\newcommand{\thistitle}{Lecture 2: Energy Balances} \input{title.tex} \section{Measuring energy} \begin{frame} \frametitle{Goal: Understand Energy Flow Through the Economy} Example: \alert{energy balance} for Germany in 2022 in Petajoule (PJ) \vspace{.2cm} \centering \includegraphics[height=6.8cm]{energiebilanzen-2022.png} \source{\hrefc{https://ag-energiebilanzen.de/en/data-and-facts/energy-flow-chart/}{AG Energiebilanzen, 2023}} \end{frame} \begin{frame} \frametitle{Example: Sankey diagram for US in 2022} \centering \includegraphics[height=7.5cm]{us-sankey-2022.png} \source{\hrefc{https://flowcharts.llnl.gov/sites/flowcharts/files/2023-10/US\%20Energy\%202022.pdf}{LLNL, 2023}} \end{frame} \begin{frame} \frametitle{Definitions: Primary Versus Final Versus Useful Energy} {\small Definitions of energy are oriented towards conventional energy sources like coal, oil and gas. \begin{itemize} \item \alert{Primary energy} is energy as found in nature before it undergoes any transformation (crude oil, coal, gas, biomass, nuclear, wind, solar). \item \alert{Secondary energy} is energy after conversion processes, either chemical or physical (refined fuels like gasoline, electricity from a coal power plant). \item \alert{Final energy} is the energy as it is sold to end users (electricity, refined fuels like gasoline, gas for building heating). \item \alert{Useful energy} is the energy after conversion by the consumer, available to be used (heat in a home, light, mechanical work). \item \alert{Energy services} is what the consumer actually wants: a warm home, transportation from A to B, manufactured goods, etc. \end{itemize} The two most commonly used definitions are \alert{primary} and \alert{final} energy, since they are \alert{easier to measure} in a fossil-fuelled world. With more focus on renewables and electrification, this \alert{may change}! } \end{frame} \begin{frame} \frametitle{Classification of Energy Sources} \centering \includegraphics[height=7.5cm]{renewables_classification.png} \source{OECD/IEA Energy Statistics Manual, 2005} \end{frame} \begin{frame} \frametitle{Units of Energy: Joule and tonne of oil equivalent} \alert{Joule} (J) is the SI unit of energy. Conventional primary energy sources are often measured in units corresponding to their natural form: volume, mass etc. We can convert from measurements of mass [kg] and volume [m$^3$] to energy units using the \alert{calorific value} [J/kg, J/m$^3$], which measures the heat from combustion. Example: the unit \alert{tonne of oil equivalent} (toe) is the energy generated by burning one metric ton of oil. Since the calorific value of oil is 41.88 MJ/kg, we have \begin{equation*} 1 \textrm{ toe} = 41.88 \textrm{ GJ} \end{equation*} \vspace{.4cm} [Reminder: k = kilo = 1e3, M = Mega = 1e6, G = Giga = 1e9, T = Tera = 1e12, P = Peta = 1e15, E = Exa = 1e18.] \end{frame} \begin{frame} \frametitle{Lower Heating Values of Energy Fuels} \centering \includegraphics[width=12cm]{fuel_lhv.png} \end{frame} \begin{frame} \frametitle{Higher and Lower Heating Values} \begin{itemize} \item \alert{Lower Heating Value (LHV)} is the maximum amount of usable heat from combustion without counting the condensation enthalpy of water vapor contained in the exhaust gas. \item \alert{Higher Heating Value (HHV)} includes the condensation enthalpy of water vapor contained in the exhaust gas. It is always higher than the LHV (e.g. 11\% higher for methane). \end{itemize} \vspace{.35cm} \centering \includegraphics[width=8cm]{Higher-and-lower-heating-values-for-various-fuels-22.png} \vspace{.35cm} \raggedright LHV is most commonly used in European statistics. HHV becomes relevant in e.g. condensing combined heat and power plants (CHP) where vapor is condensed. \end{frame} \begin{frame} \frametitle{Power: Flow of energy} \alert{Power} is the rate of consumption of energy. It is measured in \alert{Watts}: \begin{equation*} 1 \textrm{ Watt } = 1 \textrm{ Joule per second } \end{equation*} The symbol for Watt is W, 1 W = 1 J/s. \centering 1 kilo-Watt = 1 kW = 1,000 W 1 mega-Watt = 1 MW = 1,000,000 W 1 giga-Watt = 1 GW = 1,000,000,000 W 1 tera-Watt = 1 TW = 1,000,000,000,000 W \end{frame} \begin{frame} \frametitle{Power: Examples of consumption} At full power, the following items consume: \ra{1.1} \begin{table}[!t] \begin{tabular}{lr} \toprule Item & Power\\ \midrule New efficient lightbulb & 10 W \\ Old-fashioned lightbulb & 70 W \\ Single room air-conditioning & 1.5 kW \\ Kettle & 2 kW \\ Factory & $\sim$1-500 MW \\ CERN & 200 MW \\ Germany total demand & 35-80 GW \\ \bottomrule \end{tabular} \end{table} \end{frame} \begin{frame} \frametitle{Power: Supplying world's energy with wind and solar} If all energy is electrified in 2050 and energy consumption equalises between nations, the average electricity consumption of the world would be around 12~TW. Suppose half is met with wind (capacity factor 33.3\%) and half is met with solar PV (capacity factor 16.6\%). [\alert{Capacity factor} $=$ average generation $/$ capacity.] How much wind and solar capacity does the world need (assuming perfect lossless storage)? \pause \vspace{1cm} Wind: 6~TW / 0.333 $=$ 18~TW (around 1136~GW was installed by 2024) Solar: 6~TW / 0.166 $=$ 36~TW (around 2200~GW was installed by 2024) \source{\hrefc{https://www.irena.org/Publications/2023/Mar/Renewable-capacity-statistics-2023}{IRENA Statistics 2023}} \end{frame} \begin{frame} \frametitle{Power: Supplying world's energy with wind and solar} If installed wind density on average is 10~MW/km$^2$ and solar is 72~MW/km$^2$, what percentage of world land (148 million km$^2$) is taken with each? \pause \vspace{.5cm} Wind: 18~TW/(10~MW/km$^2$) = 1.8 million km$^2$ (around 1.2\% of total land $=$ area of Indonesia) Solar: 36~TW/(72~MW/km$^2$) = 0.5 million km$^2$ (around 0.3\% of total land $=$ area of Spain) \vspace{.5cm} Nota Bene: \begin{itemize} \item Wind doesn't interfere with other land uses like agriculture; can also be built offshore \item 10~MW/km$^2$ is a \alert{local} maximum installation density for wind, but to allow wind replenishment over large areas 2~MW/km$^2$ is suitable as a \alert{wide-area} limit \item Solar can be rooftop or combined with agriculture = agrivoltaics \end{itemize} \end{frame} \begin{frame} \frametitle{Units of energy: Watt-hour} In the electricity sector, energy is usually measured in `Watt-hours', Wh. 1 kWh = power consumption of 1 kW for one hour E.g. a 10 W lightbulb left on for two hours will consume 10 W * 2 h = 20 Wh It is easy to convert this back to the SI unit for energy, Joules: 1 kWh = (1000 W) * (1 h) = (1000 J/s)*(3600 s) = 3.6 MJ \end{frame} \begin{frame} \frametitle{Yearly energy to power} Germany consumes around 600 TWh per year, written 600 TWh/a. What is the \emph{average} power consumption in GW? \pause \begin{align*} 600\textrm{ TWh/a} & = \frac{(600\textrm{ TW}) * (1\textrm{ h})}{(365*24 \textrm{ h})} \\ & = \frac{600}{8760} \textrm{ TW} \\ & = 68.5 \textrm{ GW} \end{align*} \end{frame} \begin{frame} \frametitle{Tables for converting units} \centering \includegraphics[width=8cm]{conversion.jpg} \raggedright Units used in the United States: \begin{itemize} \item British thermal unit (Btu), 1 million Btu = MBtu (often written MMBtu) = 0.293 MWh \item Quad = 1e15 Btu = 293 TWh \end{itemize} \end{frame} \section{Energy conversion} \begin{frame} \frametitle{Energy conversion/transformation processes} \centering \includegraphics[width=14cm]{conversion_processes.png} \source{Zweifel, Praktiknjo \& Erdmann (2017)} \end{frame} \begin{frame} \frametitle{Energy conversion efficiency} \alert{Efficiency} of an energy conversion device (e.g. power plant, vehicle engine): \begin{equation*} \textrm{Efficiency, } \eta = \frac{\textrm{Useful energy output}}{\textrm{Energy input}} \end{equation*} Example: How much much natural gas is required for generating 100 MWh of electricity in a gas power