Public-data case study / SQL + Python / South Carolina
Capacity is only half the story.
An interactive analysis of South Carolina’s electricity capacity and generation, using 35 years of public EIA data.
Independent portfolio project developed with AI assistance. Official public data; no employer information or claimed workplace outcome.
The finding / 2024
A quarter of capacity.
Over half of generation.
Installed capacity and annual output describe different things. EIA’s South Carolina data makes that distinction visible. The difference is 26.8 percentage points—not a measured efficiency gain.
Explore / 1990–2024
Change the year. Compare the shares.
Each bar uses the same 0–100% scale and the published statewide total for that year. These four sources are a subset of the energy mix.
Capacity share · MWGeneration share · MWh
Showing 2024. Nuclear generation share exceeds capacity share by 26.8 percentage points.
Inspect the numbers behind the chart
| Source | Capacity (MW) | Generation (MWh) | Share gap (pp) |
|---|---|---|---|
| Coal | 4,754.0 | 16,841,756 | -2.5 |
| Natural gas | 6,580.6 | 22,808,743 | -3.9 |
| Nuclear | 6,600.3 | 53,770,407 | 26.8 |
| Solar | 1,646.7 | 2,925,656 | -3.8 |
Method / A traceable calculation
Choose the denominator deliberately.
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Extract without double-counting.
Read Tables 4A and 5 from EIA’s workbook. Select the total electric industry section and exclude technology subtotals. Keep the source-cell references for all 455 normalized records.
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Join by year and fuel.
Capacity and generation tables have different row positions. A keyed SQL join aligns them correctly. Missing values stay missing; zero and negative values are preserved.
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Compare like periods.
Divide each fuel’s capacity and generation by the respective statewide total in the same year. Subtract the two shares to obtain a percentage-point gap. The chart uses 140 comparisons.
capacity share = fuel MW / statewide MW × 100
generation share = fuel MWh / statewide MWh × 100
gap (pp) = generation share - capacity shareInterpretation / What this can tell us
The metric changes the conclusion.
A capacity-only view understates nuclear’s contribution to South Carolina’s annual electricity generation in 2024. Before presenting a system’s “mix,” specify whether you mean its capacity or its actual output.
This is descriptive analysis. It does not explain the causes of dispatch differences or rank technologies by cost, reliability, or emissions. The share comparison is not a capacity factor. The EIA tables report small-scale solar separately; that separate series is not added here. Storage may report negative net generation, and published totals can differ from rounded components.
Evidence / Reproduce the result
From workbook to chart.
Source: U.S. Energy Information Administration, South Carolina Electricity Profile 2024, published November 10, 2025. Snapshot retrieved September 21, 2026. The original workbook is unchanged; this page is not a live feed.
Download the files into one folder. With Python 3 and openpyxl 3.1.5 installed, run python3 analyze.py. The script recreates the CSV and JSON, checks published 2024 totals, and verifies the
nuclear shares used above.