Thursday, February 27, 2025

Common Issues and Troubleshooting Tips for Lithium-Ion Battery Chargers

Introduction

Lithium-ion battery chargers are essential for powering modern devices, from smartphones and laptops to electric vehicles and solar energy systems. However, users often encounter issues that can disrupt charging performance and battery life. In this article, we’ll explore common problems with lithium-ion battery chargers and provide troubleshooting tips to help resolve them.

1. Charger Not Recognizing the Battery

Possible Causes:

  • Poor battery connection
  • Dirty or corroded charging contacts
  • Defective battery or charger

Troubleshooting Tips:

  • Ensure the battery is properly seated in the charger.
  • Clean the charging contacts with a dry cloth or alcohol wipe.
  • Try using a different battery to determine if the issue is with the charger.

2. Slow Charging or Not Charging Fully

Possible Causes:

  • Faulty power adapter or cable
  • High battery temperature
  • Degraded battery capacity

Troubleshooting Tips:

  • Use the original charger and a high-quality charging cable.
  • Charge in a cool, well-ventilated area to prevent overheating.
  • If the battery is old or damaged, consider replacing it.

3. Charger Overheating

Possible Causes:

  • Poor ventilation
  • Prolonged charging sessions
  • Incompatible charger

Troubleshooting Tips:

  • Place the charger in an open space to allow proper airflow.
  • Avoid charging continuously for extended periods.
  • Use a charger that matches the battery’s voltage and current requirements.

4. Battery Draining Quickly After Charging

Possible Causes:

  • Incomplete charge cycles
  • Battery nearing the end of its lifespan
  • Background applications consuming power

Troubleshooting Tips:

  • Allow the battery to charge fully before use.
  • Monitor battery health using a diagnostic tool.
  • Close unnecessary apps on devices like smartphones and laptops.

5. Charger LED Indicators Not Functioning

Possible Causes:

  • Loose power connection
  • Faulty LED indicator
  • Internal charger failure

Troubleshooting Tips:

  • Check the power source and try a different outlet.
  • If charging still works despite LED failure, the issue may be cosmetic.
  • If the charger doesn’t work at all, consider replacing it.

6. Unexpected Auto Shutoff During Charging

Possible Causes:

  • Battery overheating protection
  • Charger safety feature activated
  • Power fluctuations

Troubleshooting Tips:

  • Allow the battery and charger to cool before resuming charging.
  • Use a surge protector to prevent damage from power spikes.
  • Ensure the charger is in good working condition and not malfunctioning.

Conclusion

Understanding common issues with lithium-ion battery chargers can help users troubleshoot problems effectively and maintain battery health. Regular maintenance, using compatible accessories, and ensuring proper charging conditions can enhance battery life and charger performance. If issues persist, consulting a professional or replacing faulty components may be necessary.

Wednesday, February 26, 2025

How Online UPS Protects Sensitive Equipment from Power Fluctuations

Power fluctuations, including voltage spikes, surges, sags, and blackouts, can severely damage sensitive equipment, leading to costly repairs, data loss, and operational downtime. To mitigate these risks, businesses and industries rely on Online Uninterruptible Power Supply (UPS) systems, which provide continuous and clean power to critical devices. This article explores how an Online UPS safeguards sensitive equipment from power disturbances.

1. Double Conversion Technology for Continuous Power Supply

Unlike offline or line-interactive UPS systems, an Online UPS uses double conversion technology to provide a stable and uninterrupted power supply. It converts incoming AC power to DC and then back to AC, ensuring a consistent voltage and frequency, free from fluctuations. This continuous power supply prevents sudden power disruptions that could damage delicate electronics.

2. Voltage Regulation to Prevent Overvoltage and Undervoltage Issues

Voltage fluctuations can cause irreversible damage to sensitive equipment. An Online UPS continuously monitors and regulates voltage levels, preventing:

  • Overvoltage (Power Surges): Can burn circuit components and lead to overheating.
  • Undervoltage (Power Sags): May cause unexpected shutdowns and damage hardware.

By stabilizing voltage, an Online UPS protects computers, medical devices, data centers, and industrial machinery from these risks.

