> ## Documentation Index
> Fetch the complete documentation index at: https://docs.nectarclimate.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Usage estimation

> Optional site-level usage fills for coverage and analytics when bills are missing.

<Note>
  Usage estimation is an optional module enabled for selected companies.
</Note>

<Tip>Need help in this area? See [Data Quality FAQ](/platform/data-quality/faq).</Tip>

When bills or usage are missing for a site and commodity, Nectar can apply **persisted usage fills** so [completeness](/platform/glossary#completeness) and eligible analytics stay usable. Fills are whole-site and commodity-specific — they never substitute for a bill in Data Inventory and never appear as meters or connections in the [Aggregation Inspector](/platform/sites/overview#aggregation-inspector).

**See also:** [Usage estimation rules](/platform/settings/usage-estimation-rules), [Data completeness](/platform/data-quality/completeness), [Consumption analytics](/platform/analytics/consumption)

## What usage estimation does

Usage estimation closes gaps in **site-level commodity usage** when collected data alone does not cover the required period. For each enabled site and utility type, you configure an ordered list of methods. Nectar attempts them from top to bottom until one can produce a fill.

Fills are stored as persisted snapshots. They refresh on a daily schedule and when you choose **Run site estimations** in site settings. They are not live calculations on every page load.

## Whole-site and commodity scope

Estimation applies at **site + commodity** scope only:

* One fill covers the site's combined usage for that utility type (electricity, gas, water, and so on).
* Sub-site filters — meter tags, fuel types, waste material, waste stream, and similar — do not receive fills. Analytics and completeness treat those scopes as **actual only** and explain the limitation.

Account- and meter-level completeness views always reflect collected data only; they never show **Estimated** cells.

## Where estimates appear

| Surface                                                                                       | What you see                                                                                                                         |
| --------------------------------------------------------------------------------------------- | ------------------------------------------------------------------------------------------------------------------------------------ |
| [**Data Quality > Completeness > By Site**](/platform/data-quality/completeness)              | Blue **Estimated** cells when a month meets threshold only with fills; **Estimation details** in the gap sheet                       |
| [**Analytics > Consumption**](/platform/analytics/consumption) and eligible site usage charts | Combined totals with a [Usage basis](/platform/glossary#usage-basis) filter; tooltips and exports split collected vs estimated usage |
| [**Sites**](/platform/sites/overview) **Usage** tab                                           | Same basis and provenance as portfolio consumption for that site                                                                     |
| [**Settings > Company > Sites**](/platform/settings/usage-estimation-rules)                   | Per-site, per-commodity rules and manual refresh                                                                                     |

Cost charts, bill tables, meter-level charts, and custom dashboards stay **actual only**. They do not include estimation fills.

## Coverage basis vs Usage basis

Two related filters use similar labels but answer different questions:

| Filter                                                  | Where                          | Question it answers                                                                |
| ------------------------------------------------------- | ------------------------------ | ---------------------------------------------------------------------------------- |
| **[Coverage basis](/platform/glossary#coverage-basis)** | Completeness **By Site**       | Should fill-dependent months count as covered in the timeline and portfolio score? |
| **[Usage basis](/platform/glossary#usage-basis)**       | Eligible analytics usage views | Should persisted fills add to usage totals, tooltips, and exports?                 |

Completeness classifies each day with **actual-first** rules: a day with collected usage is always an actual day, even if a fill also spans that day. **Usage basis** controls whether fill contribution is included in analytics totals; it does not change completeness day categories.

## Actual, estimated, and combined values

On eligible usage surfaces, Nectar exposes three related numbers:

| Value                          | Meaning                                                                                       |
| ------------------------------ | --------------------------------------------------------------------------------------------- |
| **Actual** (collected)         | Usage from bills and other collected source data                                              |
| **Estimated**                  | Usage from persisted site-level fills for the same scope and period                           |
| **Combined** (effective total) | What charts and KPIs display when **Actual and estimated** is selected: actual plus estimated |

With **Actual only** selected, totals and charts use collected usage only. Estimated usage may still appear in tooltips or footers as reference when fills exist.

Default behavior on eligible surfaces is **Actual and estimated**, so combined totals match what most teams expect when estimation is enabled.

## Daily refresh and manual rerun

Enabled estimation rules refresh automatically **each day at 12:00 AM UTC**. That scheduled run is the primary way fills stay aligned with newly collected usage.

Company admins with access to the module can also click **Run site estimations** on a site's **Estimation rules** tab. That queues an immediate refresh for every enabled utility type at the site without waiting for the nightly schedule.

Neither refresh deletes historical fill rows at read time. Reconciliation happens when the estimation service produces new fills.

## Stale overlap warning

If a bill arrives after the last estimation run, the persisted fill may temporarily **overlap** the same days as collected usage. That overlap is expected between refreshes.

The platform detects overlap and shows a non-blocking warning — for example in analytics tooltips, usage provenance footers, or completeness **Estimation details**:

> Estimated usage overlaps collected usage for this period. The estimate may be stale because new data arrived after the last estimation run. Rerun estimation in Site settings to refresh the fill.

Important semantics:

* The warning is a **prompt to rerun** estimation, not proof that source data changed incorrectly.
* Combined usage totals remain **additive** (collected plus the full fill contribution) until refresh reconciles fills.
* Completeness day counts stay **mutually exclusive** (actual days and fill-only estimated days do not double-count).

See [Usage estimation rules](/platform/settings/usage-estimation-rules) for how to rerun.

## When source data replaces fills

Uploading or collecting the missing bill is always the preferred fix. Once collected usage covers the period:

* Completeness may show the month as **Actual** even before the next estimation run.
* Analytics **Actual only** totals reflect the new bills immediately.
* A successful daily or manual estimation refresh updates or removes fill rows that are no longer needed.

Until refresh runs, overlap warnings may appear even though completeness already shows collected coverage.

## Related pages

* [Usage estimation rules](/platform/settings/usage-estimation-rules) — configure methods, enable commodities, rerun fills
* [Data completeness](/platform/data-quality/completeness) — **Estimated** cells, **Coverage basis**, gap sheet details
* [Filling data gaps](/platform/data-quality/filling-data-gaps) — when to fix connections vs configure estimation
* [Consumption analytics](/platform/analytics/consumption) — **Usage basis** and provenance on portfolio charts
* [Glossary — Estimated data](/platform/glossary#estimated-data), [Utility-estimated reading](/platform/glossary#utility-estimated-reading)