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Argus
29-07-2006, 03:38 PM
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Right here in the 51st state as well as in western and mid Europe in general, we?ve been noticing unusual extremes of temperature. If you watched the football in Germany you?ll know what I mean.

Temperatures in southern England have regularly reached 34 degrees in past few weeks ?probably almost 10 degrees higher than the norm for this time of year.

Whether it?s a sign of things to come or one of the irregular scorchers we get from time to time, I?ll reserve judgement, but the UK government is in high gear churning out what I term as ?Kyoto Mechanisms? The latest is a new act in mid June , ?Climate Change and Sustainable Energy Act 2006?.
The whole thing is here: http://www.opsi.gov.uk/acts/acts2006/20060019.htm


Buried in it at section 18 is the following extract on Dynamic Demand concerned with linking energy curtailment to the state of the national grid. (I should explain for non UK readers that the entire UK is one contiguous electrical supply network the state of the grid is degraded by excessive peak load and can be and is monitored across the nation by the minute).

The important keyphrases are underlined.

18 Reduction of greenhouse gas emissions: report regarding dynamic demand technologies

(1) The Secretary of State must, not later than 12 months after this section comes into force, publish a report on the contribution that is capable of being made by dynamic demand technologies to reducing emissions of greenhouse gases in Great Britain.

(2) The report must state the view of the Secretary of State as to whether it is appropriate to take any steps to promote the use of such technologies, and, if it is, what those steps are.

(3) In forming the view mentioned in subsection (2) the Secretary of State must have regard, in particular, to any matters which would prohibit or inhibit the use of any dynamic demand technology in any circumstance in which its use could be expected to make a contribution to reducing emissions of greenhouse gases in Great Britain; and the report must state the matters to which he has had regard.

(4) In this section-

"dynamic demand technology" means any technology which enables-
(a) the consumption of electricity, at a particular time, by a device connected to a network, or
(b) the generation of electricity, at a particular time, by an electricity microgenerating system connected to a network,
to be controlled or adjusted automatically by reference to, or to matters relating to, the frequency of alternating current on the network at that time;
"electricity microgenerating system" has the same meaning as in section 4;
"network" means a distribution system (within the meaning of Part 1 of the Electricity Act 1989 (c. 29)) or a transmission system (within the meaning of that Part).


Although we can and do remotely monitor and control refrigerated product in order to minimise power consumption, this appears to be a new approach and one that may assign priorities to certain consumers. Non essential central plant air conditioning, for example.

This one will be worth watching. A lot of things have to be defined and a deal of supporting legislation put in place.

This is definitely NOT another 'Energy Star' scheme or anything like it.

.
________
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US Iceman
29-07-2006, 04:58 PM
Argus,

I take it this is a measure being implemented to provide curtailment of energy demand when required to prevent grid overloading issues.

We have similar constraints on our own grid here in the US. In some areas, the on-demand load shedding is an elective rate tariff that users may select. The users receive a lower energy cost per unit, but in electing to subscribe to this tariff, their loads can be dropped within a maximum time frame by advance notification from the utility.

Some utilities have offered a program which uses simple time clocks. During a specific period of the day (usually mid to late afternoon) specific energy users are "locked-out" to provide a demand reduction.

It seems these programs are a knee jerk reaction to the larger overall problem. Energy consumption and demand can be addressed by designing much better systems (HVAC or Refrigeration, or any other electrical device(s)).

I believe a reasonably good start would be to increase the benefits to end users through improved tax and depreciation schedules (or similar vehicles).

Secondly, we are at somewhat of a cross roads. Energy is still not very expensive, which seems to contribute to a lack of consumer awareness.

In some respects, I think this tends to drive the lowest first cost systems, rather than on-going costs associated with operation.

Having seen a lot of ammonia refrigeration systems operating with discharge pressures in the range of 10 to 12 bar(g) during cool/cold weather I know there are different alternatives.

Unfortunately, the heat rejection equipment (& type of) determine the impact of this problem during summer months.

Even with evaporative devices, perhaps we should be investigating the use of larger heat exchange devices for lower energy use and demand?

There is a trend to move to higher SEER ratings for air-cooled systems. Maybe this needs to be pushed to even greater levels also?

Argus
29-07-2006, 08:22 PM
Iceman, - good to hear from you.



