Do I have to report well-to-tank emissions?

Not for SECR or a PPN 006 Carbon Reduction Plan, which don't include category 3 in their minimum. They are part of a complete Scope 3 inventory under the GHG Protocol, and many firms include them because the data is the same fuel and energy figures they already have.

How do I calculate them?

Multiply the same quantity you used for Scope 1 or 2 by the well-to-tank factor from the government set. In 2026, each kWh of gas adds 0.03021 kg CO2e and each litre of diesel 0.61101 kg CO2e.

Is well-to-tank the same as well-to-wheel?

No. Well-to-tank stops when the fuel reaches your tank. Well-to-wheel adds the emissions from burning it, so well-to-wheel is your Scope 1 figure plus the well-to-tank figure.

Why haven't the well-to-tank factors changed?

DESNZ updates them less often than the main factors. The 2026 methodology paper says the well-to-tank factors for fuels have been held constant since the 2023 release, so the gas and diesel figures are the same as in 2023.

Well-to-tank emissions explained

Well-to-tank emissions are the carbon released producing and delivering your fuel before you burn it, and they go in Scope 3 category 3. With the 2026 government factors they add about 17% on top of your gas emissions, 24% on top of diesel and 31% on top of grid electricity. They are optional for SECR and PPN 006 but easy to include.

Updated 19 October 2026 by the Carbon Recycling team. Figures use the official UK government conversion factors and are checked against the current gov.uk guidance.

What "well-to-tank" covers

The gas in your boiler and the diesel in your vans had a carbon cost before they reached you. Oil and gas were extracted, processed or refined, and transported to you. The government's methodology paper calls these the emissions "upstream from the point of use of the fuel": extraction, transport, refining, purification or conversion, and distribution. The name comes from transport: from the oil well to the fuel tank.

Tudi električna energija ima emisije well-to-tank. Plin in druga goriva, ki se kurijo v elektrarnah, je bilo treba proizvesti in dostaviti, zato vsaka kWh, ki jo porabite, nosi del te dobavne verige.

Which scope?

Izgorevanje goriva je obseg 1 (ali obseg 2 pri električni energiji). Njegova proizvodnja so neposredne emisije nekoga drugega, zato je za vas to obseg 3. GHG Protocol jo uvršča v kategorijo 3, dejavnosti, povezane z gorivi in energijo, ki zajema emisije navzgor v verigi vrednosti za goriva, ki jih kupujete, emisije navzgor za goriva, iz katerih je proizvedena vaša električna energija, in električno energijo, izgubljeno v omrežju. Ta zadnji del pojasnjuje naš prispevek o izgubah pri prenosu in distribuciji.

Najmanjši seznam obsega 3 po PPN 006 zajema kategorije 4, 5, 6, 7 in 9, SECR pa temelji na obsegu 1 in 2, zato nobeden ne zahteva emisij well-to-tank. Celovita evidenca obsega 3 po GHG Protocol jih vključuje.

The 2026 factors

Fuel	Izgorevanje (obseg 1 ali 2), kg CO2e	Well-to-tank (Scope 3), kg CO2e	Uplift
Zemeljski plin, na kWh	0.18231	0.03021	17%
Električna energija iz omrežja, na kWh	0.13096	0.04041	31%
Dizel (bencinski servis), na liter	2.58354	0.61101	24%
Bencin (bencinski servis), na liter	2.075	0.58094	28%
Kurilno olje (kerozin), na liter	2.54016	0.53078	21%

The electricity row includes the well-to-tank share of grid losses as well as of generation. Its uplift looks large because the grid factor itself is now low; see why the UK grid gets cleaner every year.

Praktični primer

Malo podjetje v letu 2026 porabi 40.000 kWh plina, 30.000 kWh električne energije in 6000 litrov dizla v kombijih:

Activity	Obseg 1 ali 2, tCO2e	Well-to-tank, tCO2e
40.000 kWh plina	7.29	1.21
30.000 kWh električne energije	3.93	1.21
6000 litrov dizla	15.50	3.67
Total	26.72	6.09

Well-to-tank adds 6.09 tonnes, about 23% on top of the Scope 1 and 2 total. No new data was needed: it is the same kWh and litres multiplied by a second factor.

