[crossthread]

http://www.uh.edu/admin/media/nr/2004/0 ... cells.html
HOUSTON, July 22, 2004 – As temperatures soar this summer, so do electric bills. Researchers at the University of Houston are striving toward decreasing those costs with the next revolution in power generation.

Imagine a power source so small, yet so efficient, that it could make cumbersome power plants virtually obsolete while lowering your electric bill. A breakthrough in thin film solid oxide fuel cells (SOFCs) is currently being refined in labs at the University of Houston, making that dream a reality.

Originating from research at UH’s Texas Center for Superconductivity and Advanced Materials (TcSAM), these SOFCs of the “thin film” variety are both efficient and compact. With potential ranging from use in the government in matters of defense and space travel to driving forces in the consumer market that include computers and electricity, this breakthrough carries tremendous impact.

“By using materials science concepts developed in our superconductivity research and materials processing concepts in our semiconductor research, we are able to reduce operating temperatures, eliminate steps and use less expensive materials that will potentially revolutionize from where we derive electrical energy,” said Alex Ignatiev, director of TcSAM and distinguished university professor of physics, chemistry and electrical and computer engineering at UH. “While there are a number of fuel cell research programs at the university, ours focuses on the application of thin film science and technology to gain the benefits of efficiency and low cost.”

Compared to the macroscopic size of traditional fuel cells that can take up an entire room, thin film SOFCs are one micron thick – the equivalent of about one-hundredth of a human hair. Putting this into perspective, the size equivalent of four sugar cubes would produce 80 watts – more than enough to operate a laptop computer, eliminating clunky batteries and giving you hours more juice in your laptop. By the same token, approximately two cans’ worth of soda would produce more than five kilowatts, enough to power a typical household.

Keeping in mind that one thin film SOFC is just a fraction of the size of a human hair with an output of 0.8 to 0.9 Volts, a stack of 100 to 120 of these fuel cells would generate about 100 volts. When connected to a homeowner’s natural gas line, the stack would provide the needed electrical energy to run the household at an efficiency of approximately 65 percent. This would be a twofold increase over power plants today, as they operate at 30 to 35 percent efficiency. Stand-alone household fuel cell units could form the basis for a new ‘distributed power’ system. In this concept, energy not used by the household would be fed back into a main grid, resulting in a credit to the user’s account, while overages would similarly receive extra energy from that grid and be charged accordingly.

“The initial applications of our thin film fuel cell would probably be for governmental entities,” Ignatiev said. “For instance, once the preliminary data satisfies the Department of Defense, we could see our fuel cell research in action in the backpacks of soldiers, replacing heavy batteries to power their computers and night vision goggles and such.

“NASA also is very interested in this research mainly because of the weight and size factors,” he said. “Thin film SOFCs offer light, compact, low mass properties of significant interest to them. Right now, the shuttle routinely uses fuel cells that require ultrapure oxygen and hydrogen, use exotic materials and are massive and large. But the thin film SOFCs we are developing at UH are not as sensitive to contaminants and are highly efficient in their design and lightweight size, which is ideal for space applications.”

Inherent to the more efficient design of these “cool” fuel cells is quite literally the fact that they operate at a much lower temperature than other solid oxide fuel cells, yet do not need a catalyst. Despite their 60 to 70 percent efficiency, SOFCs, in general, operate at 900 to 1,000 degrees Celsius, a very high temperature that requires exotic structural materials and significant thermal insulation. However, the thin film solid oxide fuel cell has an operating temperature of 450 to 500 degrees Celsius, one half that of current SOFCs. This lower temperature is largely a result of the drastically decreased thickness of the electrolyte-working region of these thin film SOFCs and negates the need for exotic structural materials and extensive insulation. The lower temperature also eliminates the need for catalysts (known as reformers) for the fuel cell. All of these features indicate a reduced cost for the thin film SOFC and positive future impact on the fuel cell market.

Ignatiev anticipates that what he and his colleagues have been developing in UH’s TcSAM laboratories will advance to the testing phase within the next six months. The collaborative test bed for this thin film SOFC testing is the Houston Advanced Research Center’s Center for Fuel Cell Research and Applications.

[Keis]

Now this would be nice!

[sidoze]

Looks neat but it sounds like they run on natural gas? Gas piped straight to the home is what its saying right?

