How To Calculate Event Generator Emissions
Temporary generators can be essential for outdoor events, temporary venues, production areas and sites without sufficient mains power, but they can also create another source of emissions that event teams need to measure.
Calculating event generator emissions starts with understanding what fuel was actually consumed. Rather than recording only that a generator was present, you need information such as the fuel type and quantity used, alongside an appropriate emission factor.
For many event organisers, the difficult part is not the final calculation. It is knowing what information to collect, what to request from a temporary power supplier and how to distinguish fuel delivered to the site from fuel actually consumed.
This guide explains how to calculate event generator emissions, what generator data to collect, how to handle leftover or additional fuel and what to do when exact consumption data is unavailable.
How Do You Calculate Event Generator Emissions?
Event generator emissions can be estimated by recording the type and quantity of fuel consumed and applying an appropriate emission factor for that fuel.
The basic calculation is:
Fuel consumed × appropriate emission factor = estimated greenhouse gas emissions
For UK activities, the UK Government greenhouse gas conversion factors provide factors that organisations can use with activity data such as fuel consumption to calculate greenhouse gas emissions.
If, for example, your temporary power supplier can tell you how many litres of a particular fuel were consumed during the event, that figure can be matched with the appropriate factor for the fuel and reporting year.
The important distinction is between fuel delivered to the site and fuel actually consumed during the reporting period.
What Generator Data Should You Collect At An Event?
The most useful generator data identifies what temporary power was used, which fuel it consumed and how much fuel was actually used during the reporting period.
A practical data request could include:
Generator data | What to record |
Generator or power unit | Which generator or temporary power source the record relates to |
Fuel type | The specific fuel used |
Opening fuel | Fuel already in the relevant tank at the start, where measured |
Fuel delivered | Additional fuel supplied during the event |
Closing fuel | Fuel remaining at the end, where measured |
Fuel consumed | Actual consumption where available |
Unit | Litres, kilograms or another clearly stated unit |
Runtime | Operating hours where available |
Supplier | The company responsible for temporary power or refuelling |
Reporting period | Which event dates or operating period the data covers |
You may not have every data point for every generator, particularly when temporary power is managed by an external supplier.
That does not necessarily mean you cannot begin measuring. The priority is to use the best available activity data, be clear about where it came from and record any assumptions or estimates so that you can improve the quality of your event power emissions data over time.
Are Event Generator Emissions Scope 1?
Event generator emissions are not automatically Scope 1 for every event organiser because their classification depends on factors including ownership or control of the emissions source and the reporting boundary being used.
The GHG Protocol Corporate Standard defines Scope 1 as direct greenhouse gas emissions from sources owned or controlled by the reporting company.
This means you should not assume that a hired generator automatically creates Scope 1 emissions for your organisation simply because it was operating at your event. Temporary power may be supplied or controlled by another organisation, and the appropriate classification depends on the reporting arrangements and organisational boundary involved.
If the distinction between the three scopes is unfamiliar, our guide to Scope 1, 2 and 3 carbon emissions explains what each category means and how they fit together.
Should You Record Fuel Purchased Or Fuel Actually Used?
Fuel actually consumed usually provides a better basis for calculating generator combustion emissions than simply recording how much fuel was purchased or delivered, where reliable consumption information is available.
Imagine that 500 litres of fuel are delivered to an event site, but 120 litres remain afterwards. Assuming that all 500 litres were burned could overstate the fuel consumption associated with the event.
This is why it can be useful for your temporary power records to distinguish between:
fuel supplied;
fuel already present before the reporting period;
additional refuelling;
fuel consumed; and
fuel remaining afterwards.
Where your supplier already monitors actual fuel consumption, asking for that information may be considerably simpler than trying to reconstruct it after the event.
Accurate fuel records also provide a stronger basis for calculating generator carbon emissions than relying only on the size of the generator or how long it was operating.
How Do You Account For Fuel Left After An Event?
Fuel remaining after an event should not automatically be treated as fuel consumed during the event if it can be reliably measured and remains available for later use.
Where you have reliable opening, delivery and closing fuel information, an illustrative calculation could be:
Opening fuel + fuel delivered − closing fuel = estimated fuel consumed
For example, if you started with 100 litres, received another 400 litres and had 120 litres remaining afterwards:
100 + 400 − 120 = 380 litres estimated fuel consumed
The resulting 380 litres is activity data rather than the emissions result itself. You would then apply the appropriate emission factor to calculate the estimated greenhouse gas emissions associated with that fuel use.
