Aeroderivative gas turbines vs. reciprocating engines

Technology comparison summary: Aeros vs. recips

PARAMETER	AERODERIVATIVE GAS TURBINES	RECIPROCATING ENGINES
Start time	Cold iron to full load in 5 mins	Cold iron to full load in >10 mins, 5 mins with hot standby
Maintenance	4,000 hr. or annual borescope inspection, 25,000 hr. intervals	2,000 hr. injection nozzles inspection/replacement, 4,000 hr. engine charge cooler inspection, 16,000 – 24,000 hr. overhaul interval, 32,000 hr. major intermediate inspection interval
Diesel pilot fuel on dual fuel engines	None required for gas operation – seamless transition	Distillate pilot fuel required(1 - 2% of fuel) for gas operation
Lube oil (150 MW - Peaker 2000 hrs/yr)	~666 liters/year due to evaporation	~133,000 liters/year direct consumption
Emissions	15/25 ppm NOx, 25 ppm CO 97 ppm NOx in liquid fuel	90 ppm NOx, 150 ppm CO, methane slips 900 ppm NOx in liquid fuel
Performance testing tolerance	No tolerance allowed	5% tolerance allowed on heat rate based on ISO 3046
Unit availability	>98%	~ 93 - 95%
Civil (foundation) requirements	Medium	Heavy
Normal ramp rate	20-50 MW/min.	~5 MW/min.

LCOE Evaluation ($/MWhr) – Aeros vs. recips

Description	Units	Aeros	Recips
No. of Units		5	8
Plant Output	MWe	149.8	141.7
Efficiency	%	37.3	45

Site Assumptions:

Plant designed to produce 150MWe output at 105 oF
LCOE calculations based on a Texas site specific data :
105 °F – 20Hrs, 93 °F – 640 hrs, 82 °F - 689 hrs, 46 °F – 660 hrs
Operating hours : 2,000/year
Number of starts : 200/year
Evaluation period : 20 years
Fuel price : $5/MMBtu*
Discounting rate : 8%

* U.S. Energy Information Administration (eia) natural gas spot price (March, 2022) is $5/MMBtu.

150 MW plant reliability

Key RAM Metrics

Metric	Aero	Recips
MTBF (hours)	~5000	~200-400
Reliability (%)	99.3%	95%
Availability	98.3%	93%

Engines require N+2 units configuration to match the Aeroderivative plant reliability.

Aeros vs. recips: Maintenance cycle comparison

5 x 30 MWe Aero

No. of events / unit

Outage hours/event

8 x 18MWe Recips

No. of events/unit

Outage hours/event

Operation cost: Lube oil and operation manpower – 150 MWe

OPERATION MANPOWER

~$10M Savings with Aero

LUBE OIL CONSUMPTION

~$3.5M Savings with Aero

Recip lube oil consumption 0.4 gms/kWh
Aero lube oil consumption 0.002 gm/kWh
Lube oil cost ~$3/kg
Operating hours/year: 2000 hrs.
~$1.2 /MWh with recips.

Exhaust emissions before treatment
for dual fuel units

@ dry 15% O2

Estimated GHG emissions comparison between aeroderivative gas turbines and reciprocating engines

Total GHG emissions for a 150 MW plant with 2000 operating hours per year

(Tonnes CO2 pa)

Methane slip

Methane slip is a huge environmental issue for recip engines
Methane has 86 times the climate impact of CO2 over a 20 years period
Recip (OEM reported) – 3.2 g/kW-hr
Recip (EPA reported ) – 4.2 g/kW-hr
Aero – 0.036 g/kW-hr
Recip GHG Emissions are 40% to 60% more compared to Aero.

Deploying aeros vs recips results in the equivalent of taking 12,000 to 17,500 cars off the roads.

EPA 4.6 tCO2/yr for typical car