Marginal abatement cost curve

Abatement, in the order it is worth buying

Two tables in: what the site emits, and what each measure claims to save. A curve, a merit order and a target cost out. Nothing is abated twice, and nothing abates carbon that was never emitted.

Prepared today Basis annual, current prices Units tCO2e and EUR Source your own figures
1

Emission streams

What the site emits now, broken into streams that measures can be tied to. A stream is whatever a measure can plausibly act on: a fuel, a load, a fleet. Two columns, a header row, comma or tab.

Streams
Streams read0rows accepted
Total baseline0tCO2e per year
Unreadable0rows skipped
Columns Name, then annual tCO2e. Anything after the second column is ignored, so you can paste a wider export without editing it.
Numbers 1.234,56 and 1,234.56 both read correctly. Currency symbols, spaces and brackets for negatives are all handled.
2

Abatement measures

Four columns: the measure, the stream it acts on, the tonnes it claims, and what it costs per year. Costs must already be annualised. Turning capital into an annual figure is a finance decision and it stays yours.

Measures
Measures read0rows accepted
Claimed0tCO2e per year
Unreadable0rows skipped
A negative cost means the measure pays for itself. Type it as -14000 or (14000). It will sort to the left end of the curve, below the axis.
A blank stream is allowed. The measure is costed and ordered, but nothing caps it, because there is no baseline to cap it against.
3

The curve

Sorted by delivered cost per tonne. Each bar is as wide as the abatement it delivers and as tall as what that costs, so the area of a bar is money and the total area is the annual cost of the programme.

Figure 1. Marginal abatement cost curve.
Pays for itself Costs money Cut back by a stream baseline
Delivered0tCO2e per year
Annual cost0EUR, area under the curve
Average0EUR per tCO2e
Area is money Width in tonnes times height in EUR per tonne is EUR. If the areas do not add up to the cost, the drawing is decoration.
4

Merit order

The order the measures are worth buying in, on the price they actually deliver at. A measure that gets cut back keeps its full cost, so its price per tonne rises and it can move a long way down this list.

MeasureStream ClaimedDelivered Annual costEUR/t quotedEUR/t delivered
Table 1. Merit order on delivered cost.
Quoted against delivered Where these two differ, something in front of the measure took the load it was counting on. The difference is the whole point of the table.
5

Reaching a target

How far down the order you have to go, and what the last measure in costs. Whole measures only: you cannot buy three fifths of a heat recovery system, so a target is met by overshooting it.

Enter a target above.
The marginal price is what the last measure in costs per tonne. It is the number to quote when someone asks what the next tonne costs.
6

Exceptions

Everything the arithmetic refused, and why. These are not warnings to dismiss. Each one is abatement somebody has already counted and is not going to get.

Not caught here Two measures that interact for a reason other than a shared stream. A control change that alters the load a motor upgrade sees is invisible to this and to every other curve.