This approach only works when the opening, delivery and closing figures relate to the same fuel stock and any transfers, additional deliveries or other uses have been recorded. Where records are incomplete, the result should be clearly treated as an estimate rather than exact consumption.
What If The Generator Is Refuelled During The Event?
Additional fuel delivered during an event needs to be included when calculating total fuel consumption for the relevant reporting period.
This can become particularly important at multi-day events or larger temporary power installations, where tanks may be topped up several times.
Rather than relying on the first delivery note, keep or request records showing:
initial fuel stock or delivery;
each additional delivery;
fuel type;
quantity supplied;
date or time where useful; and
closing fuel level or final supplier consumption figure.
Bringing these records together can provide a more complete picture of the fuel actually used during the event.
What Should You Ask Your Temporary Power Supplier For?
Ask your temporary power supplier for the underlying fuel and consumption information needed for your calculation, rather than relying only on a final carbon figure.
Depending on what the supplier records, useful information could include:
generator or power-unit details;
fuel type;
actual fuel consumption where available;
fuel deliveries and refuelling records;
opening and closing fuel readings where relevant;
generator runtime;
meter or monitoring records where available; and
the dates covered by the data.
Asking for the underlying activity data gives you a clearer record of what was measured and how your calculation was produced.
In practice, this information is also much easier to collect when the requirement is agreed before the event. Trying to reconstruct fuel deliveries, remaining stock and consumption afterwards can leave you dependent on whatever records happen to have been retained.
Can You Estimate Generator Emissions From Runtime?
Generator emissions may be estimated from runtime and an appropriate fuel-consumption assumption where actual fuel-use data is unavailable, but the result should be clearly documented as an estimate.
Runtime alone does not tell you exactly how much fuel was burned because consumption can vary according to the equipment, load and operating conditions.
If you only have runtime information, first check whether your supplier can provide measured consumption, refuelling records, fuel monitoring information or an appropriate consumption rate for the equipment and operating conditions.
If an estimate is still necessary, record the source of the consumption assumption, the runtime used and any other assumptions involved.
This is not unusual when businesses and event teams first start collecting carbon data. Our guide to estimating carbon emissions when data is missing explains how estimates can be used without presenting them as exact measurements.
How Do You Calculate Emissions From Multiple Generators?
Where several generators are used, recording their fuel consumption separately where practical can help you calculate total temporary power emissions while retaining more useful information about individual power sources.
For example:
Generator | Fuel | Consumption |
Generator A | Fuel type A | 250 litres |
Generator B | Fuel type A | 180 litres |
Generator C | Fuel type B | 90 litres |
Each fuel quantity should be matched with the appropriate emission factor for the fuel involved.
The individual results can then be combined to understand the total emissions associated with the generators included within your event measurement boundary.
Keeping the information separate initially can also make the data more useful for future planning. If one area or temporary power source consistently accounts for a larger amount of fuel consumption, the event team and power supplier have something specific to investigate.
Does Generator Fuel Type Affect The Calculation?
Generator fuel type affects the calculation because different fuels need to be matched with the appropriate emission factor.
Rather than recording everything simply as “generator fuel”, capture the actual fuel used and its quantity.
The UK Government publishes its greenhouse gas conversion factors annually, so organisations using them should select the appropriate factor set for their reporting period rather than assuming the same factor applies indefinitely.
If you are new to this part of carbon accounting, our guide to emission factors explains what they are and how activity data is converted into estimated emissions.
It is also important not to assume that switching fuel automatically creates a particular percentage reduction. The resulting calculation depends on the fuel, methodology and emissions being considered.
How Can Better Power Data Help Reduce Generator Emissions?
Better temporary power data can help event organisers understand how power is being used and identify areas worth investigating when planning future events.
Your data might show that:
fuel consumption is consistently higher in particular event areas;
some temporary power sources operate for long periods;
requirements vary significantly between event zones or event days; or
different power arrangements are worth discussing with the supplier.
That information can support conversations about generator sizing, load management, mains or grid connections, battery storage, hybrid systems or other temporary power approaches where they are technically and operationally appropriate.
Measurement itself does not reduce emissions. Instead, it gives event teams and suppliers information they can use to consider possible changes and compare the results at future events.
How Can You Improve Temporary Power Data At Future Events?
