Open-cycle gas turbine (OCGT) peaking plant

Protects divisions; far below any physical value of the model.

Market range Not applicable.

Unit multiplier used in the derating curves, the CRF and the split of the capital cost.

Market range Exact by definition.

Turns a percent input (0-100) into a fraction.

Market range Exact conversion, no range.

Turns a fraction into a percent for display.

Market range Exact conversion factor.

Converts the capacity factor into load hours and annual energy; also used by the hourly electricity outlet.

Market range 8784 h in a leap year, ignored.

Converts fuel energy per MWh of electricity into a heat rate in GJ/MWh and applies the IPCC factor (per GJ).

Market range Exact SI identity, no spread.

Converts MW into kW for the specific capital cost.

Market range Exact prefix ratio.

Converts kg of CO2 into tonnes.

Market range Exact mass conversion.

Converts the DEA start time in minutes into hours for the start-duration guard.

Market range Exact time conversion.

Converts the EPA ambient points, printed in F, to C.

Market range Exact offset.

Converts the EPA ambient points, printed in F, to C.

Market range Exact 5/9 slope.

Restates the HHV heat rate in Btu/kWh so it reads directly against US tables (EIA).

Market range Thermochemical Btu would give 948.45, a 0.07 % difference.

Share of the installed capital that is equipment in the 2020 case: 354 / (354 + 100) = 78 %. Applied to the scaled model value or to the Customized quote, so the split follows the DEA proportions.

Market range DEA prints no separate uncertainty on the split.

Share of the installed capital that is installation: 100 / 454 = 22 %.

Market range DEA gives the split for the central value only.

Lower edge of DEA's 2020 band. Not consumed by a node: it sets the lower limit of the Customized quote (363 x 2^-0.3 = 295 EUR/kW at 200 MW).

Market range DEA band 363-545 EUR/kW around 454.

Upper edge of DEA's 2020 band. Not consumed by a node: it sets the upper limit of the Customized quote (545 x 0.5^-0.3 = 671 EUR/kW at 50 MW).

Market range DEA band 363-545 EUR/kW; the 2023 CONE figure is 470 EUR/kW at 2023 prices.

Anchor of the economy-of-scale law: at 100 MW the specific cost equals the reference-case value (454 or 435 EUR/kW).

Market range DEA note A: plants typically 50-200 MW.

Total capital scales with (P/100)^0.7, so the specific cost falls as P^-0.3. The upper end of DEA's range is the conservative one (smaller savings with size). Valid only inside the 50-200 MW band of note A, which the capacity guard enforces.

Market range DEA: about 0.6-0.7.

Documents the alternative exponent; at 50 MW it would give 3 % more specific cost and at 200 MW 4 % less. Not consumed by a node.

Value of technology_case that selects the 2020 column of the DEA data sheet for CAPEX, efficiencies and O&M.

Market range Not applicable.

Value of technology_case that selects the 2030 column of the same DEA data sheet.

Market range Not applicable.

Model value of the 2020 case for the 100 MW reference unit, 2015 EUR, EPC boundary (DEA Introduction p.22). Scaled to other sizes with the 0.7 exponent.

Market range DEA uncertainty (2020) 0.363-0.545 MEUR/MW.

Model value of the 2030 case for the 100 MW reference unit (DEA learning, note K: 10 % learning rate on IEA ETP 2016 capacity growth).

Market range DEA prints no uncertainty for 2030 (only 2020 and 2050).

Equipment share of the 2030 case: 339 / 435 = 78 %, as in 2020.

Market range DEA prints no separate uncertainty on the split.

Installation share of the 2030 case: 96 / 435 = 22 %.

Market range DEA gives the split for the central value only.

Full-load net efficiency of the 2030 case at DEA ambient, corrected to site temperature with the EPA curve like the 2020 value.

Market range No independent range cited for 2030.

Annual-average efficiency of the 2030 case; nameplate / annual average (43 / 41) is its load penalty.

Market range DEA prints a single annual-average value per column.

Fixed O&M of the 2030 case per MW of ISO rating, linear in MW (DEA gives no scale effect).

Market range No independent range cited for 2030.

