2017 Government emission conversion factors company reporting

2017 Government emission conversion factors company reporting
04 August 2017

Updates to the 2017 Government emission conversion factors for greenhouse gas company reporting 

It is hard to believe that another reporting year has flown by and the next update for the UK Government greenhouse gas (GHG) conversion for company reporting (hereafter referred to as the 2017 update) has been published.

The GHG factors are continually evolving in response to specific changes and longer terms trends in activities, and their associated impacts on GHG emissions. With the 2017 GHG conversion factors now available on the GOV.UK website, it is clear that the upgrades in format and spread aren’t as big as in previous years. But there are still some important things to note.

As before, a summary of the most commonly used factors, a spreadsheet with all the factors and a flat format document will be published for users to select the one suited to their use.

A summary of all the key upgrades for 2017 is provided within the factors themselves and more detailed information is provided in the methodology paper that accompanies the annual release.

Some of the changes in factors reflect market developments. For instance, the reduction in the electricity emissions factor continues, reflecting the changing grid mix – this year’s figure is 15% lower than last year’s. Indeed, you only have to look at the news and see what has been headlining. This year has seen the first day with no coal being burnt in a power station and, in June, it was announced that more than half of the UK’s electricity came from renewable sources for the first time.[1]

In summary, the main upgrades for 2017 are:

  1. Fluctuations in factors – the biggest variation we have seen in recent years has been for electricity.
  2. The addition of emission factors for electric cars and vans.
  3. The addition of factors for an overnight stay at a hotel.
  4. Well to Tank (WTT) data source change for some of the WTT fuels.
  5. Average petrol and diesel biofuel blend factors now used in road transport emission calculations.

More detail on the upgrades, in order of likely impact, is given below.

1.            Fluctuations in factors – electricity         

The UK electricity factor is prone to fluctuate from year to year as the fuel mix consumed in UK power stations (and auto-generators) and the proportion of net imported electricity changes.

These annual changes can be large because the factor depends very heavily on the relative prices of coal and natural gas, and fluctuations in peak demand and renewables.

In the 2016 conversion factors, there was an 11% decrease in the UK electricity carbon dioxide equivalent (CO2e) factor compared with the previous year. This was due to a decrease in coal-powered electricity generation in 2014 (the inventory year for which the 2016 GHG  conversion factors were derived).

In this 2017 update, the CO2e factors have decreased again (compared with the 2016 update) – this time by 15%. This is due to a significant decrease in coal generation, and an increase in gas and renewables generation in 2015 (the inventory year for which the 2017 emission conversion factors were derived). It should be noted that the methane (CH4) emission factor has increased by 59% mainly due to an increase in CH4 emissions from power generation, in particular due to increases in incinerating municipal solid waste and wood.          

That said, the decrease in the electricity factor is likely to slow down as the decarbonisation of the grid stalls. The latest report from the Committee on Climate Change reflects that substantial progress has been made in reducing emissions through the power sector, but that contribution may decline in the future as newly constructed nuclear power stations come online more slowly than originally expected. With the GHG conversion factors being based on data collected from the previous two years’ fuel mix, this change may well not manifest itself as quickly as we would expect. However, in the future, we should expect to see a decrease in the rate of decline in the conversion factor for electricity.

2. Factoring in electric vehicles                

As we all know, plug-in electric vehicles are gaining in market share rapidly in the UK and they are becoming an increasingly common feature of business life. The market is also expected to grow so it was felt that a selection of conversion factors should be provided.   

As a result, a number of conversion factors have been provided for electric cars and vans to cover their different emissions components. These are presented in a number of data tables in the GHG conversion factors workbook, according the type/‘Scope’ of the emission component. 

For plug-in hybrid electric vehicles the situation is particularly complex since the resulting emissions can be categorised into Scope 1 (direct emissions from petrol or diesel use), Scope 2 (from electricity use) and Scope 3 (electricity transmission and distribution losses, and WTT emissions).

The result is that when you calculate your fleet emissions, you will now be able to break down mileage against the different types of vehicles. It also allows modelling of emissions reduction potential should more of your fleet get converted to electric vehicles in the future. The results of the first Energy Saving Opportunity Scheme (ESOS) round showed that, in most companies, little attention had been paid to transport emissions and implementing reduction initiatives. Providing these factors gives the ability to look at the carbon impact and that for energy.        

3. Overnight hotel stays

A number of emission conversion factors for overnight hotel stays have been added. These allow for emissions to be calculated for overnight stays in hotels in a range of countries on a ‘room per night’ basis.

4. Update to WTT data source

Despite only making up a small proportion of a company’s emissions, it is important to make sure that the factors offer the most accurate emissions estimate. Therefore, the source of data used to derive the WTT emissions for a range of transport fuels (including petrol, diesel, kerosene, gas oil, natural gas, compressed natural gas and liquefied natural gas) has been updated to strengthen their accuracy.

This also brings greater consistency as this is the source that has recently been used to update the default conversion factors in EC Directives for these fuels. The result is that most WTT factors are now significantly higher than in previous years.                                                                                                    

5. Average petrol and diesel biofuel blend factors now used in road transport emission calculations

Previously, road transport emission factors – such as those for cars, buses, vans and lorries – have been based on conventional fossil-based road transport fuels. However, the share of biofuels has been increasing for a number of years now. So, this year, the methodologies used to develop the road vehicle emission conversion factors (direct CO2 and WTT) have been modified to account for the average petrol and diesel biofuel blend in public refuelling stations.

This methodological update has resulted in a small decrease to the vehicle emission conversion factors, compared with those for the conventional fossil-based petrol or diesel.                                                                                                                       

For more information on how the updated emission conversion factors impact your g GHG reporting or for advice on developing a sustainable business strategy, please contact [email protected]


[1] http://www.bbc.co.uk/news/business-40198567