LCOE (Solar) Calculator
The formula
What LCOE does and does not tell you
The levelised cost of energy reduces an entire project — capital, financing, operating cost, degradation and lifetime — to one number: the discounted cost per kilowatt-hour delivered. It is the standard basis for comparing generation technologies, and it is why solar has moved from the most expensive to among the cheapest sources in a decade. Its limitation is equally important: LCOE says nothing about when the energy arrives. A solar plant producing at midday does not displace gas generation at 7pm, so two projects with identical LCOE can have very different system value. For that reason grid planners increasingly use value-adjusted LCOE (VALCOE), which adds the energy, capacity and flexibility value of the output profile.
Why the discount rate dominates solar specifically
Solar is almost pure capital cost with negligible fuel cost, which makes it unusually sensitive to the cost of money. Raising the WACC from 5% to 12% can increase solar LCOE by 50–60%, while the same change moves a gas plant's LCOE by perhaps 15% because most of its cost is fuel, which is not discounted. This explains the observed pattern that solar is cheap in low-cost-of-capital markets (Europe, Japan, utility-scale US) and expensive in high-cost ones (emerging markets with double-digit lending rates) even at identical irradiance. Financing terms, not panel prices, are often the binding constraint on solar deployment.
Tax equity and depreciation in the US
A US project with the 30% investment tax credit and five-year MACRS depreciation sees a materially lower after-tax LCOE than the gross figure suggests, because depreciation shelters income in the early years when discounting bites hardest. Tax-equity structures monetise these benefits for developers with insufficient tax appetite, typically at a price. When modelling a US commercial project, include both the credit and the depreciation shield — omitting depreciation overstates LCOE by 10–20% for a taxable owner.
Frequently asked questions
What is the current LCOE of utility-scale solar?
Is LCOE the right way to compare with gas?
Does adding storage change the LCOE?
Why do different sources quote different solar LCOEs?
Source & methodology
LCOE definition and methodology per the US Energy Information Administration and Lazard, "Levelized Cost of Energy Analysis"; solar capital-cost benchmarks from NREL Annual Technology Baseline; MACRS depreciation per IRS Publication 946.
LCOE (Solar) explained: formula, worked example and honest limits
You cannot reduce what you have not measured, and this page measures it with the factors printed in the open. Searchers land on an LCOE (Solar) page for three reasons — to plan, to compare options, and to check that somebody else’s arithmetic is honest. This tool serves all three, and everything after the calculator explains the model instead of hiding it.
In Energy, the same underlying quantity may be measured under different protocols with different boundaries. Knowing the boundary behind an LCOE (Solar) is what makes it comparable across reports.
A calculation like this one is worth roughly as much as a careful sentence: it forces several vague considerations into one comparable quantity. Once LCOE (Solar) is on the table, the argument can stop being about impressions.
Every figure in the prose is generated by the engine rather than written beside it — the worked example resolves to levelised cost of energy = 0.083 $/kWh on the default inputs, and the sensitivity section ranks the inputs that move the result — System capacity first, at ≈11.1 % of the headline for a ten-percent error either way in that input. Read the sections in order and you will be able to reproduce every figure by hand.
Inside the LCOE (Solar) calculation: formula and every input
The engine implements a single stated model: LCOE = (net capex + Σ O&M_y/(1+r)^y) ÷ Σ production_y/(1+r)^y. There is no hidden coefficient and no login-gated precision — the formula printed is the formula executed, which is also what makes the result citable.
Total capital cost (installed) (example value $1,850,000.00) is a money value, and money values are where rounding habits do the most damage — type the real figure, not a tidied one. Keep every money input in the same currency; mixing systems quietly corrupts the comparison.
System capacity (kW DC) (example value 1,000) is a quantity rather than a category — precision here is cheap and worth having. If you are unsure what belongs in this field, look at the printed steps: the substitution shows exactly how the engine uses it.
