The kWh, tariff and carbon saving figures grant funders want

Grant funders typically want six figures: your annual electricity and gas use in kWh, your current tariffs, your current emissions in kg or tonnes of CO2e, your projected emissions after the project, the annual saving in kWh, pounds and CO2e, and how you calculated it. The carbon savings calculation itself is simple. Multiply the kWh you will save by the UK government conversion factor for that fuel, then divide by 1,000 for tonnes. The work is in getting honest kWh figures and showing your assumptions.

Below, we go through where each number comes from, then walk through a full example.

Which figures do grant funders ask for?

Nottingham City Council’s Bulwell Business Decarbonisation Grant lists them clearly in its applicant guidance, and its list is typical of what council schemes want:

What they ask for	What it means
Annual gas and electricity consumption in kWh	12 months of usage from your bills
Current energy tariffs	Your unit rate (pence per kWh) and standing charge (pence per day) for each fuel
Estimated current carbon emissions	Your baseline: kWh multiplied by conversion factors
Estimated emissions after the project	Your new kWh multiplied by the same factors
Estimated annual carbon savings	The difference between the two
How the savings were calculated	Your assumptions and method, in plain words

Other funders use different wording, but almost all are asking for some version of this table.

Where to find each figure on your bills

Annual kWh. Your bills show consumption in kWh for each billing period. Add up 12 months, or ask your supplier for an annual consumption statement. Gas bills convert your meter reading (in cubic metres or cubic feet) to kWh using a calorific value. That conversion is already done for you.

Tariffs. Look for the unit rate in pence per kWh and the standing charge in pence per day. If you are on a fixed contract, note the end date. If you are out of contract on deemed rates, say so, because your costs will probably fall when you switch, regardless of the project.

Meter details. Some applications ask for your electricity MPAN or gas MPRN. Both are on your bill.

If you do not have bills because energy is included in your rent, ask your landlord for your unit’s meter readings or a floor area share of the building’s use.

Worked example: a small bakery

A bakery with a shop front and production area wants to apply for a grant towards LED lighting and an air source heat pump to replace its gas boiler. Its ovens are electric. The boiler provides space heating and hot water, so the gas is a Scope 1 emission and the electricity is Scope 2.

Assumptions (illustrative; use your own bills and installer figures):

• Electricity: 24,000 kWh a year at a unit rate of 27p per kWh
• Gas: 30,000 kWh a year at a unit rate of 6.5p per kWh
• Conversion factors from the 2026 UK government set, approximately 0.131 kg CO2e per kWh for grid electricity and 0.182 kg CO2e per kWh for natural gas (gross CV)

Step 1: the baseline

Fuel	kWh	Factor	Emissions	Cost
Electricity	24,000	0.131	3,144 kg	£6,480
Gas	30,000	0.182	5,460 kg	£1,950
Total			8,604 kg (8.6 tCO2e)	£8,430

Step 2: the LED saving

The bakery’s lighting is estimated at around 30% of electricity use, or 7,200 kWh. Replacing fluorescent tubes with LEDs of similar light output cuts lighting energy by about 55%, based on the supplier’s wattage comparison.

• kWh saved: 7,200 x 0.55 = 3,960 kWh
• Carbon saved: 3,960 x 0.131 = 519 kg CO2e a year
• Cost saved: 3,960 x £0.27 = £1,069 a year

Step 3: the heat pump saving

The old boiler is about 85% efficient, so 30,000 kWh of gas delivers around 25,500 kWh of useful heat. The installer quotes a seasonal coefficient of performance (SCOP) of 3.0, meaning each kWh of electricity delivers about 3 kWh of heat.

• New electricity for heating: 25,500 / 3.0 = 8,500 kWh
• Gas emissions removed: 5,460 kg
• New electricity emissions: 8,500 x 0.131 = 1,114 kg
• Net carbon saved: 5,460 minus 1,114 = 4,346 kg CO2e a year
• Cost effect: £1,950 of gas removed, £2,295 of extra electricity added, so about £345 a year more on unit costs, partly offset if the gas supply and its standing charge are removed

Step 4: the result

	Before	After
Electricity	24,000 kWh	28,540 kWh
Gas	30,000 kWh	0 kWh
Emissions	8.6 tCO2e	3.7 tCO2e
Annual saving		4.9 tCO2e (about 56%)

That is a strong carbon case. It is honest about the heat pump’s effect on running costs, and the LED saving more than covers it.

How to explain your calculation method

Funders want enough detail to follow your working, not a technical report. Something like this works:

Baseline emissions are calculated from 12 months of supplier bills (October 2025 to September 2026) using the UK Government GHG Conversion Factors for Company Reporting 2026: 0.131 kg CO2e per kWh for electricity and 0.182 kg CO2e per kWh for natural gas. LED savings use the supplier’s wattage comparison and our measured lighting hours. Heat pump figures assume 85% existing boiler efficiency and the installer’s quoted SCOP of 3.0. Cost savings use our current unit rates and exclude standing charges.

Attach supplier quotes and specifications where they support your assumptions.

Common mistakes in carbon savings calculations

• Mixing kg and tonnes. Conversion factors are in kg per kWh. Divide by 1,000 for tonnes, and label every number.
• Including standing charges in savings. They do not fall when you use less, unless you remove a supply entirely.
• Forgetting the new electricity. Heat pumps and EV chargers add electricity use. Subtract those emissions from the gas or fuel saved.
• Using lifetime figures as annual ones. If you quote a 10-year saving, say so. Note that future savings from electricity projects will shrink as the grid gets cleaner.
• Optimistic percentages. Claiming 80% savings without evidence invites doubt. Quote the source.
• Comparing across factor years. If your baseline uses 2025 factors and your projection uses 2026 ones, part of the “saving” is just the factor change. Use the same factor set for both.

Getting the baseline section done

The baseline is the part most applicants find slowest. ESG Now calculates it for you: enter your electricity and gas use, plus any vehicles, travel, waste and water, and the report gives your emissions by source using UK government conversion factors, with each line shown as activity multiplied by factor. It is the same kWh to tCO2e logic as above, done consistently, and labelled measured or estimated. Read more about the DEFRA conversion factors it uses.

Most small businesses finish in under 30 minutes. Your first report is free. Start your report, then use our guide to showing a carbon baseline for a decarbonisation grant to present it. The grant applications hub has everything else.