The Renewables Obligation (RO) is designed to encourage generation of electricity from eligible renewable sources in the United Kingdom. It was introduced in England and Wales and in a different form (the Renewables Obligation (Scotland)) in Scotland in April 2002 and in Northern Ireland in April 2005, replacing the Non-Fossil Fuel Obligation which operated from 1990.
The RO places an obligation on licensed electricity suppliers in the United Kingdom to source an increasing proportion of electricity from renewable sources, similar to a renewable portfolio standard. In 2010/11 it is 11.1% (4.0% in Northern Ireland). This figure was initially set at 3% for the period 2002/03 and under current political commitments will rise to 15.4% (6.3% in Northern Ireland) by the period 2015/16 and then it runs until 2037 (2033 in Northern Ireland). The extension of the scheme from 2027 to 2037 was declared on 1 April 2010 and is detailed in the NREAP (National Renewable Energy Action Plan). Since its introduction the RO has more than tripled the level of eligible renewable electricity generation (from 1.8% of total UK supply to 7.0% in 2010).
Suppliers meet their obligations by presenting Renewables Obligation Certificates (ROCs) to Ofgem. Where suppliers do not have sufficient ROCs to cover their obligation, a payment is made into the buy-out fund. The buy-out price suppliers pay is a fixed price per MWh shortfall and is adjusted in line with the Retail Prices Index each year. The proceeds of the buy-out fund are paid back to suppliers in proportion to how many ROCs they have presented. For example, if they were to submit 5% of the total number of ROCs submitted they would receive 5% of the total funds that defaulting supply companies pay into the buy-out fund.
ROCs are intended to create a market, and be traded at market prices that differ from the official buy-out price. If there is an excess of renewable production, beyond the supplier obligation, the price of ROCs would fall below the buy-out price. The price of ROCs could approach zero if renewable and non-renewable generation costs became similar, when there would be little or no subsidy of renewable generation. If there is less renewable production than the obligation, the price of ROCs would increase above the buy-out price, as purchasers anticipate later payments from the buy-out fund on each ROC.
Obligation periods run for one year, beginning on 1 April and running to 31 March. Supply companies have until the 31 September following the period to submit sufficient ROCs to cover their obligation, or to submit sufficient payment to the buy-out fund to cover the shortfall.
The cost of ROCs is effectively paid by electricity consumers of supply companies that fail to present sufficient ROCs, whilst reducing the cost to consumers of supply companies who submit large numbers of ROCs, assuming that all costs and savings are passed on to consumers.
ROC Percentages and Prices by Year 
|Obligation period||% of Supply||Buy Out Price (£/MWh)||Effective Price per Unit (p/kWh)|
|1 April 2002 to 31 March 2003||3.0||£30.00||0.09|
|1 April 2003 to 31 March 2004||4.3||£30.51||0.13|
|1 April 2004 to 31 March 2005||4.9||£31.39||0.15|
|1 April 2005 to 31 March 2006||5.5||£32.33||0.18|
|1 April 2006 to 31 March 2007||6.7||£33.24||0.22|
|1 April 2007 to 31 March 2008||7.9||£34.30||0.29|
|1 April 2008 to 31 March 2009||9.1||£35.76||0.33|
|1 April 2009 to 31 March 2010||9.7||£37.19||0.36|
|1 April 2010 to 31 March 2011||11.1||£36.99||0.41|
|1 April 2011 to 31 March 2012||12.4||£38.69||0.48|
|1 April 2012 to 31 March 2013||15.8||£40.71||0.64|
|1 April 2013 to 31 March 2014||20.6||£42.02||0.87|
Renewables Obligation Certificates 
A ROC is the green certificate issued for eligible renewable electricity generated within the United Kingdom and supplied to customers in the United Kingdom by a licensed supplier. ROCs are issued by Ofgem to accredited renewable generators (or in the case of generating stations subject to a NFFO (non-fossil fuels obligation), Scottish Renewables Obligation or Northern Ireland NFFO contract, to the nominated electricity supplier). It is worth noting that the Scottish Renewables Obligation was superseded by the Renewables Obligation (Scotland) in 2002.
The default is that one ROC is issued for each megawatt-hour (MWh) of eligible renewable output. Some technologies get more, some less. For instance, offshore wind installations receive 2 ROCs per MWh; onshore wind installations receive 1 ROC per MWh and sewage gas-fired plants receive half a ROC per MWh.
ROCs are issued into the ROC Register and so are electronic certificates. Normally, a renewable generator will transfer the related ROCs through Ofgem's electronic registry when it sells power to an electricity supplier.