But why go decentralized, if most power plants are 35% efficient and these are very efficient why not save on the transport costs and build a large array of these cool cells in some facility. I'm sure the transport of fuel to end users should be considered in the efficiency of the concept.

[nero]

450oC is really cool! If they have that going well there is some real hope for distributed power.

Distributed power has the added benefit of enabling the waste heat to be used on site for hot water or heating. This results in really incredible total energy efficiencies. Another benefit to distributed power as the early adopter for this technology is that a power plant has to plan for at least a 25 year life with very high reliability. It is very costly for radically new technology to spend the time and money proving itself with prototype demonstrations. Smaller scale situations where it is not mission critical if it fails would be ideal.

They are developing SOFC fuel cells for small power plants. Seimens are in the lead in this department I believe. What they hope to do is use the fule cell in combination with a turbine to achieve the best electrical efficiencies around. I haven't heard too much about their progress lately but they are past the prototype stage and are taking commercial orders.

[Devil]

And what happens to the CO2? Even so, what scares me with natural gas fuel cells is that there has to be an excess of fuel. This means there could be an emission of CH4 which is 25-75 times worse than CO2 as a GHG.

I agree with Sidoze that it is a lot easier and cheaper to distribute electricity than gas, therefore centralised generation would be more cost-effective and, probably, efficient, because it would be easier to have more complex and costly optimising controls in a large installation than in a small, household-size, one. Also, a large one could have better emission controls with useful post-combustion.

If this idea works at hundreds of °C, where does the energy come from for heating the cells?

Does the cited 60-65% efficiency last throughout the cell's useful lifetime or does the efficiency drop as the contaminants in the natural gas (which is not pure CH4) clog the cells? What is the cell's lifetime?

What are realistic capital, running and maintenance costs?

I'm not naysaying but I'm asking a lot of questions that must be asked before being able to judge the viability of the process.

[MarkR]

Well, the CO2 is a waste product, and has to be disposed of in the same way as if you were burning the gas conventionally i.e. sinking to the atmosphere, or some form of sequestration.

The cells have to be heated first to get them going, thereafter the cells generate heat due to their inefficiency. In small cells (a few kW) their self heating is not sufficient, and additional heaters are required (probably gas burneres). However, in huge cells (thousands of kW) so much heat is generated that the cells need to be cooled.

Cooling is not a bad thing - the high temperature coolant can be effectively utilised e.g. it could drive a turbine for production of additional electricity (bringing efficiency at the grid connection to 70% or more) and the waste heat from the turbine could then be used for a community heating system.

As I understand it, the presence of hydrogen and other hydrocarbon contaminants in the NG is not much of a problem for the fuel cells. However, sulphur is, and gas purifiers are required to prevent damage to the cells.

The lifetime of SOFCs is not well defined yet - conventional high temp protypes have operated for over 20k hours, and still seem to be going strong. Some groups seem to expect 'up to 40,000 hours' from the newer low temp SOFCs. One particular problem seems to be migration of dopant ions through the various components - apparently this is a major problem because many of these are highly toxic. Additionaly, as traces of contaminants can seriously impair the cells, recycling of the used materials is impractical - it's much less energy intensive to use virgin material to fabricate new cells.

Pricing is difficult to predict. SOFC systems have been built in recent years at costs of around $4/W. For a system constructed today, you'd probablly end up paying about $1-$1.5/W.

However, several companies plan to start selling small scale SOFC systems within the next 2-3 years with estimated capital costs of around $0.80/W. Some speculate that by 2015 price could have fallen to about $0.20/W.

I am not able to comment on whether those prices are realistic - however, I am certain that they are very optimistic. Fuel costs are likely to be the dominant running cost - and this, of course, depends on the volatile nature of NG.

Just for reference, estimated new constructions costs for CCGT plant are about $0.8/W, new nuclear (advanced CANDU) about $1.1/W, and clean coal (integrated gasification) about $1.5/W. If construction costs could be made less than conventional CCGT, then their higher efficiency could make this technology viable. We will have to wait to find out.

[k_semler]

$this->bbcode_second_pass_quote('MarkR', '
')Just for reference, estimated new constructions costs for CCGT plant are about $0.8/W, new nuclear (advanced CANDU) about $1.1/W, and clean coal (integrated gasification) about $1.5/W. If construction costs could be made less than conventional CCGT, then their higher efficiency could make this technology viable. We will have to wait to find out.

