Optimizing Human-Powered Energy Generation Using Gaussian Process Regression

Summary

This protocol optimizes human-powered electricity generation systems using Gaussian process regression to achieve 80%-90% efficiency while maintaining physiological safety, providing reproducible methods for converting exercise into sustainable energy production, addressing both unemployment and renewable energy challenges.

Abstract

This protocol presents a Gaussian Process Regression (GPR) optimization framework for human-powered electricity generation systems to address technological unemployment and renewable energy demands simultaneously. Seven participants performed 112 trials across 16 configurations combining four battery voltages (12 V, 24 V, 36 V, 48 V) with four electrical loads (10 W, 30 W, 50 W, 70 W) using a modified stationary bicycle generator. The GPR model incorporated automatic relevance determination (ARD) squared exponential kernels to map pedaling speed, pressure, voltage, and load parameters to generation efficiency while quantifying prediction uncertainty. Real-time data acquisition at 2 Hz captured mechanical and electrical parameters through Hall-effect sensors, strain gauges, and power analyzers with Modbus communication protocols. The optimized system achieved 80%-90% theoretical maximum efficiency with coefficient of variation (CoV) below 15%, compared to 60%-70% efficiency and 25%-35% variability in commercial systems. GPR predictions demonstrated R² = 0.713 with sub-10ms latency through sparse approximation techniques, enabling real-time control. Optimal operational parameters varied systematically: low loads required 150-180 revolutions per minute (RPM) at 50-70 N pressure, while higher loads peaked at 100-120 RPM with 100-150 N pressure. The 48 V configuration improved efficiency by 68% over 12 V baseline (measured as relative efficiency index, REI, normalized to baseline = 100%). Phase-specific monitoring identified fatigue onset at 35-40 min, triggering risk-aware control adjustments based on posterior uncertainty. The protocol establishes quantitative methods for balancing energy generation with physiological constraints, providing a reproducible framework for deploying human-powered systems in fitness facilities where break-even occurs at $0.18/kWh electricity pricing.

Introduction

The convergence of artificial intelligence-driven automation and climate change presents unprecedented challenges requiring innovative solutions that address both technological unemployment and sustainable energy transitions. Empirical analyses project 85 million job displacements by 2025, with computer and mathematical occupations experiencing 2.8 percentage point unemployment increases¹. Simultaneously, atmospheric CO₂ concentrations reached 426.9 ppm in February 2025², necessitating urgent expansion of renewable energy capacity^3,4. This paper presents a novel ....

Protocol

This study involved non-invasive exercise testing using a stationary bicycle and posed no more than minimal risk to participants. All participants were healthy adult volunteers who provided verbal informed consent after receiving detailed information about experimental procedures, their right to withdraw at any time, and data confidentiality. The procedures followed the ethical principles of the Declaration of Helsinki for research involving human subjects.

1. Assembly of the HPEG

1. Mechanical structure assembly
   NOTE: All mechanical modifications should be performed in a well-ventilated workspace with appropriate safety equip....

Results

Efficiency refers to thermodynamic conversion efficiency (0-100%). REI refers to the relative efficiency index, calculated as (observed/baseline) x 100%, which can exceed 100%. To compare heterogeneous settings, a Relative Efficiency Index is used, which is calculated by dividing the observed efficiency by a fixed baseline configuration (12 V-70 W), measured under the same pipeline. Thus, REI = 110% denotes a 10% gain relative to baseline, not a thermodynamic efficiency above 100%. Unless marked REI, efficiency refers to.......

Discussion

The successful implementation of GPR-based optimization for HPEG systems depends critically on mechanical coupling precision and computational efficiency²⁸. The rim-only configuration proved essential, as complete wheel assemblies degraded tracking efficiency by 35%-45% through rotational inertia variations²⁷. Belt tension calibration to 350 ± 50N emerged as particularly critical-deviations resulted in either premature failure or excessive parasitic losses, directly im.......

