Value of Lost Load Calculator
Calculate the economic cost incurred during a power outage. Enter the amount of power that was unavailable, the duration of the outage, and the defined value of energy not supplied (VoLL) rate.
This tool uses the formula: Total Cost = Lost Load (kW or MW) × Duration (Hours) × Value Rate ($/kWh or $/MWh). Ensure units are consistent.
Enter Outage Details
Understanding Value of Lost Load (VoLL)
What is VoLL?
Value of Lost Load (VoLL) is an economic metric representing the monetary cost or damage incurred by customers when they experience an interruption in electricity supply. It's essentially how much people or businesses are willing to pay to avoid an outage, or the economic loss they suffer when one occurs. This cost includes things like lost productivity, spoiled goods, business disruption, and inconvenience.
How the Calculation Works
The calculation is straightforward: it multiplies the amount of power lost by the duration of the outage and the economic value assigned to each unit of energy (e.g., kilowatt-hour or megawatt-hour) that was not delivered.
Total Cost = Lost Load × Duration × Value Rate
For example, if 100 kW of load is lost for 1 hour at a rate of $5/kWh:
Cost = 100 kW * 1 hour * $5/kWh = $500
If using MW and $/MWh, ensure consistency. 1 MW = 1000 kW, 1 MWh = 1000 kWh.
Importance of Calculating VoLL
Calculating VoLL helps grid operators, utilities, and policymakers understand the impact of reliability issues. It can inform decisions about infrastructure investment, maintenance scheduling, and pricing strategies to optimize grid reliability against the cost of improvements.
Value of Lost Load Examples
Click on an example to see the calculation based on different scenarios:
Example 1: Small Business Outage
Scenario: A retail store loses power during peak hours.
Known Values: Lost Load = 50 kW, Duration = 3 hours, Value Rate = $10/kWh (representing lost sales and employee time).
Formula: Cost = Lost Load × Duration × Value Rate
Calculation: Cost = 50 kW * 3 hours * $10/kWh = $1500
Result: $1500
Conclusion: The estimated economic cost of this outage for the small business is $1500.
Example 2: Residential Interruption
Scenario: A residential area experiences an outage.
Known Values: Lost Load = 500 kW (aggregate), Duration = 0.5 hours (30 minutes), Value Rate = $3/kWh (representing inconvenience, minor spoilage).
Formula: Cost = Lost Load × Duration × Value Rate
Calculation: Cost = 500 kW * 0.5 hours * $3/kWh = $750
Result: $750
Conclusion: The estimated aggregate economic cost for the residential area is $750.
Example 3: Industrial Facility Outage
Scenario: A manufacturing plant loses power, halting production.
Known Values: Lost Load = 2 MW (which is 2000 kW), Duration = 8 hours, Value Rate = $20,000/MWh (representing major production losses).
Formula: Cost = Lost Load × Duration × Value Rate
Calculation: Cost = 2 MW * 8 hours * $20,000/MWh = $320,000 (Or 2000 kW * 8 hours * $20/kWh = $320,000)
Result: $320,000
Conclusion: The economic cost for the industrial facility's 8-hour outage is estimated at $320,000.
Example 4: Data Center Downtime
Scenario: A critical data center experiences a brief power interruption despite backup systems.
Known Values: Lost Load = 1 MW (1000 kW), Duration = 0.1 hours (6 minutes), Value Rate = $50,000/MWh (very high value due to critical services).
Formula: Cost = Lost Load × Duration × Value Rate
Calculation: Cost = 1 MW * 0.1 hours * $50,000/MWh = $5,000 (Or 1000 kW * 0.1 hours * $50/kWh = $5,000)
Result: $5,000
Conclusion: Even a brief outage can incur significant costs for a data center.
Example 5: Agricultural Pump Failure
Scenario: Power failure stops an irrigation pump vital for crops.
Known Values: Lost Load = 20 kW, Duration = 12 hours, Value Rate = $7/kWh (potential crop damage costs).
Formula: Cost = Lost Load × Duration × Value Rate
Calculation: Cost = 20 kW * 12 hours * $7/kWh = $1680
Result: $1680
Conclusion: The cost associated with the pump outage is estimated at $1680.
Example 6: Office Building Outage
Scenario: An office building loses power, sending employees home.
Known Values: Lost Load = 300 kW, Duration = 4 hours, Value Rate = $15/kWh (lost productivity cost).
Formula: Cost = Lost Load × Duration × Value Rate
Calculation: Cost = 300 kW * 4 hours * $15/kWh = $18000
Result: $18000
Conclusion: The cost of lost productivity in the office building outage is estimated at $18,000.
Example 7: Street Lighting Failure
Scenario: Street lights are out in a municipality.
Known Values: Lost Load = 10 kW, Duration = 6 hours, Value Rate = $1/kWh (primarily public safety/inconvenience cost).
