How it Works and Why it Matters
As the UK accelerates towards a decarbonised energy system, solar photovoltaic (PV) deployment continues to expand across domestic, commercial and utility scale settings. Yet solar’s inherent intermittency presents a structural challenge: generation peaks do not always align with consumption peaks. Solar battery storage has emerged as a critical enabling technology, providing flexibility, resilience and cost optimisation within both domestic and national energy systems.
This article explains how solar battery storage works and details why its role is becoming essential within the evolving UK grid landscape.
How Solar Battery Storage Works
Core Components
A standard solar PV and battery storage system comprises:
- Solar PV array: generates direct current (DC) electricity during daylight
- Hybrid or AC-coupled inverter: converts DC to alternating current (AC) for household use and manages charging and discharging of the battery
- Battery storage unit: most commonly lithium-ion, chosen for high energy density, long cycle life and strong round trip efficiency
- Battery management system: ensures safety, monitors temperature and voltage and optimises performance
- Smart controls & monitoring platforms: enables real time optimisation, time of use scheduling and integration with grid services
The Operational Cycle
- Generation: solar PV produces electricity when sunlight is available.
- Self-consumption priority: the system first supplies onsite loads, reducing grid import.
- Battery charging: excess solar is diverted to the battery. During periods of low demand and high generation, storage becomes the primary sink.
- Battery discharging: stored energy is released when demand exceeds solar generation, typically in the evenings or early mornings.
- Grid interaction: modern systems can import cheap off peak electricity for charging or export stored energy during high price periods.
Performance Metrics
- Round trip efficiency: typically 85-95%, measures total losses in charge-discharge cycles.
- Depth of discharge (DoD): determines usable capacity
- Cycle life: number of cycles before capacity degradation (often 6,000-10,000 cycles).
- Energy capacity (kWh) and power rating (kW): define how long and how fast a battery can deliver energy.
Why Solar Battery Storage Matters in the UK Grid Landscape
Grid Decarbonisation and Renewables Integration
The UK grid is undergoing rapid structural change. Renewable energy – solar, wind, hydro and biomass – has surpassed 40% annually, leading to more variability in supply. Batteries provide reliable renewable output, smoothing fluctuations and stabilising availability of green energy. Battery storage offers backup power for homes and critical infrastructure, improving resilience for homeowners during grid failures.
Supporting Grid Stability
The UK’s National Grid relies increasingly on distributed flexibility resources. Solar battery systems contribute by reducing the demand on the grid during peak periods. Battery storage allows households to use their own stored electricity in the evenings instead of drawing from the grid and putting additional pressure on an already struggling grid.
Strategic Importance for the Future UK Energy System
It is now believed that battery storage is central to achieving Net Zero goals by 2050. The rise in EV charging and heat pumps is increasing peak loads, battery storage mitigates some of the grid stress, making it more resilient.
Conclusion
Battery storage is no longer a peripheral technology; it is a foundational component of the UK’s modernised, flexible and resilient energy system. For households, businesses and energy suppliers, it provides economic, operational and environmental benefits while enabling deeper integration of renewable energy across the grid, resulting in a cleaner, greener energy mix for the UK’s power.
If you’re looking to upgrade your solar PV system with battery storage or are just starting your solar journey and want more information, contact SolarTherm UK today, for a free, no obligation quote and design, tailored to your property, usage and future energy needs. No hard sell, just honest, expert advice.
Your home. Your energy. Your future.
