Data Provenance
Power Signals is a primary-source data provider. We collect, parse, and serve data directly from official sources — no third-party aggregators in the chain.
Sources
| Dataset | Source | Update Frequency |
|---|
| Grid System State | Eskom Data Portal | Hourly |
| Grid Stress Index | Computed from Grid System State | Hourly |
Timezone Handling
All timestamps in API responses are in UTC.
The original source data from Eskom uses South African Standard Time (SAST, UTC+2). We convert all timestamps to UTC during ingestion to provide a consistent, unambiguous time reference.
{
"meta": {
"timezone": "UTC"
},
"data": [
{
"ts": "2026-01-01T00:00:00Z"
}
]
}
If you need SAST timestamps for display, add 2 hours to any UTC timestamp in the response.
Data Pipeline
Source (Eskom)
→ Collection (seconds after publication)
→ Parsing & Validation
→ UTC Conversion
→ Storage
→ API Response
Derived Data
Some fields are computed from raw data rather than sourced directly:
| Field | Derivation |
|---|
renewable_share_pct | (total_re_mw / total_generation_mw) × 100 |
net_import_mw | imports_mw - exports_mw |
forecast_error_mw | residual_demand_mw - residual_forecast_mw |
ocgt_ramp_mw | Hour-over-hour change in OCGT output |
| Grid Stress Index | Multi-factor composite from system state signals |
meta.derived field in responses indicates whether data includes derived calculations:
{
"meta": {
"derived": true,
"derivation_method": "aggregation_from_1h"
}
}
Daily Aggregation
When using interval=1d, daily values are aggregated from hourly data:
- MW columns — averaged over the day
- Renewable share —
sum(total_re) / sum(total_generation) × 100
- OCGT ramp —
max (up) and min (down) of hourly ramps
- Day boundary — UTC midnight to midnight
Data Completeness
We monitor all upstream feeds continuously. If data is missing or delayed:
- The API returns an empty
data array for the affected period
- The
meta object may include a data_delay flag
- Historical backfills are applied automatically when delayed data arrives
