Scottish Affairs Committee - A Robust Grid for 21st Century ScotlandWritten evidence submitted by SSE
About SSE
1. SSE is a UK-owned FTSE 30 company with over 20,000 employees and a £1.6 billion annual investment programme until 2015. It is the largest renewable generator of electricity in the UK with nearly 2.5GW of capacity, and the second largest generator overall. It supplies over 9.5 million customers with electricity and gas through its Southern Electric, Scottish Hydro, SWALEC and Atlantic brands. It also has interests in telecoms, water, and contracting services.
2. Scottish Hydro Electric Power Distribution and Scottish Hydro Electric Transmission (along with Southern Electric Power Distribution) are subsidiaries of SSE Power Distribution, and are part of the larger SSE group. It is responsible for maintaining, repairing and investing in the electricity networks in the North of Scotland and Central Southern England.
3. The Scottish Hydro Electric Power Distribution (SHEPD) network is over 46,000 km long and serves 740,768 customers over an area of 55,000 km2 in the North of Scotland. That equates to nearly 24 customers per km of overhead line, in comparison to our network in Southern England which has almost 110 customers per km. In Argyll and West Highland there are only 12 customers per km of overhead line. In fact SHEPD covers 25% of the UK land mass but has only 2% of the customers.
4. Even given the geographical difficulties of maintaining the network, SHEPD has managed to improve network performance with the average fault rate high voltage network over five years at 5.7 per 100km opposed to 9.1 per 100km nationally, according to figures from the Energy Networks Association. SHEPD has an investment programme of nearly £160 million over the next 4 years, to upgrade and maintain infrastructure to improve the resilience of the network.
5. SSE welcomes the opportunity to submit evidence to this inquiry. This initial evidence was requested by the Committee and is intended to inform the Committee in the early part of its inquiry. SSE will submit more detailed evidence by the Committee’s deadline of 2 February.
Summary
This winter (in fact four weeks spanning December and January) has seen five exceptional weather events, to put this in perspective, the average year in the past decade has had less than three exceptional events.
The storm winds experience on Tuesday 3 January 2012 resulted in the loss of power to approximately 40,000 customers in the Scottish Hydro Electric Power Distribution area.
Scottish Hydro Electric Power Distribution experienced 600 separate faults and 1,000 points of damage in one day on 3 January.
Over 700 people were involved in restoring electricity suppliers, in some cases parts of the network had to be completely rebuilt as it was so badly damaged by wind debris and fallen trees.
On 3 January 2012 SSE’s Emergency Service Centre received 75 times the daily average number of calls. Throughout the storms the emergency service teams took over 35,000 calls from customers and made thousands of calls to vulnerable customers. This is a 50 fold increase—250 calls per day to 12,000.
Severe Weather so far During Winter 2011–12
6. So far this year there has been six Exceptional Events (five weather related, one third party damage), with a number of winter months still to go. To put this in perspective, the average year in the past decade has had less than three exceptional events, and meant that there was the equivalent workload of eight months normal fault activity in four weeks.
7. Winter 2011–12, has been an unprecedented year for electricity networks in the North of Scotland, with December 2011 having the strongest westerly winds since December 1974 and it was also exceptionally wet in western Scotland with over twice the average rainfall (Meteogroup). The high rainfall has an effect on the stability of trees in water saturated ground.
8. Wind gusts of up about 90 mph generally cause one or two faults on a circuit and when a repair is carried out supplies are generally restored. When wind gusts start to exceed 90 mph there is generally multiple damage per circuit and any particular repair may well not restore supplies as there will be multiple repairs required per circuit.
9. Below about 90 mph damage from trees is generally restricted to a small number of trees per circuit but when wind speeds exceed 90 mph trees within falling distance are blown sideways or roll down hillsides into our lines. The Forestry Commission estimated that 300,000 m3 of its forests were damaged in the storm force conditions in early January, which represents 10% of its annual production. This figure does not include the additional figures from private forestry.
