Locational Marginal Price
Definition
A locational marginal price (LMP) is, in EIA's words, 'the price for electricity that reflects the incremental cost to increase electricity generation to satisfy electricity demand at a specific location (node, load zone, reliability region, or hub).' It 'accounts for the dispatched set of generators and the limitations of the transmission system,' and may include components 'for energy, congestion, transmission system losses, and carbon charges.' Organized markets set LMPs in both day-ahead and real-time markets.
Why it matters
A project is paid at its own node, but many contracts and forecasts refer to a hub. The difference, positive or negative, flows to whoever bears it. SB Energy credited part of its 2025 revenue growth to 'generally favorable basis and node pricing in Texas,' which works the other way when node prices fall. Investors should check where a project is paid, where its contracts settle, and who bears the difference.
Common misconceptions
- •A hub price is not the price a project receives.
- •Nodal differences are not random noise; they follow transmission constraints that can persist for years.
- •A project's own LMP can fall as more generation connects nearby.
- •The label is only a starting point. Investor outcomes usually depend on the governing documents, cash-flow priority, valuation policy, disclosure quality, and manager discretion surrounding the term, not just the shorthand definition used in marketing materials.
Technical details
LMP components
Energy: the system-wide marginal cost.
Congestion: positive or negative, depending on constraints.
Losses: electrical losses between points.
Some markets add other components, such as carbon charges.
How investors apply the term
Investors usually apply this term by tying the definition back to the controlling documents and then asking which cash flows, rights, restrictions, or valuation assumptions it changes. A useful review looks at the term alongside fees, leverage, liquidity, reporting frequency, and manager discretion rather than treating it as a standalone concept.
The practical diligence test is simple: identify who benefits if the assumption is wrong, who has control when conditions change, and what evidence the investor receives after closing. Terms that cannot be reconciled to documents, cash movements, and monitoring data should be treated as marketing shorthand until proven otherwise.
Frequently asked questions
- Why do prices differ between nearby grid locations?
- Mainly because of transmission congestion and losses. When lines between two points are full, cheaper power cannot flow to where it is needed, so prices rise on the constrained side and fall on the other. A project behind a congested line can see low or negative prices while a hub nearby trades higher.
- What is a node and what is a hub?
- A node is a specific pricing point, often a project's point of interconnection; a hub is an average of many nodes used for trading and contracts. In SB Energy's Angela financing, the 'Project Node' is the point of interconnection and the 'Project Hub' is CAISO's SP-15 or NP-15 hub.
- How often are LMPs set?
- Day-ahead prices are set for each hour the day before; real-time prices are set in short intervals. Vistra describes ERCOT's real-time market as one where 'electricity and ancillary services awards are determined and priced in five-minute intervals based on the least-cost dispatch respecting transmission constraints.'