Uskmouth Power Station - Application to change environmental permit

Updated 15 September 2020

Application reference:  PAN-008534
Permit Number: EPR/LP3131SW
Company:  Simec Uskmouth Power Limited
Location: Uskmouth Power Station, West Nash Road, Nash, Newport, NP18 2BZ


Uskmouth power plant is a coal-fired power station.  It has generated electricity for export to the national grid for many years, since the 1960’s. Uskmouth power plant has operated infrequently in recent years, and was earmarked for closure.  It has been not generated since 2017.  Simec Uskmouth Power Limited have a conversion project plan which seeks to change the fuel source from coal to alternative fuel pellets derived from waste.

Uskmouth power plant already has an Environmental Permit from Natural Resources Wales to burn coal for electricity generation. Before it can change its fuel source, the company must apply to vary its permit so a full environment assessment can take place.

We have held an extended public consultation on the company’s application, which has now closed. We are now completing our technical assessment and determination, which is expected to take some time.  This assessment will consider all relevant comments received during consultation.   We have asked the company for further information, via Schedule 5 notices. When we have completed our assessment, we will advertise this on our website and social media channels. If we propose to allow the permit change, we will consult on our draft decision for at least 20 working days.

What is the Environmental Permit and a Variation?

Under the Environmental Permitting (England and Wales) Regulations 2016 (EPR), certain activities must have a permit to operate.  This is to manage and control environmental risk from the activities.     

Uskmouth power plant has a current Environmental Permit to combust coal for electricity generation.  That permit is held by the Operator, Simec Uskmouth Power Limited.   

In Wales, Natural Resources Wales is responsible for regulating this type of industry. We assess applications for permits, regulate and monitor permit holders. 

The operator must apply for a variation to the permit before making any significant changes to the installation.

What is the application for?

The company is seeking to upgrade and convert the plant and change the fuel source from coal to fuel pellets derived from waste.  The plans utilise existing infrastructure where possible. 

This means that the electricity generating equipment and overall plant layout would be retained, but that there would be substantial modification or upgrade necessary to some parts of the plant, such as burners, combustion chamber, and the equipment used to clean waste gases before they are emitted. 

Some changes are to allow the combustion of a fuel with different properties, and some changes are to allow the plant to meet current environmental standards which would apply following the proposed changes.  

How will you decide whether to allow the EPR Permit Variation?

When we receive an application, we must decide whether or not to issue a variation.  Our decision whether to issue or refuse is defined by legal requirements which are designed to control the environmental risks.   

As part of our decision-making process, we scrutinise the proposals of any application to make sure the operator will be able to comply with all relevant legislation. 

If all legal requirements will be met, we must issue the permit or variation.  We cannot refuse a permit or variation solely because of local opposition to the activity.  Our public participation statement details what matters are within our regulatory remit, and we can therefore consider. 

Our focus is on the environmental effects of the permitted activity only.  Other related activities (for example traffic and transport to and from the site) can have environmental effects but are outside of our remit (these matters are considered by the Local Authority Planning process). 

 Any relevant comments received during the consultation will be considered during our assessment.

What does the permit variation cover?

In technical terms, under the regulations, the proposed changes would involve a change in the plant scheduled activity under EPR. If permitted, the plant would change from a Section 1.1 A(1) (a) installation:

“Burning any fuel in an appliance with a rated thermal input of 50 megawatts or more” [coal fired power station],

to a Section 5.1 A(1) (b) installation:

“The incineration of non-hazardous waste in a waste incineration plant or waste co-incineration plant with a capacity exceeding 3 tonnes per hour”.

This technical change is because the proposed new fuel originates from waste material, and is classified as waste. The combustion process would still occur, with alternative fuel burnt in place of coal.

The variation also details all changes required to allow the proposed fuel change. These include modifications to the combustion furnace and gas cleaning plant specification and operation, and installation of new storage silos for the proposed fuel. The application details the changes, possible environmental risks, and controls to be implemented.

How much power would the plant be able to generate?

The plan is to convert two existing combustion units to export 110MW of electricity per unit. There are no plans to bring into service a 3rd combustion unit, on any fuel.

The applicant has advised us that they plan to commission the converted units sequentially, so initially the plant would commission and run on one unit, followed by conversion of the second unit.

Each unit burns 330MW of fuel to generate the electricity.  The efficiency of the plant (about 33%), and amount of electricity generated, are not substantially affected by the proposed change in fuel.  The main loss of energy is as heat, from the cooling tower which forms part of the steam-water circuit.

Why does the company want to switch fuel source?

The plant will not be able to operate on coal beyond June 2020, without modifications to the permit and upgrades to plant to meet new environmental legislation

The choice of alternative fuel and continued operation of the plant is a question for the Operator. Several other UK coal-fired power stations have been converted to combust biomass, either alone or alongside coal. 

In this case, the fuel proposed is formed of non-hazardous waste types that cannot be recycled and could otherwise go to landfill or other incineration facilities.  It will be formed of about 50% plastic, and 50% biogenic material – largely wood, paper and cardboard.  If permitted, the variation would only allow the use of the waste derived fuel described in the application.

The proposed variation would extend the lifetime of the plant.  It is understood to be likely that unless converted, the plant would otherwise permanently close. 

Is this an incinerator, will it burn waste, and how much?

The new fuel source is classified under waste regulations as waste, because it originates from waste. The application states that these fuel pellets will be made elsewhere from non-recyclable waste.

The application emphasises that the waste will be manufactured to meet stringent specifications, and specifically designed to ensure suitability for combustion at the facility. It will be sorted to remove materials not suitable for combustion in the plant.