Non-fuel variable O&M per MWh net of both reference cases; a value of the model, no longer an input.

Market range DEA uncertainty 3.5-5 EUR/MWh.

Lower limit of the Customized quote: the lowest cost DEA's 2020 band allows inside the 50-200 MW domain. A quote below it is refused (invalid input).

Market range Derived bound.

Upper limit of the Customized quote: the highest cost DEA's 2020 band allows inside the 50-200 MW domain. A quote above it is refused (invalid input).

Market range Derived bound.

Lower clamp of the scaled specific capital cost. Only catches out-of-domain values; never active inside the sliders.

Market range Not a market value.

Upper clamp of the scaled specific capital cost. Only catches out-of-domain values; never active inside the sliders.

Market range Not a market value.

Below 50 MW the input is refused (invalid_input) rather than extrapolated.

Market range DEA note A 50-200 MW.

Above 200 MW the input is refused rather than extrapolated: large frame units have different cost and efficiency.

Market range DEA note A 50-200 MW; frame units go beyond.

Fixed O&M per MW of ISO rating, which DEA states already contains the cost of 50 starts a year.

Market range 8,068 (2015 EUR) vs 8,236 (CONE, 2023 EUR).

Direct (fuel, power, variable O&M during the start) and indirect (life consumption) cost of one start. Used only to move the fixed O&M away from DEA's 50 starts.

Market range No independent start cost cited.

Removed then re-added at the user's start count with DEA's correction formula (Introduction p.24), so starts are never counted twice.

Market range DEA assumption, not a market range.

Denominator of the duty ratio output: how far the chosen load hours are from DEA's peak service.

Market range DEA reference duty only.

Documents why the annual-average efficiency (40 %) is below nameplate (42 %). Not consumed by a node.

Market range DEA reference duty only.

Full-load net efficiency at DEA ambient. Corrected to site temperature with the EPA curve.

Market range No independent range cited for this aeroderivative class.

Annual-average efficiency over DEA's peak duty (part load and starts included). The ratio nameplate / annual average is the model's load penalty.

Market range DEA prints a single annual-average value.

Used only for the half-load efficiency output, which shows how much a turned-down unit loses.

Market range Average value, machine-dependent.

Gives the minimum stable output at site conditions.

Market range DEA single value; emission limits often push it higher in practice.

Physical guard: the starts times their duration cannot exceed the load hours. Never binds inside the sliders (100 starts x 10 min = 17 h against at least 438 h).

Market range No independent start time cited.

Annuity period of the capital. Held fixed: DEA itself says a peaker likely outlives it, so a longer life would only lower the LCOE.

Market range DEA note E: likely above 25 years.

Documents why no interest during construction is added (about 0.8 % of capital at 8 % over 0.2 years). Not consumed by a node.

Market range DEA single value.

Re-references the DEA efficiency from 8 C to ISO 15 C before the site derate is applied.

Market range Danish annual mean.

Pivot of the piecewise-linear derate (ratio 1 at 15 C).

Market range ISO definition.

Hot end of the curve; the temperature slider stops there (no extrapolation).

Market range Single published point.

Cold end of the curve; the temperature slider stops there (no extrapolation).

Market range Single published point.

Output ratio at 37.8 C. Aeroderivatives typically lose output faster with heat than frames, so the evidence level is medium.

Market range Machine-specific hot output point; no independent range cited.

Output ratio at 4.4 C.

Market range Machine-specific cold output point; no independent range cited.

Efficiency ratio at 37.8 C, relative to ISO.

Market range Machine-specific hot efficiency point; no independent range cited.

Efficiency ratio at 4.4 C, relative to ISO. Also used to move the DEA efficiency from 8 C to 15 C.

Market range Machine-specific cold efficiency point; no independent range cited.

Converts the LHV fuel balance into the HHV basis of the natural gas inlet and of the gas price, so that a project gas price applies identically here and in the SMR/ATR calculators.

Market range Specific to the IEAGHG design gas.

Denominator of the HHV/LHV ratio.

Market range Pipeline gases span roughly 1.10-1.11 HHV/LHV; the IEAGHG value sits inside.

Direct combustion CO2 per GJ of fuel (LHV). Upstream methane and CO2 are not counted.

