Balancing monitoring

The balancing monitoring screen compares the generation plans last accepted by OCCTO with the meter actuals for the same period. It shows the estimated imbalance per grid area and balancing group, so you can review your position and prepare your own imbalance accounting without building spreadsheets from separate exports.

You can find it in the side navigation under Balancing > Monitoring, next to the OCCTO plan submission screen.

Prerequisites

• OCCTO integration: The screen is only available when the OCCTO integration is configured for your workspace. Without it, the screen shows a prompt to enable the integration.
• Meter data: Actuals come from meter data only. Meter data reaches Tensor Cloud through the TSO data provision system integration or through manual file upload. Monitoring-system data is never used on this screen.

Selecting a period

Use the date range picker at the top of the screen to choose the period to analyze. The following presets are available:

• 1 day, 1 week, 2 weeks, 1 month: Rolling windows ending today. Use the arrows to move the window backward or forward.
• MTD (month to date): From the first day of the current month until today. This is the default when you open the screen for the first time.
• Custom: Any start and end date.

A period can be up to 124 days long, enough to cover two full meter-reading months that do not align with calendar months. The earliest selectable date is April 1, 2023. Dates are in JST.

Tensor Cloud remembers your last period, grid area, and balancing group for each workspace, and restores them the next time you open the screen. Links you copy from the browser address bar include your current selection, so colleagues who open them see exactly the same view.

Grid area list

The screen lists every grid area where your workspace has assets. Each row summarizes the selected period:

Column	Description
Grid area	The grid area
Generation plan	Total of the latest accepted generation plans
Actuals	Total meter actuals
Surplus	Estimated surplus: total of the 30-minute intervals where actuals exceeded the plan
Shortfall	Estimated shortfall: total of the 30-minute intervals where actuals fell short of the plan
Coverage	Plan coverage and data completeness. Values below 100% are highlighted

Click a row to expand it and see the details for that grid area.

Grid area details

Balancing group selection

By default, the expanded area shows All BGs combined. Use the Balancing group selector to narrow the view to a single balancing group. The time of the latest actuals update is shown next to the selector.

Key figures

Five tiles summarize the selected period and scope:

• Estimated surplus: Total of the 30-minute intervals where actuals exceeded the accepted plan.
• Estimated shortfall: Total of the 30-minute intervals where actuals fell short of the accepted plan.
• Source composition: Share of actuals backed by confirmed versus preliminary meter readings. A high preliminary share means the figures can still change.
• Plan coverage: Share of the period covered by an accepted plan. Days without a usable submission lower it.
• Data completeness: Share of expected meter data that has arrived, weighted by installed capacity.

Charts

Two charts show the selected scope:

• Plan versus actuals: Daily totals for the whole period. Click a day to see its 30-minute values in the second chart.
• 30-minute values: The 48 settlement intervals of the selected day. By default, this is the last day of the period. Use Previous day and Next day (or the K and J keys) to move between days.

Each chart has its own Display mode toggle:

• Plan vs actuals: Bars for the generation plan, the sales plan, and actuals. The sales plan exists per grid area only, so it is shown when All BGs combined is selected and hidden when you select a single balancing group.
• Imbalance: The estimated imbalance around a zero line. Positive values are surplus, negative values are shortfall.

Hover over a bar to see its values, the confirmed and preliminary share of the actuals, and notes on missing plans or missing meter data. Use the spreadsheet toggle on a chart to see the same data as a table, including the confirmed and preliminary shares.

Values are recorded in kWh. Charts and tiles switch to MWh or GWh automatically for large values.

When the selected period includes today, the screen refreshes the data every 60 seconds.

How the figures are calculated

Plans

For each day, the screen uses the latest plan accepted by OCCTO for each grid area. This is the plan in effect at OCCTO gate closure, which is not necessarily the day-ahead submission. The generation plan of a grid area is the sum of its balancing groups.

• Days without a usable accepted submission are excluded and shown as missing plan data.
• A balancing group that is left out of an accepted submission counts as a plan of zero for that day.

Actuals

For each asset and each 30-minute interval, the screen uses the best available meter data: confirmed meter data if available, otherwise preliminary meter data. Actuals are then summed per balancing group and grid area.

Actuals are assigned to balancing groups based on each asset's current balancing group. If an asset moved to another balancing group, its past actuals are shown under the new balancing group.

Figures are calculated when you open the screen or export a file. As preliminary data is replaced by confirmed data, the figures for past periods can change.

Estimated imbalance

The estimated imbalance for each 30-minute interval is:

$$\text{Estimated imbalance} = \text{Actuals} - \text{Generation plan}$$

• A positive value is a surplus, a negative value is a shortfall.
• The sales plan is displayed for reference but is not part of the calculation.
• Surplus and shortfall are summed separately and never netted against each other, because settlement treats each 30-minute interval on its own.
• Intervals without meter data are excluded from the imbalance, not counted as zero.

Grid area figures net balancing groups

Within each 30-minute interval, the grid area figures net the balancing groups against each other, while settlement is per balancing group. As a result, the surplus and shortfall of the individual balancing groups add up to more than the grid area shows. Only the net totals reconcile.

