[Paper Review] A renewable power system for an off-grid sustainable telescope fueled by solar power, batteries and green hydrogen

Isabelle Viole, Guillermo Valenzuela-Venegas+2 more|arXiv (Cornell University)|Nov 25, 2022

Hybrid Renewable Energy Systems4 citations

TL;DR

This paper proposes a renewable power system for the off-grid Atacama Large Aperture Submillimeter Telescope (AtLAST), integrating photovoltaics, batteries, green hydrogen storage, and fuel cells to replace diesel generators. The optimized system achieves a levelized cost of electricity (LCOE) of $116/MWh and reduces the telescope’s carbon footprint by 95% compared to a diesel-only baseline, demonstrating a viable, low-carbon model for remote astronomical facilities.

ABSTRACT

A large portion of astronomy's carbon footprint stems from fossil fuels supplying the power demand of astronomical observatories. Here, we explore various isolated low-carbon power system setups for the newly planned Atacama Large Aperture Submillimeter Telescope, and compare them to a business-as-usual diesel power generated system. Technologies included in the designed systems are photovoltaics, concentrated solar power, diesel generators, batteries, and hydrogen storage. We adapt the electricity system optimization model highRES to this case study and feed it with the telescope's projected energy demand, cost assumptions for the year 2030 and site-specific capacity factors. Our results show that the lowest-cost system with LCOEs of $116/MWh majorly uses photovoltaics paired with batteries and fuel cells running on imported and on-site produced green hydrogen. Some diesel generators run for backup. This solution would reduce the telescope's power-side carbon footprint by 95% compared to the business-as-usual case.

Motivation & Objective

• To design a low-carbon, off-grid power system for the Atacama Large Aperture Submillimeter Telescope (AtLAST) to replace fossil fuel dependence.
• To evaluate the techno-economic trade-offs between photovoltaics, concentrated solar power, batteries, green hydrogen, and diesel backup in high-altitude, remote conditions.
• To assess the impact of technology learning rates and system centralization on cost and emissions.
• To provide a scalable, open-source model for sustainable power systems in remote scientific infrastructure.

Proposed method

• The highRES energy system optimization model was adapted to simulate and compare 100+ hybrid power system configurations for AtLAST’s unique energy demand profile.
• Hourly solar irradiation data from ERA5 and site-specific capacity factors were used, including elevation-specific derating for high-altitude performance.
• The model optimized for minimum levelized cost of electricity (LCOE) over a 30-year lifetime, incorporating CAPEX, OPEX, and technology learning rates.
• Green hydrogen was produced via alkaline and PEM electrolyzers using excess solar power and stored in compressed gas (CG) tanks for later use in fuel cells.
• Battery storage and hydrogen-based hybrid energy storage were compared to assess system resilience and cost efficiency.
• Sensitivity analyses were performed on component costs, technology learning rates, and system centralization to evaluate robustness and scalability.

Experimental results

Research questions

• RQ1 What is the lowest-cost, off-grid renewable power system configuration for a large, high-altitude telescope with seasonal but stable energy demand?
• RQ2 How do system costs and emissions vary between 100% renewable systems and those with diesel backup, and what is the trade-off in reliability and LCOE?
• RQ3 To what extent can green hydrogen and battery storage reduce curtailment and improve system stability compared to single-storage solutions?
• RQ4 How do technology learning rates and centralized infrastructure for multiple telescopes on Chajnator plateau affect system economics and emissions?
• RQ5 What is the impact of high-altitude conditions on system performance, and how do derating factors influence the optimal technology mix?

Key findings

• The lowest-cost system achieves an LCOE of $116/MWh by combining photovoltaics, batteries, and green hydrogen via fuel cells, with minimal diesel backup.
• This optimal system reduces the telescope’s power-side carbon footprint by 95% compared to the diesel-only business-as-usual scenario.
• Systems using only batteries or only hydrogen storage resulted in 1–12% higher LCOE, indicating that hybrid storage offers better cost efficiency.
• PV-based systems reduced generation costs by 31–42% and emissions by 40–100% compared to diesel-only operation.
• The inclusion of on-site green hydrogen production further enhances sustainability, with 1,048.7 kg H2 stored in compressed gas tanks in the optimal configuration.
• Centralized power systems for multiple telescopes on the Chajnator plateau could significantly reduce maintenance and cabling costs, improving economic viability.