Year-1 specific yield (kWh per kW) (example value 1,550) is a plain measured quantity — the unit shown in the label is the unit the formula expects. Check the convention first: if the source says “6.5 % per year”, type 6.5 and let the formula do the rest.
Annual degradation (%) (example value 1) is a measured number in the unit named by the label; the formula does not convert for you. Rates are the most mis-transcribed input on any page like this; copy it from the document rather than retyping from memory.
Project life (years) (example value 30) is a numeric input whose unit is fixed by the label; a wrong unit is a wrong answer wearing a plausible disguise. Be precise about the boundary (exact date, start of month); time inputs decide the exponent in most formulas.
Annual O&M (% of capex) (example value 1) is a plain measured quantity — the unit shown in the label is the unit the formula expects. Rates are the most mis-transcribed input on any page like this; copy it from the document rather than retyping from memory.
Discount rate / WACC (%) (example value 7) is a numeric input whose unit is fixed by the label; a wrong unit is a wrong answer wearing a plausible disguise. Rates are the most mis-transcribed input on any page like this; copy it from the document rather than retyping from memory.
Investment tax credit (%) (example value 30) is a plain measured quantity — the unit shown in the label is the unit the formula expects. Rates are the most mis-transcribed input on any page like this; copy it from the document rather than retyping from memory.
Effective tax rate on income (%) (example value 21) is a plain measured quantity — the unit shown in the label is the unit the formula expects. Enter it exactly as your document states it — quoted annual, monthly and effective rates are three different numbers.
LCOE (Solar) with real numbers, step by step
The tool prints its own working; this is the same arithmetic on the example values, reproduced so you can follow it by hand. Starting figures: Total capital cost (installed), System capacity (kW DC), Year-1 specific yield (kWh per kW), Annual degradation (%). The computed levelised cost of energy comes out at 0.083 $/kWh, which the interpretation band labels “$82.52 per MWh over a 30-year life”.
- Net capital cost = capex − investment tax credit = $1,850,000 − $555,000 = $1,295,000.
- Year-1 generation = capacity × specific yield = 1,000 kW × 1,550 kWh/kW = 1,550,000 kWh (capacity factor 17.7%).
- Each year: production falls by 0.5% and both O&M and production are discounted at 7%.
- Discounted production over 30 years = 18,330,792 kWh; discounted O&M = $217,630.
- LCOE = (net capex + discounted O&M) ÷ discounted production = ($1,295,000 + $217,630) ÷ 18,330,792 = $0.0825/kWh ($82.52/MWh).
Gross capital cost — $1,850,000. This is the number experienced users quote when the headline alone would mislead.
Investment tax credit — $555,000. If your inputs change, this is usually the first companion figure to move.
Net capital cost — $1,295,000. This is the number experienced users quote when the headline alone would mislead.
Capital cost per watt — 1.85 $/W. Compare it against the main result of 0.083 $/kWh before drawing conclusions.
Year-1 generation — 1,550,000 kWh. Compare it against the main result of 0.083 $/kWh before drawing conclusions.
Keep this worked example open while you enter your own figures: matching the shape of the substitution is the fastest way to spot a unit or convention mistake.
How far LCOE (Solar) can reasonably move
The honest version of any estimate is a corridor, and this one is cheap to produce: LCOE (Solar) was recomputed at 5 points along the dominant input, with every other field left untouched.
| System capacity setting | Levelised cost of energy |
|---|---|
| 80 % of the example value | 0.103 $/kWh |
| 90 % of the example value | 0.092 $/kWh |
| example inputs | 0.083 $/kWh |
| 110 % of the example value | 0.075 $/kWh |
| 120 % of the example value | 0.069 $/kWh |
The corridor runs from 0.069 $/kWh to 0.103 $/kWh across that band — which is the range worth planning inside rather than the single 0.083 $/kWh point estimate. Reproduce it in the form above by editing System capacity alone; the substitution steps will follow your figures exactly.
