Fed. funding: $2.4M Length 36 mo.

Recuperated Brayton Cycle Using a Screw and Expander PI: Jim Kesseli, Tech Lead:Chad Everbeck, Tom Wolf Project Goal • 40% LHV to electric conversion efficiency • 80% overall cogeneration efficiency • 80,000 hour product life. • CARB-compliancy Current Technical Status • Current component test support electric conversion efficiency 37% LHV • Met CARB emissions • Working toward full bread-board test this summer A miniature Brayton Cycle ‘’ ‣ Traditional radial and axial turbomachinery suffers significant efficiency limitations. ‣ Screws dominate the air moving industry in flow class appropriate for <10 kWe Brayton cycle engine. Turbomachinery for 1 kWe gas turbine ? ‣ Both are ‘rotary’ with non-contacting rotary machinery, demonstrating exceptional longevity and maturity.

1 kWe: Screw compressor (34mm) & expander diameter (52mm)

1 Brayton has designed 1 and 2 kWe power modules – building 2 kWe for early trials

General Product Characteristics - Non-contacting dry screw compressor & expander - Custom-conventional compressor - Ceramic expander - Large recuperator - Brayton proprietary - In-house pilot manufacturing - Combustor – low risk scale of CARB-compliant design

2 Validating and qualifying the principal components through rigorous performance and life testing - Compressor efficiency testing - Isolated three mechanical loss mechanisms in both compressor and expander: 1. Bearing test rig 2. Windage; measured 3. Gear mesh; measured - In previous quarters: - Tested ceramic expander – proved thermal shock Compressor and tolerance at 1110℃. mechanical - Met combustor emission loss test rigs standards.

3 Compressor Test & Model Validation: 2 kWe Rotary Screw Brayton

87 Manufacturing limit = Machining tolerances 85 Rotordynamic deflections Shaft bending 83 Σ Thermal growth 81 Target efficiency 79 ηengine = 40% 77 Near-term GENSET goal 75 Analytical model 73 DATA

71 Analysis model 69 Test data, run 1

Isentropic Efficiency (%) Efficiency Isentropic Test data, run 2 67 Test data, run 3 65 30 40 50 60 70 80 90 100 Rotor Clearance (um)

4 Recuperator Performance

‣ Recuperator production, performance test and life test. – Built full scale 2 kWe recuperator – Achieved 96.4% effectiveness at design conditions. • Derived and managed external heat losses. – Subjected cells to accelerated life testing: creep and fatigue – Conducted in-house manufacturing process trials to refine production plan.

5 In-house Development of Proprietary Near- zero CTE Ceramic for Expander

Key Technology/IP Details on Envisioned Product Offering

Metric Program Target Current Status Envisioned Product offering Device Application Residential CHP Residential CHP Residential CHP w/ black-start & off- grid operation Power (kWe) 1 1.9 (design target) 2 Fuel-to elec. eff. (%) 40 34% ±3 pct 38% System cost* ($) 2,500 2,900 2,900 O&M cost ($/kWh) ≤0.005 NA 0.005 to 0.01 Capacity factor (%) 99.9 NA 99.9 System Life (years) ≥10 NA >10 System Noise (dB(A) ≤55 <55 at 3 feet away) System Mass (kg) ≤150 120 +/-20 100 +/- 10

* excluding 30% mark-up for commercial price Current Challenges

Programmatic Challenges • Specialized ceramic production costs and schedule • Breadboard engine test schedule

Technical Challenges • Component heat losses • Bearing losses

Business Challenges • CHP heat capture and economics • Simple payback > 3 years for most US regions • Finding next stage investor Tech-to-Market Strategy

• Approach to market • Brayton GENSETS shows potential in all key categories to succeed in µ-CHP + • Roughly twice the efficiency of best available technology (>35% LHV) • CARB emissions • Near zero maintenance for 10 years continuous duty • Factory cost < $1500/kWe • Alternative Markets: µ-CHP + back-up power, remote power in developing countries • Where do you fit in the supply chain? • Component manufacturer? • Engine / generator manufacturer? • System manufacturer? • Pathway to success: partnerships, capital requirements over 4 year commercialization venture. • Approach to manufacture • Capital equipment plan: <$5M to achieve cost targets • Demand-flow manufacturing meshes well with other OEM lines Desirable Partnerships

Desirable partnerships (one or more of the following profiles could be leveraged to advance our product)

• Appliance manufacturer; for refined production experience and channel to residential market • Screw compressor manufacturer: Leverage capital equipment • Heat exchanger manufacturer; Leverage capital equipment • Emergency generator installer; for channel to market and experience with utility interface permitting