Solar Energy Storage

Detailed overview of innovation with sample startups and prominent university research

What it is

Solar energy storage involves capturing and storing excess solar energy for later use. This is crucial for addressing the intermittency of solar power and ensuring a reliable and consistent supply of renewable energy, even when the sun isn’t shining.

Impact on climate action

Solar energy storage in Distributed Solar PV boosts climate action by enhancing renewable energy integration and grid stability. By storing excess solar energy for later use, this innovation reduces reliance on fossil fuels, mitigates carbon emissions, and accelerates the transition to a resilient, low-carbon energy system, combating climate change.


  • Energy Storage Systems (ESS): ESS, such as batteries, thermal energy storage systems, and mechanical energy storage systems, store excess solar energy for later use.
  • Power Conversion Systems (PCS): PCS convert the direct current (DC) electricity generated by solar panels into alternating current (AC) electricity for grid use and vice versa for charging the ESS.
  • Energy Management Systems (EMS): EMS optimize the charging and discharging cycles of the ESS, ensuring efficient energy utilization and grid stability.
  • Grid Integration: Solar energy storage systems need to be seamlessly integrated into the electricity grid to ensure efficient energy flows and grid stability.

TRL : 6-8 (depending on the specific storage technology)

Prominent Innovation themes

  • Advanced Battery Technologies: Advancements in battery technology, such as lithium-ion batteries, flow batteries, and solid-state batteries, are improving the cost-effectiveness, energy density, and lifespan of ESS for solar energy storage.
  • Thermal Energy Storage: Technologies like molten salt storage and phase change materials are being used to store solar energy as heat, which can be used to generate electricity or provide heat for industrial processes.
  • Mechanical Energy Storage: Technologies like flywheels and pumped hydro storage are being explored for solar energy storage, offering long-duration storage capabilities.
  • AI-Powered Energy Management: AI and machine learning are being used to optimize the operation of solar energy storage systems, predicting energy demand and optimizing charging and discharging cycles.
  • Integrated Solar-Plus-Storage Solutions: Companies are developing integrated solar-plus-storage solutions that combine solar panels, ESS, PCS, and EMS into a single, optimized system.

Other Innovation Subthemes

  • Battery Innovations
  • Thermal Storage Solutions
  • AI-Driven Energy Management
  • Integrated Solar-Plus-Storage Systems
  • Grid Integration Technologies
  • Molten Salt Storage Advancements
  • Pumped Hydro Storage Solutions
  • Scalable Energy Storage Solutions
  • Low-Cost Storage Technologies
  • Long-Duration Storage Systems
  • Smart Grid Integration
  • Residential Solar Storage Solutions

Sample Global Startups and Companies

  • Tesla:
    • Technology Enhancement: Tesla is renowned for its solar energy storage solutions, including the Powerwall for residential applications and the Powerpack for commercial and utility-scale projects. These battery storage systems store excess solar energy generated during the day for use during periods of low sunlight or high demand. Tesla’s systems integrate seamlessly with solar panels to provide reliable and sustainable power backup.
    • Uniqueness of the Startup: Tesla stands out for its brand recognition, technological innovation, and vertically integrated approach to solar energy storage. Their batteries feature advanced lithium-ion technology, robust energy management software, and sleek design, making them popular choices for homeowners, businesses, and utilities seeking reliable energy storage solutions.
    • End-User Segments Addressing: Tesla serves residential customers, businesses, and utilities looking to maximize the value of solar energy by storing excess power for later use. Their solar energy storage systems are deployed in homes, commercial buildings, microgrids, and utility-scale solar farms, providing backup power, load shifting, and grid services.
  • Fluence:
    • Technology Enhancement: Fluence offers advanced energy storage solutions for solar integration, grid stabilization, and peak shaving applications. Their storage systems leverage lithium-ion batteries, advanced control algorithms, and grid management software to optimize solar energy utilization and grid performance. Fluence’s modular design allows for scalable deployment and easy integration with solar installations.
    • Uniqueness of the Startup: Fluence stands out for its partnership between Siemens and AES Corporation, combining expertise in energy technology and grid management. Their energy storage solutions are designed to enhance grid reliability, support renewable energy integration, and enable dynamic energy management for utilities, independent power producers, and commercial customers.
    • End-User Segments Addressing: Fluence serves utilities, independent power producers, and commercial and industrial customers seeking grid-scale energy storage solutions. Their systems are deployed in utility-scale solar projects, microgrids, ancillary service markets, and distributed energy resource (DER) projects, providing grid stability, energy arbitrage, and demand management.
  • IronNet:
    • Technology Enhancement: IronNet focuses on developing innovative energy storage solutions for solar power integration and grid support. Their storage systems utilize advanced battery technology and intelligent control algorithms to optimize energy flow, increase system efficiency, and ensure grid stability. IronNet’s approach to solar energy storage emphasizes scalability, reliability, and cost-effectiveness.
    • Uniqueness of the Startup: IronNet stands out for its focus on providing customizable and modular energy storage solutions tailored to the needs of solar developers and utilities. Their systems offer flexibility in deployment, allowing for seamless integration with solar installations of varying sizes and configurations.
    • End-User Segments Addressing: IronNet serves solar project developers, utilities, and commercial customers seeking scalable energy storage solutions for solar power integration. Their systems are deployed in utility-scale solar farms, commercial buildings, microgrids, and off-grid applications, providing grid stability, renewable energy storage, and backup power capabilities.