3. Protection Against Power Surges and Spikes

Power surges occur due to lightning strikes, switching of heavy loads, or faults in the power grid. An Online UPS acts as a shield, absorbing excess energy and preventing sudden spikes from reaching the connected equipment. This feature is particularly crucial for:

  • IT servers and data storage systems
  • Hospital and laboratory equipment
  • High-end manufacturing machinery

4. Eliminating Electrical Noise and Harmonics

Sensitive equipment, such as communication systems and medical devices, require clean power for optimal performance. An Online UPS filters out electrical noise, harmonics, and distortions, ensuring stable voltage and frequency. This reduces interference and enhances the lifespan of the connected devices.

5. Instantaneous Power Backup During Blackouts

Blackouts and power outages can lead to data corruption, operational disruptions, and equipment failure. An Online UPS instantly switches to battery power when a blackout occurs, allowing devices to run without interruption. This prevents abrupt shutdowns, ensuring continuous operation for:

  • Data centers and network systems
  • Surveillance and security setups
  • Industrial automation systems

6. Enhanced Battery Management for Reliable Backup

Modern Online UPS systems feature intelligent battery management, which optimizes battery charging cycles and extends battery life. This ensures that the UPS is always ready to supply backup power when needed, minimizing downtime and enhancing system reliability.

7. Safeguarding Mission-Critical Applications

For industries where downtime is not an option, an Online UPS is indispensable. It protects mission-critical applications, including:

  • Banking and financial institutions (to prevent transaction failures)
  • Healthcare facilities (for continuous operation of life-saving equipment)
  • Telecommunications (ensuring uninterrupted connectivity)

Conclusion

An Online UPS is a vital investment for protecting sensitive equipment from power fluctuations. With its double conversion technology, voltage regulation, surge protection, and instantaneous backup, it ensures smooth and reliable operations in various industries. Businesses and institutions relying on critical electronic equipment can significantly reduce risks and enhance productivity by incorporating an Online UPS into their power infrastructure.

Monday, February 24, 2025

Key Features to Consider When Buying an On-Grid Solar Inverter

Introduction

An on-grid solar inverter is a critical component in a solar power system, enabling the conversion of direct current (DC) from solar panels into alternating current (AC) that powers homes, businesses, and feeds excess energy into the utility grid. Choosing the right on-grid solar inverter ensures optimal energy efficiency, system longevity, and maximum returns on investment. With numerous options available in the market, understanding the key features is essential for making an informed decision. This article explores the essential factors to consider when buying an on-grid solar inverter.

1. Inverter Efficiency

  • Conversion Efficiency: Look for inverters with a high efficiency rating (typically above 95%). Higher efficiency means more solar energy is converted into usable electricity, reducing energy loss.

  • European Efficiency: This is a weighted average that reflects real-world performance under varying loads, providing a more accurate measure of inverter capability.

2. Capacity and Power Rating

  • System Compatibility: Ensure the inverter’s power capacity matches your solar panel system's total wattage. Over or under-sizing can lead to inefficiencies.

  • Scalability: If you plan to expand your solar system in the future, opt for an inverter that supports additional panels without needing a complete system overhaul.

3. Maximum Power Point Tracking (MPPT)

  • MPPT Technology: Inverters equipped with MPPT optimize power output by continuously adjusting the system’s voltage and current to find the maximum power point.

  • Multiple MPPT Inputs: For systems with panels oriented in different directions or partially shaded, multiple MPPTs ensure optimal energy harvest from each panel string.

4. Grid Compatibility and Safety Features

  • Anti-Islanding Protection: This safety feature automatically shuts down the inverter during power outages to prevent back-feeding electricity into the grid, ensuring the safety of utility workers.

  • Grid Code Compliance: Verify that the inverter meets local grid regulations and standards to avoid operational issues or legal complications.

5. Monitoring and Connectivity

  • Real-Time Monitoring: Choose an inverter that offers real-time monitoring capabilities via mobile apps or web portals, allowing you to track energy production, consumption, and system performance.

  • IoT and Smart Features: Modern inverters often come with Wi-Fi, Bluetooth, or Ethernet connectivity, enabling seamless integration with smart home systems and energy management platforms.

6. Durability and Weather Resistance

  • Ingress Protection (IP) Rating: For outdoor installations, select an inverter with a high IP rating (IP65 or higher) to ensure protection against dust, rain, and extreme weather conditions.

  • Temperature Tolerance: Inverters with a wide operating temperature range perform reliably in diverse climates, from hot summers to cold winters.

