# PJM Market Primer: Written for Readers Familiar with China's Power Market

**Working document — v0.1 (July 2026)**
**Positioning:** the mirror of Section 1 of `../markets/china/market_vendor_dd_en.md`
(the China market primer) — it explains PJM for readers who know China's
market, with Chinese concepts as the constant point of comparison. Chinese
version: `market_pjm_zh.md`.

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## 1. Institutional frame: who governs, who plays

PJM Interconnection is the largest US Regional Transmission Organization
(RTO), spanning 13 eastern states plus Washington DC, serving ~65 million
people, with peak load on the order of 150 GW and installed capacity above
180 GW. The frame differs fundamentally from China's "provincial markets +
national push":

- **The regulator is FERC (federal)**, not provinces/states — PJM's market
  rules (tariff/operating agreement) are FERC-approved, and rule changes go
  through a federal legal process (stakeholder proceedings + FERC rulings):
  public, slow, litigable. Contrast: Chinese rules issue as NDRC/NEA and
  provincial documents — fast and flexible.
- **PJM itself is a member-governed nonprofit**: generators, transmission
  owners, retailers, state consumer advocates — and, crucially, **financial
  institutions are a formal market-participant category**. That single fact
  is the key to most PJM–China differences.
- **One market, one rulebook**: 13 states share the same clearing engine and
  price system. There is no "one province, one policy." Inter-RTO trade
  (PJM–MISO, PJM–NYISO) resembles China's inter-provincial layer, but with
  greater volume and mechanism maturity.

## 2. Market architecture: spot-native

China is "MLT as ballast, spot as corrector"; PJM is the inverse — **the
spot market IS the market**, and all forward arrangements are off-exchange
financial contracts settling against it.

- **Day-ahead (DA)**: closes 10:30 AM ET daily, clears all 24 hours of
  tomorrow via SCUC + economic dispatch, hourly prices. Analog: the DA
  declaration/clearing in Chinese spot provinces — but with no "physical"
  MLT volume occupying space; the DA market reprices everything.
- **Real-time (RT)**: 5-minute dispatch and settlement. DA + RT form the
  **two-settlement system**: DA positions settle at DA prices; deviations of
  actuals from DA settle at RT — the same logic as Chinese spot provinces'
  DA settlement + RT deviation settlement.
- **Nodal prices (LMP)**: ~13,000 pricing nodes, each decomposed into
  energy + congestion + loss. Contrast: most Chinese provinces clear at a
  unified provincial price or coarse zones (generation-side nodal in
  Guangdong/Shanxi excepted) — PJM's spatial granularity is two orders of
  magnitude finer, which is why "congestion" is a standalone business (see
  FTR).
- **Caps and scarcity pricing**: offer cap $1,000/MWh (to $2,000 with cost
  justification), plus the Operating Reserve Demand Curve (ORDC) — an
  administrative adder that drives RT prices up when reserves run short.
  Negative prices are fully legal and common. Contrast: China's declaration
  caps anchor to industrial peak retail rates (~¥1–1.5/kWh) with
  administratively compressed tails; PJM scarcity spikes reach an order of
  magnitude higher — which is precisely why US volatility can fund
  optimization fees.

## 3. The financial layer: species absent from China

PJM's DA market is open to **purely financial participation** — the deepest
structural difference from China:

- **Virtual transactions (INC/DEC/UTC)**: entities with no physical assets
  submit virtual supply (INCs) or virtual demand (DECs) into DA, clearing DA
  and mandatorily unwinding at RT — speculation/arbitrage on the DA–RT
  spread, at meaningful volume shares. Effect: any persistent, predictable
  DA–RT gap gets arbitraged away; the spread's mean is pinned near zero.
  Contrast: China has no such mechanism — the core reason the MLT–spot basis
  can persistently diverge (see China report §1.5).
- **FTRs (Financial Transmission Rights)**: financial rights on DA
  congestion differences between two nodes, auctioned by PJM — the hedging
  and speculation instrument for congestion risk. Contrast: China's
  unified provincial pricing makes the instrument largely unnecessary;
  inter-provincial congestion rents flow to grid/government mechanisms.
- **OTC forwards/futures**: Nodal Exchange and ICE list PJM hub power
  futures (peak/off-peak, monthly, years out), liquidity concentrated at
  Western Hub; plus bilateral PPAs/virtual PPAs (CfDs against hub or node
  prices) and bank hedge structures (proxy revenue swaps, etc.). Contrast:
  functionally equivalent to China's MLT contracts, but (a) fully voluntary,
  no coverage-ratio mandates; (b) priced by financial traders with
  arbitraged basis convergence; (c) settled **outside** the market
  operator — PJM doesn't know your hedge exists. China's MLT lives *inside*
  the exchange: quasi-mandatory, priced by physical counterparties,
  settlement-integrated, and — a silver lining — visible in disclosure data.

## 4. Capacity market and ancillary services

- **RPM capacity market**: rolling three-year-forward auctions procure
  capacity obligations; cleared resources carry a **must-offer obligation**
  (must bid into DA) and performance assessment in scarcity hours (Capacity
  Performance — underperformance penalties are substantial). Contrast:
  China's coal capacity payment (容量电价, from 2024) is administratively
  priced availability compensation — no auction, no symmetric performance
  penalty; similar function (a revenue pillar outside the energy market),
  very different mechanism.
- **Ancillary services**: regulation and synchronized/primary reserves
  **co-optimized** with energy in DA/RT with endogenous prices. Contrast:
  Document 394 pushes China the same direction, but product scope and
  co-clearing depth are still evolving.

