Tides and the Jan 5th storm 2014

In this post I look at how exceptionally strong tides over the first few days of January 2014 could have played a role in the severe storm that hit the UK on the 5-6 January.

Meteociel.fr provide twice daily (midnight and midday) pressure maps of the polar regions which show how the polar Jet Stream changes rather well. The Atlantic storms last winter were all spawned in a region near off Nova Scotia where warm tropical air meets cold polar air creating instability. Did high spring tides play a role in triggering these storms? The video below shows an animation of the horizontal tractional forces acting on the Jet Stream as spring tides sweep through the Atlantic. Maximum spring tides were experienced 3-6 January which also led to coastal flooding on UK shores.

Early january saw the strongest tides of 2014. The figure below shows the relative magnitude of the combined solar/lunar gravitational tides. At the equinoxes spring tides at new moon and full moon  tend to be roughly equal, whereas in winter it is new moon tides that dominate. The chart below was prepared by Roberto Madrigali
TIDES-STORM-AND-RAIN2014

If we look in more detail at the January storm we see that large tides sweeping across the Atlantic may have affected the unstable convergence of warm tropical air and cold polar air east of Canada. This was where the very low pressure January storm was spawned.

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A tongue of warm air enters from the Gulf
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Low pressure begins to form as air rises
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A very intense low is forming
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This low merges with a pre-existing low pressure system
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The storm is born and moves westward following the Jet Stream towards the UK.

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The storm hits the UK in coincidence with high spring tides along western coasts. Severe damage and coastal flooding results.  The Met Office describe the winter storms

 5 January

In early January, the focus of concern again shifted to coastal flooding, particularly affecting exposed locations in South West England and South Wales. A large area of low pressure in the north Atlantic, driving strong winds and coinciding with high spring tides resulted in exceptionally high waves affecting coastal communities along the South Coast of England and west coast of Wales. In estuaries, the potential flood risk was exacerbated by high runoff from rivers.

Synoptic situation at 1200 UTC 5 January 2014, with a deep area of low pressure in mid-Atlantic driving very large waves towards western and southern coasts.

Met-office-map

The position and undulations of the Jet Stream determine the winter weather over Western Europe and the US. I estimate the horizontal tidal forces acting on on the Jet flow can reach the equivalent of about 5 metric tons per km and tweak the flow every 12 hours as each tidal bulge passes through. Is this enough to trigger winter storms?

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Something Fishy in the air?

I have noticed that wind power delivered to the Grid is always less than 6 GW, no matter how windy it gets. This was clearly demonstrated  on October 21st when wind speeds across the country reached around 50 mph for most of the day. The  wind output was simply bumping along continuously below 6 GW. Something fishy is going on – What is it?

Winds-21Oct

Power-21Oct

The heart of the problem becomes clearer once  you start looking at  the constraint payments made to  wind farms under the Grid’s ‘balancing mechanism’ (see: ref.org.uk). Large wind farms were paid a staggering £2 million on 21st October to disconnect from the Grid. These payments are priced at over £90 for each MWh of ‘generated’ wind energy which is then simply thrown away !

REF

Nor is this an isolated incident. Over the past year constraint payments have been increasing continuously as more capacity has been added. We can see similar periods over weekends last August and April. All these hidden costs for wind are passed on to the consumer through their monthly bills.

6GW-limit

The UK installed wind capacity is 11.2 GW but the effective load capacity on a perfect day of wind is apparently only around a maximum of 60 %.  The Grid simply cannot handle more than 6GW of instantaneous wind power, whereas it has no problem with 30GW of Coal or Gas. I think the problem lies in the Grid topology which is based on large power lines to central generators. The high voltage connections to dispersed wind farms cannot handle large power, and this is made worse by unpredictability. There is really no point adding any new wind capacity until the underlying infrastructure is upgraded. But how much would it cost to completely redesign the National Grid, and is it really worth it when we could simply build large modern gas and nuclear plants compatible with the existing Grid?

This message of course is not what the green Wind lobby want to hear. They want to instal as much as possible because they can’t lose. They get paid whatever happens reaping handsome profits from ‘phantom’ energy. Why are they not also charged for the extra expense to upgrade the Grid?

Finally lets look at the headline wind energy statistics that are often quoted. Renewable Energy UK quote that the UK fleet of wind farms generate 27,263,077 MWh of Energy each year. This is based on DECCs own DUKES review of on-shore and off-shore capacity factors (27.82%). So let’s now look at the actual electrical energy supplied to the Grid over a full year of operations. I have integrated the total energy supplied to the grid over the last 13 months based on hourly monitoring.