[MarkR]

$this->bbcode_second_pass_quote('k_semler', '
')Are you sure this is per watt? At this price of 80 cents per watt, it would cost me $416.00 per hour to operate my computer for one hour in just electrical consumption, and your clean coal quoted price would be $780.00 to run my computer for 1 hour.

[k_semler]

$this->bbcode_second_pass_quote('MarkR', '')$this->bbcode_second_pass_quote('k_semler', '
')Are you sure this is per watt? At this price of 80 cents per watt, it would cost me $416.00 per hour to operate my computer for one hour in just electrical consumption, and your clean coal quoted price would be $780.00 to run my computer for 1 hour.

[MarkR]

I've been thinking about fuel cells for a bit, and toying with ideas. One use that seems, to me, to be potentially more practical than automotive fuel cells is nuclear power stations for generation of bulk electricity.

Conventional power stations are essentially large steam engines - steam engines are by nature low efficiency. In current nuclear plants efficiency is about 33-34%.

The next big thing in nuclear technology is the high-temperature reactor. It can produce electricity at higher efficiency (because the Carnot limit to efficiency depends on temperature), but more interestingly it can be combined with a thermochemical cracking plant which splits water into hydrogen/oxygen by the application of heat and some clever chemistry.

So, by having your reactor produce hydrogen (at an efficiency of 60%), which feeds into a high-temperature fuel cell which produces electricity at an efficiency of 85% - you can get 50% efficiency of electricity production. Compared to the 45% you'd get if you simply used a gas turbine.

But that's not all - the cracking plant and the fuel cell both produce substantial heat, also at high temperature. A steam engine, or gas turbine, would be ideal for cooling these plants. This would allow recovery of a further 15%-20% of the original heat energy - for a total efficiency of 65%-70%

So what about cost? Such a plant would undoutedly be immensely expensive, considerably more so than a turbine plant - however, considerable cost is in the nuclear part of the plant. This could remain the same size, yet electrical output could double.

Fuel cells are an expensive technology - currently costing about $500-$2000/kW of power (totally unsuitable for cars - where $100/kW is bordering on unaffordable) - but are not entirely out of the question for power stations (where costs are about $1400/kW for recent nuclear, and $1500/kW for new 'clean' coal).

I can't see any immediate theoretical problems - just technical ones. All these steps work in the lab, but can they be scaled up?

Any comments?

[Jack]

It does look like it could be a useful part of bridging to whatever comes next. As was mentioned earlier, nuclear isn't sustainable -and, of course, lots of investment would be required. Still, as part of a transition, it could help.

[backstop]

MarkR - your costing of a nuclear- fuel cell bulk electricity supply appears to ignore the cost of the fuel cell capacity.

Try adding the projected costs you propose to the cost of a nuclear plant, as follows :

Assume standard nuclear plant costs $1.8bn per 1.0GW;

Your figures for fuel cells were $0.5Bn to $2.0Bn per 1.0GW;

(Being way outside present fuel-cell research scale, a gigawatt of FC capacity can be expected to be at or over the upper estimate).

The combined cost ranges from $2.3Bn to $3.8Bn per 1.0GW.
Next subtract the cost of 1.0 GW of generator.
Next I guess we should add in an energy cost premium for all the manufacturing and construction contracts.

I guess these still more unaffordable costs are the reason I've not seen this techno-combination proposed by any of the commercial pro-nuclear industry hype.

Also, I've not seen a link showing 80% fuel cell efficiencies. Those I've seen show generally show up to 44% efficiencies.

It leaves me wondering if we'd even be discussing this if 9/11 had hit a nuclear facility, and had poisoned x-million North Americans ?

The idea of expending $trillions globally on nuclear-FC power seems bizarre when what peak oil demands is a transport fuel.

To do so "as a bridging to whatever comes next" is not a strategy, its simply a further delay of appropriate investment in the sustainable energies in favour of legally-dubious corporate shareholder profit.

Finally, can you explain why you think it's OK for your generation to have a massive centralized corporate-owned power supply,
and for ten thousand generations to have to deal with its wastes ?

regards,

Backstop

[frankthetank]

I think the costs will be prohibitive of this sort of design. It seems to me that we should be reducing the amount of energy used, not trying to produce more.

I do believe that nuclear will have a future (atleast in the US) both canidates have endorsed it. Something is needed to soften the below, but like what was said above, it doesn't do much to solve the transportation situation.

