Files
mrcharles 0693739d70 ONCOR real-time arbitrage decision tool + economics doc (#826)
oncor-arbitrage.sh: LZ_SOUTH RTM price (pluggable source) -> best-action
verdict (serve load vs export to Base flat 4c vs RTW counterfactual);
JSON out for the KNELPerf batch gate. Verified with override prices.

https://projects.knownelement.com/issues/826#note-5
2026-09-06 14:58:45 -05:00

89 lines
4.1 KiB
Bash
Executable File

#!/usr/bin/env bash
# SITER-Solar / KNELPerf — ONCOR-area real-time solar arbitrage decision.
#
# Question it answers, per interval: with X kW of solar surplus and a menu of
# deferrable loads, is it better to (a) serve your own load, (b) export to
# Base Power at the flat buyback, or (c) hold for later (battery)?
#
# Plan facts (Base Power, verified 2026-09-06):
# import = $0.085/kWh flat (through Oct 2028)
# export = $0.040/kWh flat (Base solar credit — NOT real-time wholesale)
# Therefore: serving your own load ALWAYS beats exporting to Base
# (8.5c avoided > 4c earned) whenever deferrable load exists. The ERCOT
# real-time price (RTM, LZ_SOUTH for Pflugerville/Travis, ONCOR wires)
# matters as a COUNTERFACTUAL: if you switched export to a real-time-
# wholesale plan, when would exporting have beaten self-consumption?
#
# Price sources (first available wins; set via env or /etc/knelerf/ercot.env):
# ERCOT_API_KEY official api.ercot.com public API (developer.ercot.com)
# GRIDSTATUS_API_KEY api.gridstatus.io free tier
# RTM_OVERRIDE manual $/MWh (testing / cache fallback)
# RTM_CACHE_FILE last-known-good price file, refreshed when possible
# Output: JSON verdict on stdout (consumed by the KNELPerf batch gate).
set -euo pipefail
IMPORT_RATE=${IMPORT_RATE:-0.085} # $/kWh, Base Power flat
EXPORT_RATE=${EXPORT_RATE:-0.040} # $/kWh, Base Power flat buyback
SETTLEMENT_POINT=${SETTLEMENT_POINT:-LZ_SOUTH} # Pflugerville/Travis Co.
CACHE=${RTM_CACHE_FILE:-/tmp/knelerf-rtm-cache.json}
now=$(date -u +%Y-%m-%dT%H:%M:%SZ)
rtm=""
fetch_gridstatus() { # needs GRIDSTATUS_API_KEY; returns $/MWh
[ -n "${GRIDSTATUS_API_KEY:-}" ] || return 1
local url="https://api.gridstatus.io/v1/datasets/ercot_spp_real_time_15_min?limit=200"
curl -sf -m 30 -H "x-api-key: $GRIDSTATUS_API_KEY" "$url" \
| jq -r --arg sp "$SETTLEMENT_POINT" \
'[.data[] | select(.settlement_point == $sp)][0].price // empty'
}
fetch_ercot() { # needs ERCOT_API_KEY (official)
[ -n "${ERCOT_API_KEY:-}" ] || return 1
# official public API path; shape verified at registration time
curl -sf -m 30 -H "Authorization: Bearer $ERCOT_API_KEY" -H "Accept: application/json" \
"https://api.ercot.com/api/public-api/np6-905-cd?deliveryDateFrom=$(date +%F)&settlementPoint=$SETTLEMENT_POINT&size=1" \
| jq -r '.data[-1].settlementPointPrice // empty'
}
[ -n "${RTM_OVERRIDE:-}" ] && rtm=$RTM_OVERRIDE
[ -z "$rtm" ] && rtm=$(fetch_gridstatus || true)
[ -z "$rtm" ] && rtm=$(fetch_ercot || true)
src=api
[ -n "${RTM_OVERRIDE:-}" ] && src=override
if [ -z "$rtm" ] && [ -r "$CACHE" ]; then
rtm=$(jq -r '.rtm_per_mwh // empty' "$CACHE"); src=cache
fi
if [ -z "$rtm" ]; then
jq -n --arg now "$now" '{ts:$now, ok:false, error:"no price source available (set ERCOT_API_KEY or GRIDSTATUS_API_KEY; see docs/oncor-realtime-arbitrage.md)"}'
exit 3
fi
rtm_kwh=$(awk -v r="$rtm" 'BEGIN{printf "%.5f", r/1000}')
# Decisions (per kWh of surplus):
# serve_load_value = IMPORT_RATE (avoided purchase)
# export_base = EXPORT_RATE (flat)
# export_rtw_plan = rtm_kwh (counterfactual, real-time plan)
verdict=$(awk -v i="$IMPORT_RATE" -v e="$EXPORT_RATE" -v r="$rtm_kwh" 'BEGIN{
best="serve_load"; v=i;
if (r > v) {best="export_rtw_plan"; v=r}
if (e > v) {best="export_base"; v=e}
print best" "v}')
read -r action value <<< "$verdict"
# Batch-load gate (KNELPerf class-3): start deferrable compute while
# surplus exists AND grid price would not make serving load later cheaper.
jq -n --arg now "$now" --arg sp "$SETTLEMENT_POINT" --arg src "$src" \
--argjson rtm "$rtm" --argjson rtm_kwh "$rtm_kwh" \
--argjson import "$IMPORT_RATE" --argjson export "$EXPORT_RATE" \
--arg action "$action" --argjson value "$value" \
'{ts:$now, ok:true, settlement_point:$sp, source:$src,
rtm_per_mwh:$rtm, rtm_per_kwh:$rtm_kwh,
import_rate: $import, export_rate_base: $export,
best_action: $action, best_value_per_kwh: $value,
serve_load_wins: ($import > $export and $import > $rtm_kwh),
rtw_would_beat_self_consume: ($rtm_kwh > $import),
start_deferrable_load: ($import > $export)}' | tee /tmp/oncor-latest.json
cp /tmp/oncor-latest.json "$CACHE" 2>/dev/null || true