GeoThermal on a Big Scale

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Private GeoThermal on a Large Scale

A company called Süddeutsche Geothermie-Projekte GmbH part owned and financed by Hochtief, plan to build and operate the first entirely privately financed Geo-Thermal power plant in Germany.

The company will build and operate a 5 megawatt facility with an investment €35 million which will be located in Dürrnhaar in Bavaria.

According to publicity by the company, theoretically, geothermal energy plants could provide Germany‘s annual electricity consumption 600 times over. SGG also intends to use the hot water tapped in the earth‘s crust for combined heating and power and provide heat to households and industrial users in the vicinity of the power plants.

Look at that drill bit!!

Another subsidiary, Streif Baulogistik, is investing in a 52-meter tall drilling rig for drilling the boreholes, which are up to 5,000 meters deep.



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Wood Pellet Boiler Burner Price Update

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October 2007
Danish and German
Wood Pellet Boiler prices

Denmark.



A 16 Kw Boink Boiler Burner and Feed-screw set in Denmark including their higher 25% VAT is €3421 incl. tax.

A Boink 16Kw burner unit on its own is €1928 inc. tax. A 24Kw Boink burner unit is €2095 incl. 25% Danish VAT.




Germany.


A Scotte 15Kw boiler, burner and feed-screw set in Germany incl German VAT Oct 2007 price is €3265 inclusive.

How do these compare with Ireland rip-off pricing for 2007??



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Solar Cells Under 50 cents per Watt

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Solar Panels at 36 Euro Cent per Watt!!!

Conrad Burke, an Irishman, is the CEO of US company called Innovalight. The company have developed a new way of making Photo Voltaic Solar Panels using a special printing technique. The ink used to print the active substance on the panels is a secret recipe using nano-technology, the new buzzword in science.

Innovalight creates nano-particles of silicon that it uses to make the special ink which can then be sprayed, by inkjet type process, onto the backing panels. The results will be something that looks not too different from other solar cells, except that they will be substantially faster to produce and much, much cheaper because a great deal less silicone is used in the process.

Solar cells at less than 50 US Cents per Watt!!

The company believes the technology has the potential to get solar cell prices well below 50cents US per watt. The current retail price for solar cells in the US is just under $5 per watt.
Innovalight has recently had $28 million in funding pumped into it. The company, based in Santa Clara, intends to start selling its new solar cells in 2009.



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Biomass Gasification

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Major Development of Biomass Energy Technology

Nexterra Energy Corp. (www.nexterra.ca) has supplied its gasification technology as a key component of a US $16 million biomass cogeneration plant Johnson Controls is building for the University of South Carolina (USC).

Once operational, the gasification cogeneration facility will convert wood residue supplied by local sawmills into clean renewable energy that will help the university become more energy self-sufficient, reduce its reliance on fossil fuels and lower energy costs. At peak capacity, the plant will generate 60,000 lbs/hr of steam which will be used to heat the campus, as well as 1.38 MW of electricity that will be sold to the grid.



Nexterra Energy Corp. and Johnson Controls have developed patented gasification technology converts biomass into clean burning syngas (Syngas (from synthesis gas) is the name given to a gas mixture that contains varying amounts of carbon monoxide and hydrogen generated by the gasification of a carbon containing fuel to a gaseous product with a heating value.) that can be used to replace natural gas or oil to generate heat and/or electricity. The companies jointly develop biomass gasification projects that will enable users to reduce energy costs, lower greenhouse gas emissions and become less reliant on fossil fuel by using locally sourced, renewable biomass fuel.

About Johnson Controls – Johnson Controls (NYSE: JCI) integrate technologies, products and services creating smarter environments. Our team of 140,000 employees creates a more comfortable, safe and sustainable world through our products and services. For additional information, please visit: http://www.johnsoncontrols.com/.

About Nexterra Energy Corp. – Nexterra Energy is a developer of advanced biomass gasification systems that enable customers to self-generate clean, low cost heat and/or power using waste fuels "inside-the fence" at institutional and industrial facilities. Nexterra is a private company based in Vancouver, BC, Canada. For more information, please visit: www.nexterra.ca.




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7.5 MW Wind Turbine Being Developed

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Mega 7.5MW Wind Turbine Being Developed in the UK

Mega Clipper Wind Turbine

US company Clipper Windpower has announced that it is to develop the world's largest offshore wind turbine of 7.5 MegaWatts at Blyth, United Kingdom. These monsters will be used in the worlds larges off-shore wind farm planned to date. (Wonder for how long that will hold the Guinness Book of Records??)

