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Thread: Nightrate Metering

  1. #1
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    Default Nightrate Metering

    Would it be possible to measure nightrate electricity usage in Cortex,we get half price electricity between midnight and 9 am. I am using pulse type meters currently connected to an ODI which works brilliant, I would just like to add another /KWH for midnight to 9 am. Hope this makes sence.
    Thanks
    Dave

  2. #2
    Automated Home Legend Karam's Avatar
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    Just to say that we have noted your request. Surprising as it may seem this one turns out to be a non trivial task within the context of the relevant Cortex code (because of various dependency details). So its something we will put on the list but probably not get addressed in the short term.

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    Thanks Karam
    I am sure that lots of people must be using night rate electricity like economy7.

    Dave

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    Automated Home Legend chris_j_hunter's Avatar
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    just a thought, but how accurate will people be wanting this to be - eg: start times for night-rates are staggered & commanded by longwave signals ... also, if people were wanting to track cost as well as kWhr, for ready family understandability (ie: good thing to do), there are a surprising number of different tariffs around, when it comes to the detail - involving standing charges, day rates, night rates, dual-fuel discounts, first so many units at one price, next at something else (higher or lower), and so on ... in various combinations !
    Last edited by chris_j_hunter; 10th March 2009 at 07:22 PM.

  5. #5
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    Here in Ireland we just have 2 rates, nightrate is from 11pm to 8 am and costs 9cent (8p) kwh where as daytime rate is 18cent (16p) kwh so there are some great savings to be made. By using cortex to track usage I have been able to get our heat pump to do 2/3s of the heating on nightrate.

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    Automated Home Legend Karam's Avatar
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    I think providing cost information probably has more psychological than accuracy importance. I'd agree that with tariffs being the way they are in the UK at least, it is not straightforward to provide an accurate cost calculation - as you say Chris you'd also need an unbroken historical record over a period of time before you could factor in the banding in some tariffs. Also you'd need to ensure that you have accurate meters that measure VA rather than just A. Of course it is possible to do - just a case of balancing effort against benefit.

    I think when people see that its presently costing them x pence/hour as opposed to y pence per hour then that hits home much more effectively than how many KW are presently being used (mental block to less understood unit even as a relative measurement). So long as its understood that its a rough figure I guess it will still have some of the desired effect.

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    Automated Home Legend chris_j_hunter's Avatar
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    yep, don't disagree - maybe a good way would be to headline current rate of spend per hour (at current charge rate, night or day) against a background of historical power usage - ie: have a graph of kWhr vs time for the last (say) month, or year, in the background, and a foreground digit showing current rough rate of spend - would work for me, anyway !!

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    Moderator Kevin's Avatar
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    I haven't tried this but maybe it's possible to take the pulse information via an AND logic symbol input, the second input of which was only true over the nightrate time period ? I meant to look at this in conjunction with another requirement I had for enabling actions only during certain time periods. Being able to set logic inputs for time periods seems most useful.

    Maybe it's not possible. It would still generate two views - rather than a compound view of electricity usage anyway but maybe that's adequate ?

    K

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    Automated Home Legend chris_j_hunter's Avatar
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    in terms of display, this looks not bad :

    http://www.ethicalsuperstore.com/pro...nergy-monitor/

    ??

  10. #10
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    Quote Originally Posted by Kevin View Post
    I haven't tried this but maybe it's possible to take the pulse information via an AND logic symbol input, the second input of which was only true over the nightrate time period ? I meant to look at this in conjunction with another requirement I had for enabling actions only during certain time periods. Being able to set logic inputs for time periods seems most useful.

    Maybe it's not possible. It would still generate two views - rather than a compound view of electricity usage anyway but maybe that's adequate ?

    K
    This sounds great if it will work Kevin, Will give it a try tonight and see how I get on.

    Dave

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