UK gas storage capacity slashed

A couple of weeks ago Centrica Storage quietly made an announcement on its website:

As part of CSL’s assurance programme and as a responsible operator and given the age of the field and installation, CSL has decided to limit the maximum operating pressure of the Rough wells to 3000 psi. CSL has decided to take the prudent step to test and verify the operating parameters of the Rough wells. It is anticipated that this limitation will last up to 6 months.

 Rough is an undersea gas storage facility, connected by pipeline to the terminal at Easington in Yorkshire:

It's able to store about 4 billion cubic metres of gas - or at least it was before the above announcement. Some more detail from Platts indicates that the reduction in operating pressure will reduce Rough's capacity by about a quarter. Because Rough comprises about 72% of the UK's total gas storage, this is equivalent to losing just under 20% from total storage capacity.

Now, Centrica Storage has said this is for six months, while tests are carried out, but Platts notes that the tests are needed because of concerns about well integrity - so it's possible that the capacity will be permanently reduced. Even if it isn't, the coming six months are exactly when the storage is normally refilled, so if full capacity is restored at the end of the testing period, it may well be too late to completely fill the storage.

So, let's assume the UK goes into next winter with 1 billion cubic metres of gas less in storage than usual - what might the impact be? 2013/14 was a mild winter, and Rough still had over 1.5 billion cubic metres left in it in March 2014. It was a different matter in April 2013, when it had actually gone below 'zero', eating into the gas cushion that was supposed to be left untouched. This year, there's about 0.5 billion cubic meters left in it right now - the situation was similar every year from 2008-2011 inclusive. This means that if the coming winter is mild, we should have no problems; if it is average, then we will probably need to increase imports, which will bump up prices; if it is cold, then we could well have a problem.

The graph below shows the levels in Rough over the past few years in GWh (10 GWh is about the same as 1 million cubic metres), so you can see the situation for yourself. Any year where the level dropped below 10,000 GWh is a year when the announced capacity reduction might have been a problem:


Let's hope and pray for a mild winter!

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Gas Bills 'Could Rise' Due To Low Reserves

Good to see that some people are aware of the issues the UK has with gas supply - Sky News in this case!

Gas prices could soar this winter if the national supply runs short during another cold snap, an energy expert has warned. Industry analyst Peter Hughes told Sky News that a "perfect storm" last March of extreme weather and the shutdown of two major pipelines caused prices to double. And that could happen again because the Government has refused to support the storage of more gas. "It foreshadows things to come," he said.

"The situation in terms of the risks will only get worse as North Sea production runs down and demand rises. That's the double whammy. And if you don't have more storage that translates into real vulnerability."

Britain currently stores enough gas for 13 days of supply. But Germany has reserves to last 69 days, in case there is a problem with the supply from countries such as Russia.

Even the gas storage that we DO have is not always working properly... News out today from Reuters says that withdrawals from Centrica's Rough storage site, the largest in the UK, will be limited for a few hours today and for four days from 21 Nov. More importantly perhaps, no gas can be injected back into for two weeks starting on 18 Nov. Presumably this is all down to maintenance work, but that really should have been completed earlier in the year... Let's hope we get a mild winter!

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Britain's biggest gas storage runs out of normal supply

Following up on my post on Friday, here's a report from Reuters with more details:

Britain's biggest gas storage site ran dry of normal supply on Friday and is using gas usually reserved for the technical operation of the site, National Grid data showed.

Unusually cold weather in Britain has boosted gas consumption, forcing the Rough storage site off Scotland's east coast to take the unusual step of dipping into its so-called cushion or base gas.

What's very useful is that they got some figures out of Centrica on how much of this 'cushion gas' can actually be extracted:

"There is potentially an additional 1.1 TWh (terawatt hours) (100 million cubic metres) that could be produced from the Rough reservoir below this opening stock level... The opening stock published by National Grid may ultimately be at -1 TWh)," Rough operator Centrica said in a regulatory update on Friday.

