Release: Design Load Trend

Major updates to our Design Load views!

We’re very excited, because we’ve just pushed our latest major update, our new version of the design load view, into production! That means that all of our customers now can analyze what the highest load is likely to be in the network, parts of the network or even for single substations.

The design load view, found under the Distribution tab, has been with us for quite some time and has now received a much deserved face lift. Both in terms of design and in functionality. The highlights are these:

• Calculate the design load for filtered substations
• See the volume flow during the design load of the network
• See the return temperature during the design load of the network
• See the coincidence factor (sammanlagringseffekt) between the design load of the system and the design load of individual substations
• See what the weather is like when the design load occurs
• See how the design load has changed over the years

Neat! How do I use it?

Expand the distribution tab on the left hand main menu, then click “Design Load”.

Voila, here’s your brand new view! All numbers shown here refer to the system design load (described in detail further down if you’re interested), e.g. the highest heat energy load that Utilifeeds machine algorithms have calculated for your network.

Choose to show either daily or hourly design load values. If you select daily values, the design load will be lower than with hourly values selected because the value shown is the average daily load, not the summed load during a day.

One of the biggest new features in this view is that it is now completely filterable! This is great if you want to look at if the currently installed production and/or distribution capacity in a part of the network is enough if new heat demand is added.

Simply open up the filters menu at the top and set a filter any way you want. The design load numbers will update instantly to show the sum of the system design load of the substations that have passed your filter criteria.

You can even filter the results down to a single, individual substation! This can be useful if you need to dimension the heat exchanger of a newly constructed building and you want to use a similar building in your network as a reference.

That’s the short version, we hope you’ll find the design load view useful when taking strategic investment decisions, designing new grid extensions and discussing needed capacity with consultants and construction companies!

If you’re curious about the details, here’s an excerpt of our upcoming Utilifeed Wiki, explaining the concepts of design load as defined by Utilifeed:

Design Load

The design load of a network or a substation (a resource) is the highest load that would statistically occur if it was exposed to a weather scenario identical to 20 years of reference weather data. It is also possible to calculate the design load for a part of a network. The design load can for example be used to decide if more production and/or distribution capacity is needed in a network in order to meet upcoming demand.

In short, the way design load is calculated for a resource is by training machine learning models of the resource with measured data from a training period. Then, 20 years of hourly weather and calendar data is used as input for the models, which simulate the hourly energy consumption of the resource in the same 20 years. Once there is simulated data for each hour in 20 years, the highest energy consumption is found. This energy consumption is what is said to be the design load. This period of 20 years, includes the same data that is used by SMHI in Sweden to set the DUT (Design outdoor temperature).

Design loads are calculated once each year, when a calendar year has ended and measurement data from that year is available to train models on. Therefore, there are several design loads available in a network, one for each calendar year that is used as a training period for the machine learning models. If the design load changes between the calendar years, this means that the behavior of the substations in the network has changed. This can be caused by the number of substations increasing or decreasing, different social behavior in buildings and changed energy consumption due to efficiency measures.

Even though training periods change, simulation periods do not. This is to give a common ground to compare design loads between years. The simulation period for calculating design loads is the same as the calculation period used for normal energy calculations.

Example

• A substation has a measured highest hourly load in 2021 of 60 kW.
• A machine learning model is trained on all hourly measured data from the substation in 2021. For every hour, the machine learning model also uses the weather and calendar data that applies to the substation.
• The machine learning model is fed hourly weather and calendar data from the years 2000 to 2019.
• The machine learning model outputs the energy use that the substation would have in every hour in the year 2000 to 2019, based on what it learned about the substation in 2021.
• The highest simulated energy use in 2000 to 2019 is found to be 85 kW. This would have occurred at 23:00 on January 5th 2001.
• The design load of the substation is 85 kW.