They currently make a 2.5 MW turbine called the Liberty. The Liberty C100 has a tower of 80 meters height. The blades are 48.7 meters long. The diameter of the rotor is 100 meters. Compare that to a 747 jet which has a wind span of 64.4 meters - this baby's span is half as big again and this - is only the baby!!

I love this kind of technology - don't you?



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Plurion Battery further Comment

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Some More Comment on Plurion

I have just received this further note from my last correspondent, it is enough to make me feel a bit uneasy if I had a lot of money stuck in the project:




Hi there,

And might I just add this thought (same request that confidentiality be respected);

Batteries are constantly being developed. Scientists in the battery industry know what data to look for: open circuit voltage; voltage under load (varying load); battery capacity for shallow and deep discharge; battery life (decrease in capacity with number of cycles); battery life - self-discharge; charging/discharging rates, variation in capacity with discharge rate. effect of ambient temperature on capacity.

Some of this data for the Plurion system was presented at the San Francisco 2002 Meeting. It seems none has been shown since. That a large-scale battery be due to be delivered, as Dr Vallance states, in approx. 12 months from now, without at least some such data being available, strains credulity. If Plurion have this data, there is absolutely no reason why they should not present it. If they're not in a position to do so, one must question just how far down the "development" road they really are.

Regards.



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Questions about Plurion the Technology and the Company

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Some Questions about Plurion and their Battery

Plurion is one of the exciting looking technology in Redox Battery development. They are claiming some really useful advances in the reliability and capacity of this type of storage.

However, there are a number of questions regarding the actual technology and about the provenance of the company itself. These questions have been very well articulated by one of the correspondents to this blog. This person wishes to remain anonymous, I would guess because of connections with the business and/or work contracts. I totally understand and respect this need for keeping the head below the parapet.

The views published are the opinions of an individual.


The Letter:

I don't know how much you know about Plurion, which started life in California, around 2001, raised $1.5 million from J F Mackie, of Calgary, and a similar amount from Berens Energy, also of Calgary. In the last case, Plurion changed its name to Berens. However the investors were unhappy and, I believe, asked for their money back - and the company changed its name again, back to Plurion.

The underlying technology seems attractive, more so in many ways than the similar technology, the vanadium redox battery, developed by VRBpowersystems in Vancouver. (all of this information is on the web, if you care to look for it). You'll also find a piece entitled "The curious history of Plurion" by Bill Jamieson, financial columnist of The Scotsman.

There's only one small question - does the technology actually work ? The only hard technical information I've been able to locate was a presentation given at a meeting in San Francisco, in April 2002. At one time, this was included in the Plurion website. The data there was extremely promising - incl. a scale-up to 1 sq. metre, which would in fact meet your domestic requirements. But since then, as far as I am aware, total silence for 5 and a half years. Which, given that these guys are skilled self-publicists, I find distinctly ominous. That there appears to have been nothing newsworthy for that length of time, none of the usual developmental milestones, is very odd.

As someone who has been in the field myself, I can guess what the problem might be - which is the behavior of the zinc, which doesn't always "recrystallise" in the fine-grain structure that is necessary. But that's only a guess.

Leaving Plurion aside, you'll know it is a subsidiary of AIC, Applied Intellectual Capital, an AIM stockmarket quoted company. The people behind AIC have a long and - believe me - chequered history of failed R&D companies. I have little doubt that AIC will fail, as did its predecessor companies.

In the October issue of "Chemistry World" is a newsbrief to the effect that a major US wind farm operator have placed an order for a storage battery. They chose the sodium sulfur system, and presumably only after having surveyed the field. VRB have, they state, obtained an order from an Irish windfarm operator. So leaving aside whatever technical problems there might be, Plurion now have a catch-up exercise as well. In terms of energy density, VRB score lowest, then Plurion, with sodium sulfur highest. You might not wish to have to store 2000 liters of electrolyte on your premises (not that it's hazardous, just a lot of liquid to store).

Feel free to use any of the above comments in your excellent blog, any way you choose, but not quoting me.


Many thanks for this very informative and question provoking essay.