plant with an efficiency of 50\%? \end{frame} \begin{frame} \frametitle{Efficiency} When fuel is consumed, much/most of the energy of the fuel is lost as waste heat rather than being converted to electricity. The thermal energy, or calorific value, of the fuel is given in terms of MWh${}_{\textrm{th}}$, to distinguish it from the electrical energy MWh${}_{\textrm{el}}$. The ratio of input thermal energy to output electrical energy is the \alert{efficiency}. \ra{1.1} \begin{table}[!t] \begin{tabular}{lrrrrr} \toprule Fuel & Calorific energy & Per unit efficiency & Electrical energy \\ & MWh\(_{\text{th}}\)/tonne & MWh\(_{\text{el}}\)/MWh\(_{\text{th}}\) & MWh\(_{\text{el}}\)/tonne \\ \midrule Lignite & 2.5 & 0.4 & 1.0 \\ Hard Coal & 6.7 & 0.45 & 2.7\\ Gas (CCGT) & 15.4 & 0.58 & 8.9\\ Uranium (unenriched) & 150000 & 0.33 & 50000 \\ \bottomrule \end{tabular} \end{table} \end{frame} \begin{frame} \frametitle{Fuel costs to marginal costs} The cost of a fuel is often given in \euro/kg or \euro/MWh\(_{\text{th}}\). Using the efficiency, we can convert this to \euro/MWh\(_{\text{el}}\). For the full marginal cost, we have to also add the CO$_2$ price and the variable operation and maintenance (VOM) costs. \ra{1.1} \begin{table}[!t] \begin{tabular}{lrrrrr} \toprule Fuel & Per unit efficiency & Cost per thermal & Cost per elec. \\ & MWh\(_{\text{el}}\)/MWh\(_{\text{th}}\) & \euro/MWh\(_{\text{th}}\) & \euro/MWh\(_{\text{el}}\)\\ \midrule Lignite & 0.4 & 4.5 & 11\\ Hard Coal & 0.45 & 11 & 24\\ Gas (CCGT) & 0.58 & 19 & 33\\ Uranium & 0.33 & 3.3 & 10\\ \bottomrule \end{tabular} \end{table} \end{frame} \begin{frame} \frametitle{CO2 emissions per MWh} The \co2 emissions of the fuel. \ra{1.1} \begin{table}[!t] \begin{tabular}{lrrr} \toprule Fuel & t\(_{\text{CO2}}\)/t & t\(_{\text{C02}}\)/MWh\(_{\text{th}}\) & t\(_{\text{CO2}}\)/MWh\(_{\text{el}}\)\\ \midrule Lignite & 0.9 & 0.36 & 0.9 \\ Hard Coal & 2.4 & 0.36 & 0.8 \\ Gas (CCGT) & 3.1 & 0.2 & 0.35\\ Uranium & 0 & 0 & 0 \\ \bottomrule \end{tabular} \end{table} Current \co2 price in EU Emissions Trading Scheme (ETS) is around \euro 50-100/t${}_{\textrm{CO2}}$ \end{frame} \begin{frame} \frametitle{You calculate: What CO$_2$ price to switch gas and lignite?} What CO$_2$ price, i.e. x \euro/t${}_{\textrm{CO2}}$, is required so that the marginal cost of gas (CCGT) is lower than lignite? NB: It helps to track units. \pause We need to solve for the switch point by adding the CO$_2$ price to the fuel cost. Left is lignite, right is gas: \begin{equation*} 11 \textrm{ \euro/MWh}_{\textrm{el}} + (0.9 \textrm{ tCO}_2/\textrm{MWh}_{\textrm{el}}) \cdot (x \textrm{ \euro/tCO}_2) = 33 \textrm{ \euro/MWh}_{\textrm{el}} + (0.35 \textrm{ tCO}_2/\textrm{MWh}_{\textrm{el}}) \cdot (x \textrm{ \euro/tCO}_2) \end{equation*} Solve: \begin{equation*} x = \frac{33 - 11}{0.9 - 0.35} = 40 \end{equation*} \end{frame} \begin{frame} \frametitle{CO2 and import costs change over time...} \centering \includegraphics[width=14cm]{import_costs-2019.png} \source{\hrefc{https://www.agora-energiewende.de/fileadmin2/Projekte/2019/Jahresauswertung_2019/AGORA_State_of_Affairs_German_Power_Sector_2019_Webinar_28012020.pdf}{Agora Energiewende, 2019}} \end{frame} \begin{frame} \frametitle{...which affects the marginal costs of generation} \centering \includegraphics[width=14cm]{marginal_costs-2019.png} \source{\hrefc{https://www.agora-energiewende.de/fileadmin2/Projekte/2019/Jahresauswertung_2019/AGORA_State_of_Affairs_German_Power_Sector_2019_Webinar_28012020.pdf}{Agora Energiewende, 2019}} \end{frame} \begin{frame} \frametitle{CO2 emissions from electricity sector} \co2 emissions in electricity generation stagnated for years because of coal, which is slowly being pushed out by the \co2 price and in the longer term by the Kohleausstieg. \centering \includegraphics[width=11cm]{co2-strom-2022.png} \source{\hrefc{https://static.agora-energiewende.de/fileadmin/Projekte/2022/2022-10_DE_JAW2022/A-EW_283_JAW2022_WEB.pdf}{Agora