They finish up by saying:

Gas traders said next week a planned strike by workers on Norway's offshore gas fields could hurt gas flows to Britain.

Supply could also be impacted by unplanned outages because of technical problems that are a regular occurrence in the vast network of gas platforms and pipelines that crisscross the North Sea.

However forecasted milder weather and two deliveries of LNG to Britain due next week could take pressure off prices, traders said.

So, we can draw a further 100mcm, or 1,100 GWh out of Rough below 'zero'. By 6am on Sat 6 April 2013 we'd already drawn 290 of these GWh of gas out of there, as shown by this screenshot taken from the Prevailing View page:

 

Thankfully it's warming up now, because soon this store really will be empty... The problem, and cost, of refilling it in time for next winter still remains though...

Mike

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UK long-range gas storage drained

Yesterday (4 April 2013) afternoon, the UK long-range gas storage facility at Rough went 'below empty' for the first time. This is possible because Centrica normally leaves some 'cushion gas' in the depleted Rough reservoir to make sure there’s enough pressure to keep it flowing properly. Here's the status, taken from the Prevailing View page, showing figures valid for 6am on the 3 and 4 April 2013:

The 4pm udpate today gives the Long Range stock level as -132 GWh, a negative stock level! I got this from the spreadhseet on this page, as the Prevailing View is being a bit slow to update today - maybe it's struggling over what to do with a negative stock level?

It was clear this was going to happen, because the Entry Zone graphs have been showing gas flowing out of Rough at over 20 mcm/day (image shows 24 hours from 4-5 April 2013):

20mcm is about 220 GWh, so with only 108 GWh in Rough yesterday at 6am, it was clear we were going to dip below zero. The fact that we are now burning through this normally untouched 'cushion gas' reserve is a sign of the problems we have right now, and does not bode well for next winter, as everything that is pumped now ought to be put back in before the end of October to guarantee winter supplies.

According to National Grid, gas can be injected into Rough at a rate of 220 GWh/day, and the maximum capacity is 39,405 GWh. In practice, the injection rate varies according to the stock level, because the more gas is stored, the higher the pressure, so the harder it is to force more gas in. I've plotted injection/withdrawal rates vs. stock level from 2007 to date on the graph below (click for a larger version on Flickr):

As you can see, the injection rate can get up to around 300 GWh/day when the store is nearly empty, but drops steadily towards 220 GWh/day as it fills, and drops quickly to 100 GWh/day when it is nearly full. Withdrawals are relatively unaffected by stock level - they are lower at the top end simply because demand is lower, and there are tentative signs of them dropping off a bit at the bottom end, presumably because of the falling pressure.

Anyway, if we assume 220 GWh/day is an average value, this implies 179 days, or about six months, to refill from empty. This year, we will be starting from below what is normally considered 'empty', so it seems unlikely that we will be able to refill the long-range stores by the end of October. Another barrier to refilling storage is planned outages, with the UK's Teeside gas terminal undergoing maintenance from tomorrow and possible reductions in Norwegian gas supplies to the UK from Monday, according to Reuters.

Combine the above with the shutdown of several GW of coal-fired power stations in 2013 and the continuing decline in North Sea gas output, and it is clear that wholesale gas prices are going to stay very high throughout 2013. This will inevitably feed through into higher gas and electricity prices for domestic and business customers, as the alternative is to let the lights go out.

The only action that can be taken in the time available is to launch a crash-programme of energy saving between now and Autumn, insulating homes, improving heating system efficiency and persuading people to wear warmer clothes and turn the thermostat down. Doing this brings a direct benefit, as your heating bills will come down, and if enough of the UK population does it, the reduced demand could help reduce wholesale prices too, as we will be able to import less gas.

Will this action be taken by more than a handful of people? Sadly, I doubt it, as nobody in a position of power is pushing for it.

Mike

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