## 5. Settlement and deviations: BORD vs. the Two Detailed Rules

PJM disciplines deviations through **Balancing Operating Reserve Deviation
(BORD) charges**: real-time balancing uplift is allocated by cost causation
to parties who deviated from DA positions (generation deviations, load
deviations, virtuals), at a daily rate scaled to actual costs incurred.
China disciplines forecast accuracy and schedule compliance through the
administrative 两个细则 assessments, decoupled from actual daily system
cost. One-line contrast: **PJM prices the externality; China grades the
homework.** Product implication: in PJM, deviations are optimized against a
forecastable stochastic *price*; in China, forecasts are engineered against
a fixed *rulebook* — which is why China developed a compliance-procurement
forecasting market and the US never did. (Details: `../markets/us/pjm/design_models_en.md`
§4.1.)

## 6. Renewables: tax credits, not mechanism prices

The US never had "guaranteed volume, guaranteed price": renewables were
always market-absorbed (PPAs are voluntary commercial contracts, not policy
procurement). Policy support flows through **tax credits**:

- **PTC**: ~$27.5–30/MWh of generation for 10 years ⇒ a rational *negative*
  offer floor (≈ −$25 to −$35/MWh) — the plant pays to generate because the
  credit outweighs the negative price.
- **ITC**: a one-time 30%+ credit on capex ⇒ no effect on marginal cost;
  offer floor ≈ $0.
- Contrast with China's **mechanism price**: both are revenue stabilizers,
  but the mechanism price is a *price-type* instrument (a CfD stabilizing
  the realized price) while tax credits are *tax-type* (leaving price
  formation untouched but distorting offer floors). A neat mirror: China's
  mechanism auctions (lowest bids win) and America's PTC-shaped negative
  floors each create a distinctive supply-curve signature at the low end of
  their respective markets.
- Curtailment in PJM is **economic** (you're dispatched down when price
  falls below your offer floor — a market-clearing outcome), not an
  administrative quota; "curtailment rate" statistics are therefore not
  directly comparable across the two systems.

## 7. Data and access: the transparency gap

- **Data Miner 2**: PJM's public data platform — full nodal DA/RT LMPs with
  component decomposition, load and forecasts, fleet wind/solar forecasts
  and actuals, outages, binding constraints — web access without login, API
  with free registration. Contrast: China has no equivalent; provincial
  disclosures vary and sit behind member portals. In China, *data
  acquisition* is a moat; in PJM data is free and **insight** is the moat.
- Bid submission uses the separately authenticated **Markets Gateway**;
  participant status involves registration and credit/collateral (logic
  parallel to Chinese exchange membership + performance bonds).
- Note the asymmetry, though: PJM unit offers publish only at a 4-month lag,
  masked, and the network model is CEII-restricted — "transparent" is not
  "fully transparent."

## 8. Quick-reference comparison table

| Dimension | PJM | China (spot provinces) |
|---|---|---|
| Regulator | FERC (federal); procedural, slow rule change | NDRC/NEA + provincial; document-driven, fast |
| Market scope | One market, one rulebook across 13 states | One province one policy; 31 provincial markets |
| Dominant settlement layer | Spot (DA+RT two-settlement) | MLT majority; spot settles deviations |
| Forwards/MLT | Voluntary OTC financial contracts (PPA/futures), outside the operator | Quasi-mandatory exchange contracts, curved, settlement-integrated |
| Forward price formation | Financial traders, arbitraged convergence | Physical counterparties inside coal-benchmark ±20%; persistent basis |
| Financial participants | Formal category (virtuals, FTR, futures) | Essentially absent |
| Spatial pricing | ~13,000 nodal LMPs | Unified provincial / zonal mostly |
| Price tails | $1,000–2,000/MWh caps + ORDC adders; negative common | ~¥1–1.5/kWh caps; floors at 0 or slightly negative |
| Capacity compensation | RPM auctions + must-offer + performance penalties | Capacity payment (administered, coal-centric) |
| Deviation discipline | BORD cost-causation allocation (priced) | Two Detailed Rules administrative assessment (ruled) |
| Renewable support | PTC/ITC tax credits (shaping negative floors) | Mechanism-price CfD (auction-set) |
| Public data | Data Miner, free and comprehensive | Provincial, member-gated, inconsistent |
| Service-provider moat | Nodal congestion insight + point-in-time archive | Provincial rules library + data acquisition + relationships |

## 9. Three counter-intuitive notes for readers coming from China

1. **"No MLT market" does not mean "no hedging"** — hedging is everywhere,
   just grown outside the market operator and carried by the financial
   system. Analyzing a PJM plant's revenue requires asking about its
   PPA/hedge structure, which public data won't show (contrast China: the
   contracts live inside the exchange, so aggregate data is visible).
2. **Price volatility is a feature, not a bug** — ORDC scarcity adders are
   deliberate design, paying for reliability through a few extreme hours.
   The Chinese instinct of "caps for stability" misreads where the
   commercial opportunity comes from in PJM: optimization fees are
   ultimately funded by volatility.
3. **Slow rules reshape the moat** — PJM rules evolve on a multi-year cycle
   with precedent to consult, so model risk is dominated by *market* risk;
   Chinese rules evolve quarterly, making *rule* risk itself a modeling
   object. The same company needs different organizational muscles in the
   two markets.

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*Glossary: appendix of `../markets/us/pjm/design_models_en.md`; China-side concepts: appendix
of `../markets/china/market_vendor_dd_en.md`.*