7. Warranty and After-Sales Support

  • Extended Warranty: Look for manufacturers offering warranties of 5 to 10 years, with options to extend. A longer warranty reflects confidence in the product’s durability.

  • Customer Support: Reliable technical support and easy access to spare parts are crucial for maintaining long-term system efficiency.

8. Cost vs. Value

  • Price-Performance Ratio: While it’s tempting to choose the cheapest option, consider the overall value, including efficiency, durability, and additional features.

  • Government Incentives: Check for any government rebates, tax credits, or subsidies available for installing certified on-grid inverters.

9. Brand Reputation and Reviews

  • Market Standing: Opt for reputable brands with positive customer reviews and a proven track record in the solar industry.

  • Third-Party Certifications: Certifications like IEC, UL, or IS standards ensure the inverter meets safety and performance benchmarks.

Conclusion

Selecting the right on-grid solar inverter is crucial for maximizing energy efficiency, reducing electricity bills, and ensuring a reliable solar power system. By considering factors like efficiency, MPPT capabilities, grid compatibility, monitoring options, and warranty terms, you can make an informed decision that aligns with your energy goals and budget. As solar technology continues to evolve, investing in a high-quality inverter today ensures long-term benefits and seamless integration with future energy advancements.

Harnessing solar power is a smart choice—make sure your inverter is just as intelligent!

Key Factors to Consider When Choosing a Battery Energy Storage System

Introduction

As renewable energy adoption grows, Battery Energy Storage Systems (BESS) have become essential for enhancing energy reliability, efficiency, and sustainability. Whether for residential, commercial, or industrial use, selecting the right BESS is crucial for maximizing performance and cost-effectiveness. This guide explores the key factors to consider when choosing a battery energy storage system, helping you make an informed decision tailored to your energy needs.

1. Energy Capacity and Power Rating

  • Energy Capacity (kWh): This measures how much energy the system can store. Assess your daily energy consumption to determine the appropriate storage size.
  • Power Rating (kW): Indicates the amount of energy the system can deliver at a given time. Ensure the power rating matches your peak energy demand.

Tip: A balance between energy capacity and power rating ensures consistent energy supply during peak hours and outages.

2. Battery Chemistry

Different battery chemistries offer varying levels of efficiency, lifespan, and safety:

  • Lithium-Ion (Li-Ion): High energy density, longer lifespan, and low maintenance but relatively expensive.
  • Lead-Acid: Cost-effective with lower energy density and shorter lifespan.
  • Flow Batteries: Suitable for large-scale applications with long cycle life but bulkier and costlier.
  • Nickel-Cadmium (Ni-Cd): Durable and resistant to extreme temperatures but less environmentally friendly.

Tip: For residential and commercial use, lithium-ion batteries are often preferred due to their efficiency and compact size.

3. Depth of Discharge (DoD)

DoD refers to the percentage of the battery’s total capacity that can be used without causing damage. A higher DoD means you can use more of the battery’s energy:

  • Lithium-Ion Batteries: Typically offer 80-90% DoD.
  • Lead-Acid Batteries: Usually range from 50-60% DoD.

Tip: Choose a battery with a higher DoD for greater energy utilization and longer lifespan.

4. Efficiency and Performance

  • Round-Trip Efficiency: The percentage of energy retained during the charge-discharge cycle. Lithium-ion batteries offer efficiencies around 90-95%.
  • Charge/Discharge Rates: Determines how quickly the battery can be charged or provide energy.

Tip: Opt for a BESS with high round-trip efficiency to minimize energy loss and reduce operational costs.

5. Lifespan and Warranty

The lifespan of a battery is measured in cycles or years, depending on usage:

  • Cycle Life: Indicates how many complete charge-discharge cycles the battery can handle before its capacity degrades.
  • Warranty: Look for warranties covering at least 5-10 years or a specified number of cycles.

Tip: Consider the total cost of ownership by evaluating both the initial cost and the expected lifespan.

6. Safety Features

Safety is paramount, especially for high-capacity energy storage systems. Look for the following features:

  • Thermal Management Systems: Prevent overheating.
  • Overcharge/Discharge Protection: Safeguards battery health.
  • Short Circuit and Overcurrent Protection: Minimizes fire risks.

Tip: Ensure the BESS complies with local safety regulations and industry standards.