Power delivery by Fuel type to meet Peak demand every day since September 2013. Weekdays peak demand occurs around 18:00 and fat weekdays around 20:00.

Power delivery by Fuel type to meet Peak demand every day since September 2013. Weekdays peak demand occurs around 18:00 and at weekdays around 20:00.

The total electrical energy  supplied to the Grid by Wind farms between  1st September 2013 and 1st October 2014 was 22,833,000 MWh. The total energy generated in a 12 month period September to September was 20,217,523,383 MWh.  This demonstrates that up to 26% of the reported energy paid out to wind farms is simply  thrown away. This fact is well hidden from public scrutiny because we all pay for such wastage through our electricity bills. Wind drives energy prices up. DECC and the Wind industry would prefer you not to know because it undermines their economic case for green energy.

Similarly the real ‘savings’ of CO2 emissions from wind were 3 million tonnes less than the official DECC figures of 11.7 million tonnes, and which also ignores the  increased emissions of Gas plants to balance Wind.  The real capacity load factor of Wind Farms was 20.6% and not the quoted 28.7%, once you take into account the discarded excess wind energy.

The real costs of Wind electricity should  be revised upwards by  35%. Only if and when the Grid gets upgraded to handle multiple power lines to such a dispersed energy source as wind can the current DECC and wind industry figures be believed. The costs of upgrading the Grid are enormous and must be factored into the real costs of expanding wind energy. Until the Grid is upgraded  it makes hardly any sense at all to add any new UK wind capacity. That is unless you are a wind operator with  guaranteed 20% return on investment underwritten by the UK government.

Posted in Energy, renewables, Science, Technology, wind farms | Tagged | 29 Comments

Wind power results – 2013/14

I have been monitoring the UK peak power demand every day for the last 12 months, and how that power was delivered. The UK government has invested about £50 billion into Wind energy since 2005,  so how has it performed?

The average Wind component of UK peak power demand was 5.7% over a full year. The maximum power output was 6GW on 21 February 2014 at 18:10, while  the maximum proportion of demand was 16.8% on Sunday 17th August 2014 at 20:08. The minimum proportion was 0.15% on 31st May 2014 when total Wind output was 49MW (0.05GW).

Power delivery by Fuel type to meet Peak demand every day since September 2013. Weekdays peak demand occurs around 18:00 and fat weekdays around 20:00.

Power delivery by Fuel type to meet Peak demand every day since September 2013. Weekdays peak demand occurs around 18:00 and at weekdays occurs around 20:00.

For comparison Nuclear Power averaged 18.1% of demand and never fell below 15%. The bulk of UK power is still met by fossil fuels and it is impossible to imagine a future Grid based purely on Wind power. The mix of coal and gas is interesting. Coal is dominant in Winter while gas dominates in summer. I also monitored the daily energy “trough” or the lowest demand for electricity which usually occurs each day at around 4am . This is shown below.

Power delivery by fuel type at minimum daily power demand (~4am)

Power delivery by fuel type at minimum daily power demand (~4am)

It is Coal that keeps the lights on during winter nights! Gas output is ramped down at night, probably because it is easier to regulate power in Gas power stations. The exception to this is during the summer when several coal power stations would appear to be mothballed.

The statistics for Wind power at night appear better because the overall demand is much less. The average contribution of wind power to minimum demand was 9.8%, and the  maximum Wind supplied was 22.5% on 2nd February at 05:30 (6GW).  However Nuclear also contributes proportionately more at night averaging 30%, which is 10% more than Gas. The difference between the 2 extreme demand curves is shown below over the 13 month period. Note the sharp drop in power demand over the Christmas period.

Daily Peak and Minimum demand  over  a 13 month period Sep 2013 to Oct 2014

Daily Peak and Minimum demand over a 13 month period Sep 2013 to Oct 2014

This analysis makes it clear, to me at least, that the UK should shift the balance of investment towards Nuclear and away from Wind. Even doubling Wind generating capacity to 20GW would still leave some days with essentially zero output, thereby undermining energy security. Furthermore Gas will always be needed with at least the same generating capacity as Wind in order to continuously balance Wind’s erratic output. Nor can energy storage save the day, since it reduces the EROEI for Wind to below sustainable levels.

The data used for this analysis was collected through BM reports – the National Grid balancing mechanism. There are about 10% of wind farms that are not metered by BM so the above figures should probably be adjusted upwards by 10%. The conclusion is the same.

The live monitoring of peak demand over the last 30 days is shown below.

Posted in coal, Energy, nuclear, renewables, Science, Technology, wind farms | Tagged | 35 Comments