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Wind Energy and Battery Storage - a follow-up

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I am delighted to say that this important subject is receiving a good deal of attention, hits on the blog are up, and the e-mails are ticking away. Here is one of the letters I received from Alan Smith and the answer to it from Shay McGowan is reproduced below. Thank you both!!


The Letter:

Hi WoodPellet,

In the Essay Shay says: "The Sorne Hill Wind Farm will now receive €85 for each MW delivered to the grid, the same price as conventional electricity supply such as coal and gas. This will allow the projected rate of return (known as the IRR) to increase from the normal 9-11% to approximately 17.5% according to the study."

This is the only time that I have seen the 85Pounds a MW as a done deal.

The sale to Tapbury was conditional on Tapbury being able to negotiate the higher price.

Could you please give me a verification that it is indeed a done deal.
Or can you please ask Shay if I can communicate with him.

Thanks and Regards
Alan Smith


The Reply:


Mr. Alan Smith is quiet correct. I may have inadvertently sent you an older version of my essay. The sentence should read :

'The Sorne Hill Wind Farm could receive up to €85 for each MW delivered to the grid, the same price as conventional electricity supply such as coal and gas. This will allow the projected rate of return (known as the IRR) to increase from the normal 9-11% to approximately 17.5% according to the study.'

I'd appreciate if you could amend this on your blog.

Thanks,
Shay



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EcoWatts - Airoption's Core Tech - Steorn

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Over Unity Energy Devices and the Moving Statues Phenomena

For some time I have been considering the mind-set of the thousands of people world wide who are either directly involved with, or are born-again believers in over-unity energy claims such as; Steorn's "Orbo", Perendev's "Magenetic Motor", Airoption's "Core Tech" heating, or EcoWatts "Heater".

I do believe that the majority of the people involved are completely sincere and truly believe what they claim. At the same time, none of these projects, some of which have been in the pipeline for many years, have been clearly scientifically proven, nor have they become available for sale, complete with a 5 year money back warranty at WalMart etc.

I believe that what is happening is some form of mass hypnosis similar to what happens in religious circles on a regular basis. I refer to the phenomena of moving statues. This display of mass suggestion has been extensively detailed by the media in Ireland on several occasions. Many thousands of sincere people will swear to have seen a plaster stature move. I do believe that these people are telling the truth and truly accept the reality of their visions.

I have also attended several "shows" by "hypnotists" where people truly believed that they were bunny rabbits etc.

Suggestion is one factor, desire is another. Suggestion is a very powerful thing. Suggestion in a crowd that there is some immediate danger can cause a crush ending in many deaths. Powerful desire in a religious setting is the second factor that, I believe, contributes to collective visions. There is a huge desire to have a spiritual experience or a blessing or cure.

In the over unity situation we all (well most of us anyway) hope and want so badly to believe in free energy - the prize is just so attractive and desirable. Add peer suggestion to this need and IMHO you have a formula for "visions".

I still hope that science can prove some of these claims and that WalMart will have these gizmos for sale with money back guarantees soon!!!


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Wind Energy and Battery Storage a Letter

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I had an interesting letter from Kevin Cullen. I think you too might be interested in its content. Kevin has been kind enough to allow its publication and it is reproduced below.

My reply to Kevin:
Hi Kevin, Liked your letter and thank you for the nice words. The kudos however must go to Shay McGowan who wrote the essay - all I did was mess up the formatting attempting to get it to sit on the blog. May I publish your letter?? And if that is OK would you prefer anonymity or is it OK to credit you???

Cheers,



Dear Woodpellet,

A good read in your Wind Energy Intermittently and Grid Stability post on your blog.

I've been actively following the development of redox batteries and the company that's pushing its commercialization, Vancouver-based VRB Power, for the past four plus years. My google alert bots dutifully brought your contribution to my attention.

Your title touts a salient point that few people still realize about renewable power sources like wind or solar -- it's intermittentcy. Or as Alan Greenspan testified before Congress shortly after the August 2003 blackouts on the North American east coast, "utilities are an industry without inventory."

We can't effectively store mass quantities of electricity. That fact, combined that the wind doesn't blow all the time or when she does, demand might be very low, wind power has had to be "backed up" with convention generation facilities. All of which cost money. And that spells a very low price for wind power electricity for the simple economics that a utility needs a constant and reliable source of electricity -- and will pay a higher price for it.

