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W4.1 Energy Balances

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Key points

  • Table = one-year energy wallet; fill blanks with row/column checks → Energy balance
  • Future scenario: work up from demand (TFC) to supply (chain below) → Capacity factor for installed power and area
  • CO₂ per sector “along the value chain” = direct (fuels burned) + indirect (share of power-plant CO₂, allocated by Eel,sector/Eel,TFCE_{el,sector}/E_{el,TFC}); result depends on what is counted (CHP) → state the assumption
  • Heat pump row has a positive total (free environmental heat) → COP. Coefficient of performance

Chain (future scenario)

TFC per sector → H₂ and electricity needed → electrolyser input (Eel=EH2/ηE_{el} = E_{H_2}/\eta) → power-plant output (column check) → wind/solar → Pnom=E/(Cft)P_{nom} = E/(C_f t) → area

Typical traps
  • Imports reduce what must be produced (H₂ import 4000)
  • E=CfPnomtE = C_f P_{nom} t: don’t forget tt = 8760 h
  • Time per point ≈ 1.8 min: an ambiguous 4-point question → simple model + one line stating the assumption
  • “Compare to the global average” → ~65 kWh/(person·day) (lecture, not given)
Exam

Energy balance is Task 3 in every SET3014 exam (18 pt).

  • Nov 2023 Task 3 (NL 2018 → NL-Green 2050): plant η 45.8%; highest CO₂ sector (direct + electricity share: Transport in the key; with CHP counted Industry); TFC H₂ 12276 ktoe; power plants 25439, wind/solar 23333; wind 46.8 GW (8.1% North Sea), solar 123 GW (2.1% land)
  • Oct 2025 Task 3 (EU27+UK 2050 Sankey): table from Sankey (heat pump row total +307 = environmental heat); 97 kWh/(person·day) ≈ 1.5× global; COP 1.74; “Other” = agriculture, public services, government, military; CO₂ 3.4 → 0.854 Gt (−75%)
  • Answer key slips: Oct 2025 Other total 169 → 159
  • Old SET3013: Nov 2016 T3 (Italy), Jan 2017 T3 (NL), Jan 2018 T3 (China), Feb 2019 T4 (Brazil), Nov 2019 T3 (NL)

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