Utter Tosh from Frost & Sullivan !
May 12, 2010
Please someone pinch me ! I’ve just read this article on the Renewable Energy Focus website, which usually has some good pointers to decent reports, but this press release is just stoopid.
Apparently HVDC is the only viable transmission system for offshore wind (which its not) but it suffers from being too expensive at short distances (which it does) and apparently AC doesn’t work under water (?!?).
Now, news aggregators like REF can’t check everything. Its simply not economic to do so. But when a press release starts with a direct contradiction to existing reality (quote “Underwater electricity transmission is not possible with alternating current”) you have to at least have a flirt with checking the source.
I couldn’t get a hold of the report that this press release is publicising. Frost & Sullivan don’t give away their “research” for free, but if the report is of a similar quality to the press release I don’t want to read it !
For the record ALL the UK’s current offshore wind installations use AC transmission. HVDC is hampered by its expensive transformer/rectifier costs which mean that you need to have a cable run over about 30km before it’s better performance in terms of lower transmission losses outweigh the extra upfront expense in hardware.
Yes, its true that with more installations that cost will come down, but it will always remain as long as the onshore grid is AC. If you take the extreme example of Scroby Sands, 2.5km off Gt Yarmouth’s seafront. That wind farm just plugs straight into the grid through a small sub-station with no need for extra rectification kit. If it were forced to use HVDC you would need a rectifier at either end to gain virtually nothing in decreased transmission losses over 2,500m of cable.
So Mr Frost & Sullivan. Your report is wrong. Your press releases are misleading. How’s business ?
Superconductors – Part Four A New Hope
January 11, 2010
Superconductors have been around in the labs for decades now. They have been a mainstay of high-end scientific research and niche medical applications for decades, but on the industrial scale they have always been a bit to expensive to run in mass market applications, like the energy sector. Theirs has been a story of potential energy efficiency boosts, power savings, zero transmission losses and all the first order energy system changes that no-one is against. Its time to take a look at them a little closer since I dismissed them so off-handedly in my previous post regarding the North Sea super grid.
Crash course
Superconductivity was discovered 99 years ago.
Different materials become superconductors at different temperatures.
HTS (High Temperature Super-Conductors) are defined as having a transition temperature above 30K (-243C), and the highest temp superconductors have a validated operating temperature around 135K. The boiling point of liquid nitrogen is 77K, so this has made HTS much more accessible and practical as nitrogen is commonly used as a liquified gas.
However, recently an HTS material that operates at 254K (-19C) has been claimed. This would clearly be a massive leap forward as standard compression-cycle refrigeration techniques could be used rather than immersion in liquified gas. Obviously these are lab findings and there is no guarantee that production of these materials could be scaled up to industrial quantities (they use some relatively commonplace elements, so there shouldn’t be any resource availability problems for once). The standard 10 years+ from first publication warning applies here i.e. no field application will arise from a lab discovery within 10 years of first publication.
So industrially we are looking at the 135K materials, which is still OK, but not the massive jump that we’d all like to see.
Energy Applications
Cabling – Zero transmission losses over long distances, or high capacity transmission without the current massive infrastructure (overhead pylons) are the main lures.
Power:Weight improvements – instead of copper conductors, using HTS in motors greatly increases their power:weight ratio. The applications in electric vehicles are obvious, so I won’t labour that point, but also consider all those static motors in air-conditioning units, factory assembly lines, and my personal favorite the conveyor belt. The infrastructure to hold these in place could be smaller and lighter, their maintenance quicker and safer as well as their operating costs lower.
For ‘motors’ also read ‘generators’ and you see the application for wind turbines and other renewable generating technologies. Smaller lighter nacelles means smaller lighter towers, means cheaper generating capacity and lower maintenance costs.
Renewable Energy Focus has done this two parter (Part One & Part Two) which covers all these much better than I ever could. You’ll need to subscribe for free to access the full articles, but its worth it.