Nonetheless, redox batteries -- for all their promise of a paradigm shift -- have hithertofore, had a most torturous business path. If you followed the history of these batteries from the labs of Skyllas-Kazacos to Australia's Vanteck and now the incarnation of the patents at Canadian VRB Power, this is still a technology that keeps promising" but has yet to deliver -- at least in terms successful commercialization.

Even the now not so recent Sorne Hill Wind Farm sale has yet to be commissioned -- and VRB paid.

For all the "demo" units and trial sales, the jury is very much out on whether these batteries can be successful commercialized. Or is its deployment "cusp" that much longer than most investors can wait?

You closed your posted noting the recent vanadium bromide research being done by Skyllas-Kazocos. You may wish to note that the former UK company Regenesys also pioneered a similar polysulfide-bromine chemistry now called the RGN-ESS. Except for the chemical composition of the two electrolytes, this flow battery exactly resembles the vanadium redox battery. Indeed, in a design commissioned by the Tennessee Valley Authority, a Regenesys system was slated to provide up to 12 MW of power output for hours at a time in batteries that were targeting huge electrical storage situations.

That project was never completed even though the storage tanks were constructed. Last I heard, the RGN-ESS suffers from cross-contamination of the two solutions across the membrane, giving the chemical solutions limited lifetime in use. As well, periodic maintenance is required to unblock the membranes. However, compared to a VRB-ESS, the RGN-ESS is capable of generating power at much lower cost. And much higher quantities.

Rengensys is gone, it patents now be licensed by VRB Power it a deal with the German utility REW. It's technology is still under development.

A couple of Phd tech type analysts have been championing this technology. Jonathan Hykawy penned this:

"An efficient storage technology for large amounts of electrical energy provides the basis for a complete change in the thinking surrounding power generation and use. Yet this same technology can be applied today to cost-effectively solve some existing problems.

VRB-ESS takes the solution into the scale of small power generators and individual users, while RGN-ESS has the potential to turn the power industry upside down. The result would be a world in which hydroelectricity and other Kyoto-friendly technologies (wind, nuclear, etc.) can be allowed to dominate the power generation landscape. If recent work on scenarios regarding the impact of greenhouse gases on our weather are correct, such a change may prove to be far more valuable than the simple economics of selling VRB-ESS or RGN-ESS systems would suggest.

We are confident that the technology developed by VRB Power is capable of being sold on an economic basis to motivated customers. We are confident that VRB Power has an attractive product ready for sale and has started to form the relationships necessary to successfully bring this product to the market. And, we are also confident that the future uses for both the VRB-ESS and the RGN-ESS hold even greater promise for investors."

Hykawy wrote that in March of 2005...with his "strong buy" recommendation.

And then there's MacMurray Whale -- touted by one newsletter writer as one of the best alternative energy analyst in N. America -- who recommended the company in March 2006. A copy of his (and Hykawy's) reports are attached.

By now you may be concluding that I'm bit cynical of the promise of vanadium redox's batteries. You would not be correct. What I am is much more cognizant that building a successful mousetrap is NOT the same thing as successfully commercializing it. That takes a lot, lot more time than most realize. Or longer than most investors can wait.

Indeed, if your reading this note on a PC, you may be interested in knowing that Windows 3.0 took over 8 years before an Microsoft graphic user interface start to sell in the market. And that was after a proven implementation of the GUI (called the Macintosh) was already out there.

Yes, vandium redox do hold tremendous "game changing" promise. Just don't say "holy grail." For that, I'll read Dan Brown.

Frazzled in Bangkok,

Kevin Cullen



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WoodPellet Boiler Prices update

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Atmos Pellet Boiler Price

I haven't checked Irish pellet boiler prices recently so I am not up to scratch. I am currently checking some prices further afield and here is one of interest.

Pellets Boiler Model ATMOS D 15P - 4,5-15 kW
Feeding screw With feeding screw Iwabo 1,5meter
With pellets burner Iwabo Villas 22kW

And the price in Poland is: €3,620
The company will ship to Ireland for €300
You will need a container for pellets which you could have made at a sheet metal works for reasonable money.

How does this compare with Irish prices???



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Redox Batteries and Wind Power part 2

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Wind Energy Intermittency and Grid Stability
-Are Flow Batteries the Answer?

