Heat rate, efficiency, exhaust flow and temperature of a simple-cycle gas turbine from plant readings, corrected to ISO conditions, with the yearly cost of degradation and an inlet air cooling what-if.
USD 49 one-time purchase
Download the sample report (PDF)
Need it once? Use it online: check your data free, unlock results from USD 9 for 3 runs.
What it does
Heat rate and efficiency
LHV and HHV heat rate, thermal efficiency, specific fuel consumption and where the fuel heat goes.
Fuel from a library
Pipeline natural gas, lean gas, hydrogen-rich refinery gas, or your own gas analysis and heating value.
Exhaust from a heat and mass balance
Air flow, exhaust flow, temperature and composition, with a thermocouple cross-check that flags measurement problems.
Corrected to ISO conditions
Output and heat rate at 15 °C, 101.325 kPa, 60 % RH, with generic coefficients or your maker curve points.
Cost of degradation
Output shortfall, extra fuel, extra CO₂ and lost sales per year against new-and-clean or guarantee values.
Inlet cooling what-if
Output at other ambient temperatures and an evaporative cooler: effectiveness, water used, value per year.
Built for engineers
- Visible formulas — nothing hidden, so you can check every step.
- Fully referenced — methods from the standard references, checked against their published worked examples.
- Safe to share — sheets are protected against accidental edits, with an open password so you can still customise.
- Built-in input checks — clear warnings for impossible inputs and values outside typical ranges.
For engineering estimates; verify against site data. Code-based methods are aligned with the publicly documented procedure; they are not a licensed reproduction or a certification.
Preview the workbook
Real pages from the workbook with its built-in example loaded (example data, not a measured plant). Choose a page below, or select the large image to enlarge it.
Specification and checks
| Format | Excel workbook (.xlsx), no macros |
| Version | v1.0 |
| Works in | Excel 2010 or later, Windows and Mac |
| Units | SI, US and British, mixed freely |
| Includes | Guide tab with method and references, calculator, print-ready report |
| Checked against | 438 cases against an independent Python model (NASA thermodynamic polynomials, CoolProp humid air), more than 40,000 values compared: heat rate, efficiency, flows and corrected values within 0.5 %, temperatures within 0.25 K, identical in three unit systems. |
| Free version | Try the free boiler efficiency calculator |
Online tool or Excel workbook?
| Online tool | Excel workbook (this page) | |
|---|---|---|
| What it does | The same sheet as the Excel workbook, run in your browser | Heat rate, efficiency, exhaust flow and temperature of a simple-cycle gas turbine from plant readings, corrected to ISO conditions, with the yearly cost of degradation and an inlet air cooling what-if. |
| Cost | Check your inputs free. Results: 3 runs for USD 9, or every online tool for USD 15 a month (USD 99 a year) | USD 49 once, yours to keep |
| Input checks and findings | Every input checked; findings with the unlocked results | Every input checked, with findings and recommendations |
| Report for your calculation file | Printable results sheet | Print-ready report with your plant, tag, document number, revision and sign-off |
| Formulas | Method described in the guide | Every formula visible in its cell |
| Save, edit and rerun your cases | Each run separately | Yes: keep and edit your own file |
| Works offline, on a plant PC | No, needs the internet | Yes: Excel 2010 or later, Windows and Mac |
Online access and the Excel workbook are separate licences: one does not include the other.
Compatibility, licence and support
| File | Excel workbook (.xlsx), no macros, version v1.0; works in Excel 2010 or later on Windows and Mac. Sheets are protected against accidental edits, with an open password so you can customise. |
| Licence | Single user. A team licence (up to 5 named users) is 3 × the shop price; site licences on request — licence terms. |
| Updates | Updates to this major version are included; download them again from the link in your receipt. |
| Support | Email [email protected] with your order number — questions on the method, your inputs or your results are welcome. |
| Refunds | If the tool does not work as described, or has an error we cannot fix, email [email protected] with your order number within 14 days of purchase and we will refund you in full. Refunds are not offered for a change of mind once a file has been downloaded. Read the full refund policy. |