Sensitivity: which inputs change LCOE (Solar) the most
Generic advice says “it depends on your inputs”; this section says exactly how much. Each field was perturbed by ±10 % in isolation and the levelised cost of energy recomputed, so the ranking below is measured rather than asserted. For LCOE (Solar) the ranking is measured rather than guessed, and it belongs to these defaults: shift the starting point and the order can shift with it.
- Nudge System capacity by ±10 % and LCOE (Solar) lands between 0.075 $/kWh and 0.092 $/kWh (sensitivity ≈11.1 %)
- Year-1 specific yield +10 % → LCOE (Solar) = 0.075 $/kWh · −10 % → 0.092 $/kWh (the levelised cost of energy shifts ≈11.1 %)
- Total capital cost: ten percent up gives 0.091 $/kWh, ten percent down gives 0.074 $/kWh — ≈10.0 % of the levelised cost of energy either way
- Discount rate / WACC +10 % → LCOE (Solar) = 0.087 $/kWh · −10 % → 0.078 $/kWh (the levelised cost of energy shifts ≈5.9 %)
- Nudge Investment tax credit by ±10 % and LCOE (Solar) lands between 0.079 $/kWh and 0.086 $/kWh (sensitivity ≈3.7 %)
- Project life: ten percent up gives 0.081 $/kWh, ten percent down gives 0.085 $/kWh — ≈2.7 % of the levelised cost of energy either way
System capacity is the dominant lever here: ten percent either way moves the result by about 11.1 %, from 0.075 $/kWh to 0.092 $/kWh. Spend your verification effort there first, and Year-1 specific yield is effectively tied with it (≈11.1 % for the same nudge), so verify the pair together. The rest of the inputs earn only a rounding-error of attention, and that asymmetry is the practical payoff of measuring rather than asserting.
Reading the result: bands, zones and thresholds
The value above only becomes useful the moment you know what it is being measured against. The verdict attached to the default calculation — “$82.52 per MWh over a 30-year life” — is one band on a ladder your own figure may sit somewhere else on. How much of that band is luck? On System capacity alone ten percent either way covers 0.075 $/kWh to 0.092 $/kWh. The practical reading rules: ask what would have to change to move you one band. If the answer is “a small, plausible input difference”, the band itself is not the finding — the uncertainty is.
Related measures answer related questions, and the distinctions matter: LCOE (Solar) is the quantity, Levelised cost of energy is this tool’s reading of it, and the decision that follows belongs to neither of them separately.
Common mistakes with LCOE (Solar) (and the fix)
A US project with the 30% investment tax credit and five-year MACRS depreciation sees a materially lower after-tax LCOE than the gross figure suggests, because depreciation shelters income in the early years when discounting bites hardest. Tax-equity structures monetise these benefits for developers with insufficient tax appetite, typically at a price. When modelling a US commercial project, include both the credit and the depreciation shield — omitting depreciation overstates LCOE by 10–20% for a taxable owner.
Using stale inputs. LCOE (Solar) is only as current as the numbers behind it — an estimate carried over from a previous season, rate table or report quietly biases every output. Re-measure the inputs first; that single habit fixes more bad LCOE (Solar) figures than any formula change.
One mistake is specific to this engine: assuming every input matters equally. The computation above shows System capacity dominating — a careful figure there beats false precision everywhere else.
A final trap is presentation: reporting LCOE (Solar) to more decimal places than the inputs support. The tool prints what the arithmetic gives; you should quote only what your least precise field justifies.
LCOE (Solar) verification checklist
- Record the date and the inputs alongside the number so future-you knows what was assumed.
- Compare the output against one published benchmark or a colleague’s independent estimate.
- Re-verify System capacity against a source document — ten percent of error there moves the headline by ≈11.1 %.
- Recompute once with the dominant input deliberately set low, and see whether the decision changes.
