-25_H2_hydro_diw2030_solar1_7-eps-converted-to.pdf}

  \end{column}

  \begin{column}{3cm}
    \vspace{1cm}
    \begin{itemize}
    \item Hydro reservoirs are \alert{seasonal}
    \item Hydrogen storage is \alert{multi-weekly}
    \end{itemize}

  \end{column}

\end{columns}
\end{frame}



\begin{frame}
  \frametitle{Different flexibility options have difference temporal scales}

\begin{columns}[T]
  \begin{column}{10.5cm}

    \vspace{0.5cm}
  \includegraphics[width=11cm]{soc_series_LV0-25_all_2011-08_diw2030_solar1_7-eps-converted-to.pdf}

  \end{column}

  \begin{column}{3cm}
        \vspace{2cm}
    \begin{itemize}
    \item Pumped hydro and battery storage are \alert{daily}
    \end{itemize}

  \end{column}

\end{columns}
\end{frame}


\begin{frame}
  \frametitle{Features of this example}

  This example has several features which will accompany us through the lecture course:
  \begin{enumerate}
  \item We have to account for the variations of wind and solar in \alert{time} and \alert{space}.
  \item These variations take place at \alert{different scales} (daily, multi-week, seasonal).
  \item We often have a choice between balancing in \alert{time} (with storage) or in \alert{space} (with networks).
  \item Optimisation is important to increase cost-effectiveness, but
    we should also look at \alert{near-optimal} solutions.
  \end{enumerate}

  \vspace{1cm}
  Full paper reference: D. Schlachtberger, T. Brown, S. Schramm, M. Greiner, ``The Benefits of Cooperation in a Highly Renewable European Electricity Network'', Energy, 134, 469-481, 2017, \hrefc{https://arxiv.org/abs/1704.05492}{arXiv:1704.05492}.
\end{frame}


\end{document}