CLIM-18 / SPM.C / Research primer
Is clean electricity displacing fossil generation or meeting new demand?
How much of the change in fossil electricity generation is accounted for by total generation growth and changes in non-fossil output?
NASA Glenn Research Center. The experimental Mod-1 wind turbine in Boone, North Carolina, in 1979; historical energy-technology context. Contextual image; not used to estimate a trend. Image credits.
The question
Rising clean generation can coexist with rising fossil output if the system expands. The proposed account separates this arithmetic from claims about why demand or investment changed.
Why it matters
Capacity announcements alone do not reveal displacement; energy-system progress requires distinguishing installed capability, actual generation and total system growth.
The AR6 anchor
AR6 assesses the need for far-reaching system transitions and finds feasible mitigation options already available, with differences across systems and regions (high confidence).
AR6 Synthesis Report (2023) / C.3; C.2.
Evidence and comparison
- Unit of analysis
- Country-year, distinguishing capacity stocks from annual energy flows.
- Baseline and denominator
- Use 2019 and fixed five-year comparisons. Define non-fossil generation explicitly; electricity demand and generation are not interchangeable when trade and losses matter.
- First descriptive test
- Reconcile the change in fossil output as total-generation change minus non-fossil change, separately displaying wind, solar, hydro, nuclear and other documented components.
- Deeper analysis
- Compare generation changes with capacity additions and alternate start years; isolate hydro variability and avoid estimating marginal displacement from aggregate annual correlations.
- Attribution status
- descriptive observation
- Uncertainty
- Flag provisional generation estimates and capacity revisions. An accounting decomposition is exact only within a reconciled source boundary, not a causal policy estimate.
Principal sources
- Ember Yearly Electricity Data
Generation by fuel (TWh); Total generation; Electricity demand where reported.
Target 2000-2025 complete years; country and release checks pending. Candidate source; import and publication checks are still required. - IRENA Renewable Capacity Statistics
Installed wind and solar capacity (MW); Country and technology.
Target 2010-2025, Renewable Capacity Statistics 2026; table checks pending. Candidate source; import and publication checks are still required.
Alternative explanations
- Electricity trade
- Weather-dependent output
- Nuclear availability
- Industrial demand shifts
The visual argument
Provisional: change decomposition with country and period selectors; annotate the accounting identity, unclassified generation and the distinction between demand and generation.
- Installed-capacity companion
- Generation-mix trajectories
- Hydro sensitivity comparison
- Exact fuel-account table
What these data do not show
- Annual output cannot identify hourly marginal emissions.
- Capacity growth does not establish grid adequacy, curtailment or system reliability.
Reproducibility and next release
Plan src/build.mjs and data/processed/electricity-change.csv from frozen data/raw aggregates; test fuel sums, generation-demand boundaries, units and capacity mappings, recording missing categories, hashes and licenses in provenance.
- After approval: electricity-change study
- Article and accounting methods
- Responsive decomposition and exact values
- 16:9 hero and LinkedIn launch
- Optional PDF carousel
- Chart exports and processed CSV