Materials

List of materials used in this article

Name	Company	Catalog Number	Comments
AC outlet module (China GB/T, panel type)	10/16 A, embedded cassette, child-protection shutters	Five-hole desktop AC power socket (black)	Wanyu
Adjustable polyurethane V-belt	ABCZM type, jointed PU belt	ABCZM universal jointed polyurethane V-belt (with/without studs) / —
Adjustable wrench	6-inch, laser scale	Adjustable wrench 6-inch open-jaw, polished handle 250006	Ruineng
Alternator, three-phase permanent magnet	300 W, 24 V (as listed)	300–400 W three-phase AC permanent-magnet alternator, 300 W 24 V	Jiunian
Battery pack, portable power station	2400 W large-capacity portable unit	2400 W portable backup power station, multi-function solar energy storage / —
Bicycle chain	1/2" × 1/8", 920kgf tensile strength, 0.5% elongation limit	KMC X101
Bicycle computer (wireless)	Waterproof, night backlight, speed/odometer	Wireless large-screen bicycle computer, waterproof, backlight / —
Bicycle trainer (magnetic roller, folding)	Magnetic resistance, ventilated flywheel, dual-lock knobs	Magnetic-resistance roller trainer, foldable / —
Bicycle, road (700C)	700C wheels, geared	700C aero road bicycle, multi-speed	Forever, Yongjiu
Charge controller, MPPT (12/24 V)	Auto 12/24 V, 20 A (as listed)	MPPT solar charge controller 12/24 V 20 A	Lansheng
Current sensor, Hall-effect	±100A, 20mV/A±0.5%, BW=120kHz	ACS758LCB-100B
Diode (blocking) — verify exact device	Listing mixes Schottky diode / bidirectional TRIAC / IXFN132N50P3	IXFN132N50P3 (listing claims Schottky diode & bidirectional TRIAC) / —
Diode, ultrafast recovery	200V V_RRM, 30A I_F(AV), <35ns t_rr	RHRG30120
Electrical tape (PVC)	9 m roll	Electrical tape ET6 9 m	Bull
Electronic load, programmable	200W continuous, 0--500V, 0--120A	BK Precision 8500
Microcontroller, 32-bit	ARM Cortex-M4, 72MHz, 12-bit ADC@5MSPS	STM32F334C8T6
MOSFET, P-channel	RDS(on)<10mΩ, 200V, -12A	IRFP9240
Multimeter, digital	Backlit, overload-protected	Digital multimeter DEM23, backlit, anti-burn	Delixi
Multimeter, precision	6.5-digit, 0.0035% DCV accuracy	Fluke 8845A	Fluke
Operational amplifier, quad	Rail-to-rail, Vos<2mV, 1MHz GBW	MCP6004
Permanent magnet generator	24V/300W, 12-pole, NdFeB N42 magnets	YC-FD300
Resettable circuit breaker (push-to-reset)	3–50 A series (as listed)	Thermal reset circuit breaker 88/98 Series/AR 3–50 A	Kuoyuh
Screwdriver set (Phillips/flat)	6×100 mm, magnetic tips, 2-piece	Magnetic flat screwdriver set 6 x 100 mm (2 pcs)	Phillips
Software, programming language	Version 3.8, with GUI framework		Python
Terminal block, single-position (DIN/panel)	IN-100BK, 130 A class (as listed)	DIN-rail terminal block IN-100BK, single position	WeilianDun
Terminal block, single-position (DIN/panel)	IN-411S, 60 A class (as listed)	DIN-rail terminal block IN-411S, single position	WeilianDun
Tire levers (pair)	12-inch (30 cm), 2 pcs	Tire levers 12-inch (pair)	Chengzhou
TVS diode	135V clamping, 1500W peak, <1ps response	1.5KE100A
Wire connectors, crimp quick-disconnect (bullet)	1.5–2.5 mm², nylon, blue, 100 sets	Bullet quick-disconnect wire connectors, blue (100 sets)	Gotoele
Wire stripper/crimper	7-inch, multi-function	7-inch multi-function wire stripper DL902200	Deli
Wire, silicone (12 AWG ≈ 3.4 mm²)	High-temperature silicone insulation, 1 m	Silicone wire 12 AWG (≈3.4 mm²) 1 m	Lanjiang