The legislation 
The Utilities Act 2000 gives the Secretary of State the power to require electricity suppliers to supply a certain proportion of their total sales in the United Kingdom from electricity generated from renewable sources. A Renewables Obligation Order is issued annually detailing the precise level of the obligation for the coming year-long period of obligation and the level of the buy-out price. The Renewables Obligation (England and Wales) was introduced by the Department of Trade and Industry, the Renewables Obligation (Scotland) was introduced by the Scottish Executives and the Northern Ireland Renewables Obligation was introduced by the Department of Enterprise Trade and Investment (DETINI). The Orders were subject to review in 2005/06 and new Orders came into effect on 1 April 2006. The relevant pieces of legislation for the period April 2006-March 2007 are:
- The Renewables Obligation Order 2006 (Statutory Instrument (SI) 2006 No. 1004)
- The Renewables Obligation (Scotland) Order 2006 (SI 2006 No. 173), and
- The Renewables Obligation Order (Northern Ireland) 2006 (SI 2006 No. 56).
All pieces of legislation are published on the National Archives legislation site .
Ofgem’s role 
The Orders detail Ofgem's powers and functions to administer the Renewables Obligation. These functions include:
- Accrediting generating stations as being capable of generating electricity from eligible renewable sources
- Issuing ROCs and revoking these as necessary
- Establishing and maintaining a Register of ROCs
- Monitoring compliance with the requirements of the Orders
- Calculating annually the buy-out price
- Receiving buy-out payments and redistributing the buy-out fund
- Receiving late payments and redistributing the late payment fund, and
- Publishing an annual report on the operation of and compliance with the requirements of the Orders.
Ofgem also administers the Northern Ireland Renewables Obligation (NIRO) on behalf of the Northern Ireland Authority for Energy Regulation (NIAER).
Types of energy eligible 
The following sources of electricity are eligible for ROCs:
- Biogas from anaerobic digestion
- Hydro electric
- Tidal power
- Wind power
- Photovoltaic cells
- Landfill gas
- Sewage gas
- Wave power
Co-firing of biomass is also eligible. Not all technologies which are eligible will actually be supported due to cost. Some renewable sources of electricity are not eligible for ROCs (e.g. larger hydroelectric schemes which were in operation before April 2002).
Government review 
The scheme is currently being reviewed by Government  following a consultation period that finished in September 2007. The document at the centre of the consultation set out an amended form of the RO which will see different technologies earn different numbers of ROCs. This has not yet been adopted as policy.
On 22 January 2007, Ofgem called for the Renewables Obligation to be replaced, claiming that the scheme is a 'very costly way' of supporting renewable electricity generation . In particular they are concerned that electricity customers pay for renewables projects even if they are not built due to problems obtaining planning permission, and the failure of the Renewables Obligation to link financial support for renewables to either the electricity price or the price of renewables in the European Union Emissions Trading Scheme.
The British Wind Energy Association, whose members are major beneficiaries of the existing scheme, claims that Ofgem is partly responsible for the costs because it has failed to prioritise work on the National Grid which would allow more renewable capacity to be connected. They also stressed the need to maintain stability in the marketplace to maintain the confidence of investors .
The Scottish Wind Assessment Project has criticised the scheme for rewarding reductions in renewable electricity output: two electricity suppliers, Scottish and Southern Energy and Npower, down-rated several large hydro-power stations in order to qualify for Renewables Obligation Certificates .
Banding of the Renewables Obligation 
The Renewables Obligation represents the UK Government’s main policy measure for stimulating the growth of electricity generation from renewable sources. The Government envisages that 30% of electricity demand will need to be generated by renewable sources in order for the UK to meet a legally binding EU target of obtaining 15% of energy from renewable sources by 2020.
The Renewables Obligation is a market-based mechanism designed to incentivise the generation of electricity from renewable energy sources over more traditional alternatives at a reasonable cost to the consumer.
When it was first introduced in 2002, each form of renewable energy technology received the same level of support, namely one ROC/MWh of electricity generated. This was a conscious decision as the Government was keen to promote a market-led approach, emphasising competition between technologies to minimise cost, and did not want to distort the market by appearing to place the importance of certain technologies above others.
As a result, whilst being ostensibly technology-neutral, the Renewables Obligation in its original form in fact favoured the deployment of the more established, near-market technologies such as landfill gas and onshore wind, those which were most economically efficient, over less well developed technologies that were further from commercial viability.
A review of the performance of the Renewables Obligation was announced in the 2003. Modelling of future deployment scenarios indicated that targets would not be met with current levels of support due to constraints on the availability and deployment of the most established technologies. A significant contribution would therefore be required from less mature technologies which lacked sufficient incentive to develop into feasible alternatives under the original scheme.