Indicative figures

The estimated imbalance is an indicative figure for your own analysis. It is not a settlement result and does not include imbalance prices.

Missing data

Missing plans or missing actuals are never shown as zero. Instead, charts mark them with a hatched No data pattern, and the tooltips explain what is missing.

• Plan coverage shows how much of the period has an accepted plan.
• Data completeness shows how much of the expected meter data has arrived, weighted by installed capacity. Weighting by capacity means that a few large plants without data lower the figure more than many small ones.

Missing meter data makes the estimated imbalance lean toward shortfall, so check data completeness before drawing conclusions from the imbalance figures.

Exporting data

Chart downloads

Each chart has a download menu to save the data shown in the chart as CSV or Excel. The file contains one row per day or per 30-minute interval, with values in kWh and the confirmed and preliminary shares. CSV files use the character encoding set in your account settings.

Export files

Click Export in an expanded grid area to generate files for the selected period. The files are generated on demand and can take a moment for long periods. All export files use Japanese column headers, are encoded as UTF-8 with BOM, and contain values in kWh. File names include the period and the time of export, because the figures can change when new meter data arrives.

The following files cover the whole grid area, regardless of the balancing group selection:

• Plan vs actuals (aggregated): One row per balancing group per 30-minute interval, followed by a grid area total row. Contains the plans, actuals, source composition, estimated imbalance, data completeness, and missing-data flags.
• Generation actuals by plant: One row per power plant per 30-minute interval, with the plant name, supply point identification number, actuals, and whether each value is confirmed or preliminary.

The following files are generated once per balancing group. With All BGs combined selected, you get one file for each balancing group in the area:

• Plan vs actuals (unified): One row per 30-minute interval, with the balancing group's plan and actuals followed by one column per planned plant and its power plants.
• Plan vs actuals by plant: One row per power plant per 30-minute interval, for the power plants currently in the balancing group. Each row has the plan submitted for the planned plant, the power plant's own part of it, and the power plant's actuals. This file is available when enabled for your workspace; contact Tensor to enable it.

In all files, timestamps mark the start of the 30-minute interval in JST. An empty cell means that there is no data, while 0 is a real value such as a metered zero. Rows are never left out because data is missing.

Plans by power plant

On screen, the balancing group is the most detailed level. The two balancing group files go one level deeper and show plans per power plant. This section explains where those values come from and how to read them.

Planned plants and power plants

A generation plan submitted to OCCTO lists planned plants by grid code. A planned plant is not always a single power plant:

• A power plant with an AC capacity of 50 kW or more is submitted as its own planned plant.
• Low-voltage power plants (AC capacity under 50 kW) are not submitted one by one. Tensor Cloud combines the low-voltage power plants of a balancing group that share a grid code into one planned plant and submits their total.

For a combined planned plant, OCCTO receives only the total. Both balancing group files therefore show the submitted plan per planned plant, and the by-plant file adds the part of each power plant as a reference.

The export files identify planned plants by grid code. If a plan lists the same grid code more than once for a balancing group, for example a high-voltage power plant next to a combined low-voltage entry with the same grid code, the files treat them as one planned plant and add their values together.

Each time Tensor Cloud builds a plan, it records which power plants the plan covers. The export files link each power plant to a planned plant based on the accepted plan of the latest day in the selected period that covers the power plant. Both files use the same plans and the same links, so they always agree with each other.

The files list the power plants that belong to the balancing group today:

• A power plant that is not covered by any accepted plan in the selected period is marked as not in plan and has no plan values. Its actuals are still included.
• A power plant that has left the balancing group is not listed, even if a plan in the period covered it.

Plan vs actuals (unified)

The unified file is a wide table with one row per 30-minute interval. It starts with three header rows:

Header row	Plan columns	Actuals columns
1	計画｜ (keikaku, plan) followed by the name of the planned plant	実績｜ (jisseki, actuals) followed by the name of the power plant
2	Grid code	Supply point identification number
3	構成資産数 (kōsei shisan sū, number of component plants) followed by the number of power plants listed under the planned plant	Grid code of the linked planned plant, or 計画対象外 (keikaku taishōgai, not in plan)

The first data row, 期間合計 (kikan gōkei, period total), contains the total of each column over the period. The first two value columns, 発電計画(kWh) (hatsuden keikaku, generation plan) and 実績_Tensor(kWh) (jisseki, actuals), contain the plan and actuals of the whole balancing group and are marked BG集計 (BG shūkei, BG total) in header row 3. After them, each plan column is immediately followed by the actuals columns of the power plants it covers, so you can compare a submitted plan with the actuals behind it. Planned plants are sorted by grid code, and power plants not in plan come last.

A planned plant with exactly one power plant listed under it takes the name of that power plant. Any other planned plant, such as a combined planned plant, has no name of its own and is labeled with its grid code, for example 系統コード1A234の発電所 (keitō kōdo 1A234 no hatsudensho, the plant with grid code 1A234). For a combined planned plant, the unified file shows only the submitted total. To see the part of each power plant, use the by-plant file.

