It is now Mon, 22 Oct 2018, 14:00

All times are UTC + 1 hour [ DST ]



Post new topic Reply to topic  [ 13 posts ] 
Author Message
 Post subject: Sainsbury's rolls out 'dynamic demand' heating
PostPosted: Wed, 02 Mar 2011, 10:50 
Offline

Joined: Fri, 31 Jul 2009, 15:33
Posts: 665
Location: Holbrook, Horsham
Quote:
Just days after announcing that it has been trialling innovative smart grid technology in one of its stores, supermarket giant Sainsbury's has confirmed that it has installed dynamic demand management technology in 200 outlets.

The retailer had conducted trials of the technology in three stores in the South East and, following a successful pilot period, the company is rolling out the technology in a further 200 supermarkets across the country after signing a 10-year deal with UK smart grid start-up RLtec.

The start up said the move will save an estimated 10,000 tonnes of carbon emissions a year as part of Sainsbury's goal of cutting emissions 25 per cent by 2012.

RLtec said its technology would boost Sainsbury's energy efficiency by managing the power consumption of its heating and ventilation systems, ensuring that when appropriate they are powered down.

The company's device responds automatically to second-by-second changes in the balance between supply and demand on the grid and aligns the timing of the heating and cooling systems to match them.

RLtec predicts that if rolled out widely, the technology will reduce the need for backup power which would otherwise be required to balance out variable renewable energy output. This reserve typically uses coal or gas power stations that offer predictable, but carbon-intensive, energy.

It added that large-scale deployment of the system could save two million tonnes of CO2 per year in the UK alone.

The Sainsbury's deal represents the first wide-scale rollout of the technology anywhere in the world and follows on from a contract with Hotpoint/Indesit to install the equipment in more than 1,000 fridges nationwide.

"The fact that dynamic demand can so easily be fitted to such a huge range of appliances across all sectors, from the domestic to the industrial and commercial, makes it a vital tool in our efforts to tackle climate change," said RLtec managing director Paul Lazarevic.

"With no behavioural change necessary on the part of the consumer or business and no disruption to performance as a result of its installation, it is a simple and effective solution that delivers for customers and the environment alike."

Original article (containing links to interesting places)

I'm attempting to find out whether Horsham is one of the 200 stores. The person at the local store who answered didn't know anything about it, so I suspect not. She will find out and call me back...

_________________
Advertising is the rattling of a stick inside a swill bucket - George Orwell


Top
 Profile  
 
 Post subject: Re: Sainsbury's rolls out 'dynamic demand' heating
PostPosted: Wed, 02 Mar 2011, 12:37 
Offline

Joined: Fri, 31 Jul 2009, 15:33
Posts: 665
Location: Holbrook, Horsham
I've heard back. Apparently Sainsbury's Head Office has yet to decide where this will be rolled out. It will be decided in the next few days. That appears to conflict with what the Guardian article says ...but not with yesterday's RLtec press release!
Quote:
Sainsbury’s join forces with RLtec in world first Smart Grid Technology deal

The green smart grid technology that could save the UK two million tonnes of carbon a year has taken another big leap forward after a deal was signed with Sainsbury’s to put it into over 200 of its stores.

The agreement, which is the world’s first commercial deal of its kind, has seen RLtec - the providers of the innovative ‘dynamic demand’ technology - fit the equipment to the supermarket’s heating and ventilation systems. It will help to better manage electricity supply and demand across the entire national grid as well as boosting Sainsbury’s energy efficiency. The 10-year deal follows a successful trial of the technology at three Sainsbury’s stores in the south east and is expected to save 10,000 tonnes of carbon a year when it goes live from today (March 1st). The roll out of this technology will also provide The Grid with significant cost savings.

Dynamic demand works by managing the power consumption of equipment, responding automatically to second-by-second changes in the balance between supply and demand on the grid. As a result the CO2 producing power stations that are currently held in reserve to perform this balancing service will not be needed as much and so UK emissions can be dramatically reduced. Appliances such as heating and ventilation systems, switch off and on throughout the day and RLtec’s technology merely changes the timing of these switchings to match demand on the grid. If widely deployed it could save two million tonnes of CO2 per year in the UK alone.