Here is the continuation of Shay McGowan's paper:

Flow Batteries:
Flow batteries date back to the 19th century. They are best described as: ‘…..a form of battery in which electrolyte containing one or more dissolved electro-active species flows through a power cell / reactor in which chemical energy is converted to electricity. (3)

Vanadium-based redox (VRB) flow batteries operate by having two separate electrolyte solutions with a different ‘redox’ potential. This solution is stored in tanks outside the battery. When there is a demand for electricity the electrolyte solutions are fed into two halves of the reaction chamber. They are kept separated by a membrane which allows one electrolyte to ionise the other by exchanging electrons. The membrane allows this exchange to happen while preventing the two solutions to physically mix.

Until recently VRB’s were considered prohibitively expensive in common with other storage technologies. However, the technology has progressed beyond the development stage with a number of proven installations. It is on verge of wide spread commercialisation. Costs have considerably reduced and will further with economies of scale and ongoing refinements of the technology.

‘The additional layer of equipment adds perhaps 15% to the cost of a stand-alone wind farm, but more than makes up for the additional cost by increasing the value of the electricity generated.’ (4)

Advantages of VRB’s:
• Scalability – unlimited capacity - easily expanded by increasing the number of electrolyte storage tanks.
• Low toxicity – does not use heavy metals
• Raw material readily available and cost effective.
• Long life – 10-15 years plus - replacing the membranes in the cell stacks can extended this further. The electrolyte solution is reusable and will retain a residual value close to its original.
• Low maintenance – High tolerance to charge/discharge (up to 10,000 cycles) – only two moving parts
• Instantaneous response – can discharge energy in milliseconds.
• No harmful emissions.
• Quite operation – suitable for urban sites if space permits.

Disadvantages of VRB’s :
• Large area required (generally not a problem with wind farm remote locations)
• Greater system complexity compared to conventional batteries i.e. control units, sensors, pumps etc. required.

Commercial Scale
Operational VRB Energy Storage Systems to date:

Kings Island, Tasmania, Austrailia
This VRB System provides a 200kW x 4 hour storage to complement the existing 5 wind turbines (ranging from 250 to 850 kW) and diesel generators. The use of the VRB has allowed for considerable reduction in the use of the diesel generators and provides a dependable deliverable electricity supply to the island.

PacifiCorp, Moab, Utah, U.S.A.
This installation was the first large-scale commercial VRB-ESS in North America. The system consists of a 250kW x 8 hour (2 MWh) storage unit. It is being used as a load levelling device to supply peak power to a remote location in southeast Utah allowing for the deferral of the need for a new electrical sub-station.

Other applications of the technology include a 1.5MW UPS system for a semiconductor fabrication plant in Japan and a 275 kW output balancer for a wind power project in the Tomari Wind Hills of Hokkaido, Japan.

Sorne Hill Wind Farm, Buncrana, Donegal, Ireland
The 32MW Sorne Hill wind farm will have the largest installation of VRB Storage System worldwide and is the subject of a comprehensive feasibility study ‘VRB ESS Energy Storage & the development of dispatchable wind turbine output – Feasibility study for the implementation of an energy storage facility at Sorne Hill, Buncrana, Co. Donegal’ commissioned by Sustainable Energy Ireland, the statutory authority charged with promoting and assisting the development of sustainable energy and Tapbury Management Ltd., a private company formed to provide administrative and management services to Sorne Wind Energy Ltd.

Findings of the Sorne Hill feasibility study:
The Sorne Hill feasibility study is extremely important as it validates economic viability of the VRB Storage systems for wind farms such as this. It will facilitate the further rollout of up 3000 MW of contracted and proposed wind generation in Ireland, removing uncertainties about intermittency and income streams.

SEI estimates that up to 700MW of storage will be required in the years to come. Final contracts worth US$9.4 million are about to signed with a planning permission application for the VRB storage building about to be processed for the Sorne Hill site.

The report comes to the conclusion that a 2MW of power VRB 6 hour (12MWh) Storage System is required which will have the ability to dispatch 3MW for 10 minutes ever hour to accommodate fluctuations in the wind energy generation.

Wind generated electricity is bought at a discounted rate of €57 per MW because of the variability of supply.

The Sorne Hill Wind Farm will now receive €85 for each MW delivered to the grid, the same price as conventional electricity supply such as coal and gas. This will allow the projected rate of return (known as the IRR) to increase from the normal 9-11% to approximately 17.5% according to the study.