Sample Research At Top-Tier Universities

  • Massachusetts Institute of Technology (MIT):
    • Research Focus: MIT is at the forefront of research on Solar Energy Storage, focusing on developing advanced energy storage technologies and system integration solutions to enhance the reliability, efficiency, and grid integration of distributed solar PV systems.
    • Uniqueness: Their research involves exploring novel battery chemistries, materials, and architectures for grid-scale energy storage applications, including lithium-ion, flow batteries, and emerging technologies such as solid-state batteries and redox flow cells. They also investigate hybrid storage systems, demand-side management strategies, and grid-balancing algorithms to optimize the utilization of solar energy and mitigate intermittency challenges.
    • End-use Applications: The outcomes of their work have applications in residential, commercial, and utility-scale solar projects, as well as microgrid and off-grid electrification initiatives. By advancing solar energy storage technologies, MIT’s research contributes to enhancing energy resilience, reducing electricity costs, and enabling higher levels of renewable energy penetration in the power grid.
  • Stanford University:
    • Research Focus: Stanford University conducts pioneering research on Solar Energy Storage, leveraging its expertise in materials science, electrochemistry, and renewable energy systems to develop innovative solutions for storing and dispatching solar power on-demand.
    • Uniqueness: Their research encompasses the development of next-generation energy storage materials, devices, and control algorithms for optimizing the performance and cost-effectiveness of distributed solar-plus-storage systems. They also explore integrated energy management platforms, smart inverters, and predictive analytics to enable real-time optimization of solar generation, storage, and consumption.
    • End-use Applications: The outcomes of their work find applications in residential energy storage systems, grid-connected storage projects, and community microgrids. By advancing solar energy storage technologies, Stanford’s research supports the transition to a more flexible, resilient, and sustainable energy infrastructure, capable of accommodating higher shares of variable renewable energy sources like solar PV.
  • University of California, San Diego (UCSD):
    • Research Focus: UCSD is engaged in innovative research on Solar Energy Storage, leveraging its expertise in power electronics, control systems, and energy management to develop integrated solutions for coupling solar PV with energy storage technologies.
    • Uniqueness: Their research involves designing and testing advanced battery systems, thermal storage technologies, and hybrid energy storage configurations tailored to the unique requirements of distributed solar applications. They also explore grid-connected storage architectures, virtual power plant concepts, and community energy storage models to enhance grid stability and resilience.
    • End-use Applications: The outcomes of their work have applications in campus microgrids, community solar projects, and islanded power systems. By developing scalable and cost-effective solar energy storage solutions, UCSD’s research contributes to reducing greenhouse gas emissions, enhancing energy security, and promoting decentralized energy generation and distribution.

commercial_img Commercial Implementation

Solar energy storage systems are being increasingly deployed around the world, both at the utility-scale and residential level. For example, the 100 MW Tesla Powerpack system at the Hornsdale Power Reserve in Australia is one of the largest lithium-ion battery storage systems in the world, providing grid stability and supporting the integration of renewable energy.