Our responsibility for the environment as a major power supplier goes beyond reducing carbon dioxide and we manage our wider environmental impact, including other emissions to air, discharges to water, disposal of waste, biodiversity and the responsible use of natural resources.
At Drax Group, we are committed to being an innovative leader in the management of the environment across our business activities. Our Group environmental policy outlines our approach.
Our Environmental Management System (EMS) covering Drax Power Station and its associated ash disposal site is certified to ISO 14001. We are committed to complying with all relevant environmental legislation. During 2017 there were no major or minor breaches of our environmental permits at Drax Power, compared with two minor infringements in 2016. We periodically review our environmental objectives and targets for Drax Power, such as zero environmental permit breaches. Our EMS is externally audited twice per year.
At Drax Power, our environmental enquiries procedure ensures that any grievances we receive are thoroughly recorded and investigated within an appropriate period of time and that corrective actions are taken where necessary. In 2017, Drax Power received five enquiries which we subsequently investigated and resolved.
In addition to carbon, we manage our other emissions to air, including sulphur dioxide (SO2), nitrogen oxides (NOX) and particulates. All our emissions to air in 2017 were well within the compliance limits set by the Environment Agency. Our mass release of sulphur dioxide, nitrogen oxides and particulates have reduced significantly over the last ten years and nitrogen oxide emissions alone have reduced by around 70% since 2007. In 2017, our total SO2 and NOX emissions did increase, by 7.2% and 1.4% respectively.
Our coal units all use flue gas desulphurisation equipment, which reduces emissions of SO2 to within current and anticipated regulatory limits before the flue gas is released via the chimney into the atmosphere.
In 2008 we completed a programme to retrofit all units with primary low NOx technology – Boosted Over Fire Air systems – to ensure compliance with the NOx limits under the Large Combustion Plant Directive (LCPD) which were strengthened in 2008.
In order to meet the requirements of the European Union’s Industrial Emissions Directive which superseded the LCPD from 2016, we are investing tens of millions of pounds to implement a number of further NOx abatement measures. We are working to reduce the NOx emissions at Drax Power Station through the installation of selective non-catalytic reduction technology. We measure gas composition and temperature by means of an array of lasers fitted to the sidewalls of our furnaces. The lasers scan for furnace exit gases – the information gathered is then added to other emissions data to provide real-time feedback, enabling us to optimise combustion in order to optimise emissions of NOx and carbon monoxide.
Drax Power Station complies with all UK and EU emissions limits and we report our data to the Environment Agency (EA) on a quarterly basis. The EA scrutinises our data and makes it publicly available.
We are focused on meeting the requirements of the Best Available Techniques Reference document (BREF) published in August 2017. BREF will further reduce air emission limits when it enters into force, which will be no later than mid-2021.
Particulate emission rates from Drax Power Station have increased slightly since 2013, but remain well within the permitted limits. The increase is due to a number of factors relating to the operation of our coal units. These factors include the increasing use of high ash content fuels such as pond fines (the filtered residue of coal washings) and increasingly intermittent “flexible” coal-fired generation.
Where possible, we use fuels such as pond fines. The cost savings achieved from using these fuels, combined with our efficient generating units, helps us to remain economical and keep electricity costs lower for everyone. It also reduces the amount of new coal extracted and burned. However, pond fines have a higher ash content and typically have a lower calorific value, meaning they produce less energy when burned.
In 2017, particulate emissions from biomass were around 20% lower when compared to coal generation, although for reporting purposes the figures for coal and biomass generation are combined.
At Drax Power, we have also been undertaking some testing to identify the impact of the transition to sustainable biomass on the level of PM10 and PM2.5 from biomass combustion compared to coal. The limited testing undertaken has identified that the emissions of both PM10 and PM2.5 are significantly lower for biomass compared to coal, although further research is required in this area.
Total SOX emissions to air
Total NOX emissions to air
Drax Power Station uses water from the River Ouse and much smaller volumes of borehole and mains water. The water we abstract is principally used for cooling, with smaller quantities used in the steam system and ancillary processes, such as our selective non-catalytic reduction equipment that reduces our nitrogen oxide emissions. Around half of the water abstracted for cooling is returned to the River Ouse. Procedures are in place on site to manage and monitor drainage and water systems and ensure that all discharge consent limits are met.
Borehole water use has decreased since 2016, from 2.2 million tonnes to 1.7 million tonnes.
Each of our generating units has a specific water requirement for cooling, which is a key factor in operating the unit efficiently. We strive to find opportunities for process optimisation, such as turning off the cooling water pumps when possible to aid further resource and efficiency gains. We monitor a number of flow meters around the station for excessive demand, which allows us to investigate and address significant leakages.
As our business has moved towards increased biomass generation and the electricity market has evolved, our coal-generating units are not required to run at as high an output as they have historically. These units are increasingly required to be more flexible such that they need to be turned off and on more often than in the past. This has the effect of increasing the volume of water used per unit of electricity generated from these units (the rate of use), although the total volume of water used will be lower as the coal units do not operate for as long. The increased number of starts also increases the amount of boiler water required compared to units running at baseload (the permanent minimum power load that the national grid is required to deliver).
Drax Power is striving for zero waste to landfill by 2020 other than the disposal of asbestos and ashes, and we have been undertaking research to identify alternative disposal options for difficult waste streams. In 2017 total waste production fell 28% compared to 2016. Of our waste generated, 92% was diverted from landfill.
The burning of solid fuels produces pulverised fuel ash (PFA) and furnace bottom ash (FBA). Our operations produce on average 700,000 tonnes of ash every year. To ensure that these materials are utilised as products, they are produced to conform to European construction product standards. Around 750,000 tonnes of our ash products are sold into the construction industry every year as a replacement for virgin aggregates and cements.
The ash content of compressed wood pellets is much lower than coal. Less ash is produced as we make electricity with pellets. We consider biomass ash to be a valuable product – not waste – and we are currently exploring suitable markets. Now that we are generating more than two-thirds of our electricity using compressed wood pellets rather than coal, we are producing much less coal ash. As of mid-2016, several of our coal ash customers are utilising wood pellet fly ash and we are working with universities to find new, innovative applications for it, for example within agriculture for the FBA.
We pay landfill tax on the PFA disposed at the Barlow Mound. Through the Landfill Tax Credit Scheme, we are able to claim a tax credit against our donations to recognised environmental bodies.
Gypsum is also produced as a by-product of our operations at Drax Power and is sold for use in manufacturing products such as plasterboard.
At Drax Group, we actively work with others to consider biodiversity and improve our management of it. Our Group sustainability policy requires that the biomass pellets we use do not adversely affect protected or vulnerable biodiversity and gives preference to biomass production that strengthens biodiversity. Across our biomass supply chain, we carry out regional risk assessments to identify biodiverse areas which may not be adequately protected by local legislation. With this knowledge, we can then ensure that our suppliers are not just complying with their own local legislation but also that where appropriate additional protective measures are applied .
Our Skylark Centre and Nature Reserve is open to the public and regularly offers experiences for schoolchildren to learn about nature and ecology.
We also manage and maintain Barlow Mound, the restoration of which has had a positive impact on biodiversity locally. The ash disposal site has been transformed into a mix of agricultural grazing, woodland and wild flower meadows.
- Further strengthen external reporting and assurance