Temporary power data is generally easier to manage when reporting requirements are agreed before the event rather than reconstructed afterwards.
Before your next event, consider:
Which temporary power sources you want to include in your measurement boundary.
Who is responsible for collecting the relevant data.
Which fuel or electricity information you need.
Whether actual consumption can be recorded.
How refuelling will be documented.
When suppliers need to provide their final information.
How any estimates or assumptions will be recorded.
Your first event may rely on relatively broad information, while the next could include better fuel records, measured consumption or more detailed supplier data.
Improving the quality of the underlying information over time can make future comparisons more useful without pretending that your first calculation was more precise than the available data allowed.
How Can Scope Help You Track Temporary Power Emissions?
Scope's event carbon tracking platform includes a dedicated Temporary Power section where event teams can record fuel used for generators and other temporary event power sources.
Within the Energy & Water area of an event, Scope separates Main Electricity, Main Gas, Temporary Power and Event Water, helping teams keep different event energy sources organised rather than combining them into one figure.
For temporary power, the platform currently allows users to select and enter quantities for:
diesel;
renewable biodiesel (HVO);
biodiesel;
bottled gas/LPG;
natural gas; and
propane (LPG).
The available units depend on the fuel being recorded. For example, the screenshots show litres being used for diesel, HVO and biodiesel, while other fuel options can use relevant units such as kilograms, gigajoules or cubic metres.
Once the activity data has been entered, Scope calculates the associated results in kgCO₂e. The platform can also display different emissions components separately rather than presenting temporary power as a single unexplained number.
There is also an Invite Supplier option within the Energy & Water area. This gives event teams a way to involve the relevant supplier in the data-collection process where the supplier holds the information needed for the event record.
This is particularly useful for temporary power because the event organiser may not be the person recording fuel consumption or managing the equipment on site.
Scope does not remove the need for good underlying data. Instead, it provides a structured place to bring that event data together and turn the information you have collected into a clearer emissions record.
You can explore Scope's Event Carbon Tracking if you need to collect and manage carbon data across your events.
Measure Temporary Power As Part Of Your Wider Event Carbon Footprint
Temporary power is only one part of an event carbon footprint, so generator emissions should be considered alongside the other activities included within your event measurement boundary.
Depending on the event, these could include venue energy, attendee and staff travel, accommodation, catering, freight and logistics, production materials and waste.
Our guide to measuring and reducing your event carbon footprint explains how these different areas fit together.
If you are at an earlier stage and want to start with an initial calculation, you can also use Scope's free Event Carbon Calculator.
The aim does not need to be perfect data from day one. Starting with the information you can reasonably collect, documenting estimates and improving your data at future events can give you a much more useful picture over time.
Event Generator Emissions FAQs
How Do You Calculate Event Generator Emissions?
Event generator emissions can be estimated by recording the type and quantity of fuel consumed and multiplying that activity data by an appropriate emission factor for the fuel.
Where actual consumption data is unavailable, an estimate may be necessary, but the methodology and assumptions behind it should be recorded.
What Generator Fuel Data Should Event Organisers Collect?
Event organisers should aim to collect the fuel type and quantity consumed, alongside any supporting information needed to understand how that figure was obtained.
This could include fuel deliveries, opening and closing fuel levels, runtime and the generator or power source the information relates to.
Are Generator Emissions Always Scope 1?
Generator emissions are not automatically Scope 1 for every event organiser because classification depends on factors including ownership or control and the reporting boundary being used.
Where generators are hired or managed by another organisation, the event organiser should not classify them as its own Scope 1 emissions solely because the equipment was present at the event.
Should You Calculate Generator Emissions From Fuel Purchased Or Fuel Consumed?
Fuel actually consumed is generally the more representative activity measure for combustion emissions where reliable consumption information is available.
Fuel purchased or delivered can differ from consumption if fuel was already present, remains after the event or is transferred elsewhere.
Can Generator Emissions Be Estimated Using Operating Hours?
Operating hours can potentially support an estimate when actual fuel consumption is unavailable, but runtime alone does not establish exact fuel use.
Any consumption rate used to turn operating hours into estimated fuel use should therefore have an appropriate source, and the resulting figure should be identified as an estimate.
Does Generator Fuel Type Matter For Carbon Reporting?
Different generator fuels require the appropriate emission factor, so event teams should record the actual fuel used rather than grouping every temporary power source into a generic “generator fuel” category.
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