7. Scalability and Flexibility

Choose a system that can adapt to your growing energy needs:

  • Modular Designs: Allow easy addition of more batteries.
  • Compatibility: Ensure the BESS integrates with your existing solar panels, inverters, or other energy systems.

Tip: Scalable systems are ideal for businesses or homeowners planning future energy expansions.

8. Cost and Return on Investment (ROI)

While upfront costs can be significant, consider long-term savings:

  • Installation Costs: Factor in labor, hardware, and any permits required.
  • Operational Savings: Calculate potential reductions in energy bills and benefits from time-of-use rates.
  • Incentives and Rebates: Explore government programs that may offset initial costs.

Tip: Conduct a cost-benefit analysis to determine payback periods and long-term ROI.

9. Environmental Impact

Consider the ecological footprint of the battery system:

  • Recyclability: Opt for batteries with recyclable materials.
  • Sustainability Certifications: Look for eco-friendly product certifications.

Tip: Lithium iron phosphate (LiFePO4) batteries are known for their lower environmental impact compared to traditional chemistries.

10. Integration with Renewable Energy Systems

Ensure the BESS can seamlessly integrate with renewable sources like solar or wind:

  • Hybrid Inverter Compatibility: Supports both solar panels and grid power.
  • Energy Management Systems (EMS): Provides real-time monitoring and optimization of energy usage.

Tip: Smart integration maximizes renewable energy use, reduces reliance on the grid, and increases overall efficiency.

Conclusion

Choosing the right Battery Energy Storage System requires a comprehensive understanding of your energy needs, system capabilities, and long-term goals. By considering factors like capacity, efficiency, battery chemistry, safety, and cost, you can invest in a solution that enhances energy independence, reduces operational costs, and supports sustainable power management. As BESS technology continues to evolve, making an informed choice today ensures your energy system remains efficient and future-proof for years to come.

Tuesday, February 18, 2025

The Role of AI and IoT in Smart Energy Storage Systems

Introduction

In the era of sustainable energy solutions, Artificial Intelligence (AI) and the Internet of Things (IoT) are transforming the way we manage and utilize energy storage systems (ESS). As the demand for efficient, reliable, and intelligent energy solutions grows, AI and IoT play a crucial role in optimizing energy storage, reducing waste, and ensuring a seamless energy supply.

Understanding Smart Energy Storage Systems

A smart energy storage system integrates battery storage, renewable energy sources, and grid management technologies to efficiently store and distribute power. Traditional storage systems lacked real-time intelligence, leading to inefficiencies in energy utilization. However, with AI and IoT, energy storage systems can now predict demand, optimize supply, and enhance grid stability.

The Role of AI in Energy Storage Systems

AI-driven energy storage systems leverage machine learning algorithms, predictive analytics, and automation to improve performance. Here’s how AI enhances energy storage:

1. Predictive Analytics for Energy Demand

AI can analyze historical energy consumption patterns and forecast future energy demand, helping users and businesses optimize energy storage and usage.

2. Battery Health Monitoring and Maintenance

Machine learning models can analyze battery performance, predict failures, and recommend maintenance schedules, thereby extending battery life and reducing downtime.

3. Optimized Energy Distribution

AI algorithms ensure that stored energy is efficiently distributed based on real-time grid demand, reducing overloading and energy losses.

4. Grid Stabilization and Load Balancing

AI can adjust power supply in real-time, balancing the grid by managing fluctuations and preventing blackouts.

The Role of IoT in Energy Storage Systems

IoT enables real-time monitoring and control of energy storage systems by connecting various devices through the internet. Key contributions of IoT in ESS include:

1. Real-Time Data Collection and Monitoring

IoT sensors collect real-time energy data, including temperature, voltage, and battery charge levels, helping users make informed decisions.

2. Remote Management and Control

IoT-enabled smart energy systems allow users to remotely monitor and control energy storage through mobile apps and cloud platforms.

3. Enhanced Energy Efficiency

With IoT-enabled automation, energy storage systems can automatically switch between power sources, optimizing energy consumption.

4. Integration with Renewable Energy Sources

IoT ensures seamless integration of solar panels, wind turbines, and other renewable sources, enabling efficient energy storage and utilization.