Market range IPCC 95 % interval 54.3-58.3 kg/GJ.

Lower edge of the CO2 intensity band output.

Market range IPCC lower 95 % bound.

Upper edge of the CO2 intensity band output.

Market range IPCC upper 95 % bound.

Origin of the gas price default: 6 EUR/GJ LHV x 3.6 / 1.106899 = 19.514 EUR/MWh HHV. Not consumed by a node: the input is in EUR/MWh HHV.

Market range IEAGHG sensitivity 2-18 EUR/GJ LHV.

Origin of the gas price slider minimum (6.505 EUR/MWh HHV).

Market range IEAGHG sensitivity lower end.

Origin of the gas price slider maximum (58.542 EUR/MWh HHV).

Market range IEAGHG sensitivity upper end.

Origin of the carbon price slider maximum.

Market range IEAGHG 0-100 EUR/t.

Origin of the discount rate slider minimum (0.03).

Market range PCGE 3-10 % real.

Origin of the discount rate slider maximum (0.10).

Market range PCGE upper rate.

Cross-check basis only: at 7 % the model is compared with the PCGE ranges in the description. Not consumed by a node.

Market range PCGE middle rate.

Documents an alternative rate a Danish capacity-market reviewer would use. Not consumed by a node.

Market range CONE single value.

Origin of the capacity factor slider maximum. Above 30 % a combined cycle is the relevant comparison.

Market range PCGE 10 % and 30 % cases.

Cross-check of the specific capital cost, at another price level. Not consumed by a node.

Market range Single value, 2023 EUR.

Cross-check of the fixed O&M, at another price level. Not consumed by a node.

Market range Single value, 2023 EUR.

Cross-check of the heat rate output in Btu/kWh (9.63 GJ/MWh). Not consumed by a node.

Market range EIA aeroderivative 9,124 to industrial frame 9,905 Btu/kWh.

Cross-check of the heat rate output in Btu/kWh (10.45 GJ/MWh). Not consumed by a node.

Market range EIA pair 9,124-9,905 Btu/kWh.

Cross-check of the LCOE at 30 % CF. Not consumed by a node.

Cross-check of the LCOE at 30 % CF. Not consumed by a node.

Market range Upper end of the PCGE 30 % CF range.

Cross-check of the LCOE at 10 % CF. Not consumed by a node.

Cross-check of the LCOE at 10 % CF. Not consumed by a node.

Market range Upper end of the PCGE 10 % CF range.

SCOPE. A single simple-cycle aeroderivative gas turbine of 50-200 MW for peaking duty, from gas at the fence to net electricity at the high-voltage terminals. No heat recovery, no inlet cooling, no SCR or CEMS (DEA assumes the under-500-h exemption, p.349), no black-start diesel, no fuel oil backup.

Market range Not applicable (scope statement).

CAPEX BOUNDARY. costs.capex.isbl exports the installed EPC cost, so costs.capex.battery_limit is 'installed': project mode adds working capital and contingency (about x1.17 at its defaults) on top. The calculator's own LCOE uses the DEA cost without that uplift, so the project LCOE will be somewhat higher.

Market range Not applicable (boundary statement).

REAL BASIS. Every cost is in constant EUR (DEA 2015 for capital and O&M, IEAGHG 4Q-2014 for the gas default, not re-indexed, about 1 % apart), so the discount rate is real and nothing is escalated. Fixed O&M exported to project mode is an undiscounted annual cash amount in 2015 EUR.

Market range Not applicable (convention statement).

STARTS. DEA's fixed O&M already pays for 50 starts a year. The model corrects it to the user's start count and never adds a separate start line. The fuel burnt during starts is priced inside DEA's 43 EUR/MW at DEA's own fuel assumption, so a small part is counted twice with the gas line; it is not netted out.

Market range Not applicable (method statement).

EFFICIENCY. The fuel balance uses DEA's annual-average efficiency, not nameplate: the 5 % gap carries part load and starts of DEA's peak duty. The model keeps that gap constant across the 5-30 % capacity-factor range; a unit that runs longer at full load would do slightly better, so the gas line is conservative at the top of the slider.

Market range Not applicable (method statement).

