Methodology & Limitations

1. Overview

321ZERO calculates greenhouse gas (GHG) emissions using the GHG Protocol Corporate Standard scope framework. Users enter activity data (e.g. kWh of electricity, litres of fuel, tonnes of waste) and the platform multiplies each figure by a published emission factor to produce a CO₂e value.

Every emission factor in the platform carries a visible source, publisher, version and reference URL. You can see the provenance of each calculation in the platform — no black boxes.

2. Scope framework

Emissions are categorised into three scopes per the GHG Protocol:

• Scope 1 — Direct emissions: Fuel burned on-site or in company-owned vehicles (heating oil, gas oil, LPG, petrol, diesel).
• Scope 2 — Purchased electricity: Electricity bought from the grid. In Jersey this uses the island-specific grid factor (0.0441 kgCO₂e/kWh for 2026), not the UK DEFRA grid factor (0.250+ kgCO₂e/kWh). Using a UK factor would overstate Jersey electricity emissions by 5–10×.
• Scope 3 — Value chain emissions: Waste, water, business travel, employee commuting and purchased goods/services. These are calculated using UK DEFRA factors where no Jersey-specific equivalent exists.

3. Jersey-specific emission factors

The platform uses locally sourced factors for activities where Jersey differs materially from UK averages:

Jersey’s electricity is imported from France via undersea cable, predominantly from nuclear and hydro sources. This is why the grid factor is far lower than the UK average. The factor may change year to year as supply mix shifts — always confirm the reporting-year value against the current Government of Jersey or supplier publication before assured reporting.

4. UK DEFRA conversion factors

For activities without a Jersey-specific factor, the platform uses the UK Government GHG Conversion Factors for Company Reporting (2026), published by the UK Department for Energy Security and Net Zero. These cover:

• Stationary combustion: gas oil, LPG, kerosene, natural gas, coal, wood pellets
• Mobile combustion: petrol, diesel, biodiesel, hybrids
• Business travel: ferry, flights (domestic/short-haul/long-haul), car, taxi, EV
• Employee commuting: car, bus, motorcycle, walking/cycling, EV
• Waste: mixed recycling, glass recycling, food/garden composting
• Purchased goods (spend-based): office supplies, IT, professional services, construction materials, food & catering, cleaning

Source: gov.uk/government/collections/government-conversion-factors-for-company-reporting

5. How calculations work

The calculation is a simple multiplication:

For example:

• 18,000 kWh × 0.0441 kgCO₂e/kWh = 793.8 kgCO₂e (Jersey electricity)
• 2,500 litres × 2.6736 kgCO₂e/litre = 6,684 kgCO₂e (gas oil)
• 1.5 tonnes × 485 kgCO₂e/tonne = 727.5 kgCO₂e (La Collette waste)

The platform organises each result by scope and by reporting period (month, quarter, year). Results are summed across activities to give a total footprint for the chosen period.

6. Spend-based Scope 3 estimates

For purchased goods and services, the platform uses a spend-based method: the user enters a monetary value (in GBP) and the platform applies an industry-average emission factor per pound spent. This is an estimation technique, not a primary-data calculation. It is useful for identifying hotspots but should be refined with supplier-specific data when available for formal reporting.

Available spend-based categories include office supplies, IT services, professional services, construction materials, food & catering, and cleaning services.

7. Eco-Active annual return alignment

The platform’s data categories align with the Government of Jersey’s Eco-Active annual return, which is due by 31 March each year. The export feature compiles your entries into a reviewable summary covering:

• Electricity consumption (kWh) and resulting Scope 2 emissions
• Stationary and mobile fuel consumption (Scope 1)
• Waste, water, travel and commuting (Scope 3)
• Total emissions by scope for the reporting year

The platform produces the data for your return — it does not submit the return on your behalf. You review the export and submit it to ecoactive@gov.je yourself. This keeps you in control of what is reported to government.

8. Limitations

We are transparent about what this platform does and does not do:

• Not an audit or verification service: 321ZERO is a calculation and reporting tool. It does not verify your data, provide assurance, or certify your footprint. Engage a qualified environmental professional when independent assurance is required.
• Not ISO 14064 certified: The platform is not itself certified to ISO 14064 or any other verification standard. The calculation methodology follows the GHG Protocol, but the platform has not undergone formal third-party methodology assurance.
• Factors may change: Emission factors are updated periodically by their publishers. The platform stores the factor version used for each calculation so you can trace which version was applied. Always confirm the current factor before formal submission.
• Scope 3 is estimative: Spend-based factors are industry averages. They provide a useful picture but are less precise than supplier-specific or activity-specific data.
• User responsibility: The accuracy of results depends on the accuracy of the activity data you enter. The platform does not validate that your figures are correct — it calculates from what you provide.
• Eco-Active Leader: Achieving Eco-Active Leader status requires your own certification from an approved body (ISO 14001, B-Corp, 5* environmental audit or equivalent). The platform does not issue this accreditation.

9. Factor versioning & audit trail

Every calculation in the platform records:

• The emission factor applied and its source publication
• The factor version and year
• The publisher and reference URL
• The date the factor was last accessed
• Whether the factor is Jersey-specific or UK-sourced

This creates an audit trail you can present to stakeholders, regulators or auditors to show exactly how each number was derived.

10. Questions

If you have questions about the methodology, emission factors, or how a specific calculation works, email hello@321zero.je.