...continues
Quote:
Neil Sachdev, Sainsbury’s property director said: “... Our customers trust us to make sure we minimise our environmental impact, so we are constantly working to ensure we meet their expectations.”
Your local Sainsbury's store details, if you'd like to lobby for Horsham to be one of the 200...

_________________
Advertising is the rattling of a stick inside a swill bucket - George Orwell


Top
 Profile  
 
 Post subject: Re: Sainsbury's rolls out 'dynamic demand' heating
PostPosted: Sat, 05 Mar 2011, 23:44 
TH member
Offline

Joined: Fri, 07 Aug 2009, 22:22
Posts: 275
"Dynamic demand works by managing the power consumption of equipment, responding automatically to second-by-second changes in the balance between supply and demand on the grid."

Great idea, but How?

Anybody understand this? Voltage sensor, signals sent out from control centres?

Trevor - where are you when we need you...any ideas?


Top
 Profile  
 
 Post subject: Re: Sainsbury's rolls out 'dynamic demand' heating
PostPosted: Sun, 06 Mar 2011, 13:35 
TH member
Offline

Joined: Sun, 02 Aug 2009, 21:25
Posts: 471
Location: Holbrook, Horsham., UK
How it works: see http://www.dynamicdemand.co.uk/the_technology.htm.

Pending input from our/a guru - as I understand it the system switches time insensitive equipment on and off in order to reduce the peak demand in a facility. For example, heaters, ventilators, fridges and freezers in a supermarket will come on and go off randomly and sometimes they could all come on at once creating a high electricity demand. If they could be managed to come on and go off at different times (within the parameters of maintaining required ventilation/temperatures) then the electricity demand profile would be smoothed out and the peak demand would be reduced.

What I don't understand is how the supermarket gains a benefit. Perhaps there's an incentive from the Government and or energy provider (e.g., pricing differentials for peak loading)?


Top
 Profile  
 
 Post subject: Re: Sainsbury's rolls out 'dynamic demand' heating
PostPosted: Sun, 06 Mar 2011, 19:41 
TH member
Offline

Joined: Fri, 07 Aug 2009, 22:22
Posts: 275
Brilliant! Thanks Chris - the story i wanted right there on - http://www.dynamicdemand.co.uk/grid.htm#

So the sensor 'sees' the generator rpm through the ac frequency - if demand is high the frequency dips a little and the gadget switches off for a while.

Did you find the link through to the CO2 intensity graph? http://www.realtimecarbon.org/

Both these items are pretty marginal in their effect but if a lot of little improvements were added together it may make a difference?


Top
 Profile  
 
 Post subject: Re: Sainsbury's rolls out 'dynamic demand' heating
PostPosted: Mon, 07 Mar 2011, 10:43 
TH member
Offline

Joined: Sun, 02 Aug 2009, 21:25
Posts: 471
Location: Holbrook, Horsham., UK
Quote:
Did you find the link through to the CO2 intensity graph? http://www.realtimecarbon.org/


No, I googled 'dynamic demand'.

(Google is great - not so sure about the server farms!)


Top
 Profile  
 
 Post subject: Re: Sainsbury's rolls out 'dynamic demand' heating
PostPosted: Mon, 07 Mar 2011, 11:17 
Offline

Joined: Fri, 31 Jul 2009, 15:33
Posts: 665
Location: Holbrook, Horsham
If you're only interested in the theory of it why don't you just ask RLtec? - or save them some effort and visit their "How does our product work?" page first? :?

If you're interested in this practical application... ask Sainsbury's? :mrgreen:

_________________
Advertising is the rattling of a stick inside a swill bucket - George Orwell


Top
 Profile  
 
 Post subject: Re: Sainsbury's rolls out 'dynamic demand' heating
PostPosted: Mon, 07 Mar 2011, 13:33 
TH member
Offline

Joined: Wed, 26 Aug 2009, 22:29
Posts: 126
I skip a few days and you see what happens? Funnily enough my thesis was on extending the use of dynamic demand beyond refrigeration to other household appliances...