Energiewende Jahresauswertung 2022}} \end{frame} \begin{frame} \frametitle{Hydrogen in REPowerEU by 2030} The European Commission's REPowerEU plan, published in March 2022, aims for 10~Mt/a of clean hydrogen to be produced domestically in the European Union by 2030, with another 10~Mt imported. If electrolysis of water to hydrogen is 70\% efficient (LHV) and there is 33~MWh/tH$_2$ (LHV), what will be the electricity consumption from electrolysis for hydrogen in the EU in 2030? \pause Consumption will be \begin{equation*} \frac{ 10 \textrm{ MtH}_2/\textrm{a} * 33 \textrm { MWh}_{\textrm{H}_2}/\textrm{tH}_2}{ 0.7 \textrm{ MWh}_{\textrm{H}_2}/\textrm{MWh}_{\textrm{el}}} = 471 \textrm{ TWh}_{\textrm{el}}/\textrm{a} \end{equation*} Compare to the current electricity consumption in Europe of around 3200~TWh\el/a. \end{frame} \begin{frame} \frametitle{Capacity Factors and Full Load Hours} A generator's \alert{capacity factor} is the average power generation divided by the power capacity. For variable renewable generators it depends on weather, generator model and curtailment; for dispatchable generators it depends on market conditions and maintenance schedules. A generator's \alert{full load hours} are the equivalent number of hours at full capacity the generator required to produce its yearly energy yield. The two quantities are related: \begin{equation*} \textrm{full load hours} = \textrm{per unit capacity factor} \cdot 365 \cdot 24 = \textrm{per unit capacity factor} \cdot 8760 \end{equation*} Typical values for Germany: \begin{table}[!t] \begin{tabular}{lrr} \toprule Fuel & capacity factor [\%] & full load hours \\ \midrule wind & 20-35 & 1600-3000 \\ solar & 10-12 & 800-1000 \\ nuclear & 70-90 & 6000-8000 \\ open-cycle gas & 20 & 1500 \\ \bottomrule \end{tabular} \end{table} \end{frame} \begin{frame} \frametitle{Measuring primary energy of renewables} How to value primary energy of carriers which do not have a calorific value, e.g. wind, solar PV, hydroelectricity? \begin{itemize} \item \alert{Fictive Efficiency Principle:} (also known as `Physical Energy Accounting Method' or `Direct Equivalent Method') (most common: used by IEA, OECD, Eurostat, IPCC) assume there is a 1-to-1 correspondence between primary energy and electricity for wind, solar, hydro (i.e. 100\% conversion efficiency) \item \alert{Substitution Principle:} (also know as the `Input-Equivalent Method') (used by BP) assume the conversion efficiency from primary energy to electricity is the same as in a thermal (fossil or nuclear) powerplant (e.g. 35-45\%) \item \alert{Efficiency Principle:} actual efficiency of respective technology (hydro 80-90\% gravitational potential energy of water to electricity, wind 30-55\% kinetic energy of air to electricity, solar 10-25\% radiation to electricity) \end{itemize} \end{frame} \begin{frame} \frametitle{Fictive Efficiency vs Substitution Principle for Electricity Generation} \begin{columns}[T] \begin{column}{7cm} \centering \alert{Fictive Efficiency Principle} \vspace{.3cm} \begin{tikzpicture}[ scale=1.1, demand/.style={blue, thick}, supply/.style={red, thick}, axis/.style={very thick, ->, >=stealth', line join=miter}, important line/.style={thick}, dashed line/.style={dashed, thin}, every node/.style={color=black}, dot/.style={circle,fill=black,minimum size=4pt,inner sep=0pt, outer sep=-1pt}, ] % axis \draw[axis,<->] (2.5,0) node(xline)[right] {} -| (0,2) node(yline)[above] {energy}; \draw[draw=none,fill=black] (0.5,0) rectangle ++(0.3,1.8); \draw[draw=none,fill=black] (1.5,0) rectangle ++(0.3,0.72); \node[below] at (0.65,0) {primary}; \node[below] at (1.65,0) {final}; \node[above] at (1.2,1.7) {fossil}; \begin{scope}[yshift=-3cm] % axis \draw[axis,<->] (2.5,0) node(xline)[right] {} -| (0,2) node(yline)[above] {energy}; \draw[draw=none,fill=blue] (0.5,0) rectangle ++(0.3,0.72); \draw[draw=none,fill=blue] (1.5,0) rectangle ++(0.3,0.72); \node[below] at (0.65,0) {primary}; \node[below] at (1.65,0) {final}; \node[above] at (1.2,1.7) {wind}; \end{scope} \end{tikzpicture} \end{column} \begin{column}{7cm} \centering \alert{Substitution Principle} \vspace{.3cm} \begin{tikzpicture}[ scale=1.1, demand/.style={blue, thick}, supply/.style={red, thick}, axis/.style={very thick, ->, >=stealth', line join=miter}, important line/.style={thick}, dashed line/.style={dashed, thin}, every node/.style={color=black}, dot/.style={circle,fill=black,minimum size=4pt,inner sep=0pt, outer sep=-1pt}, ] % axis \draw[axis,<->] (2.5,0) node(xline)[right] {} -| (0,2) node(yline)[above] {energy}; \draw[draw=none,fill=black] (0.5,0) rectangle ++(0.3,1.8); \draw[draw=none,fill=black] (1.5,0) rectangle ++(0.3,0.72); \node[below] at (0.65,0) {primary}; \node[below] at (1.65,0) {final}; \node[above] at (1.2,1.7) {fossil}; \begin{scope}[yshift=-3cm] % axis \draw[axis,<->] (2.5,0) node(xline)[right] {} -| (0,2) node(yline)[above] {energy}; \draw[draw=none,fill=blue] (0.5,0) rectangle ++(0.3,1.8); \draw[draw=none,fill=blue] (1.5,0) rectangle ++(0.3,0.72); \node[below] at (0.65,0) {primary}; \node[below] at (1.65,0) {final}; \node[above] at (1.2,1.7) {wind}; \end{scope} \end{tikzpicture} \end{column} \end{columns} \end{frame} \begin{frame} \frametitle{Beware: primary energy can underestimate renewables share} Suppose 50\% of electricity is provided by wind and solar, the rest by fossil plants with 33\% efficiency. What is the fraction of renewables in primary energy for electricity: \begin{enumerate} \item Using the Substitution Principle \item Using the Fictive Efficiency Principle \end{enumerate} \pause \begin{enumerate} \item 50\% (since we assume renewables need as much primary energy for each unit of electricity as a thermal plant) \item $\frac{50}{50 + 50/0.33}\% = \frac{50}{50 + 150}\% = 25\%$ \end{enumerate} Bad faith actors will often present renewable shares in terms of primary energy to make it look small. \end{frame} \begin{frame} \frametitle{Primary and final energy change with electrification} {\small Primary energy in grey and green; useful energy in blue. NB: Also in \alert{industry}, \hrefc{https://doi.org/10.1088/1748-9326/abbd02}{electrification} of process heat can be more efficient since the heat can be focused better than e.g. burning gas.} \centering \includegraphics[height=6.5cm,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} \frametitle{Primary and final energy change with renewables and electrification} Switching from thermal power plants to wind, solar and hydro leads to an \alert{automatic decline in primary energy} using the Fictive Efficiency Principle, since thermal losses are no longer counted. With electrification and efficiency, \alert{final energy also declines} (compare gasoline required for a car versus electricity need; similarly natural gas for boiler versus electricity for a heat pump). Both primary and final energy would decline! Primary by $\sim 50\%$, final by $\sim 33\%$. Expect roughly a \alert{doubling of electricity demand} (assuming widespread electrification of end demands, indirect electrification with H2 and efficiency measures). Electricity would become the dominant final energy, primary energy becomes less relevant. Most important \alert{new metrics} become: fraction of electricity from non-emitting sources; efficiency of electricity meeting energy services. \end{frame} \section{Energy Balances} \begin{frame} \frametitle{Energy Balances} Energy is always \alert{conserved} as it flows through the energy system. \alert{Energy balances} tabulate this energy conservation at each step of conversion from primary energy supply to primary energy consumption to final energy to energy services for consumers. At each interface, inputs and outputs \alert{balance}. \vspace{.2cm} \centering \includegraphics[height=4cm]{400px-Balanced_scales.svg.png} \source{\hrefc{https://upload.wikimedia.org/wikipedia/commons/thumb/c/ce/Balanced_scales.svg/400px-Balanced_scales.svg.png}{Wikimedia}} \end{frame} \begin{frame} \frametitle{Principles