Argus,

I take it this is a measure being implemented to provide curtailment of energy demand when required to prevent grid overloading issues.




In fact this is not the case with this act. From my understanding, the new act is intended to put into statute the present government?s policy on Carbon abatement.
It covers the whole issue of energy sustainability, security of supply, fuel poverty etc.
The whole of Europe at the moment is gripped by the fact that energy security does not exist.

Grid overloading is already catered for in the Supply of Electricity Act that has been around for decades. The supply companies can enforce supply restrictions for a range of reasons. Various voluntary tariffs are also available.
Indeed Central London was at 34-plus degrees for much of last week and the West End of London had power cuts, according to the press, due to air conditioners working overtime. The fact remains that many premises operate an open-door trading policy spilling conditioned air onto the street.

From my understanding, the new act is intended to put into statute the present government?s policy on Carbon control by encouraging new technologies including micro-generation and a top-down approach to energy use.

Your second point about energy cost is a huge political hot potato. Increasing energy costs will impact all the way down the social chain and so-called energy poverty for vulnerable parts of society is a no-go area as far as policy is concerned.

It seems to me that this starts with report, an invitation if you will, for new technologies to address the problem whilst introducing fiscal encouragements. I really do sniff a large carrot in there somewhere instead of a big stick. They are not interested in small appliances even though the savings would be huge. The reality is that most of this stuff is not made in either the UK or the EU any longer so that part will have to wait for global inducements. The potential for big industrial users to sign up to carbon reduction technology coupled with carbon trading is very interesting.

We need to see what will come of it all. It?s sure to take some years.

Here?s an interesting UK site that will help to explain some of the rationale.

http://www.dynamicdemand.co.uk/index.htm

.
________
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US Iceman
29-07-2006, 11:13 PM
Well... This is certainly turning out to be an interesting topic.



Demand control technologies could provide significant stability and peak demand management for the electricity network. This could lead to significant carbon dioxide savings and may help facilitate the connection of greater amounts of intermittent renewable energy generation, such as solar and wind power.


The way I read this, it seems that we are both on the same track. Demand management results in carbon reduction, which I assume means from primary energy sources, not renewable.

Renewable energy sources (solar, wind, water, etc) have a variability that introduce a degree of uncertainties that makes using them unpredictable to assist in load balancing of the grid. At least I am not aware of how it would be done.

As a result, here in the States we tend to use gas fired turbines (sometimes called peakers) to produce the additional demand. The increased demand can lead to overloading the grid resulting in brown outs or blackouts.

The grid is enormously complex and one failure can contribute to cascading failures. This has happened already here in the US and Canada.

I believe there is already a precedent being set for the carbon abatement (or at least similar to); carbon credits.

See below:
http://en.wikipedia.org/wiki/Carbon_credit

http://en.wikipedia.org/wiki/Emissions_trading

From my understanding of this, this process creates an accounting scenario that allows these credits to be sold, or traded to others who do not have such an energy efficient generation process.

The web site link you posted seems to address this from a different direction by the use of a "black box" of sorts. Which is still extremely interesting...

Argus
30-07-2006, 11:37 AM
Well... This is certainly turning out to be an interesting topic.




Indeed. I hope we can encourage more debate, because this is nearer to our industry than we realise and if a week in politics is a long time, 5 years or even 10 years engineering development is quite short.




The web site link you posted seems to address this from a different direction by the use of a "black box" of sorts. Which is still extremely interesting...



The thrust of section 18 of new law in the UK does indicate ?black-box? monitoring. I don?t think this is new at all. What may be a new departure is the ability of this black box to over-ride other controls to preserve the supply network.

What I would like to know is, who controls it? Government? The power supply industry?

The supermarket industry in the UK is dominated by half a dozen or so big companies, most of whom contract off-site monitoring. It is not a huge leap of the imagination to couple the control of equipment to a device that is able to monitor the state of the incoming supply. In effect you have a closed-loop control.

In my view the whole issue of energy planning in this country is completely fragmented.

What is at the heart of the problem ? demonstrated by the series of knee-jerk reactions to circumstances is that we have a series of 5 year administrations dealing with a 100 year problem.

I shall be keeping an eye on this one because it won?t go away.

.
________
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US Iceman
30-07-2006, 05:28 PM
What I would like to know is, who controls it? Government? The power supply industry?