Anyway, the dynamic demand website has a pretty good explanation of what it's all about - matching the load to the supply rather than the other way round should reduce the amount of generating capacity needed to stabilise the grid. That stabilising capacity is normally provided by coal or gas powered generators operating below their peak efficiency.

I'm still a bit puzzled by what Sainsburys get from the deal though, one of the problems with dynamic demand is that the end-user pays for the technology but the electricity supplier gets the benefits. Maybe Sainsburys have managed to negotiate with their supplier(s)?

The Real Time Carbon site is quite fun too - and James Smith (Sustainable Rudgwick, came to Green Drinks once) had a hand in its creation.


Top
 Profile  
 
 Post subject: Re: Sainsbury's rolls out 'dynamic demand' heating
PostPosted: Tue, 08 Mar 2011, 01:22 
TH member
Offline

Joined: Fri, 07 Aug 2009, 22:22
Posts: 275
The description on the DD website says that the sensor 'sees' the overall system load as being as a drop in frequency - like a car engine slowing down as it goes up a hill. It is not actually seeing the load, just the symptom of it.

Drifting slightly off topic, the grid therefore relies on a number of fossil, hydro or nuclear steam powered alternators spinning away on base load to set that frequency to which solar and other inputs chime in. (as far as I can see)

So how does the "synthetic" ac output of a solar installation relate to the "natural" ac of traditional generators? I imagine that as it reduces whole system load, the 'traditional' generators increase speed and frequency edges back up again, and the DD sensors start cutting back in. (I realise the changes are very marginal). As the DD is automatic, the whole system is slightly easier to balance. I guess the power engineers have probably been using macro version for a long time.

A very clever invention, but quite marginal in its effect compared to the "big picture" stresses we are told are in the pipeline by the likes of Prof David McKay and vitually everyone else who seem to have looked at the arithmetic.

If we think in terms of 'clouds' of discrete generating-consuming units rather than the grid, overall efficiency may (?) go down the but the security factor may increase due to the unlikeliness of many individual plant failing at the same time - there are systemic risks associated with the grid such as the possibility of sunspots-surges or cyber vandalism!

Back to load smoothing, Trevor there are huge numbers of lighbulbs in use, most of them have an electronic circuit built in. (I dont know if this applies to leds or how voltage sensitive they are). Bearing in mind way that a large voltage drop causes only a small reduction in the light emitted (by flourescent lighting, again I dont know about LEDs) did you look at the possibility of putting tiny DD circuits into each lightbulb?

Alan


Top
 Profile  
 
 Post subject: Re: Sainsbury's rolls out 'dynamic demand' heating
PostPosted: Tue, 08 Mar 2011, 12:14 
TH member
Offline

Joined: Wed, 26 Aug 2009, 22:29
Posts: 126
Dynamic demand systems use the grid frequency as a proxy for the level of 'stress' on the grid: if the load on the grid is more than the generators are supplying then the first place that any 'extra' energy can come from is the angular momentum of all the rotating masses attached to the grid - generators, turbines, and motors too - so they slow down and reduce the frequency of the grid. If there's an excess of power being generated then that has the opposite effect and speeds up all the rotating masses. For a whole slew of reasons the frequency of the grid needs to be kept in a narrow range: 49.5Hz to 50.5Hz are the statutory limits but National Grid use 49.8Hz to 50.2 Hz as working limits.

It's a simplification, but you can think of all the rotating machines on the grid as being locked together - when one slows down they all slow down and so on. One of the issues with connecting generators to the grid is getting the frequency and phase to match the grid before connection, otherwise there's a noisy moment as your generator snaps into alignment with the rest of the grid. When the generator is a big rotating machine the matching is done by very carefully controlling the amount of power being fed to the generator from the turbine so that frequency and phase exactly match. In the case of 'synthetic' systems with inverters the inverter has to sense the frequency and phase and synthesise a waveform that matches before connecting.

The point of dynamic demand isn't to reduce energy consumption (in fact the energy consumed might marginally increase) but to reduce CO2 emissions by reducing the need for electricity suppliers to keep fossil-fuelled plant spinning inefficiently in order to be able to respond to a spike in demand. Dynamic demand also helps offset some of the short-term variability effects associated with energy from renewable resources.

