Solar Batteries and Energy Storage: The Complete Topic Guide

Start here. This is the map to all 32 of our battery and storage guides. Before choosing a product, decide what the battery is for. Backup during outages and daily bill arbitrage lead to different sizes and different chemistries. Our battery sizing calculator works out the capacity you actually need from your own loads.

On this page

• Choosing a battery
• Which guide fits you
• Chemistry and technology
• Sizing, cost and installation
• Backup power
• Safety, warranty and upkeep
• Business and grid scale
• FAQ

Choosing a battery

• Best home storage systems — the main options compared for a house
• Powerwall alternatives — five competing home batteries, honestly compared
• Generac PWRcell compared — modular DC-coupled storage versus the fixed-capacity rivals
• Residential battery options — the current product landscape
• Home battery storage — the category explained from scratch
• Storage system comparison — specifications side by side
• Types of battery storage — the families and what separates them

Which guide fits you

Chemistry and technology

Chemistry decides cycle life, thermal behaviour and how much of the nameplate capacity you can actually use.

• Battery chemistry — LFP, NMC, lead-acid and sodium-ion compared
• Sodium-ion storage — the emerging alternative to lithium, and its trade-offs
• Flow batteries — long-duration storage that decouples power from capacity
• Thermal storage — storing heat or cold instead of electricity
• Degradation over time — how capacity fades and what accelerates it
• Maximising battery life — the settings and habits that matter

Sizing, cost and installation

• Sizing calculator — a working tool that sizes against your actual backup loads
• Storage for solar panels — AC versus DC coupling, and retrofit implications
• Installation cost — what the install itself adds
• Battery storage cost — current pricing and what drives it
• Storage ROI for homes — when a battery pays back and when it buys resilience

Backup power

• Backup during outages — what a battery can and cannot keep running
• Storage vs generator — the honest comparison, decided by outage duration
• Benefits of home storage — the full list, including the ones rarely mentioned
• Off-grid battery guide — sizing, chemistry and safety with no grid to fall back on

Safety, warranty and upkeep

• Fire safety — the real risks and how they are engineered out
• System safety — installation standards and siting
• Storage warranties — the throughput limit you may hit before the years run out
• Maintenance — the short list of things that actually need doing
• Round-trip efficiency — the energy you lose on the way in and out

Business and grid scale

• Storage for business — commercial demand charges and resilience
• Grid-scale storage — what utilities are building and why
• Clean energy storage — the role of storage in a renewable grid
• The future of storage — where the technology is heading
• Solar battery storage systems — seven approaches in current use

FAQ

How big a battery do I need?
Size it against the loads you must run during an outage and the hours you need them, not against total daily household use.

Is LFP better than NMC?
LFP trades some energy density for longer cycle life and better thermal behaviour. For a stationary home battery that trade usually favours LFP.

Will a battery pay for itself?
It depends on your tariff. A wide peak-to-off-peak spread builds real value. On a flat rate, a battery mostly buys resilience.

Can I add a battery to existing solar?
Yes. AC-coupled batteries are usually the cheaper retrofit because they do not require replacing your inverter.

How long do home batteries last?
Typically ten years or more, limited by both time and total energy throughput. Check which limit you would reach first.

Does solar keep working in an outage without a battery?
No. A standard grid-tied array shuts down when the grid does, for line-worker safety.

More

Browse the full Energy Storage Systems category, or see the inverter guide for the hybrid inverter side of the decision.

Storage performance research is published by the National Renewable Energy Laboratory and the U.S. Department of Energy.