Conclusion:
The maturation of VRB technology could release the full potential of wind generated electricity worldwide and make such targets as Ireland’s 33% of electricity from renewables by 2020 a very realistic goal. The ability of renewables with VRB Storage Systems to dispatch electricity as efficiently or more efficiently than conventional plant, (commonly combine cycle gas turbines which can take up to 15 minutes to dispatch (5) , removes one of the major obstacles to their wide scale deployment and potential significant contribution to world energy.

The essay could be broadened in its scope to detail the other discussed storage technologies to a further degree as they all have merits and potential for the future. Furthermore, zinc bromine and polysulphide bromide flow batteries offer many of the advantage of VRB’s and are worthy of further discussion.

Another development that’s worth noting is the research by Skyllas-Kazacos (of the University of News South Wales who developed the VRB technology in the 1980’s) into vanadium bromide revox batteries. This chemical would be twice as soluble as vanadium sulphate allowing battery plant to half in size opening up their use for smaller applications from cars to domestic applications.

(5) Mechanical Engineering Magazine – September 2005 – http://memagazine.org

Thanks again to Shay for his permission to publish in full his excellent essay. I have not included the extensive references and appendix as I am a bit lazy and the formatting would take a good bit of work. If anyone wants the information included, you can e-mail me and I will ask Shay if I can send you the material.


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Redox batteries and Wind Power

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I am publishing, with permission, a paper sent to me by Shay McGowan on Wind Generation and the use of battery backup to eliminate power fluctuations. I had intended to quote you parts of this paper, but I liked what I read so much, that I have decided to put the complete essay on the site. Thanks for the paper Shay.

Wind Energy Intermittency and Grid Stability
-Are Flow Batteries the Answer?

Introduction:
According to the European Wind Energy Association most parts of the UK and Ireland have the largest wind energy resource in Europe.

At present, there is an installed capacity of 745 MW in Ireland of wind energy. The island has a theoretical 125.7 GW or 344.9 TWh/yr accessible resource available according to ESB International and Sustainable Energy Ireland (SEI) respectively. With winter peak electricity demand of 5000 MW estimated by ESB National Grid for the period 2007-2010, it can be seen that a substantial wind energy resource is there to be exploited.

Ireland could presently generate 25% of its electricity from the wind with no increase in electricity prices to the consumer. If this was done, there would be wind turbines scattered across only 1/2 of one percent of the country, assuming no offshore development. (1)

Recent binding commitments by the EU to provide 20% of the unions energy needs from renewable sources calls for a rapid deployment of renewable energy technologies.
This 20% target is conservative and well short of what is required if the carbon reduction levels required to mitigate the worse effects of climate change as recently indicated by the I.P.C.C. (Intergovernmental Panel on Climate Change) are to be achieved.

In order to substitute fossil fuel generated electricity to a significant degree a number of different renewable technologies will be required with wind energy most likely contributing the majority of this renewable electricity.

However, due to the intermittent or variable nature of wind the output from a wind turbine can range from above its maximum rated level down to zero. At present, due to the small number of commercial scale wind farms connected to the grid this variability is not an issue and at present has no effect on grid stability. The national grid requires a base load of generated electricity to accommodate the normal every day demands but also requires a fast responsive generating capacity to facilitate peaks in demand (typically Combined Cycle Gas Turbine Generators) otherwise the grid would get unstable with brownouts or blackouts occurring.

In countries such as Denmark and Germany which have a large amount of wind energy penetration most of the variability is ironed out by been interconnected to the UCTE grid, i.e. the continental European power system supplying approximately 450 million people. This allows the importation across borders of electricity when peaks in demand dictate.

Island nations such as Ireland and the U.K. have some interconnectivity with each other and Europe but not with the same capacities and flexibility.

Presently grid stability from wind generation is maintained by:

• More accurate wind forecasting
• Wind management and curtailment
• Interconnectors
• Storage

(1) Staudt.L -Centre for Renewable Energy, Dundalk Institute of Technology

These options shall be briefly explored with a focus on vanadium-based redox flow batteries as a storage solution. Following the recently published feasibility study ‘VRB ESS Energy Storage & the development of dispatchable wind turbine output – Feasibility study for the implementation of an energy storage facility at Sorne Hill, Buncrana, Co. Donegal’2 commissioned by Sustainable Energy Ireland, it would appear that this storage technology could offer the most viable solution to wind energy variability and allow wind generated electricity to be ‘dispatched’ in a similar fashion as conventional fossil fuel generated electricity.

