Drax biomass running at half capacity

Breakdowns and planned shutdowns meant the plant had a technical availability of 76%, but Drax’s currently limited storage facilities for biomass fuel - it can hold just two days’ worth of material - has forced it to operate on average at a load factor of just 57%.

The unit, which has been operational since April, has achieved output levels of up to 585MW, but generating capacity has typically varied between this peak and a lower level of 250MW.

“With only two days’ storage it doesn’t take much of a supply chain disruption to affect the operation of the unit,” Drax production manager Peter Emery told Process Engineering.

Drax’s first biomass unit to be converted from a coal-fired system, which will be followed by two more 585MW units from next year onwards, currently burns around 6,500 tonnes of material each day.

With two days’ storage it doesn’t take much of a disruption to affect the operation of the unit

Drax production manager Peter Emery

The plant currently on average holds around 12,000 tonnes of biomass feedstock, with the materials that Drax uses including sustainable forestry and forestry residues, residual agricultural products, such as straw, sunflower seed husks and peanut husks, and purpose grown energy crops.

It is in the process of building new delivery, storage and distribution systems that Emery said would enable the unit to run at a much higher load factor. This includes a dedicated rail freight facility, while the storage element will be two domes, each capable of storing 75,000 tonnes of material - effectively at least 20 days’ storage.

EPC contractor Shepherd Engineering Services has hired Capula to deliver the control and automation systems for both the biomass storage domes and the biomass boiler distribution system. Capula intends to use Schneider products for both control systems.

Drax hopes the storage and distribution systems will be in place by the end of this year.