The Synergy of AI and IoT in Smart Energy Storage

By combining AI’s predictive capabilities with IoT’s real-time data processing, smart energy storage systems achieve higher efficiency, cost savings, and reliability. Here’s how the two technologies work together:

  • AI analyzes IoT-generated data to optimize energy distribution.
  • IoT-enabled sensors provide real-time updates, allowing AI to make data-driven decisions.
  • Automated energy management reduces reliance on manual intervention and improves grid resilience.

Benefits of AI and IoT in Smart Energy Storage

  1. Reduced Energy Waste: Efficient storage and distribution prevent energy loss.
  2. Lower Costs: AI-driven optimization reduces operational costs and maintenance expenses.
  3. Sustainability: Smart energy storage promotes the use of renewable energy sources.
  4. Reliability: AI and IoT enhance system stability, preventing outages and power failures.

Conclusion

The integration of AI and IoT in smart energy storage systems is a game-changer for the energy sector. With real-time monitoring, predictive analytics, and automation, these technologies ensure optimal energy usage, grid stability, and sustainability. As the world moves towards renewable energy adoption, AI and IoT will continue to revolutionize the way we store, manage, and utilize power for a greener future.

Thursday, February 13, 2025

What is a Hybrid Solar System? A Comprehensive Guide

 Introduction

As the demand for renewable energy solutions grows, hybrid solar systems have gained significant attention due to their ability to combine the best features of both grid-tied and off-grid systems. A hybrid solar system integrates solar panels, a battery storage system, and a connection to the electrical grid, allowing users to maximize energy efficiency while ensuring backup power during outages.

Understanding Hybrid Solar Systems:

A hybrid solar system is a combination of a grid-tied solar system and an off-grid system, offering the flexibility of battery storage while remaining connected to the grid. Unlike traditional grid-tied systems that rely solely on solar energy during the day and switch to the grid at night, hybrid systems store excess energy in batteries for use when solar production is low or during power outages.

How Does a Hybrid Solar System Work?

A hybrid solar system operates through the following key steps:

Solar Power Generation – Solar panels convert sunlight into direct current (DC) electricity.

Power Conversion – A hybrid inverter converts the DC electricity into alternating current (AC) for home appliances.

Battery Storage – Excess energy generated during the day is stored in a battery bank for later use.

Grid Connectivity – If the battery is depleted, the system seamlessly switches to grid power to meet energy demands.

Power Backup – During a power outage, the system automatically supplies stored energy from the battery to keep essential appliances running.

Components of a Hybrid Solar System:

A typical hybrid solar system consists of:

Solar Panels – Capture and convert sunlight into electricity.

Hybrid Inverter – Manages power conversion, battery charging, and grid connectivity.

Battery Storage – Stores excess solar energy for later use.

Charge Controller – Regulates voltage and prevents overcharging of batteries.

Grid Connection – Provides backup power when solar and battery power are insufficient.

Benefits of a Hybrid Solar System

1. Energy Independence: With battery storage, users can reduce dependence on the grid, ensuring access to power even during outages.

2. Lower Electricity Bills: By maximizing self-consumption of solar energy and reducing reliance on grid power, hybrid systems help lower electricity costs.

3. Backup Power Supply: Unlike grid-tied systems, hybrid solar systems provide uninterrupted power supply during blackouts.

4. Optimized Energy Usage: A smart hybrid inverter efficiently manages energy distribution, ensuring that power is used optimally between solar, battery, and the grid.

5. Grid Stability and Net Metering: Excess energy can be exported to the grid, enabling homeowners to earn credits through net metering programs.

How to Choose the Right Hybrid Solar System

When selecting a hybrid solar system, consider the following factors:

Energy Consumption – Assess your household's daily energy needs.

Battery Capacity – Choose a battery with sufficient storage to meet your backup power requirements.

Inverter Efficiency – Opt for a high-efficiency hybrid inverter for better performance.

Scalability – Ensure the system allows for battery expansion in the future.

Cost and ROI – Compare initial investment costs with long-term savings on electricity bills.

Conclusion

A hybrid solar system offers the best of both worlds by combining solar energy with battery storage and grid connectivity. It enhances energy security, lowers electricity bills, and ensures backup power when needed. As solar technology advances, hybrid solar systems will continue to play a crucial role in achieving sustainable and cost-effective energy solutions for homes and businesses. Investing in a hybrid solar system is a smart choice for those looking to embrace renewable energy while maintaining flexibility and reliability in their power supply.


