Q3 2019: Headlines

by Dr Iain Staffell – Imperial College London

The biggest event of the last quarter was undoubtedly the blackout of August 9th which left over a million people without power and caused travel chaos. 

We deep dive into the event and find that while there are several lessons to learn, Britain has one of the world’s most reliable power systems and so further improvement will be difficult to achieve (see our special report on the blackout).

The plummeting cost of renewable energy also made headlines. Over 5 GW of new offshore wind capacity was auctioned for around £40 per MWh – well below the recent wholesale price of electricity. These could potentially be the world’s first offshore wind farms with a negative subsidy, meaning they pay money back to consumers (see Article 3).

Increasing the share of renewables will be essential for meeting the UK’s net-zero target, but this will create unprecedented challenges in balancing the power system. While wholesale electricity prices have fallen to a 3-year low, the cost of balancing the power system hit a record high of £3.80/MWh last quarter. For the first time, keeping the power system stable makes up a tenth of the total cost of generating electricity.

We look at the role of energy storage in helping to balance Britain’s power system. Article 4 looks at some technologies to watch out for in the future, and Article 5 investigates how Britain’s storage capacity may need to increase 10-fold in the coming decades.

The last three months saw nuclear output down 20% and wind up 33% on the same period last year. Coal output reached its lowest levels since the 1920s, supplying an average of less than 1 GW over the past year (see Article 6).

Generation from fossil fuels hit record lows in Quarter 3, and the carbon intensity of electricity also entered new territory. For the first time ever it fell below 50 g/kWh for an hour and below 80 g/kWh averaged over a day. September’s carbon intensity was under 160 g/kWh – some two-thirds lower than this time five years ago. This brings the average carbon intensity over the last 12 months to below 200 g/kWh for the first time – another major milestone on the road to zero-carbon electricity. (see Article 7).

The quarterly-average price of generating electricity and balancing the system¹ over the last decade in £/MWh

1: The costs incurred by National Grid to maintain system stability, including ancillary services such as frequency response and voltage control.

Lead author: Dr Iain Staffell