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Balancing Services Use of System (BSUoS) charges

The BSUoS charge recovers the cost of day-to-day operation of the transmission system. 

Generators and suppliers are liable for these charges, which are calculated daily as a flat tariff for all users. BSUoS charges depend on the balancing actions that we take each day, but we provide a monthly forecast of BSUoS. You can also consult historical BSUoS charges.

The methodology that calculates BSUoS is set out in Section 14 of the Connection and Use of System Code (CUSC). The monthly forecast of BSUoS is provided as part of the current Monthly Balancing Services Summary report.

For more general information about the BSUoS charging process please consult our introduction presentation:

Download the Introduction to BSUoS (PDF) document 


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BSUoS links

Historical BSUoS data - II

Historical BSUoS data - SF

Published Sort ascending Name
2017-2018 SF
2016-2017 SF
2015-2016 SF
2014-2015 SF
2013-2014 SF
2012-2013 SF
2011-2012 SF
2010-2011 SF
2009-2010 SF
2008-2009 SF
2007-2008 SF
2006-2007 SF
2005-2006 SF
2004-2005 SF
2003-2004 SF
2002-2003 SF
2001-2002 SF
2000-2001 SF

Historical BSUoS data - RF

Here you will find historic BSUoS data for all Reconciliation Final (RF) data for financial years dating back to 2001.

Published Sort ascending Name
2016-2017 RF
2015-2016 RF
2014-2015 RF
2013-2014 RF
2012-2013 RF
2011-2012 RF
2010-2011 RF
2009-2010 RF
2008-2009 RF
2007-2008 RF
2006-2007 RF
2005-2006 RF
2004-2005 RF
2003-2004 RF
2002-2003 RF
2001-2002 RF
2000-2001 RF
Transmission losses

During the transmission of electricity, some energy is 'lost' from the transmission system, usually in the form of heat. This lost energy is known as transmission losses. Transmission network losses result from the transport of power between power producers and grid supply points through transmission infrastructure equipment, such as power transformers, overhead lines, cables, and switchgear. We have a duty, as part of our licence obligation, to report on transmission losses. We publish an annual transmission losses report along with a strategy that sets out how we intend to deal with losses.

As part of the Electricity Incentives consultation, Ofgem proposed replacing the old financial incentive on transmission losses with a reputational incentive. This reputational incentive acknowledges that National Grid only manages around three per cent of the total energy on the system through the balancing mechanism (BM), and therefore its limited control over the level of losses.

By removing the financial incentive, it removes the possibility of windfall gains and losses due to market developments beyond our control. These market developments could affect the level of transmission losses, which therefore affects our performance against the incentive scheme and BSUoS charges.

Under the new scheme, we are required to report on any actions taken in which we consider transmission losses and system transmission losses more generally. This information can be found in the Monthly Balancing Services Statement 

We are also required to report on the level of transmission losses and expected impact of market developments. This information can be found in our Electricity Ten Year Statement (ETYS). The Transmission Losses Strategy and annual Transmission Losses Report are to be used in conjunction with the ETYS.

A busy city road at night with blurred lights moving through the image


Transmission Network Use of System (TNUoS) charges recover the cost of installing and maintaining the transmission system in England, Wales, Scotland and offshore. Transmission customers pay a charge based on which geographical zone they are in, whether they are generation or supply, and the size of that generation or supply. 

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