Current methods for accommodating wind variability:

More accurate wind forecasting
Presently in order to account for wind intermittency (where significant interconnectivity is unavailable) meteorological forecasts are used to assess trends and eventually to produce day-ahead forecasts and then hourly production estimates. The predicted hourly loads are compared to the hourly production estimates with the shortfall accounting for the amount of reserve electricity generation required from conventional plant.

The accuracy of meteorological forecasts could be marginally increased but with fast moving weather systems tracking across the Atlantic, affecting Ireland and Northwestern regions of the UK, errors in the region of 30% in predicted generation output can occur.

Wind management and curtailment
Sometimes the only option is to curtail the amount of wind generated electricity entering the grid so as to avoid instability. This leads a greater dependence on fossil fuel plant to make up the reserve capacity and negates the environmental and fuel saving benefits of wind energy. Such uncertainties about generating capacity would have an adverse affect on wind farm developments as the return on the investment would be reduced and difficult to predict.

Interconnectors
Ireland at present is interconnected to Europe via Northern Ireland and Scotland with a capacity of 450MW. In addition they is a proposal for a submarine interconnector of 500MW below the Irish sea to Wales.
Concern over security of energy supplies is for ever increasing with the continuing growth of international terrorism, conflict in the middle east and political unrest in Nigeria but to name a few. A more confident and wealthy Russia has proved to be far from a reliable gas supplier and has appeared to have used its natural gas monopoly as a political weapon, most notably by turning off gas supplies to the Ukraine in January 2006.

For this reason It could be argued, that from a security of supply point of view that increasing dependence on imported electricity from Europe should be minimised if possible, as total electricity energy consumption by the EU-25 comprised 37% of oil and 24% gas. Germany for example gets 40% of its natural gas from Russia and with the continuing growth of gas powered generating stations and gas fuelled space heating this dependence will only increase further.
Furthermore, traditional centralised energy production feeding into pan national grids is a highly inefficient way to generate electricity with only approximately 30% of the primary energy reaching the distant end user. These losses occur due inefficient generation, non-recovered waste heat and transmission and distribution losses. Reliance on interconnectivity across borders would increase this inefficiency further with increased transmission distances.

Also at issue is the length the time it takes to provide interconnectivity as according to Wolfgang Kerner, policy officer at the European Commission, on talking about interconnection between European nations stated that - The construction of new powerlines and inteconnectors is an arduous process, It takes 10 to 15 years to construct a line....


(2 http://www.sei.ie/index.asp?locID=1030&docID=-1 - Sustainable Energy Ireland)


Storage Systems
The most common storage systems available or in current development are:
• Battery Storage
• Compressed Air Energy Storage
• Hydrogen Fuel Cells
• Super and Ultra Capacitors
• Flywheels
• Pumped Storage
• Flow Batteries

Battery Storage:
Conventional battery storage consists of lead acid batteries in various forms. They are relatively inexpensive when compared to other storage technologies but have performance limitations, short life spans and contain highly toxic substances which are difficult to treat and dispose of. Other battery technologies such as Nickel cadmium, Nickel Hydride, Lithium ion, Lithium polymer and Sodium sulphur are under development for large scale systems but are more expensive than conventional lead acid batteries

Compressed Air Storage:
Compressed air storage relies on the availability of suitable geological formations which can store the compressed air. Such formations are rare which limits the suitability of this system and its wide scale use.

Hydrogen Fuel Cells:
Fuel cells harness the chemical energy of hydrogen to generate electricity without combustion or pollution. They are currently an emerging technology at the prototype stage.
Super and Ultra Capacitors:
Super and Ultra Capacitors store energy electrochemically. They are suitable for high value short burst energy. Their application for large scale storage systems is still under development.

Flywheel Storage:
A flywheel is a mass rotating about a shaft. They store energy mechanically in the form of kinetic energy, have a high turn around efficiency and a relatively long life. They have been used for UPS systems for server farms but are very expensive to construct due to the high precision engineering required and at present have maximum power outputs of around 100kw for 1 hour. They occupy a niche market at present.

Pumped Storage:
Pumped hydroelectric storage plants are characterized by long construction times and high capital expenditure. Similarly to Compressed Air Storage systems, the locations available for pumped storage are limited or have already been exploited.

(I will publish the next section in a day or so. It is taking me a bit of time to re-format the text to suit the blog)