- Re-run the calculation with a ±10 % stress on the two most sensitive inputs.
- Confirm the answer against one independent method or published benchmark for LCOE (Solar).
Five steps from raw inputs to a figure you can defend
The tool does the arithmetic; the routine below is what makes the arithmetic trustworthy. Five steps, a minute total — and afterwards you will know not just what the number is, but which assumption produced it.
Step 1 — start from evidence. The inputs behind LCOE (Solar) are total capital cost (installed), system capacity (kw dc), year-1 specific yield (kwh per kw), annual degradation (%), project life (years), annual o&m (% of capex) and the remaining fields listed above. Write them down with their source next to each one; if you cannot name where a figure came from, that is the input most likely to be wrong. When in doubt, prefer the boring input: the interesting one is usually the one you misread.
Step 2 — baseline before exploration. Get one defensible Levelised cost of energy on screen before you start nudging numbers. Without a baseline, every variation looks interesting and none of them means anything. Say the answer out loud before you save it; if it sounds wrong, the model did not change, your understanding did.
Step 3 — play with the inputs on purpose. Ten percent up, ten percent down, one field at a time. Within a few minutes you will know this calculation better than most people who quote its results. The test of a good estimate is not that it feels right but that it changes what you do.
Step 4 — ask what would have to be true. Take the result you want and work backwards through the inputs until you find the assumption that produces it; then decide honestly whether that assumption is defensible. Estimates improve most when the worst case is written down in ink.
Step 5 — schedule the next run. In Environmental & Sustainability the inputs drift quietly. Put a reminder a quarter out, re-enter the same fields, and read the change rather than the level. The point of transparency is that a reader can disagree with a specific line rather than with you.
The real-world conversations LCOE (Solar) settles
Most Energy disagreements are arithmetic disagreements in disguise. When Levelised cost of energy of 0.083 $/kWh sits on the table with its working shown, the conversation stops being about who sounds more confident and starts being about which input is wrong. When in doubt, prefer the boring input: the interesting one is usually the one you misread.
The companion outputs — Gross capital cost and Investment tax credit — exist for the second stage of that screen: the headline sizes the prize, while the companions describe the trade-off you are accepting to get it. The test of a good estimate is not that it feels right but that it changes what you do.
Nothing here is stored or transmitted, so the habit of checking is free: open the page, re-enter current figures, compare with the number you saved last time. Estimates improve most when the worst case is written down in ink.
The questions that come up most about LCOE (Solar)
What affects LCOE (Solar) the most?
Measured on this engine, System capacity is the dominant lever: moving it ±10 % shifts the levelised cost of energy across 0.075 $/kWh to 0.092 $/kWh — about 11.1 % of the headline, with Year-1 specific yield next at ≈11.1 %. The ranked list in the sensitivity section is computed live, not asserted from a template.
Do year-1 specific yield and system capacity matter equally?
Effectively. Measured on this engine they land at ≈11.1 % and ≈11.1 % for the same ten-percent nudge, so the honest advice is to get both right; chasing precision in only one of them buys almost nothing.
What is a typical LCOE (Solar)?
With the example inputs on this page the result is 0.083 $/kWh, labelled “$82.52 per MWh over a 30-year life”. “Typical” varies with situation, which is why every result here ships with its verdict band and its sensitivity list: they turn one figure into a range you can locate yourself inside.
How do I calculate LCOE (Solar) by hand?
Three steps: write the formula (LCOE = (net capex + Σ O&M_y/(1+r)^y) ÷ Σ production_y/(1+r)^y), insert your values, and simplify. The worked example section shows exactly that chain for the default inputs; replicating it once on paper teaches you more about LCOE (Solar) than any number of calculator runs.
What happens to LCOE (Solar) if system capacity changes by 10 %?
The engine was re-run with that field moved by ten percent while everything else stayed fixed: the levelised cost of energy goes across 0.075 $/kWh to 0.092 $/kWh, a swing of roughly 11.1 % around the 0.083 $/kWh baseline. That ratio is the practical definition of how much this input matters.