Summary of the Storms—3 to 7 January
10. The storm force winds of over 90 mph experienced on Tuesday 3 January 2012 had affected Argyll and Bute and parts of Tayside resulting in a significant amount of damage to the network, resulting in the loss of power to approximately 40,000 properties in the SHEPD area.
Tuesday 3 January—40,000 customers without power. 31,000 customers had their power restored throughout the course of the day (77%).
Wednesday 4 January—Although good progress was made with restoration, the return of strong winds overnight resulted in further damage to the network, resulting in around 9,000 homes still being without power the next day.
Thursday 5 January—9,000 homes without power at the start of the day. The vast majority of these were restored with 800 remaining without power overnight Thursday (98%).
Friday 6 January—the remaining 800 properties had their power restored over the course of the day.
|
Argyll & West |
Max Gust Speed (Mph) |
|
Port Ellen |
97 |
|
Campbeltown |
92 |
|
Dunoon |
90 |
|
Brodick |
84 |
11. SHEPD experienced 600 separate faults and over 1,000 points of damage in one day on 3 January 2012 and undertook the equivalent of three months of fault repair work in four days.
12. In particular Argyll & West Highland had an additional difficulty due to length of circuits and topological challenges and this in part meant that restoring its power was more challenging. The average length for high voltage distribution network in Argyll & West Highland circuit is over 30km, in comparison to just over 10km in the North East of Scotland and 4km in of network in the South of England.
SHEPD Response
13. Over 700 people, working for SSE from across the UK and Ireland, were involved in restoring electricity supplies, and in some cases parts of the electricity network had to be rebuilt as it was so badly damaged. When wind conditions eased, and where safe to do so, helicopters were used to speed up the process of identifying the extent of damage to power lines. Three helicopters flew every day where conditions allowed from Wednesday onwards. Additional mobile generators were brought into some of the worst affected areas as access allowed ensuring customers had their power supplies restored much quicker.
Communicating with Communities
14. During the storm conditions the volume of calls received by our Emergency Service Centre also increased dramatically and can be seen below, but on 3 January it received 24,866 calls on 3 January 2012, 75 times the winter daily average. See table below:
|
Nov-11 |
Dec-11 |
|
|
Daily Max |
1,597 |
19,518 |
|
Daily Average |
330 |
2,258 |
|
Monthly Total |
9,912 |
67,754 |
15. Additionally the Centre proactively contacted thousands of vulnerable customers to ensure provisions were made to ensure that there was adequate support. Support included SHEPD offering accommodation to many customers who were off supply overnight, in addition to over 500 beds that were booked for staff repairing faults per night in hotels/guest houses throughout Argyll. SHEPD also organised 5 hot food catering vans and worked with the Scottish Hydro shop in Rothesay to provide food and refreshment facilities. Less mobile members of the community were transported to and from the food vans by SHEPD staff as well as delivering hot food and drinks to some of the more vulnerable members of the community.
16. In attempts to innovate in the approach to communicating with customers SSEPD used twitter to directly communicate with over 300 customers who were without power and over 70 update messages were broadcast using the social networking site.
17. After the storm SHEPD offered to pay an ex-gratia payment of £75 as compensation to every customer that was off supply for 48 hours. This compensatory package went well above the statutory minimum requirements set by the regulator, Ofgem.
Working in Partnerships
18. SHEPD has a well practised and rehearsed 24 hour operation for storms, maximising the efficiency during repairs by making the most of daylight hours, using the overnight period to prepare properly for the following morning. Before, during and after storm events, SHEPD, has a very good relationship with a number of communities, local authorities, NGOs, emergency services and the Scottish Government, amongst other stakeholders.
19. This being said, SHEPD is not complacent with its performance during the recent storm conditions which have been unprecedented. SHEPD recognise that there are a still a number of winter months to go, and is looking to engage proactively with all relevant stakeholders to ensure that future performance is continually improved by learning from the experiences of every storm event.
APPENDIX
GRAPHS HIGHLIGHTING EXCEPTIONAL WINTER 2011–12
(EE = EXCEPTIONAL EVENT)
23 January 2011