Solar panels are transformative—but solar plus battery storage is revolutionary. Adding batteries to your solar system enables backup power during outages, maximizes self-consumption of clean energy, and can significantly improve your financial returns. As battery technology advances and prices decline, more homeowners are discovering the compelling benefits of this powerful combination.
Why Add Batteries to Solar?
Solar panels alone have a limitation: they only produce electricity when the sun shines. Batteries solve this by storing excess solar production for use anytime—evening, night, or during grid outages.
The Key Benefits
- Backup power: Keep essential circuits running during grid outages
- Energy independence: Use your own solar power around the clock
- Time-of-use savings: Avoid expensive peak electricity rates
- Maximize solar investment: Use more of what you produce
- Grid services: Participate in utility programs for additional income
How Solar Battery Systems Work
Understanding the system architecture helps you make informed decisions:
Basic System Components
- Solar panels: Generate DC electricity from sunlight
- Inverter: Converts DC to AC for home use
- Battery: Stores excess energy in chemical form
- Battery management system: Controls charging/discharging
- Smart energy controller: Optimizes energy flow between solar, battery, grid, and home
Energy Flow Throughout the Day
Morning (6-9 AM):
- Solar production begins, ramping up
- Home draws power from solar first
- Battery may supplement during high-use breakfast time
Midday (9 AM - 4 PM):
- Peak solar production
- Home needs are met by solar
- Excess charges battery
- If battery full, excess goes to grid
Evening (4-10 PM):
- Solar production declines
- Battery powers home instead of grid
- Avoids high time-of-use rates
Night (10 PM - 6 AM):
- Battery continues powering home if capacity remains
- Grid supplements as needed
- Off-peak rates minimize grid costs
Backup Power: Protection When You Need It
The most compelling reason many homeowners add batteries is backup power during outages.
What Batteries Can Power
A typical home battery (10-15 kWh capacity) can power essential loads:
- Refrigerator: 1-2 kWh/day
- Lights (LED): 0.5-1 kWh/day
- Phone/device charging: 0.1-0.2 kWh/day
- Internet/WiFi: 0.2-0.5 kWh/day
- Medical equipment: Varies
A single battery can typically power essentials for 8-12 hours. During multi-day outages, solar recharges the battery each day for extended backup.
Whole-Home vs. Essential Loads
Systems can be configured two ways:
Essential loads backup: Specific circuits (refrigerator, lights, outlets) backed up. More economical, longer runtime.
Whole-home backup: Entire electrical panel backed up. Requires larger battery capacity and potentially upgraded inverter.
Automatic Transfer
Modern battery systems detect outages instantly and switch to backup power within milliseconds—you may not even notice the grid went down.
Financial Benefits of Battery Storage
Beyond backup power, batteries can significantly improve solar economics:
Time-of-Use Arbitrage
Many utilities charge higher rates during peak demand periods (typically 4-9 PM). Batteries store cheap/free solar power and deploy it during expensive peak hours.
Example savings:
- Peak rate: 35¢/kWh (4-9 PM)
- Off-peak rate: 12¢/kWh (all other times)
- Daily peak usage: 20 kWh
- Battery capacity: 15 kWh
- Daily savings: 15 kWh × (35¢ - 12¢) = $3.45
- Annual savings: $1,260
Demand Charge Reduction (Commercial)
Commercial electric bills include demand charges based on peak power draw. Batteries can "peak shave" by supplementing grid power during high-demand periods, significantly reducing these charges.
Virtual Power Plant Programs
Some utilities offer payments for battery owners who allow limited grid support during emergencies. Programs like Tesla's Virtual Power Plant pay $2/kWh for battery dispatch during grid stress events.
Increased Self-Consumption
Without batteries, solar owners typically use only 30-40% of their production directly. Batteries can increase self-consumption to 70-80% or higher, maximizing the value of every kWh produced.
Popular Home Battery Options
Several quality battery options are available:
Tesla Powerwall
- Capacity: 13.5 kWh
- Power output: 5 kW continuous, 7 kW peak
- Warranty: 10 years
- Notable feature: Sleek design, excellent app integration
Enphase IQ Battery
- Capacity: 3.4 kWh or 10.1 kWh modules
- Power output: Scalable based on modules
- Warranty: 10 years
- Notable feature: Microinverter integration, modular scaling
LG RESU
- Capacity: 9.6-16 kWh options
- Power output: 5-7 kW
- Warranty: 10 years
- Notable feature: Proven reliability, competitive pricing
Franklin WholePower
- Capacity: 13.6 kWh
- Power output: 5 kW continuous
- Warranty: 12 years
- Notable feature: Designed for whole-home backup
Battery System Costs and Incentives
Typical Costs
Home battery systems typically cost $10,000-$15,000 per battery including installation. Whole-home backup systems with multiple batteries may cost $25,000-$40,000.
Federal Tax Credit
Batteries charged primarily from solar qualify for the 30% federal Investment Tax Credit. A $15,000 battery system would receive a $4,500 tax credit, reducing net cost to $10,500.
State and Utility Incentives
Additional incentives exist in many areas:
- California SGIP: Significant rebates for battery storage
- Maryland: State tax credit for batteries
- Massachusetts: SMART program incentives
- Various utility rebates nationwide
Is Battery Storage Right for You?
Consider batteries if:
- You experience frequent power outages
- You're on time-of-use electricity rates
- You want maximum energy independence
- Your net metering credits are valued below retail rate
- You want backup for medical equipment or essential business operations
- You have electric vehicle charging needs
Batteries may be less necessary if:
- Your area has reliable grid power
- You have full retail net metering
- Your budget is constrained (solar alone still provides excellent returns)
- You're primarily focused on environmental impact (solar alone achieves this)
The Future of Home Batteries
Battery technology continues advancing rapidly:
- Falling costs: Battery prices have dropped 90% since 2010 and continue declining
- Increasing capacity: More storage in smaller packages
- Longer warranties: Manufacturers now offer 10-15 year warranties
- Better integration: Seamless software connecting solar, batteries, EV chargers, and smart home devices
Get Started with Solar and Storage
Whether you're installing new solar or adding batteries to an existing system, Synergic can help you design the optimal solution for your needs and budget. Check out our residential and commercial battery storage options.
Request your free quote or contact us today to explore how solar plus battery storage can transform your energy future. True energy independence is closer than you think!