The Government announced its intention to reform the Renewables Obligation in 2006. Banding was introduced in 2009 to provide differing levels of support to groups of technologies depending upon their relative maturity, development cost and associated risk. Whilst increasing the incentive for technologies in the early stages of development this also allowed the level of support for well established technologies to be reduced to avoid over-subsidisation.
In reforming the Renewables Obligation in this way, and scheduling regular future reviews, the Government recognised that the market would not deliver the mix of renewable energy generation required to meet the targets if the incentives remained technology-neutral. It was therefore necessary for the Government to perform a continuing strategic role and retain the capability to intervene if necessary. The introduction of banding allowed the Government to steer industry towards investment in less well developed forms of renewable energy to enable them to contribute to meeting the long-term targets, rather than concentrating investment in technologies that are economically favourable in the short-term.
The Government has reviewed the banding levels for appropriate incentives for the period 2013-2017. These bands include a reduction in the tariff for onshore wind to 0.9 ROCs/MWh and an increase for small wave and tidal stream projects, under 30 MW, to 5 ROCs/MWh.
Electricity Market Reform and the Future of the Renewables Obligation 
The UK Government has proposed wide-ranging reforms to the UK electricity market which will eventually see Feed-in Tariffs with Contracts for Difference (CfD) replace the Renewables Obligation as the main renewable generation support mechanism. Unlike ROCs, CfDs will also be available to generators of nuclear electricity.
The Renewables Obligation will remain open to new generation until 31 March 2017, allowing new renewable generation that comes online between 2014 (when it is anticipated the CfDs will start) and 2017 to choose between CfDs and ROCs. After that date, the Government intends to close the Renewables Obligation to new generation and ‘vintage’ existing ROCs, meaning that levels and length of support for existing participants in the Renewables Obligation will be maintained.
See also 
- Future Energy (former green electricity accreditation scheme)
- Green electricity
- Green tags
- Non-Fossil Fuel Obligation
- Renewable Energy Certificates (United States) - a similar mechanism in the US
- United Kingdom Climate Change Programme
- 8 January 2007, New Builder: BWEA warns on UK renewables policy as Germany leads the way
- 9 October 2006, ePolitix.com: Granting of renewables obligation certificates to be reformed
- 9 August 2006, Guardian Unlimited: Tickell, O: Treasury takes £150m out of renewable energy fund
- Ofgem and ROC Ofgem: What is the Renewables Obligation
- Renewable Energy. Parliamentary Office of Science and Technology. October 2001. postnote 164. Retrieved 13 June 2011.
- "eRoc FAQs". Non-Fossil Purchasing Agency. Retrieved 12 June 2011.
- Ofgem First annual report 2002/2003 on Renewable Obligation
- Ofgem Second annual report 2003/2004 on Renewable Obligation
- THE RENEWABLES OBLIGATION BUY–OUT PRICE AND MUTUALISATION CEILING
- THE RENEWABLES OBLIGATION BUY–OUT PRICE AND MUTUALISATION CEILING 2010-11
- THE RENEWABLES OBLIGATION BUY–OUT PRICE AND MUTUALISATION CEILING 2011-12
- THE RENEWABLES OBLIGATION BUY–OUT PRICE AND MUTUALISATION CEILING 2012-13
- THE RENEWABLES OBLIGATION BUY–OUT PRICE AND MUTUALISATION CEILING 2013-14
- Collins, Peter. Renewables Obligation: Guidance for licensed electricity suppliers page 2 Office of Gas and Electricity Markets (Ofgem), 22 April 2010. Retrieved: 29 September 2010.
- DTI. (2007). ‘Reform of the Renewables Obligation’, May 2007
- DECC. (2010). ‘National Renewable Energy Action Plan for the United Kingdom’
- European Union. (2009). Directive 2009/28/EC of the European Parliament and of the Council of 23 April 2009 on the promotion of the use of energy from renewable sources
- Wood, G. and Dow, S. (2011). ‘What lessons have been learned in reforming the Renewables Obligation? An analysis of internal and external failures in UK renewable energy policy’, Energy Policy, 39(5), 2228-2244.
- Foxon, T.J. and Pearson, P.J.G. (2007). ‘Towards improved policy processes for promoting innovation in renewable electricity technologies in the UK’, Energy Policy, 35(3), 1539-1550.
- Wood, G. and Dow, S. (2010). ‘The likely impact of reforming the Renewables Obligation on renewables targets’, International Journal of Energy Sector Management, 4(2), 273-301.
- Woodman, B. and Mitchell, C. (2011). ‘Learning from experience? The development of the Renewables Obligation in England and Wales 2002-2010’, Energy Policy, 39(7), 3914-3921.
- "Renewable energy to bring £25bn of investment into uk economy - Davey". DECC. July 2012. Press Notice 2012/086. Retrieved 31 October 2012.