The combustion plant and fuel have significant technical differences from a typical municipal waste incinerator. The plant does not propose to burn unsorted municipal, commercial or industrial waste. If permitted, the variation would only allow the use of the waste derived fuel described in the application.
Up to 1% of the fuel may be biomass, which is already allowed under the current permit.

To generate the amount of electricity stated when fully converted, the plant is expected to bur around 875,000 tonnes of waste derived fuel per annum, with a maximum of 1,093,000 tonnes per annum stated in the application.

How much waste/fuel will the site store at any one time?

The fuel pellets would be stored in silos – there would be no unprocessed waste on site, and the pellets have to be carefully stored to keep them dry and prevent degradation.

Four main storage silos would store approximately 10,000 tonnes of waste each, with two smaller silos (“day silos” closer to the combustion plant) each having a capacity of 1,600 tonnes.

Does the fuel/waste pose a fire risk or other environmental problems?

The silos, reception and conveying systems would be enclosed and have measures to prevent dust release. They would have fire prevention, detection and firefighting systems. Odour is not expected to be an issue from the manufactured pellets.

We will assess these proposals fully during our determination, and consult the Fire and Rescue Service on them.

Many fuels with a biological content can be “self-heating”, i.e. they get warm because of biological activity, especially if wet. This is why purpose-built dry silos are needed, with fire protection measures.

There would be a quarantine area for emergency use (including hot/smouldering fuel), which could see waste temporarily stored outside, before being cooled and removed from site for disposal.

How will materials be transported to and from site?

The impact of traffic on roads outside of the permitted area are the remit of the Local Planning Authority, not the Natural Resources Wales Environmental Permit.  

The application indicates that the main fuel transport will be by rail, as has happened previously for coal.  There will be a backup fuel delivery system for road vehicles.  Other raw materials, biomass and outgoing ash will be transported by road.

What carbon dioxide emissions would be caused by the change in fuel?

Combustion of any fuel containing carbon releases carbon dioxide.   

In the application, carbon dioxide emissions from combustion of the proposed fuel pellets are an estimated annual tonnage of carbon dioxide of 1,550,000 tonnes.  Half of this is from renewable sources, meaning the fossil fuel global warming potential would be half this figure.  

In 2013, the coal-fired power station burned 600,000 tonnes of coal, producing approximately 1,330,000 tonnes of carbon dioxide, all of which is non-renewable. The combustion of fuel pellets will therefore result in a fossil-fuel carbon dioxide emission that is less than two thirds of that of the previous coal-burning operation, although the total carbon dioxide emissions are comparable.

How does the proposed alternative fuel compare with coal?

The application states that “the feedstock is waste with consistent characteristics that is comparable to a virgin fuel (coal)”.

A detailed comparison of the similarities and differences between coal and the proposed fuel has not yet been made by Natural Resources Wales, and will form part of our determination. This would consider differences in emissions to air, and solid residues such as ash (both quantities and composition).

If permitted to burn alternative fuel, the plant will have to meet emission limits for all emitted air pollutants.  These will be the same, or in many cases considerably lower, than current limits when burning coal.

What about ash produced?

The application states that “The type and quantities of these residues are not expected to change significantly from those already permitted taking into account that only two units will be re-energised rather than all three”.  The application anticipates production of about 27,600 tonnes per annum of bottom ash and boiler ash.  This would be sent to an off site facility, and is expected to be re-used as aggregate.  110,500 tonnes per annum of Air pollution Control Residue and Fly Ash are anticipated.  This may be treated off-site, and re-use opportunities will be sought, but it is expected that this material may be safely disposed of via landfill.

Where do I find further information on the application?

You can access all available documents associated with the application via our online public register.

The existing permit number is LP3131SW and the variation number is PAN-008534.

Why can't I access documents from the online public register?

You may need to download software applications to view certain documents on our on-line system – for example, if your email system isn’t compatible with Outlook.

If you don’t want to do this, or if you need a document in a different or more accessible format, please contact us.

How have you raised awareness of the application?

On 26th March 2020 we published a press release to the local press to inform the public of the consultation; and how to respond.

We also published posts on social media informing the public of the application, the consultation and how to respond.

We also advertised the consultation on our website.

We have also informed local politicians of the consultation.

Previous experience shows that this is the most effective way of informing the local community.

For further information please refer to our public participation statement.

What organisations have you consulted with?

We have consulted with the following organisations:

  • Food Standards Agency
  • Newport Harbour Commissioners
  • South Wales Fire and Rescue Service
  • Newport Council (Planning and Environmental Health Departments)
  • Public Health Wales; and
  • The Royal Society for the Protection of Birds

What kind of things will you take into consideration when assessing the company’s application?

Our decisions on whether to issue or refuse a permit or licence are defined by legal requirements.  We are required to justify our decision within the boundaries of these legal limitations. 

For information on what is within our remit to consider, see our public participation statement.

Will your decision be published to the public and will there be a period for consultation and challenge before the report is final?

Yes, we consult at set times and for set timeframes during our regulatory decision-making process, to give people and organisations an opportunity to comment and challenge.

There is an initial consultation period when an application of this type is first received.

When we have completed our determination, if we decide to refuse the changes, there is no need to consult and we would publish our decision.   

If following our determination we propose to allow the permit changes applied for, we would consult again to allow people to see our proposed decision and how we’ve come to it. People and organisations have a further opportunity to comment on and challenge our draft decision, and we would take these comments into account when making our final decision.




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