Outputs

Each output is defined here once; the methodology explains how it is made, and valuation/2 gives its exact form.

A valuation's slots

Output	Definition
marginal_cost	what one more kWh used in the slot costs the site, averaged over the PV scenarios
marginal_cost_p10	the same, priced on one PV day: the forecast's 0.1 quantile in every slot
regime	what one more kWh displaces, in the median PV case
surplus_kw, surplus_kw_p10	surplus, in the median and the p10 PV case
certainty_spill, certainty_covered	the certainties
pv_value, battery_value	the value of a kWh by source, and what set it (values by source)
supply	the supply stack: how much power each price holds for
unserved	unserved load
p_import, p_export	the input prices for the slot

A valuation also has its kind, its causes (degraded), each input's state (inputs) and horizon_cut (Causes and kinds). A battery valuation without the battery's lots names battery_lots and keeps its values: all the battery holds is priced as bought, at the import.

The median PV case

The forecast's 0.5 quantile in every slot, projected once on its own. It is not one of the ten scenarios, which run from the 5th to the 95th percentile. The regime, surplus_kw and the supply stack come from it; marginal_cost and the certainties come from the scenarios.

A live value

A live value is for the slot from now. It has marginal_cost, regime, surplus_kw, certainty_spill, certainty_covered, pv_value, battery_value, p_import and p_export as above (the prices null when it is unpriced), plus its time at, its kind, the engine's causes (degraded) and the client's own (external). It has no p10 values, no supply stack and no unserved.

Regime

What one more kWh in the slot would displace:

Regime	One more kWh would be	So it costs about
export	PV that would have been exported	the export price
curtail	PV that would have been curtailed (more curtailed than exported)	nothing
battery	energy the battery would otherwise hold or deliver	what the energy in the battery cost, through its losses and wear; no more than the sun that will refill it
import	an import	the import price

The regime says where the kWh comes from; marginal_cost says what that costs. A battery slot can cost about the export price (the battery holds solar, or the sun will refill it) or more than the import price now (it holds grid energy bought dearer).

Surplus

PV the plant would export or curtail, in the projection: more than the house takes and the battery can store. While the battery is still charging and nothing is exported there is none, however strong the sun. Battery export is never surplus. Every load that is running is in the load forecast, so the surplus is net of its draw. Summed over a day, it is the PV energy there is to share.

Certainties

Each is a share of the scenario weight, 0 to 1.

• certainty_spill: in what share of the scenarios the kWh is paid for only with PV that would have been exported or curtailed, now or when the battery fills.
• certainty_covered: in what share of the scenarios the battery covers the expensive hours ahead without an import. A slot is expensive when the battery or the grid serves the house in it (PV does not cover it) and its import price is above the cheapest import in the 24 hours from this slot. The expensive hours ahead are the first unbroken run of expensive slots at or after this one. Covered means the house does not import from this slot (or the run's start, if later) to the run's end. The run is read from the price curve, whatever its shape.

Unserved

The share of the scenario weight in which the slot has load a stored kWh would serve, but cannot: at the grid's import limit, or a DC-bus load beyond the hybrid's rating with the battery on its bus at its reserve or limit. In those scenarios the kWh is priced at the import price, as a floor. Load beyond any stored kWh's reach is not counted.