[Rembrandt]

First of all people please either don't comment or read MarkL's post. It's also about creating hydrogen by nuclear plants so that has to do with hydrogen and stuff.

Here's a link which outspreads some things, not really an objective site but the facts are good.

http://www.uic.com.au/nip73.htm

The most direct example here is around 52% effeciency at 1000 degrees.

I do think that nuclear is at the moment one of the better ways to create hydrogen on the short term. This lies in the efficiency and the space requirement.

The problem though is that it costs an enormous amount of energy to create such a plant and investing energy to get uranium to keep it running.

[MarkR]

First of all, I must apologise for a simple mistake in my first post. I mistakenly quoted the efficiency of Solid-oxide fuel cells (SOFCs). I quoted 85% - this is, of course, greater than the theoretical maximum efficiency for fuel cells (so I really should apologise). The efficiency of SOFCs is between 60-70%. The 85% is potentially achievable if a recovered heat turbine is used.

I didn't attempt to calculate the price of such a hybrid system, because there are far too many unknowns. Yes, the price would be considerably higher than a conventional system.

The SOFC is being developed as a direct competitor to natural gas power stations - because they can burn natural gas (as well as hydrogen) directly. A hybrid FC/turbine system would be significantly more efficient than the current state-of-the-art combined cycle turbine plant.

The other feature of the hydrogen/fuel cell/turbine system is that it does directly address transport issues - by production of hydrogen (if you believe that is a solution).

[backstop]

MarkR - while you do acknowledge part of the maths errors in your proposal, you don't answer the questions I posted as to its basic utility and relevance.

As they were equably phrased, and in no sense abusive and deserving to be ignored, your silence on them makes nonsense of your proposal. So please answer them.

regards,

Backstop

[MarkR]

I can't predict what would have happened if there had been a major terrorist attack at a nuclear facility.

My understanding is that the containment structure around reactor buildings is sufficiently strong to withstand a direct hit from an airlines without causing serious damage to the reactor. (Sorry, no references to hand).

I'm not an architect or structural engineer, so this is outside my area of expertise.

The concept of burying the reactor underground is also taken up by several new designs - this prevents attack from the sides, and attack from the top is significantly more difficult.

--

I don't think that there is a major problem with large central power generation. Distributed generation doesn't work so well in cities, where demand is high, and opportunity for generation is relatively low (technologies like solar, and small-scale wind) are unlikely to satisfy the demand of a modern city.

I don't take issues with your comment about corporate greed and shareholder-profit. My belief has always been that energy supply should be a government responsibilty, not driven by short term goals, and need for profit.

Nuclear waste is a problem, but the volume of it is relatively small, and produced in a concentrated contained form. If it remains contained then it is of relatively little significance to the surrounding environment. If it buried in an uninhabitable desert, then even future generations face little risk from this.

The problem that will limit nuclear power take up is satisfactory waste storage. However, development of an efficient fuel recycling scheme could drastically reduce both our requirement for additional storage capacity, and also our inventry of spent fuel awaiting permant disposal.

We've got a catch-22 situation here, without new nuclear investment, we are left with a huge volume of waste for which we have no disposal capacity (the planned site at Yucca is already full).
Yet new nuclear power investment and taxation on it would bring sufficient funds to build recycling plants, which could add another 100 years capacity to the Yucca storage site, and potentially cut the radioactive life time to hundreds (instead of 10s of thousands of years).

[backstop]

MarkR - about six months after 9/11 the internationally respected 'New Scientist' magazine published a long article detailing the projected impact of a hijacked plane on the UK's Windscale nuclear facility. As far as I remember, deaths, including the slow lingering ones, were potentially counted in hundreds of thousands.

In response to my question -

"It leaves me wondering if we'd even be discussing this [nuclear energy] if 9/11 had hit a nuclear facility, and had poisoned x-million North Americans ?"

-With that outcome I think you know very well that all the relaunched nuclear hype would have been left in its box and we wouldn't now be wasting time over it.


