Why 30mins?

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dan_b
Posts: 1861
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Location: SW London

Why 30mins?

#1

Post by dan_b »

The recent Octopus/National Grid demand side response trials are obviously a good thing. And for consumers are clearly enabled by Smart Meters. "At last!", some might say, a real discernible benefit to the customer for the whole programme...

However it got me wondering (I have too much time on my hands)...

How was the time period of 30mins per meter reading/energy block of different pricing landed upon and not, for example, 10 mins, or 15? Or 1 hour?

On the one hand, shorter time blocks mean you can adjust demand/supply/incentives on a more frequent/granular basis, which may be a good thing?
On the other hand, shorter time blocks may just mean "too much data" and actually increase variation of demand/supply issues?

Any grid engineers out there with any insight?

Are there other countries/markets that have different time blocks for this sort of thing?
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Countrypaul
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Joined: Sun Jul 18, 2021 11:50 am

Re: Why 30mins?

#2

Post by Countrypaul »

Doesn't the electricity market work on 3 minute periods so 48 settlement periods per day?
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nowty
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Re: Why 30mins?

#3

Post by nowty »

https://bscdocs.elexon.co.uk/guidance-n ... ners-guide

What are Settlement Periods?
Electricity is traded in half hour ‘chunks’. These half hour chunks are referred to as Settlement Periods. Each day (Settlement Day) is split into 48 Settlement Periods, with Settlement Period 1 equivalent to 00:00 to 00:30, Settlement Period 2 to 00:30 to 01:00, Settlement Period 3 to 01:00 to 01:30 and so on, through to Settlement Period 47 (23:00 to 23:30) and Settlement Period 48 (23 :30 to 00:00). Settlement Periods always refer to local time (whether this is GMT or BST).
Each Settlement Period is settled in isolation from the Settlement Periods around it. This means that all information used in the settlement calculations must be at Settlement Period level which includes metered data, contract data, and physical data.


https://www.power-technology.com/featur ... e/?cf-view
It seems its relatively recent we went to 30 min periods from hourly periods.
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dan_b
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Location: SW London

Re: Why 30mins?

#4

Post by dan_b »

Great article.

Also seems to answer the question about why 30mins and if other countries do the same…

“ In 2020, Ofgem granted an exemption from European rules requiring 15 minute settlement by 1 January 2021.”
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John_S
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Re: Why 30mins?

#5

Post by John_S »

When I worked in Hong Kong in the late seventies/early eighties, I recall that one element of the electricity bill for non-residential customers was their maximum demand in each monthly billing period and that the maximum demand was over a half hour period.

It is still the case

https://www.hkelectric.com/en/customer- ... ial-tariff

It also states that there are 48 'demand values' in a day and that suggests that the 30 minute periods run 0-60 and 31-60.
AE-NMidlands
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Re: Why 30mins?

#6

Post by AE-NMidlands »

I was thinking that aggregating the shortest monitoring bits into 30-minute periods would make far less data to handle (on the public-facing and charging websites) than revealing all of the 3-minute data, even if the output was based on the finer resolution stuff.
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Oliver90owner
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Re: Why 30mins?

#7

Post by Oliver90owner »

John_S wrote: Sat Dec 09, 2023 6:30 pm When I worked in Hong Kong in the late seventies/early eighties, I recall that one element of the electricity bill for non-residential customers was their maximum demand in each monthly billing period and that the maximum demand was over a half hour period.

It is still the case

https://www.hkelectric.com/en/customer- ... ial-tariff

It also states that there are 48 'demand values' in a day and that suggests that the 30 minute periods run 0-60 and 31-60.
Was, in the UK, back then. I expect it is the same these days. We dropped something like 10MW in the morning. Prices were ‘negotiated’ for each month with higher costs for that period, dependent on the maximum loads in any one half hour period. Lower costs were also negotiated dependent on lowering the grid supply by 2MW (or occasionally 5MW?) for a period (of up to two hours, IIRC) at a minimum notice of half an hour. We usually received a longer period of notice than half an hour, mind.

We could consume near to 26MW at off-peak times, so were not a light power user by any means of the term!

If they did that (unit cost dependent on maximum 1/2 hour average load) for residential consumers, it would upset a lot of BEV owners!
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