DERATE. One industrial-turbine curve (Solar Taurus 70) stands in for a generic 100 MW aeroderivative, linear between the three printed points. Aeroderivatives usually lose more output in heat, so the hot-site output may be optimistic. Altitude derate is not modelled: EPA gives it only as a figure, without a printed number.

Market range Not applicable (evidence statement).

SCALE. The 0.7 exponent is used only inside DEA's 50-200 MW band; the capacity input is refused outside it. DEA's sheet describes a 100 MW aeroderivative (large aeroderivatives are rated 20-100 MW, note A) and the efficiency is held at the DEA value from 50 to 200 MW: 150-200 MW is read as a block of several aeroderivatives (same efficiency, economy of scale on the shared balance of plant), not one larger machine. An industrial frame turbine (EIA AEO2023 lists one at 9,905 Btu/kWh HHV, around 237 MW, size to be checked) is out of scope and has no case here. The fixed O&M stays linear in MW: DEA prints it per MW with no scale effect, and no source of the bundle prices an OCGT of the same technology at two sizes.

Market range Not applicable (domain statement).

CO2. Direct stack CO2 from gas combustion only. Upstream methane leakage, CH4 and N2O from combustion and construction emissions are not counted. The carbon price enters the LCOE but is not exported as O&M; project mode prices emissions from the exported direct CO2.

Market range Not applicable (scope statement).

CROSS-CHECK. At 7 %, no carbon price and the IEAGHG gas price, the model gives 77.1 EUR/MWh at 30 % and 112.9 EUR/MWh at 10 % capacity factor, in fixed 2015 EUR. PCGE ranges are in 2018 USD (PCGE 2020, PDF p.43): 77.50-137.09 USD/MWh at 30 % and 140.51-182.18 USD/MWh at 10 %. Converted with the Danish HICP from 2015 to 2018 (Eurostat prc_hicp_aind, 100 to 101.8) and the ECB 2018 annual average reference rate (1.1810 USD/EUR), a factor of 1.202, the model gives 92.7 and 135.7 USD2018/MWh. At 30 % it sits inside the PCGE range, in its lower third; at 10 % it sits just below the floor (135.7 against 140.51, -3.4 %). That remaining gap is smaller than the 30 USD/t CO2 price PCGE includes (about 15 USD/MWh at the model's 512 kg/MWh), which the model's default carbon price of zero leaves out.

Market range PCGE ranges quoted above.

CROSS-CHECK. EIA heat rates are stated on a higher heating value basis (US practice), so only the model's HHV heat rate is compared: 10.09 GJ/MWh HHV (9,567 Btu/kWh) at 15 C, inside the EIA simple-cycle pair 9.63-10.45 GJ/MWh (9,124-9,905 Btu/kWh). The LHV heat rate (9.12 GJ/MWh) is not comparable with EIA and is not used in this check.

Market range EIA pair quoted above.

CROSS-CHECK. CONE 2024 gives 0.47 MEUR/MW and 8,236 EUR/MW/year at 2023 prices for an OCGT on gas; the sheet used here gives 0.454 MEUR/MW and 8,068 EUR/MW/year in 2015 EUR. Indexed with the Danish HICP (Eurostat prc_hicp_aind, 2015=100: 117.6 in 2023), the sheet's figures become about 534 EUR/kW and 9,490 EUR/MW/year at 2023 prices, so CONE is about 12 % (capex) and 13 % (fixed O&M) lower in real terms. Deflated to 2015 EUR, CONE's capex is about 400 EUR/kW, inside DEA's own uncertainty band of 363-545 EUR/kW. The model default sits on the high side of the more recent DEA estimate.

Market range CONE values quoted above.

BATCH ALIGNMENT. Gas is priced per MWh HHV under the key ng_price_eur_per_mwh and exported as an HHV inlet, so a single project gas price applies consistently to gas turbines and reformers. The CCGT calculator of the same batch uses the same economic basis.

Market range Not applicable (alignment statement).

CURRENCY. EUR 2015, the DEA price level, declared as currency_year 2015 in the meta. The IEAGHG gas price (4Q-2014 EUR) is not re-indexed.

Market range Not applicable.