of Energy Flow} \vspace{.2cm} \centering \includegraphics[width=13.5cm]{energy_flow.png} \source{Zweifel, Praktiknjo \& Erdmann (2017)} \end{frame} \begin{frame} \frametitle{Energy Flow In Germany} Example: \alert{energy balance} for Germany in 2022 in Petajoule (PJ) \vspace{.2cm} \centering \includegraphics[height=6.8cm]{energiebilanzen-2022.png} \source{\hrefc{https://ag-energiebilanzen.de/en/data-and-facts/energy-flow-chart/}{AG Energiebilanzen, 2023}} \end{frame} \begin{frame} \frametitle{Energy Balance Structure (AGEB)} \centering \includegraphics[height=7.5cm]{balance_structure.png} \source{\hrefc{https://ag-energiebilanzen.de/}{AG Energiebilanzen}} \end{frame} \begin{frame} \frametitle{Simplified Energy Balance for EU28 in 2016} \begin{columns}[T] \begin{column}{9cm} \centering \includegraphics[width=9.4cm]{eb-eu-2016.png} \end{column} \begin{column}{5cm} \begin{itemize} \item Gross inland consumption = Primary energy consumption = Production + Imports + Stock changes - Exports - Bunkers \item Bunkers is e.g. marine fuel stored at ports \item Around 330 Mtoe lost in transformation \item Final consumption = Final non-energy + Final energy consumption \end{itemize} \end{column} \end{columns} \source{\hrefc{https://ec.europa.eu/eurostat/web/energy/data/energy-balances}{Eurostat Energy Balances}} \end{frame} \begin{frame} \frametitle{Questions} \begin{itemize} \item What is the average electrical efficiency of conventional power stations in the EU? \item What is the average electrical efficiency of nuclear power stations in the EU? \item What fraction of industry/transport/residential final energy consumption is electricity? \item What is non-energy consumption? \end{itemize} \end{frame} \begin{frame} \frametitle{Moving Beyond Energy Balances: JRC IDEES Database} Includes more granular estimates of useful energy, efficiency, CO$_2$ emissions, breakdown e.g. industry by process. From Joint Research Centre (JRC) of the European Commission. \urlc{https://data.jrc.ec.europa.eu/dataset/jrc-10110-10001} ``The `Integrated Database of the European Energy Sector' (JRC-IDEES) is a one-stop data-box that incorporates in a single database all information necessary for a deep understanding of the dynamics of the European energy system, so as to better analyse the past and to create a robust basis for future policy assessments. JRC-IDEES offers a consistent set of disaggregated energy-economy-environment data, compliant with the EUROSTAT energy balances, as well as widely acknowledged data on existing technologies. It provides a plausible decomposition of energy consumption, allocating it to specific processes and end-uses.'' \end{frame} \begin{frame} \frametitle{JRC IDEES: Residential energy appliances} \begin{columns}[T] \begin{column}{10.5cm} \centering \includegraphics[width=11cm]{res-spec.png} \end{column} \begin{column}{5cm} \begin{itemize} \item NB: Peak electricity consumption in Europe is around 500 GW. \item If all 1760 GW of appliances came on simultaneously, system would be overwhelmed. \item What do you notice about the ratio of total energy consumption to installed power? \end{itemize} \end{column} \end{columns} \source{\hrefc{https://data.jrc.ec.europa.eu/dataset/jrc-10110-10001}{JRC IDEES}} \end{frame} \begin{frame} \frametitle{JRC IDEES: Residential heating efficiency} \begin{columns}[T] \begin{column}{10.5cm} \centering \includegraphics[width=11cm]{res-eff.png} \end{column} \begin{column}{5cm} \begin{itemize} \item Ratio of final energy to actual heating for space/water/cooking. \item Which fuel source is most efficient? \item Why is `air conditioning' efficiency greater than one? \item Why is `advanced electric heating' efficiency greater than one? \end{itemize} \end{column} \end{columns} \source{\hrefc{https://data.jrc.ec.europa.eu/dataset/jrc-10110-10001}{JRC IDEES}} \end{frame} \end{document}