Things that trip people up

Prištevanje k obsegu 1. Ohranite ga v obsegu 3. Če ga primešate, je vaš obseg 1 videti večji kot pri drugih podjetjih in primerjave niso več mogoče.
Vključitev v enem letu, v naslednjem pa ne. Odločite se enkrat, to navedite v opisu metode in ohranite enako, sicer bo vaš skupni seštevek skakal brez pravega razloga.
Pozabljanje potovanj in tovornega prevoza. Tudi službena potovanja, prihod na delo in tovorni prevoz imajo faktorje well-to-tank. Gorivo kupi nekdo drug, zato so emisije v vsakem primeru v obsegu 3.
Domneva, da biogoriva nimajo emisij. Biogoriva imajo nizke neposredne faktorje, a dejanske emisije v dobavni verigi. Naš prispevek o HVO pokaže, kako velike so lahko.

The real-world point

Well-to-tank is a reminder that every litre or kWh you save cuts emissions twice: once where it is burned and again in the supply chain behind it. In the example above, each litre of diesel saved avoids 3.19455 kg CO2e in total, not just the 2.58354 kg in Scope 1.

How Carbon Recycling helps

Well-to-tank is a single setting in Carbon Recycling. Switch it on and every gas, fuel, electricity, travel and freight entry gets its matching well-to-tank line from the same year's government set, filed in Scope 3, with category 3 for the fuel and energy you buy and travel and freight lines kept in their own categories. Changing the setting recalculates every existing entry, so all your years stay on the same basis. To see the uplift for your own bills first, tick the Scope 3 box in the free kWh to CO2e calculator, and see the guide to the 15 Scope 3 categories for where category 3 sits.

Frequently asked questions

Kaj so emisije well-to-tank?

The emissions from producing fuel before you use it: extracting it, refining or processing it, and transporting it to you. For electricity, it is the same for the fuels burned in power stations. They are Scope 3, category 3.

Ali moram poročati o emisijah well-to-tank (od vira do rezervoarja)?

Ne za SECR ali Carbon Reduction Plan po PPN 006, ki kategorije 3 ne vključujeta v svoj minimum. So del popolne evidence obsega 3 po GHG Protocol in številna podjetja jih vključijo, ker so podatki isti podatki o gorivu in energiji, ki jih že imajo.

Kako jih izračunam?

Isto količino, ki ste jo uporabili za obseg 1 ali 2, pomnožite s faktorjem »well-to-tank« iz vladnega nabora. Leta 2026 vsaka kWh plina doda 0,03021 kg CO2e, vsak liter dizla pa 0,61101 kg CO2e.

Ali je well-to-tank enako kot well-to-wheel?

Ne. »Well-to-tank« se konča, ko gorivo pride v vaš rezervoar. »Well-to-wheel« doda emisije njegovega izgorevanja, zato je »well-to-wheel« vaš podatek za obseg 1 plus podatek »well-to-tank«.

Zakaj se faktorji well-to-tank niso spremenili?

DESNZ jih posodablja redkeje kot glavne faktorje. Metodološki dokument za leto 2026 navaja, da so faktorji well-to-tank za goriva od izdaje 2023 nespremenjeni, zato so podatki za plin in dizel enaki kot v letu 2023.

Ali lahko v svoji programski opremi uporabljate pretvorbene faktorje britanske vlade? Pojasnilo licence
What the Open Government Licence v3.0 allows for the DESNZ factors, the attribution statement to use, no endorsement and no warranty.
Podatki CBAM in vaš obseg 3: en podatek, dve uporabi
Kako preverjene emisije dobavitelja na tono določijo vašo dajatev CBAM in nadomestijo oceno obsega 3 na podlagi stroškov, s primerom izračuna za jeklo.
Kako od dobavitelja iz tujine zahtevati podatke o emisijah za CBAM, s predlogo e-poštnega sporočila
What a UK importer needs from each producer to use actual data on a CBAM return, and an email you can copy and send.

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