Hourly and daily design load

The design load is calculated on either an hourly or daily basis:

Hourly design load: The one (1) highest hourly heat energy consumption of a resource

Daily design load: The average heat energy consumption in the 24 hour period with the highest sum of heat energy consumption of a resource

Example

1. The highest simulated hourly energy for a resource is 450 kW, then the hourly design load = 450 kW
2. The consecutive 24 hour period with the highest sum of simulated hourly heat energy for a resource is: 450, 400, 440, 445, 442, 380, 400, 410, 450, 430, 430, 435, 440, 415, 405, 400, 390, 450, 400, 420, 420, 425, 430, 440. Then, the daily design load = 422.8

Substation design load

The substation design load is the design load of a single substation. This means that a machine learning model of the single substation has been trained on a given set of data. Thereafter 20 years of hourly energy, flow and temperatures have been simulated. For that single substation, the maximum energy use (hourly or daily) in the simulated 20 years is the substation design load.

Substation design load: The design load of an individual substation

System design load

The system design load is the design load of a network (or a part of a network e.g. a cluster). This means that a machine learning model based on sums and averages for the network/cluster has been trained on a given set of data. Thereafter 20 years of hourly energy, flow and temperatures have been simulated. For the network/cluster, the maximum energy use (hourly or daily) in the simulated 20 years is the system design load.

There is also a system design load calculated for each substation. The system design load of a substation is the simulated load in that substation at the time of the system design load of the network/cluster.

System design load: The design load of an entire network or cluster and the load of each individual substation in that network/cluster at the time of the system design load.

Design load coincidence factor

Since the substation design load is calculated individually for each substation, the date and time at which the design load occurs can be different for each substation in the network!

If all substation design loads are summed together, the result is a very high load that is very unlikely to ever occur. It is unlikely that every substation in a network uses its design load at the same time.

The sum of system design loads of all individual substations is equal to the system design load of the network. The sum of substation design load of all individual substation is not equal to the system design load.

The difference between the sum of substation design loads and the system design load of the network is called the design load coincidence factor (Swedish: Sammanlagringsfaktor) and is expressed as a percentage.

Design load coincidence factor: The relation between the sum of substation design loads and the system design load of the network/cluster. Design load coincidence factor = System Design Load / Sum of Substation design loads

Example

A network has five substations, 1, 2, 3, 4 and 5. If we calculate the System Design Load of this network, we find that it would occur at 2001-12-20 01:30. The System Design Load is 20 MW and the five substations contributes to this load accordingly:

However, if we would look for the highest individual load of each substation in the network, the Substation Design Load, we would find the following numbers:

The sum of Substation Design Load (28 MW in this case) is thus not the same as the System Design Load. This is because the highest loads of individual substations does not often occur at the same time as the highest load of the entire network.

In this example the Coincidence Factor is thus 20/28=71%

Design load date

The date and time when the design load of a resource is found is called the design load date. Design load dates are available for hourly and daily values, as well as for substation and system design loads.

For hourly values the design load date is one (1) date and time.

For daily values the design load date is a 24 hour period.

Reminder: Design loads are calculated by simulating the heat energy consumption in 20 years of hourly weather and calendar data. The design load date is a date in this 20 year period and is the date when the highest simulated heat energy is found.

The substation design load date can differ between substations since the heat energy consumption in buildings in a network are differently affected by e.g. weather and time of day. Some buildings may be more affected by wind than others. Some buildings may have ventilation systems that are shut off during the night.

The system design load date is the date when the load would be highest for the entire system and therefore there is only one system design load date for a network.

Weather at design load date

For both substation design loads and system design loads, the observed weather conditions at the networks location at the design load date are noted. The conditions are outdoor temperature, wind speed and wind direction.

For daily design load values, the values noted are the average values of the design load date.

Flow and temperature at design load

For both substation design loads and system design loads, the simulated flow and return temperature of the resource are noted.

Flow at substation design load: The simulated volume of a single substation at its design load

Return temperature at substation design load: The simulated return temperature of a single substation at its design load

Flow at system design load: The sum of simulated volume flow for all substations in the network at the date and time of the system design load.

Return temperature at system design load: The flow weighted average simulated return temperature for all substations in the network at the date and time of the system design load.