I could go on about this for hours...

There are pros and cons for small-scale distributed generation - the more generators you have the more that can fail, you still have issues about balancing supply and demand ... who's generator do you turn off when supply exceeds demand? Lots of small generators mean lots of maintenance, but (probably) a more resilient system. It's certainly true that the present grid structure was designed for centralised generation.

I didn't think about using dynamic demand for lighting because generally I didn't think that lighting was a deferrable load. You want the light on and I think you'd get pretty annoyed if it was turned off or dimmed while you were reading your book. Designing a controller to reduce the voltage is much more challenging than just turning off a fridge or water heater for a while.


Top
 Profile  
 
 Post subject: Re: Sainsbury's rolls out 'dynamic demand' heating
PostPosted: Wed, 09 Mar 2011, 18:10 
TH member
Offline

Joined: Sun, 02 Aug 2009, 21:25
Posts: 471
Location: Holbrook, Horsham., UK
Well said Trevor (and for not going on for hours).

Do we need some more Dynorwigs? 0 to 1,320 MW in 12 seconds sounds pretty responsive but maybe it's not enough. (I'd be happy to wait 12 seconds for a cup of tea.)


Top
 Profile  
 
 Post subject: Re: Sainsbury's rolls out 'dynamic demand' heating
PostPosted: Thu, 10 Mar 2011, 12:21 
TH member
Offline

Joined: Wed, 26 Aug 2009, 22:29
Posts: 126
More Dinorwigs? There are another 3 pumped storage schemes in Scotland (Cruachan, Foyers and Loch Sloy) but they're all considerably smaller than Dinorwig. There are a couple of big hydro schemes at Lochaber and Mossford also in Scotland which can also be turned on quickly. There's some discussion about raising the height of the dam at Loch Sloy to increase capacity, but that's the only development I know of. The problem is that for pumped storage you need two big-ish bodies of water so that you have the capacity and also so that you don't flood the surrounding area when you exchange the water between the two "reservoirs". I have an idea that there is a scheme (not in the UK) that uses the sea as the lower reservoir and a lake as the upper one.

Big hydro schemes are big engineering projects though - building Dinorwig involved excavating 12 million tonnes of material, 1 million tonnes of concrete and 4500 tonnes of steel (apparently!). And we'd be unlikely to have had Dinorwig without having had nuclear power stations - the pumped storage schemes were partly conceived as a way to provide an off-peak load for nuclear stations if I recall correctly.

Oh, and that 0 to 1320 MW in 12s figure is only true if the system is ready and waiting for the load with all the pipes full of water. I'm not sure that the turbines don't have to be turning but not loaded as well. But it is a fast response.


Top
 Profile  
 
 Post subject: Re: Sainsbury's rolls out 'dynamic demand' heating
PostPosted: Thu, 10 Mar 2011, 17:06 
TH member
Offline

Joined: Sun, 02 Aug 2009, 21:25
Posts: 471
Location: Holbrook, Horsham., UK
Thanks Trevor - you are a mine of information - some of it useful as well!

Continuing to keep off topic, according to Wiki, and others,
Quote:
The 30 MW Yanbaru project in Okinawa was the first demonstration of seawater pumped storage. A 300 MW seawater-based project has recently been proposed on Lanai, Hawaii, and several seawater-based projects have recently been proposed in Ireland. Another potential example of this could be used in a tidal barrage or tidal lagoon.

Instead of wasting all that money to keep gambling banks going HMG should have financed a Severn Barrage - employing 10's of thousands of people during the construction phase and producing sustainable energy for decades to come - that is, unless you know better.

I've visited Dynorwig. It's truly amazing.


Top
 Profile  
 
Display posts from previous:  Sort by  
Post new topic Reply to topic  [ 13 posts ] 



All times are UTC + 1 hour [ DST ]


Who is online

Users browsing this forum: No registered users and 1 guest


You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot post attachments in this forum

Search for:
Jump to:  
cron
Powered by phpBB © 2000, 2002, 2005, 2007 phpBB Group