Formula: Cost = Lost Load × Duration × Value Rate
Calculation: Cost = 10 kW * 6 hours * $1/kWh = $60
Result: $60
Conclusion: The estimated cost for this street lighting outage is relatively low per kWh compared to business outages.
Example 8: Refrigerated Storage Loss
Scenario: Power failure affects cold storage containing perishable goods.
Known Values: Lost Load = 75 kW, Duration = 2 hours, Value Rate = $30/kWh (high value due to potential product loss).
Formula: Cost = Lost Load × Duration × Value Rate
Calculation: Cost = 75 kW * 2 hours * $30/kWh = $4500
Result: $4500
Conclusion: The cost of the outage is estimated at $4500, reflecting the value of the stored goods.
Example 9: Using MWh Units
Scenario: A large facility outage calculated using MWh.
Known Values: Lost Load = 5 MW, Duration = 10 hours, Value Rate = $8000/MWh.
Formula: Cost = Lost Load × Duration × Value Rate
Calculation: Cost = 5 MW * 10 hours * $8000/MWh = $400,000
Result: $400,000
Conclusion: Using consistent MWh units, the cost is calculated directly.
Example 10: Short, High-Impact Outage
Scenario: A very brief outage affects sensitive equipment or process.
Known Values: Lost Load = 200 kW, Duration = 0.05 hours (3 minutes), Value Rate = $50/kWh (reflecting equipment damage or batch loss).
Formula: Cost = Lost Load × Duration × Value Rate
Calculation: Cost = 200 kW * 0.05 hours * $50/kWh = $500
Result: $500
Conclusion: Even a very short outage can be costly if the value of lost load is high.
Understanding Units
Ensure your input dimensions use a consistent unit system for the calculation to be meaningful. If your Lost Load is in kW and Duration in hours, your Value Rate should be in $/kWh for the result to be in $. If Lost Load is in MW and Duration in hours, your Value Rate should be in $/MWh for the result to be in $.
| Quantity | Common Units | Relation |
|---|---|---|
| Lost Load (Power) | kilowatt (kW), megawatt (MW) | 1 MW = 1000 kW |
| Duration (Time) | hour (h), minute (min), second (s) | 1 hour = 60 min = 3600 s |
| Energy | kilowatt-hour (kWh), megawatt-hour (MWh) | 1 kWh = 1 kW × 1 hour 1 MWh = 1 MW × 1 hour 1 MWh = 1000 kWh |
| Value Rate (VoLL) | $/kWh, $/MWh, £/kWh, €/MWh, etc. | $/MWh = $/kWh × 1000 |
| Total Cost | $, £, €, etc. | Matches currency unit of Value Rate |
Frequently Asked Questions about Value of Lost Load (VoLL)
1. What is the basic formula used by this calculator?
The calculator uses the formula: Total Cost = Lost Load × Duration × Value Rate.
2. What inputs do I need to provide?
You need to provide values for Lost Load (power), Duration (time of outage), and the Value of Lost Load Rate (cost per unit of energy not supplied).
3. What units should I use for the inputs?
Consistency is key. If your Lost Load is in kW and Duration in hours, your Value Rate should be in currency/kWh. If Lost Load is in MW and Duration in hours, your Value Rate should be in currency/MWh.
4. What is "Lost Load"?
Lost Load refers to the amount of electrical power (measured in units like kW or MW) that customers were expecting or needing but could not be supplied due to an outage.
5. What does "Value of Lost Load Rate" mean?
This is the economic value assigned to each unit of energy (e.g., kWh or MWh) that is not delivered. This rate is often determined through economic studies, surveys, or regulatory standards and varies significantly depending on the customer type (residential, commercial, industrial) and the time/duration of the outage.
6. Does this calculator account for different customer types (residential, commercial, industrial)?
The calculator itself is generic, but you can use it for different customer types by using the appropriate Value of Lost Load Rate (VoLL Rate) that applies to that specific customer category or scenario.
7. What kind of costs does the VoLL Rate include?
VoLL Rates typically attempt to quantify the direct and indirect economic impacts of an outage, such as lost production, lost sales, damaged equipment, spoiled goods, restart costs, and the cost of inconvenience to residential customers.
8. Can I calculate the cost for multiple separate outages?
Yes, but you need to calculate each outage separately using its specific lost load, duration, and potentially different value rate (if the rate varies by time or circumstance).
9. What happens if I enter zero for one or more inputs?
If any of the inputs (Lost Load, Duration, or Value Rate) are zero, the calculated Total Cost will be zero, which is correct as no economic cost from lost load occurs in that instance.
10. Is this calculator suitable for very short duration outages (e.g., momentary)?
Yes, you can enter durations as decimals or fractions of an hour (e.g., 0.1 hours for 6 minutes, 0.0167 hours for 1 minute). The accuracy depends on having a relevant VoLL Rate for very short interruptions, which can be different from longer outages.
