# Make peak values move to low value region - Peak Lopping - HELP!

1. ## Make peak values move to low value region - Peak Lopping - HELP!

Hi guys,

I am trying to create a spreadsheet of daily energy use and have the ability to shift the max values to a period when the values are lower. Effectively I want to shift the peaks to trough regions. The spreadsheet will be used to model an energy usage profile by shifting the peaks to a lower region to create a peak lopping.

Effectively I would like to shift the peak at around 7:00pm of this profile to between 1:00am - 5:00am. How can I do this?

Picture 5.png

FINALEnergyCalc.xlsx

3. ## Re: Make peak values move to low value region - Peak Lopping - HELP!

Effectively, I will have to create an IF(A1:AN>Setpointvalue then you move that max data to a when the data is between 00:00 to 06:00.

Is this possible?

4. ## Re: Make peak values move to low value region - Peak Lopping - HELP!

Hi GB,

You like your detail don't you?

Here's a tip based on something a very wise individual once said to me...

"Its better to be approximately correct in time to take evasive action than to be 100% correct after the torpedo has hit..."

First step is to question why your consumption per item is as high as reflected and to identify ways in which to reduce the value WITHOUT time-shifting.
Typically, a water heater's usage is driven the temperature difference between input water and thermostat-controlled output temperature - two options:

1) Install solar water heating or a heat-pump to raise the temperature of the incoming feed
2) Lower the thermostat setting

In your model, I'd focus on the big ticket items (i.e. 1kW+) and create a demand pattern with 30 or even 60 minute intervals - a 15-minute level of granularity is overkill

Next, examine these and flag those items where you actually have some flexibility in when you have to use them. (Typically, most kitchen food-related appliances tend to either be driven by mealtimes and I doubt you'd want to breakfast at 3am or eat dinner at midnight, or - as with refrigerators - need to be on all the time).

Having culled things down to a more manageable list of items that have an elective usage time, sit down with all involved and agree on a more balanced schedule that is "doable" and acceptable to all. In other words, here's where you introduce the more fuzzy-logic to the equations (human objections)...

NB: There are times when being too mechanistic is just not appropriate for the circumstances - this initiative of yours seems to qualify...

Of course, if this Excel project is just a "let me see if this can be done" exercise, then let me wish you luck and leave you with a parting bit of advice - if this is an academic exercise, make sure it remains one and don't fall into the trap of trying to implement it in your home...

Dave

5. ## Re: Make peak values move to low value region - Peak Lopping - HELP!

Originally Posted by DaveDeV
Hi GB,

You like your detail don't you?

Here's a tip based on something a very wise individual once said to me...

"Its better to be approximately correct in time to take evasive action than to be 100% correct after the torpedo has hit..."

First step is to question why your consumption per item is as high as reflected and to identify ways in which to reduce the value WITHOUT time-shifting.
Typically, a water heater's usage is driven the temperature difference between input water and thermostat-controlled output temperature - two options:

1) Install solar water heating or a heat-pump to raise the temperature of the incoming feed
2) Lower the thermostat setting

In your model, I'd focus on the big ticket items (i.e. 1kW+) and create a demand pattern with 30 or even 60 minute intervals - a 15-minute level of granularity is overkill

Next, examine these and flag those items where you actually have some flexibility in when you have to use them. (Typically, most kitchen food-related appliances tend to either be driven by mealtimes and I doubt you'd want to breakfast at 3am or eat dinner at midnight, or - as with refrigerators - need to be on all the time).

Having culled things down to a more manageable list of items that have an elective usage time, sit down with all involved and agree on a more balanced schedule that is "doable" and acceptable to all. In other words, here's where you introduce the more fuzzy-logic to the equations (human objections)...

NB: There are times when being too mechanistic is just not appropriate for the circumstances - this initiative of yours seems to qualify...

Of course, if this Excel project is just a "let me see if this can be done" exercise, then let me wish you luck and leave you with a parting bit of advice - if this is an academic exercise, make sure it remains one and don't fall into the trap of trying to implement it in your home...

Dave

Hi Dave,

The exercise that I am trying to model is a battery energy storage system which essentially is a system that involves charging lithium-ion batteries in the low-demand periods and using this stored energy during higher tariff, peak demand periods to save the consumer money and relieve the strain on the electricity distribution network by effectively peak lopping.

At the moment I intend on modeling this with my spreadsheet by having a set point at which any energy demand over this value is peak lopped and shifted to a lower consumer demand period in my excel spreadsheet.

As I see it right now, I need to set a maximum parameter which can be varied in a cell... If the values increase above this maximum value, the energy will need to be smoothed out over that off peak period.

How do you think I can do that?

6. ## Re: Make peak values move to low value region - Peak Lopping - HELP!

Hi GB,

Okay, so you want to use Lithium-Ion cells to load balance demand to reduce any surcharges arising from demand peaks (your overall usage should remain constant, just more evenly distributed across a 24-hour period)... Am I right?

Your workbook focuses on KwH as your unit of power - do you need to also consider current drain in Amp-Hrs? (My memory of uni physics is weak after 45 years)

Also, some types of battery are more effective when not subjected to peak demands close to the maximum load levels - how do these shape up in this regard?

Finally, modeling is one thing, but implementation is another - the modeling will help identify what needs to be done and why, but the how and when may well be beyond the scope of the model.

One approach I'd consider is to calculate my "desired maximum load" as a threshold level and then to identify when normal usage patterns result in a peak load exceeding this as well as when peak loads are below. For each time interval you need to accumulate, in two separate totals, the sum of:

1) Total usage above threshold (i.e. sum of total load minus threshold)
2) Total unused capacity (i.e. threshold minus total load)

The threshold level then need to be adjusted until you attain the optimum balance between totals 1 and 2.

You should be able to use Goal Seeking to set the threshold at the appropriate level.

That determines the "what". I'll leave the how to you...

Dave

There are currently 1 users browsing this thread. (0 members and 1 guests)

#### Posting Permissions

• You may not post new threads
• You may not post replies
• You may not post attachments
• You may not edit your posts

Search Engine Friendly URLs by vBSEO 3.6.0 RC 1