---
title: "Availability factor"
description: "Availability factor is the percentage of total hours in a period (typically a year, 8,760 hours) during which a plant is available to operate, whether or not it actually does. It is calculated as (total period hours − unavailable hours) / total period hours, where \"unavailable\" includes both planned and forced outages."
canonical_url: "https://sylio.co/glossary/availability-factor"
last_updated: "2026-06-28T02:29:34.202Z"
---

**Availability factor** is the percentage of total hours in a period (typically a year, 8,760 hours) during which a plant is available to operate, whether or not it actually does. It is calculated as (total period hours − unavailable hours) / total period hours, where "unavailable" includes both planned and forced outages.

## Typical industrial availability

<table>
<thead>
  <tr>
    <th>
      Sector
    </th>
    
    <th>
      Typical availability
    </th>
  </tr>
</thead>

<tbody>
  <tr>
    <td>
      Coal-fired utility
    </td>
    
    <td>
      80–88%
    </td>
  </tr>
  
  <tr>
    <td>
      Combined-cycle gas turbine
    </td>
    
    <td>
      90–95%
    </td>
  </tr>
  
  <tr>
    <td>
      <a href="/glossary/waste-to-energy">
        Waste-to-energy
      </a>
    </td>
    
    <td>
      85–92%
    </td>
  </tr>
  
  <tr>
    <td>
      Cement plant kiln
    </td>
    
    <td>
      88–94%
    </td>
  </tr>
  
  <tr>
    <td>
      Refinery <a href="/glossary/fluid-catalytic-cracking">
        FCC
      </a>
    </td>
    
    <td>
      95%+ (4-year turnaround cycle)
    </td>
  </tr>
  
  <tr>
    <td>
      <a href="/glossary/recovery-boiler">
        Pulp mill recovery boiler
      </a>
    </td>
    
    <td>
      90–96%
    </td>
  </tr>
</tbody>
</table>

## Why availability matters

Every percentage point of availability translates directly to revenue for a tipping-fee-driven [WtE](/glossary/waste-to-energy) plant, a cement plant constrained by clinker output, or a recovery-boiler-limited pulp mill. Cleaning systems that defer [forced outages](/glossary/forced-outage) are central to availability defence — [sonic horns](/glossary/sonic-horn) installed for fouling control protect availability against the most common cleaning-related outage causes.

## Related terms

- [Capacity factor](/glossary/capacity-factor)
- [Forced outage](/glossary/forced-outage)
- [MTBF](/glossary/mtbf)