Your statement -

"Nuclear waste is a problem, but the volume of it is relatively small, and produced in a concentrated contained form. If it remains contained then it is of relatively little significance to the surrounding environment. If it buried in an uninhabitable desert, then even future generations face little risk from this. "

- shows various ducking and weaving.
For instance what does "relatively small" mean in terms of plutonium's lethality, with a mere 2lbs weight containing a lethal dose for the world's entire human population ?
"If it remains contained" relates to the half-life of the materials in question, some of which are up to 250,000 years, with god knows what geological upheavals in that time.
"If it is buried in uninhabitable desert" shows a similar lack of knowledge of ecological change which can transform desert to flowering savannah in a mere 10,000 years.

I think your next statement is one of the better critiques of nuclear that I've seen :

"We've got a catch-22 situation here, without new nuclear investment, we are left with a huge volume of waste for which we have no disposal capacity (the planned site at Yucca is already full). "

- as it admits that nuclear power to date has not even paid for the management of its wastes and has no means of doing so. It is thus trading while bankrupt. Is this a crime in the US as in the UK ?

Your idea of paying for those wastes' management out of taxation on the eventual projected taxes on the 'profits' of building new nuclear facilities seems laughable - particularly as you previously suggested that they should rather be a bridge "to whatever comes next"

I note that again you completely bypass the question of investing instead without further decades of delay directly in the sustainable energies that this society actually needs.

Please do not be offended by my critique of your posts; youve been trying to defend the indefensible and I'm delighted to observe that you are not a paid professional in doing so.

We have far better options to consider, including wave energy's potential for urban-scale power, so let's focus on them instead.


regards,

Backstop

[Rembrandt]

I'm truly sorry about the way i put the words in my previous post in this topic. Now it allmost looks flaming MarkL. (I must have been totally swamped and not knowing what to post now i look at things)

Let me rephrase what i said to put things in good order (and to undo the justice i have done to MarkL since i found his post very good)

What i ment was: Please totally read MarkR's post, He also refers to creating hydrogen by nuclear plants. This was mainly a comment to MarkL's post about the transportation.

Well my apologies i'll try not to let this happen again

Now on to some constructive content:

First of all for the terrorist attack or nuclear meltdown problems in relativity to other fuels.

I yesterday heard on a dutch energy conferecne that each year in china 15.000 people die in the coal mining industry. If you look at the factor of deaths because of tsjernobyl the immediate deaths were around 30, the amounts of cancer around 10.000 because of it in the first generation of which most have been treated. Should we then because of something we call irradiation and thus our personal fears stand in the way of rational thought?

i say no.

I also would not like backstop does put nuclear energy down. Why not Consider it as an possible option but one on the lower side of you're option list. We should invest into the negative sides of it i think. Also the market will probably decide in a big part to which alternate fuels we turn too.

[Andy]

I have previously posted about the inherent intractability of the so-called nuclear option. Let me repeat. Investing in nuclear to help mitigate peak oil problems is a waste of resources, time and energy. It is not a long term sustainable solution and should be given no further consideration. In 50 years, it has proven that it cannot even stand on its own two feet without numerous subsidies like the Insurance liability subsidy, the waste management subsidy and others.

There is no way any rational person who seriously considers the issues with nuclear storage can even dream that waste can be securely contained for 500 much less 250,000 and more years given the vagaries of geology and the natural environment. We cannot predict when a so-called stable geological formation will suddenly move, allow water in, develop fissures or some future human simply out of ignorance disturb the waste.

For those who discount the health impact of Chernobyl, Three Mile Island and other nuclear catastrophes, please browse through the site http://www.ratical.org and other radiation health sites to see the terrible toll that nuclear (including medical radiation like X-rays and so called harmless background radiation) has taken on life and will continue to take for generations. I agree, thousands die from coal, oil etc. every year but there is a crucial difference. The principal effects are short term. They kill people today, they don't kill/harm the presently unborn. This characteristic makes nuclear particularly insidious. They also don't permanently contaminate. Please read about mutagenicity (malformed body parts) and teratogenicity(missing body parts) to understand how they are related to low-level ionizing radiation.

Now, regarding fuel cells in combination with nuclear. Why take one very expensive technology, add more complexity and the expense of another expensive technology when other simpler solutions can do the job far more effectively. SOFC fuel cells even in combination with heat recovering turbines will not likely attain better than about 75% efficiency. > 80% is certainly not possible. At present, such combinations appear to be just under 60% with prospects for 70% in large units in the future. It would be simpler to just generate electricity directly with nuclear as is presently done.

One last point. The terrorists did not have to breach the containment building, they simply had to disturb the waste storage pools and casks outside reactor containment to cause major trouble.