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NABO Fuel and CO₂ Estimating Tool

The idea is that you can quickly understand the costs and carbon footprint of the boating life. The model can be set for a range of lifestyles, and then edited if you so wish to suit your usage and fuel use. Press the recalculate button and the tools will display an annual summary of the cost and carbon dioxide emissions. It may also suggest some changes. You can experiment by changing your consumption pattern or fuel selection to see what happens. The tool has preset figures for costs based on common knowledge. If you know better, please tell us. This is an estimating tool, it is not a predictor of the present or future. Data is saved on your device and not ours.

Select Preset

Liveaboard heavy use Leisure light use Share boat Leisure summer use Day boat Leisure all year Liveaboard minimum use Liveaboard towpath mooring Liveaboard marina mooring All zeros

Boat & Use

Date (dd-mm-yyyy):
Boat Name:
Summer Days: Days on board with no heating.
Winter Days: Days on board with heating.
Navigation Days: Days cruising.
Cruising Hours per Navigation Day: Hours cruising per day.
Engine Days (stationary, heat/charge): Days running engine but not cruising.
Engine Hours per Engine Day: Hours running engine but not cruising per day.
Heating Hours per Winter Day: Hours heating is on per day, gas and LPG only.
Domestic Electrical Load (kWh/day): Domestic electricity per day in KwH.
Electric Heating (kWh/day, optional): Additional electricity for heating KwH per day.

Fuel Choices

Fuel for Propulsion: Red Diesel HVO Petrol Hybrid All Electric Hybrid (genset supplies motor energy; Red diesel and HVO only.) Hybrid power to domestic load fraction: (0–1)
Fuel for Heating: Smokeless Solid Fuel (25kg) Dry Wood (20l) Gleaned Wood (20l) Heating Oil Heating HVO Oil LPG (13kg)
Fuel for Cooking: LPG (13kg) Heating Oil Heating HVO Oil

Alternative Energy Sources

Solar Panels Size (kW):
Shore Hook-up Available kWh/day:
Petrol Generator Available kWh/day:
Engine Alternator Alternator Ah (@12V):

Summary for Unnamed Boat on 20-10-2025

Your usage preset is Leisure summer use
Your annual occupancy is 155 days.
Your annual engine hours were 600 hours.
Your propulsion fuel was at a pump price of £1.20/litre (HRMC 60/40 split) This is used for the cost of the main fuel calculation.
Your calculated usage split is 60.0% propulsion and 40.0% heating, compared to HMRC’s fixed 60/40 split.
Your heating fuel was Smokeless Solid Fuel (25kg), with an annual consumption of 5 bags at £20.00/bag.
Your cooking fuel was LPG (13kg), with an annual consumption of 4 bottles at £45.50/bottle.
Overall, your propulsion + heating + cooking costs were £788.46 with associated CO₂ emissions of 1,621.7 kg.

Fuel	Annual Usage	Unit Cost	Annual Cost (£)	Annual CO₂ Emissions (tonnes)
Red_diesel	450 L	£1.20/L	£540.00	1.21
Smokeless Solid Fuel (25kg)	5 bags	£20.00/bag	£85.71	0.28
LPG (13kg)	4 bottles	£45.50/bottle	£162.75	0.14
Total	-	-	£788.46	1.63

Advisories

• Consider switching propulsion fuel to HVO for lower CO₂ emissions and potential cost benefits.
• Cooking with LPG is already a very low carbon footprint. Changing to diesel or generated electricity will increase CO₂.
• Consider installing solar panels and an immersion heater to reduce diesel use when running engine for heat and power.

Alternative Energy Annual Totals

Source	Estimated kWh	Notes	CO₂ Emitted (t)
Solar	146.0 kWh	Free from the sun (weather dependent)	0.000 t
Engine Alternator	504.0 kWh	Charging while engine runs	0.000 t
Total (kWh)	650.0 kWh		0.000 t

Daily energy balance winter on mooring

Source / Load	kWh per Day
Solar	0.4
Shore Hook-up	0.0
Petrol Generator	0.0
Engine Alternator	1.7
Hybrid Power to Domestic	0.0
Total Generation	2.1
Domestic Load	2.0
Electric Heating	0.0
Total Demand	2.0
Net Balance	0.1

Calculation Logic Summary

This tool estimates annual fuel use, cost, and CO₂ emissions for propulsion, heating, cooking, and electricity based on your inputs.
Propulsion fuel is calculated from navigation days, engine hours per day, and fuel burn rate. Heating fuel is estimated from winter days, heating hours per day, and fuel-specific burn rates or bag counts.
Hybrid assumptions: motor 5kw, generator 10kw, part of power for domestic use 20%.
Cooking fuel is based on total occupation days and daily usage rates. Electricity sources (solar, generator, hook-up) estimate kWh use and associated costs and emissions, with generator fuel consumption based on kWh produced and generator fuel efficiency assumptions. LPG is split between heating and cooking for separate cost and CO₂ accounting.
The summary tables provide a breakdown for informed decision-making. It does not constitute engineering advice and design, or tax advice.
Copyright NABO September 2025. v3.4

Show / Hide Fuel Rates and Costs

Fuel	Propulsion rate	Heating rate	Cooking rate	Cost	CO₂ per unit
Red Diesel	1.25 L/h	-	0.2 L/day	£1.40	2.68 kg/L
HVO	1.25 L/h	-	0.2 L/day	£2.10	0.195 kg/L
Petrol	1 L/h	-	-	£1.50	2.31 kg/L
Heating Oil	-	0.6 L/h	0.2 L/day	£0.90	2.52 kg/L
Heating HVO Oil	-	0.6 L/h	0.2 L/day	£1.60	0.195 kg/L
LPG (13kg)	-	0.25 kg/h	0.3 kg/day	£45.50	2.95 kg/kg
Smokeless Solid Fuel (25kg)	-	1.5 bags/week	-	£20.00	2.6 kg/kg
Dry Wood (20l)	-	4 bags/week	-	£10.00	0.015 kg/kg
Gleaned Wood (20l)	-	5 bags/week	-	£0.00	3.5 kg/kg
Shore Hook-up	-	-	-	£0.34	0.233 kg/kWh