Plan vs actuals by plant

The by-plant file is a long table with one row per power plant per 30-minute interval. Power plants are sorted by name, and all intervals of a power plant are listed together. The columns have these Japanese headers:

Column header	Romanization	Meaning
対象日時	taishō nichiji	Start of the 30-minute interval
エリア	eria	Grid area
BGコード, バランシンググループ	BG kōdo, baranshingu gurūpu	Code and name of the balancing group
系統コード	keitō kōdo	Grid code of the planned plant that the power plant is linked to
発電所名, 受電地点特定番号	hatsudensho-mei, juden chiten tokutei bangō	Name and supply point identification number of the power plant
提出計画(kWh)	teishutsu keikaku	Submitted plan: the value submitted to OCCTO for the planned plant. For a combined planned plant, the same total is repeated on the rows of every power plant it covers, so do not add it up across power plants
計画内訳(kWh)	keikaku uchiwake	Plan breakdown: the power plant's own part of the submitted plan
計画種別	keikaku shubetsu	Plan type: how to read the two plan columns, see the following list
実績(kWh), 実績ソース	jisseki, jisseki sōsu	Meter actuals and whether they are confirmed or preliminary, identical to the generation actuals file

The plan type takes one of the following values:

• 提出値 (teishutsuchi, submitted value): The power plant is its own planned plant. The plan breakdown repeats the submitted plan.
• 内訳（参考） (uchiwake sankō, breakdown for reference): The power plant is part of a combined planned plant. The submitted plan is the total of the combined planned plant, and the plan breakdown is the part of this power plant. It is a reference value because OCCTO never received it on its own.
• 内訳未記録 (uchiwake mikiroku, breakdown not recorded): The power plant is part of a combined planned plant, but no part was recorded for it in this plan. The submitted plan is shown, and the plan breakdown is empty.
• 計画対象外 (keikaku taishōgai, not in plan): The power plant is not covered by any accepted plan in the selected period. Both plan columns are empty.
• 計画なし (keikaku nashi, no plan): The day has no usable accepted plan. Both plan columns are empty for every power plant on that day.

On a day whose accepted plan does not include the planned plant, both plan columns are also empty, while the plan type stays the same.

How the plan breakdown is determined

Tensor Cloud records the part of each power plant at the moment it builds the plan, from the same inputs as the submitted plan. The export shows these recorded values. They are not recalculated afterward, so they do not change when forecasts or trades are updated after the plan was built.

What the part represents depends on where the electricity of the planned plant is sold:

• Sold to a counterparty balancing group, for example under a PPA: The submitted plan is the sum of the generation forecasts of the power plants. The part is the forecast that was used for the power plant when the plan was built, rounded down to whole kWh and never below zero.
• Sold on JEPX: The submitted plan follows the volume sold on the JEPX spot market, not the generation forecast. The part is the power plant's share of that volume. If the JEPX bid and contract data attributes the volume to power plants when the plan is built, the part is the volume attributed to the power plant, plus a share by AC capacity of any volume that could not be attributed to a submitted power plant. Without that data, Tensor Cloud splits the volume in proportion to AC capacity.

For plans that were built before Tensor Cloud started recording these parts, the parts are reproduced afterward from the inputs of that time. A reproduced part is only recorded when the reproduction matches the submitted plan exactly. Where a plan has not been or cannot be reproduced, the rows have the plan type breakdown not recorded.

When the plan breakdown does not add up to the submitted plan

For each planned plant and 30-minute interval, the plan breakdown of its power plants adds up to the submitted plan. A difference has one of the following causes:

• A power plant has left the balancing group: The file lists only the current power plants of the balancing group, so the part of that power plant is missing from the sum.
• A power plant joined or left the planned plant during the period: On days when the accepted plan did not cover the power plant, its plan breakdown cell is empty, while the submitted plan is still shown.
• Rounding of volume sold on JEPX: Submitted plans are whole kWh. For volume sold on JEPX, values are rounded down per planned plant, not per power plant. The parts can therefore contain decimals, and their sum can exceed the submitted plan by less than 1 kWh per interval. In addition, the remainder left by rounding is added to the submitted plan of the planned plant with the largest AC capacity in the grid area (in an interval where that planned plant has an offline primary reserve (FCR) offer, to another planned plant of its balancing group), so that the total matches the volume sold on JEPX. For that planned plant, the parts add up to less than the submitted plan.
• A negative forecast: For a planned plant sold to a counterparty balancing group, a part is never below zero, while the submitted plan is the sum of the rounded forecasts including negative ones. A power plant with a negative forecast therefore makes the parts add up to more than the submitted plan.
• No recorded part: Rows with the plan type breakdown not recorded have no plan breakdown.

The export never distributes a difference across power plants and never adds a balancing row.

The plan breakdown is a reference

OCCTO receives only the value of the planned plant, and imbalance is settled per balancing group. Use the plan breakdown to compare plan and actuals for individual power plants in your own analysis. It is not a settlement figure.