The time-based availability is a measurement of an asset's availability or the fraction of time the asset is operational. It is calculated as the ratio of hours available as a fraction of the full period and is defined as:
TBA [%] = [(Possible uptime [h] - Downtime [h]) / Possible uptime [h]] * 100= [Time available [h] / Total time in consideration [h]] * 100
These terms explained:
- Downtime is measured per asset in hours. Working on the asset and critical component failures is an example of the downtime period among other causes.
- Possible uptime is the total time being considered regardless of asset availability. It is the number of hours from the start until the end of the simulation multiplied by the number of assets (simulated years * 8,760[h] * the number of assets).
An example of one asset:
- Hours in the year: 8,760
- Downtime hours due to weather: 90
- Downtime hours due to errors and repairs: 85
- Downtime hours due to scheduled maintenance: 40
So in sum, the asset was down for 215 hours during the whole year, and up for 8,545 hours. Possible uptime is 8760 hours.
215 h / 8,760 h = 0.0245 = 2.45 % is the time-based availability loss
8,545 h / 8,760 h = 0.9755 = 97.55 % is the time-based availability
There are multiple TBA outputs to download: yearly, monthly, and non-aggregated. Example outputs can be found on the bottom of this article.
Click the heading to go directly to the table information:
TBA Monthly
Please note that the TBA Monthly is displaying the average values for each month the simulation was run.
| Cell | Description |
|---|---|
| Column A | Displays the wind farm name (if no name is provided, "default" is used as standard). |
| Column B | Displays the month of the simulation. |
| Column C | Displays the average TBA for all the P-values. Please see more about the P-values in this article. |
| Column D | Displays the P10 TBA values. |
| Column E | Displays the P20 TBA values. |
| Column F | Displays the P30 TBA values. |
| Column G | Displays the P40 TBA values. |
| Column H | Displays the P50 TBA values. |
| Column I | Displays the P60 TBA values. |
| Column J | Displays the P70 TBA values. |
| Column K | Displays the P80 TBA values. |
| Column L | Displays the P90 TBA values. |
| Column M | Displays the minimum value between the different P-values. |
| Column N | Displays the maximum value between the different P-values. |
| Column O | Displays the standard deviation. You can read more about the standard deviation on the Wikipedia page. |
| Column P | Displays the minimum confidence interval (read more about confidence interval here). |
| Column Q | Displays the maximum confidence interval (read more about confidence interval here). |
| Row 1 | Displays the column header information. |
| Row 2 | Displays the average TBA for January - to be used in reference to the different columns. |
| Row 3 | Displays the average TBA for February - to be used in reference to the different columns. |
| Row 4 | Displays the average TBA for March - to be used in reference to the different columns. |
| Row 5 | Displays the average TBA for April - to be used in reference to the different columns. |
| Row 6 | Displays the average TBA for June - to be used in reference to the different columns. |
| Row 7 | Displays the average TBA for July - to be used in reference to the different columns. |
| Row 8 | Displays the average TBA for August - to be used in reference to the different columns. |
| Row 9 | Displays the average TBA for September - to be used in reference to the different columns. |
| Row 10 | Displays the average TBA for October - to be used in reference to the different columns. |
| Row 11 | Displays the average TBA for November - to be used in reference to the different columns. |
| Row 12 | Displays the average TBA for December - to be used in reference to the different columns. |
| Row 13 | Displays the total average for all months. |
TBA Yearly
Please note that the TBA Yearly is displaying the average values for each year the simulation was run.
| Cell | Description |
|---|---|
| Column A | Displays the wind farm name (if no name is provided, "default" is used as standard). |
| Column B | Displays the year of the simulation. |
| Column C | Displays the average TBA for all the P-values. Please see more about the P-values in this article. |
| Column D | Displays the P10 TBA values. |
| Column E | Displays the P20 TBA values. |
| Column F | Displays the P30 TBA values. |
| Column G | Displays the P40 TBA values. |
| Column H | Displays the P50 TBA values. |
| Column I | Displays the P60 TBA values. |
| Column J | Displays the P70 TBA values. |
| Column K | Displays the P80 TBA values. |
| Column L | Displays the P90 TBA values. |
| Column M | Displays the minimum value between the different P-values. |
| Column N | Displays the maximum value between the different P-values. |
| Column O | Displays the standard deviation. You can read more about the standard deviation on the Wikipedia page. |
| Column P | Displays the minimum confidence interval (read more about confidence interval here). |
| Colum Q | Displays the maximum confidence interval (read more about confidence interval here). |
| Row 1 | Displays the column header information. |
| Row 2 and down | Displays the average TBA for the simulation year 1 - to be used in reference to the different columns. Please note that the number of rows will change depending the number of years the simulation was run. |
| Bottom row | Displays the total average for all years. |
TBA Non-aggregated
Please note that the TBA non-aggregated is displaying the TBA for each month and year.
| Cell | Description |
|---|---|
| Column A | Displays the wind farm name (if no name is provided, "default" is used as standard). |
| Column B | Displays the year of the simulation. |
| Column C | Displays the month of the simulation - to be used in accordance with column B (displaying the year). |
| Column D | Displays the average TBA for all the P-values. Please see more about the P-values in this article. |
| Column E | Displays the average P10 TBA values. |
| Column F | Displays the average P20 TBA values. |
| Column G | Displays the average P30 TBA values. |
| Column H | Displays the average P40 TBA values. |
| Column I | Displays the average P50 TBA values. |
| Column J | Displays the average P60 TBA values. |
| Column K | Displays the average P70 TBA values. |
| Column L | Displays the average P80 TBA values. |
| Column M | Displays the average P90 TBA values. |
| Column O | Displays the minimum value between the different P-values. |
| Column P | Displays the maximum value between the different P-values. |
| Column Q | Displays the standard deviation. You can read more about the standard deviation on the Wikipedia page. |
| Column R | Displays the minimum confidence interval (read more about confidence interval here). |
| Column S | Displays the maximum confidence interval (read more about confidence interval here). |
| Row 1 | Displays the column header information. |
| Row 2 and down | Displays the average TBA for January for the simulations first year. NOTE: 12 rows are created for each year the simulation runs, so the number of rows depends on the number of years you simulation was run. |
| Bottom row | Displays the total average TBA for all months in all years. |
Example files can be found below.