The take home from these two articles is that super conductors should be on the shopping list of industry. I was too quick to dismiss them for the North Sea grid. With 150 times the carrying capacity per unit weight and 1/3 of the transmission losses superconducting cabling should be the first option for mega projects, not the last.
When/if those properly room temperature super-conductors reach the supermarket shelves a revolution will take hold.
Big Wind Movements
January 9, 2010
Round three of the UK offshore wind tender process totaled 32.2 GW of nameplate generating capacity. That’s a lorra lorra windmills and well above the expected 25GW power output. Lets be middle of the road and say for the sake of convenience that 3.22 MW turbines exist, that’d be 10,000 turbines located between 22km and 190km from the nearest landfall.
The London Array has started to hand out contracts. Nexans, the submarine cable specialist, has won the power export (windfarm to shore) cable contract. It is 100M Euro for 4x 53km long 150kV capacity copper cables to carry up to 1GW of power from 175 turbines.
If we do a quick bit of maths on that for 32 times the power, roughly twice the distance and 57 times the number of turbines, if the Round Three windfarms use the same technology as the London Array, the export cables alone should cost in the order of 6.5bn Euros (not including inflation or commodity risk). Using my previous estimation of the intensity of copper use in wind power, 10,000 offshore turbines and their associated cabling will use around 310,000 tonnes of conductor grade copper. Copper’s current price is around US$7,200 per tonne giving an embodied copper cost today of US$2.23bn. By the time these windmills get built, that figure looks cheap to me.
Perhaps that’s why the North Sea Supergrid got a bunk up the probability ladder by the nations next to the water. For an estimated one-off cost of 30bn Euro you get a ‘local’ connection, cutting the need for those expensive connections to shore and you get the ability to load balance using Norway’s hydro power excess.
If I had an extra billion or two I’d be looking at building a submarine cabling capacity right now. Not just the cable factory but the cable laying vessel and some upstream capacity in copper recycling. It’d be nice to think that we’d be at super conducting cables for this job, but at 6,000km total length and multi-GW capacity I’m not sure that the tech will be with us in time. Looks like HVDC instead, shame.
One Hundred and One Nights
August 28, 2009
With just over three months to go until the Copenhagen session of the United Nations Convention on Climate Change and less than a year left in office Ed Miliband his folks at DECC are working overtime.
The latest consultation is on improving grid access. Now I don’t pretend to understand all the details of how the process works right now or how the Security and Quality of Supply Standard (GB SQSS) and BETTA interact, but given that less than four years after BG SQSS’s introduction its proposed that it be completely re-written I’d surmise that its not been an un-alloyed success.
The fact of the matter is that there are literally dozens of electricity generating projects waiting in a queue to be connected to the grid. DECC estimates that projects totaling around 60GW of capacity is waiting for a date that they, and their investors, can work to. That’s a lot of advanced projects sitting on the shelf, waiting for a market into which they can sell their product. Not all of them will get all the way to production, but still that is a very slow queue when, lets face it, we could do with the work and the UK’s grid could do with some action on replacing the big coal plants that have to be phased out under the EU’s Large Combustion Plant Directive.
On a lighter note with COP15 just around the corner the government appears to be starting to flap. Malcolm Wicks wants a tripling of nuclear power while Ed Miliband was again vilified by some in the UK over coal plans after a speech to the South African Centre for CCS , while £1 billion of loans are guarenteed for offshore wind and £10m of grants to its even offer shore floating cousin (I’ll say some more on offshore wind at a later date).
Its all starting to look a bit desperate. You can make your own mind up as to why, but I have to ask who are we trying to impress here ? Most commentators agree that there is little point trying to appeal to UK voters, except maybe on a ‘look what we achieved last time we were in government’ ticket in 2014/15. The US is busy trying to convince itself that we kill our grannies as a matter of health policy. The Russians hate us. The Chinese couldn’t give a damn. So is it the Commonwealth that we are playing to ? A wider alliance of minor nations that will buy our climate friendly products after we defend their honour at COP15 ? Who is it ?
The answer may come in 101 nights time.
