Project finance, written as code · v0.43.0
Rufineer is a language for project finance models. You write what each number means, in plain lines with units, in your browser; a live preview beside the editor compiles and solves the model as you type, and every value can be audited. With Pro, Export to Excel gives a FAST-standard workbook a lender can check cell by cell.
module ops "Operations" {
/// 1 in the first year, then 0.3% less each year
performance = decline(inputs.degradation)
energy: MWh = inputs.capacity * inputs.capacity_factor
* inputs.availability * performance | during operations
revenue sales = energy * inputs.tariff "Revenue"
}| B | C | D | H | I | J | |
|---|---|---|---|---|---|---|
| 5 | Period end | 30-Sep-28 | 31-Dec-28 | 31-Mar-29 | ||
| 7 | Imports | |||||
| 8 | Hours in period | h | 2,208 | 2,208 | 2,160 | |
| 10 | Capacity | MW | 40 | |||
| 11 | Capacity factor | % | 34.0% | |||
| 14 | Tariff (indexed) | USD/MWh | 86.70 | 86.70 | 86.70 | |
| 15 | Calculations | |||||
| 16 | Performance | index | 1.000 | 1.000 | 1.000 | |
| 18 | Energy | MWh | 29,128 | 29,128 | 28,495 | |
| 19 | Revenue | USD '000 | 2,525.4 | 2,525.4 | 2,470.5 | |
Audit any number
Every value in the preview opens the audit panel: no tracing precedents across sheets, no guessing which cell a formula meant. It is the review a lender's modeller does, done for you, beside your code.
ops.generation, GWh, on the Ops sheet.rfn file, one click away in the editor| B | C | D | AK | AL | AM | |
|---|---|---|---|---|---|---|
| 5 | Period end | 30-Sep-35 | 31-Mar-36 | 30-Sep-36 | ||
| 24 | Imports | |||||
| 26 | Year fraction | years | 0.50 | 0.50 | 0.50 | |
| 29 | Operations flag | flag | 1 | 1 | 1 | |
| 33 | Yield (active case) | GWh/y | 104.0 | |||
| 36 | Calculations | |||||
| 38 | Performance | index | 0.9704 | 0.9704 | 0.9655 | |
| 39 | Generation | GWh | 50.46 | 50.46 | 50.21 | |
| 41 | Revenue | USD '000 | 6,065.5 | 6,065.5 | 6,276.6 | |
Why a language
Before writing Rufineer we read 698 project finance workbooks: training models, course exercises and lender models, from solar and wind to toll roads and tax equity. Three failures came up again and again. Each one is a compile error or an automatic check in Rufineer.
Lender cases built by copying a block of rows. One copy still pointed at the wrong case, and nothing looked wrong because the numbers were plausible.
Every line is written once and named. A sensitivity case runs the same model with changed inputs, so there is no second copy to drift.
Circular references broken with copy-paste macros, then saved before the macro ran. Differences of thousands sat in models marked complete.
A circular reference won't compile unless solve breaks it, and every solve gets its own check. An unsolved workbook fails its master check.
Thousands divided by units, dollars divided by naira. The ratio was nonsense and no cell said so.
Every number has a unit. Adding MWh to USD is a compile error, and each conversion (MWh to kWh, a year to a quarter) is written into the formula.
A model that compiles with every check passing is internally consistent. It is not thereby right: the inputs and the logic still need the review a lender's modeller gives them. Rufineer makes that review faster, because every number can be traced to the line that made it.
How it works
A Rufineer model is a folder: inputs, calculations and outputs, one file per module. It is kept with your account, and you can download it as a .zip any time. The guide goes further.
Describe the timeline, the inputs with their units and sources, and what the project earns, costs, builds and borrows, each line saying what it is. Rufineer writes the statements.
revenue sales = energy * inputs.tariff
cost om = inputs.om | during operations
capex epc = spread(inputs.epc, over: construction) life 25y
senior = loan(share: 70 %, rate: inputs.rate, over: tenor, repay: annuity)The preview beside the editor compiles and solves the model as you type, in your browser: the editor underlines unit, name and loop errors, the preview shows every sheet laid out the FAST way, and any value can be clicked to see how it is made. explain, in the app's console, says the same in words.
$ rfn explain ops.energy
ops.energy "Energy"
where Ops!H24 (first period; the same formula runs across the row)
unit MWh
formula =$D$10*$D$11*$D$12*H$23*H$15*8760*H$16
read by ops.salesExport to Excel (with Pro) writes the workbook, already solved. Every formula is live, the master check tells you the model is sound, and the Solve and Run sensitivities macros are there for when inputs change in Excel.
Master check (0 = all OK) 0
Balance sheet balances 0
Loan repaid by maturity 0
IDC solved (run the Solve macro) 0Learn by building
From an empty folder to a lender-grade model in about 100 lines: you write what it earns, costs and borrows, Rufineer writes the statements, the waterfall and the checks.
The same wind farm with everything the conventions write written out: corkscrews, solved loops, a reserve account, the dividend trap and the statements.
Monthly, quarterly and half-yearly columns, VAT and a bridge, a funding cascade, preference shares, deferred tax and a dividend trap.
Rents per unit and per square metre, a lease-up, an S-curve, a construction loan at 60% of cost, a sale at an exit yield and a joint venture with a promote.
Sales by the bag and by the tonne, a quarry, a kiln and a mill, make or import, coal scenarios, a balance sheet, payback and a DCF valuation.
A PPA of 20 or 25 years, costs in rand, a senior loan refinanced, mezzanine and shareholder loans paid from what is left, and a lenders' report by half-year.
Pricing
Everything you need to build and review a model is free. Pro, a monthly subscription, builds the lender-grade workbook. Online payments are coming soon: during early access, write to blessedsibanda263@gmail.com to subscribe.
check, explain, generate, fmt, conventions, data.xlsm with its Solve and sensitivity macros, or a plain .xlsxbuild in the consoleGet started
Nothing to install: Rufineer runs in the page, on any computer with a modern browser. Writing, checking and previewing models is free; Pro adds Export to Excel (pricing). Your models are kept with your account, and you can download their files any time: they stay yours.