Now that brings up an interesting question: Who decides what is "mission critical"? HVAC for hospitals would be one that should remain, but what about others;

a) supermarkets: Perhaps some of this might be justifiable to shed, but perhaps this and other similar "required users" could purchase "energy credits". They can either pay a penalty for demand use (over and above the existing demand charges), or do something to reduce the impact of their energy demand.

Those that install very efficient systems and provide for demand control might be able to be credited some of these "energy credits".

The way I see it the approach will have to either require the users to implement something on their own by some form of incentive, or legislation which forces them to comply.

A sticky wicket either direction.

I think a lot of users will fall into this type of scenario, which might require a carrot and stick approach.

I'm still waiting for some other members to jump into the discussion...

Argus
30-07-2006, 05:54 PM
A sticky wicket either direction.



Do you follow cricket, Iceman?


We could carry this on indefinitely but I agree, the other members need an input.

As a see it, this is a far reaching piece of legislation that covers the entire energy spectrum. If we concentrate on our sector we risk a myopic approach and this UK legislation covers microgeneration, renewables and the muddled moved to new generation nuclear.

But if we focus down to RAC, there is a great scope for removing profligate use of energy and the report when it comes out (years, probably) will reflect the evolution of government policy and changing patterns in the insecure energy field.


I think this has to be my last word ? unless there is a move forward on the debate.

Any takers?

.
________
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US Iceman
30-07-2006, 11:27 PM
Do you follow cricket, Iceman?

To be honest, I don't. It's just one of those expressions I picked up somewhere and use when it seems appropriate.

I agree with your comments. This is much bigger than one field. I was trying to add some sparks to get a good discussion brewing.

Hopefully, someone else will jump in...

Lc_shi
31-07-2006, 02:29 AM
I've just read these post. It's a good topic. I don't think Dynamic Demand Technology is a new technology. The demand is dynamic in essence all the time. The supply system must accomodate it. In China, there are two ways for this situation : one is to set up more electricity generator plant ;one is to move the peak load by mandatory regulations (Ice storage system is also a recommendation). There're some big electricity consuming enterprise buy oil generator to ba a backup in the case electricity cutoff for government warrant the domestic use as priority.


regards
LC

US Iceman
31-07-2006, 02:54 AM
...one is to set up more electricity generator plant.


Yes, that will provide more capacity LC, but it also contributes to additional fossil fuel being consumed. This increases the carbon release to the environment, but does not help the electrical distribution grid.

At some point, only so much energy can be transported on the grid before something has to break.

The standby generating capacity (generators) or additional generating capacity (power plants) can in some regard make up for deficiencies in supply, but do not really contribute to demand reduction.

Ice storage is a good idea for that.

As China continues to grow, how will they manage the power generating capacity and try to minimize the environmental impacts?

I think this is something all countries have to face.

Lc_shi
31-07-2006, 04:27 AM
Hi Sir
It's a very challenging issue especially for developing countries like China. As the GDP grows,the more energy is needed. China's coal and oil consuming increase rapidly every year.The actions are :improve the energy efficient in the industries and in the building. HVACR is very key sector to save energy. The madatory regulation for energy efficient building is valid soon. The vast area of heating in winter is of great potential in energy saving. HP and floor heating is got wider application. But the long term action is seek alternatives and better renewable energy use tech.
It's a long time war for each country. HVACR guys can make much contribution in this battle:).

regards
LC

Darshi
31-07-2006, 01:57 PM
Here is a very interesting link http://www.at-the-edge.org.uk/co2debate24.pdf
explaining Dynamic demand technology.

This is not only UK problem .It is now a universal issue that requires participation of all disciplines of science and technology if we want our next generations to have some fossil fuel left for their use.
Thermal power plant efficiencies are in the range of 30 t0 40%and transmission losses account for an other 16 to 30 depending upon the country.At best we get 40 % overall efficiency .
Imagine the fossil fuel demand after 10 years to meet power requirements in Asia alone when China and India reach 25% market penetration of air conditioners .India had 0.05% penetration a decade back .It now has reached 2.5%.
I understand china is already concerned about being able to match the energy requirement for its domestic refrigerator demand, which is still round 30 % of the potential.
Refrigerator manufacturers are struggling to get the annual power consumption of a refrigerator, down to 600 Kilowatt hours per annum.
Demand Side Management is an area where we all can help. I have seen locally assembled air conditioning systems in Asia with EER as low as 7 Btu/watt .
System over sizing is a common practice in most of the Asian countries. Refrigeration engineers can contribute a lot by choosing thermal storage and other low energy cooling technologies such as indirect evaporative cooling, air to air heat recovery especially in 100 % fresh air applications.