Tuesday, February 11, 2025

How to Extend the Life of Your Solar Inverter in India? Expert Tips

Introduction

A solar inverter is one of the most critical components of a solar power system. It converts the direct current (DC) generated by solar panels into alternating current (AC) for home and commercial use. In India, where extreme weather conditions and power fluctuations are common, ensuring the longevity of your solar inverter is essential to maximize your investment. This guide provides expert tips on maintaining and extending the lifespan of your solar inverter.

1. Choose the Right Solar Inverter

Investing in a high-quality solar inverter from a reputed brand is the first step in ensuring durability. Consider the following factors while selecting an inverter:

MPPT vs. PWM: MPPT inverters are more efficient and last longer in Indian weather conditions.

Capacity Matching: Choose an inverter that matches your solar panel and battery capacity.

Brand Reputation & Warranty: Opt for inverters with a good warranty period and reliable after-sales service.

2. Ensure Proper Installation

Improper installation can reduce the efficiency and lifespan of your inverter. Follow these installation best practices:

Location Matters: Install the inverter in a well-ventilated, shaded area away from direct sunlight and moisture.

Avoid Overloading: Ensure the inverter capacity is not exceeded by the solar panel and battery combination.

Use Quality Wiring: Low-quality cables and loose connections can lead to overheating and premature failure.

3. Regular Cleaning and Maintenance

Dirt, dust, and debris can accumulate on the inverter, leading to overheating and reduced efficiency. Maintain your inverter by:

Cleaning it with a dry cloth periodically.

Checking for dust accumulation in the vents and cooling fans.

Ensuring there are no obstructions around the inverter.

4. Monitor and Update Software

Modern solar inverters come with remote monitoring and firmware update options. To enhance performance:

Regularly check the inverter's digital display for error messages or unusual readings.

Update the inverter's firmware when manufacturers release improvements or bug fixes.

Use smart monitoring apps to track energy efficiency and detect potential faults.

5. Protect Against Voltage Fluctuations

Power surges and grid fluctuations are common in India. Protect your inverter by:

Installing a surge protector or voltage stabilizer to shield against sudden power spikes.

Using an uninterruptible power supply (UPS) to provide backup power during grid outages.

Ensuring proper earthing and grounding of the system to prevent electrical damage.

6. Maintain Battery Health (For Hybrid & Off-Grid Systems)

If your inverter is connected to a battery storage system, battery maintenance is equally important:

Use high-quality lithium-ion or tubular batteries for longer life.

Check battery water levels (for lead-acid batteries) and refill with distilled water as needed.

Avoid deep discharges and overcharging to prevent battery degradation.

7. Conduct Periodic Inspections by Professionals

Even if your inverter appears to be working fine, scheduling annual inspections by a certified technician can:

Identify and fix minor issues before they escalate.

Ensure the wiring, fans, and internal components are functioning optimally.

Improve inverter efficiency and prevent unexpected failures.

8. Ensure Proper Ventilation and Cooling

Overheating is a major cause of inverter failure. To prevent this:

Keep the inverter in a cool, shaded, and ventilated area.

Ensure there is enough space around the inverter for proper airflow.

Use external cooling fans or heat sinks if overheating persists.

9. Avoid Frequent Switching On & Off

Frequent power cycling can put stress on inverter components. To avoid this:

Keep the inverter running consistently and only switch it off when necessary.

Use auto-restart features to allow the inverter to restart safely after a power cut.

10. Understand Manufacturer Guidelines

Each inverter brand has specific operating and maintenance instructions. To maximize lifespan:

Read and follow the user manual for proper handling.

Register the product for extended warranty benefits.

Use only manufacturer-approved spare parts for repairs and replacements.

Conclusion

Extending the life of your best solar inverter in India requires a combination of proper installation, routine maintenance, and preventive measures. By following these expert tips, you can ensure your inverter runs efficiently for years, reducing downtime and maximizing your solar investment. Regular inspections, monitoring, and protective measures will help keep your system operational in India’s diverse climatic conditions, ultimately leading to better energy savings and system longevity.

Why Energy Storage Systems Are Critical for a Sustainable Future

As the world accelerates its shift toward renewable energy, one challenge remains at the heart of this transformation — how to store energy ...