Is the LCOE (Solar) result of 0.083 $/kWh good or bad?
Good and bad are comparisons, so the honest test is three questions: where does your own LCOE (Solar) sit against the 0.083 $/kWh reference above, how far would a plausible input error move it (≈11.1 % per ten percent on System capacity), and what does the alternative option compute to?
What affects LCOE (Solar) the most?
Sensitivity depends on where you start, but the inputs Total capital cost (installed) and System capacity (kW DC) typically move LCOE (Solar) further than the rest because they enter the formula multiplicatively. If you can only measure two things well, measure those and hold the others at conservative defaults.
Which emission/consumption scope does LCOE (Solar) cover?
Whatever your inputs encode — typically direct consumption at the meter. Broader scopes (embodied, upstream) require adding their own inputs; do not compare a narrow LCOE (Solar) against a whole-life figure.
What is the current LCOE of utility-scale solar?
Roughly $30–45 per MWh in the best US and European resources according to Lazard's recent analyses, and as low as $20/MWh in exceptional auctions. Residential rooftop solar is two to four times higher per MWh because installation cost does not scale down proportionally.
Is LCOE the right way to compare with gas?
Only partially. A gas plant can run whenever demand peaks, so its output is worth more per MWh even when its LCOE is higher. Compare LCOE alongside capacity factor, dispatchability and the system cost of integrating intermittent generation.
Does this LCOE (Solar) tool store my numbers?
No. The entire calculation runs in your browser session; nothing entered above is transmitted or saved, which is the correct behaviour for sensitive Environmental & Sustainability figures and the reason you can re-run this page as often as you like.
Key terms on this page
- Gross capital cost
- $1,850,000 on the example inputs — a companion figure printed beside the headline of LCOE (Solar) so that no result is read in isolation.
- Investment tax credit
- $555,000 on the example inputs — a companion figure printed beside the headline of LCOE (Solar) so that no result is read in isolation.
- Net capital cost
- $1,295,000 on the example inputs — a companion figure printed beside the headline of LCOE (Solar) so that no result is read in isolation.
- Levelised cost of energy
- The primary output of this tool: 0.083 $/kWh for the default inputs, computed exactly from LCOE = (net capex + Σ O&M_y/(1+r)^y) ÷ Σ production_y/(1+r)^y.
- Worked example
- The calculation written out in full so that nothing on this page has to be taken on trust.
- Verdict band
- The plain-language label — here “$82.52 per MWh over a 30-year life” — mapping the computed figure onto experience-based ranges for Environmental & Sustainability.
- Sensitivity (±10 %)
- How far the LCOE (Solar) moves when a single input is nudged ten percent either way; the ranked list on this page is computed live from this engine.
The provenance of this LCOE (Solar) calculation
There is no black box on this page — the engine evaluates LCOE = (net capex + Σ O&M_y/(1+r)^y) ÷ Σ production_y/(1+r)^y. Source of record: LCOE definition and methodology per the US Energy Information Administration and Lazard, "Levelized Cost of Energy Analysis"; solar capital-cost benchmarks from NREL Annual Technology Baseline; MACRS depreciation per IRS Publication 946. Specialist software layers extra coefficients on top of the same algebra; none are hidden here, and that transparency is what makes a disagreement traceable to a specific input instead of a black box.
This page is an estimation aid, not professional advice. The design rule is simple: two people entering identical figures must get identical answers. The promise to the reader is narrow and testable: same inputs, same output, no silent rounding, and no figure presented without the formula that produced it.
Next steps after the calculation
Record the figure with today’s date and re-run quarterly; the trend is the actionable number, not the snapshot.
The audience here is households and teams measuring consumption or impact. Everything you need to defend the result — formula, substitution, sensitivity, source — is printed above, so the only remaining variable is the honesty of your inputs.