Evaporative condensing reduces peaking by as much as 10 to 20% in many climates depending on the ambient conditions.

Thermally activated technologies such as closed cycle and open cycle sorption technologies for air//water cooling should be adopted to reduce electrical energy use .
It is common knowledge that about 30% -40% of the energy is used in the buildings. More than 50% of this energy is used by cooling and heating appliances.
This leaves a great responsibility on the HVAC engineers optimize the energy use.

Andy
31-07-2006, 07:06 PM
Thermal power plant efficiencies are in the range of 30 t0 40%and transmission losses account for an other 16 to 30 depending upon the country.At best we get 40 % overall efficiency .
use .


That is the key to our problems.

Why do we not use gas engines to power our refrigeration and use the waste heat off these to heat our buildings in the winter:)

Kind Regards Andy:)

US Iceman
31-07-2006, 11:02 PM
Why do we not use gas engines to power our refrigeration and use the waste heat off these to heat our buildings in the winter?


The industrial engines used for this purpose are very expensive to install and maintain. These are usually only installed where there is: A) no primary electric power available, or B) the natural gas company buys part of the project to reduce first costs.



This leaves a great responsibility on the HVAC engineers optimize the energy use.


Yes, and it also makes our job more difficult trying to explain to the customer why he needs to spend more money to install an efficient system.

There will always be some person/firm selling cheap junk telling the customer the cheap junk will work just as well.

Not only do we have to be designers/engineers we also have to be in involved in marketing and education.;)

Argus
01-08-2006, 05:33 PM
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Hi Iceman,

There are a number of commercially available Gas Engine VRF heat pumps on the UK market at present and they seem to have captured a small niche, not because they are particularly energy efficient, (some of them undoubtedly are) but by virtue of the fact that they can address a limited power supply at any given location.

You can even get a UK tax-break for this technology if it meets minimum energy efficiency levels.

CHP has been on the sidelines all through Europe, again attempting to break the market, but the issue of using gas is not as clear cut as it appears because of the carbon conversion equations in comparison to the local electrical system, plus the proportion of gas used in generation. The main problem with CHP, as I see it, is the utilisation of instantaneous waste heat in Absorption machines ? you can?t easily and economically store it, plus the issue of cost. The kit is expensive.

Back at the core subject of Dynamic Demand, a major rationale from the power generator?s point of view is that in order to maintain the power quality at an optimum condition, a proportion of the national generating potential has to be constantly running in stand-by mode to trim any variations. This is sometimes in the order of Giga Watts and it is the unnecessary Carbon emissions from this constant ?slack? that they are trying to redress.

There are undoubted areas for economy in refrigeration and air conditioning, but, the figures that we see are always for an instantaneous value. If the total integrated energy that included the energy used in recovery of the process after a ?modification? of the running condition due to, say, Dynamic Demand or a similar technolgy, were factored in we may see that the savings are not so good after all.
These and others are the issues that are to be addressed in the forthcoming report that I mentioned.

.
________
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US Iceman
02-08-2006, 01:45 AM
Hi Argus,



If the total integrated energy that included the energy used in recovery of the process after a ‘modification’ of the running condition due to, say, Dynamic Demand or a similar technology, were factored in we may see that the savings are not so good after all.


I have to agree with that. This is one of those issues that makes for an interesting discussion as it has more than two angles. We can look at it in both, macroscopic and microscopic terms.

From the view of the utilities they are interested in a "big picture", i.e., how is the grid and generation capacity affected and the impact of subsequent carbon release.

Other changes we might make on a "local" effort may not be effective, or visible in the larger terms.

The other issue is one of being able to sustain the "control" of the Dynamic Demand.

Wouldn't you consider this to be similar to load leveling of generation capacity and the ability to predict and control the operation and reaction times of the loads?

This is really fascinating.

US Iceman
02-08-2006, 06:54 PM
Argus,

Here is something that be interesting...

http://www.iea.org/dbtw-wpd/Textbase/techno/iaresults.asp?Ia=Demand-Side%20Management

Look at Annex 13 & 15