Winter Storm Fern left more than 230,000 Tennessee households without power this January. While many families experienced extended outages, customers with solar and battery storage had a significant advantage: the ability to operate independently from the grid.
That said, having a battery system does not mean unlimited power. During an outage, your home transitions into what is known as a “microgrid.” In simple terms, you become your own utility company. How long your system performs — and how comfortably — depends entirely on how you manage energy consumption.
We want to take a moment to outline what that means in practical terms.
First Things First: Confirm You’re in Backup Mode
When the grid goes down, your battery system should automatically isolate from the utility and begin powering your home.
It’s crucial that you have your smartphone and/or tablet set up to receive alerts from your battery system. You can do this by going to your notifications settings, clicking the app, and turning notifications on.
We’ve had several clients not realize that the utility power was off. They continued to use electricity normally not realizing that they could have conserved their precious battery energy and unintentionally ran out of battery power. The quickest way to confirm your system’s status is through your monitoring app.
Open your battery's monitoring app and confirm:
- Grid status shows outage
- System indicates Backup or Island Mode
- Battery state of charge is visible
If the system does not transition properly, first contact the manufacturer’s support line. They have direct monitoring access and can quickly determine whether the system is functioning correctly or if service is required. Our team does not have as much access to your system so we will not be able to diagnose the problem as quickly as the manufacturer would.
Most systems perform exactly as designed. Issues during outages are rarely system failures — they are almost always load-related.
The Reality of Load Management
The biggest misconception about battery storage is capacity. A battery can support essential loads very effectively, but large electric appliances can drain it rapidly or exceed its output limits. Electric heat strips, dryers, ovens, EV chargers, and electric water heaters are the most common culprits. These devices can pull thousands of watts instantly. If several operate at the same time, they can overwhelm the system.
During an outage:
- Prioritize refrigeration, lighting, internet, and medical equipment.
- Avoid running multiple large appliances simultaneously.
- Stagger usage whenever possible.
- Conserve early rather than waiting until the battery is nearly depleted.
The customers who performed best during Winter Storm Fern were those who actively monitored consumption and adjusted accordingly.
For Customers with Tesla Powerwalls
Homes equipped with Tesla Powerwall automatically separate from the utility and form a self-powered microgrid when the grid goes down. If severe weather is forecasted, Storm Watch may automatically charge the batteries to 100% in preparation for potential outages.
During an outage, the Tesla app becomes your primary tool. It provides real-time visibility into home consumption, solar production (if installed), battery state of charge, and grid status. Monitoring usage in the app is critical — it allows you to see load spikes as they occur and adjust accordingly.
As a general rule, a single Powerwall supports approximately 5 kW of continuous output. Multiple Powerwalls increase available capacity, but high-demand appliances such as electric heat strips, dryers, ovens, and EV chargers can still exceed system limits or drain stored energy quickly. Managing those loads is essential to maintaining stability during extended outages.
If your solar array is clear of snow or fallen trees and receiving sunlight, it will recharge the battery during daylight hours. However, snow-covered panels will produce little to no energy, meaning the home will operate strictly on stored battery capacity until production resumes.
If you experience unexpected shutdowns, persistent alerts, or behavior that does not appear normal, contact Tesla Energy Support first. Tesla can remotely access system data and determine whether the issue is related to load demand, system configuration, or equipment performance.
Those with Tesla Battery Issues:
- First, call Tesla Energy Support at +1 (877) 798-3752 – Select option 4, then option 2. Their Support Portal is tesla.com/support/energy. They have direct access and can help fix any issues faster plus they have 24 hour support.
- Next, if Tesla determines that on-site service is required, contact our team by submitting a service ticket online here: lightwavesolar.com/customers/submit-a-service-request.
- Lastly, if your issue is urgent or involves system downtime, please contact us directly at +1 (615) 641-4050 for immediate assistance.
For Customers with FranklinWH Battery Systems
Homes equipped with systems from FranklinWH automatically isolate from the utility during a grid outage and begin powering the designated backup circuits. The transition is seamless, but performance during extended outages still depends on how energy is managed inside the home.
The Franklin monitoring app provides real-time visibility into battery state of charge, household consumption, and backup status. Some systems include advanced load management features, but no system can overcome sustained high-demand usage. Runtime ultimately comes down to disciplined consumption.
During an outage, monitor your state of charge closely. If battery levels begin to drop rapidly, reduce load immediately. Stagger appliance use, turn off non-essential breakers, and avoid running multiple heavy-draw appliances at the same time. These simple adjustments can substantially extend available runtime.
If you notice unexpected shutdowns, persistent alerts, or behavior that appears abnormal, contact FranklinWH support first. Their team has direct remote access to system monitoring and can determine whether the issue is related to load demand, configuration, or equipment performance.
Take These Steps:
- First, call FranklinWH Support at +1 (888) 851-3188. Their support portal is franklinwh.com/support/contact. They have direct access and can help fix any issues faster plus they have 24-hour support.
- Next, if FranklinWH determines that on-site service is required, contact our team by submitting a service ticket online here: lightwavesolar.com/customers/submit-a-service-request.
- Lastly, if your issue is urgent or involves system downtime, please contact us directly at +1 (615) 641-4050 for immediate assistance.
For Battery-Only Systems (No Solar)
For homes equipped with battery backup that charges from the grid but does not include solar, the operating reality during an outage is straightforward.
When utility power fails, the battery begins supplying your backed-up circuits immediately. However, without solar production, there is no way to replenish stored energy during the outage. Once the battery reaches its minimum state of charge, power to those circuits will remain off until the utility restores service.
Because there is no daytime recharge, conservation must begin at the start of the outage — not when the battery is nearly depleted. Reduce usage to essential loads only. Turning off non-critical breakers early can significantly extend runtime and prevent unnecessary shutdowns.
Monitor your battery’s state of charge closely through the manufacturer’s app. If you experience unexpected shutdowns, fault notifications, or behavior that appears abnormal, contact your battery manufacturer’s support team first. They have remote access to system data and can confirm whether the system is operating as designed or if a configuration or equipment issue exists.
If the manufacturer determines that on-site service is required, contact our team and we will coordinate dispatch and corrective action.
Snow, Solar Production & Winter Performance
Winter conditions introduce another variable: panel coverage. Snow accumulation can significantly reduce or eliminate solar production. Ground-mounted systems are easier to clear safely. Roof-mounted systems should never be accessed during icy conditions.
If the panels are covered, your system operates as battery-only until production resumes.
When to Contact Us
If your system does not transition into backup mode, displays persistent faults, or shuts down unexpectedly, reach out. Our team can help determine whether the issue is equipment-related or load-related.
Escalation Path During an Outage
- Check your monitoring app.
- Reduce large loads.
- Contact manufacturer support if faults or irregularities occur.
- Contact LightWave Solar if manufacturer recommends field service.
This approach ensures:
- Faster diagnosis
- Reduced unnecessary service calls
- Correct identification of load vs. equipment issues
Call: +1 (615) 641-4050
Email:
Online Service Request: lightwavesolar.com/customers/submit-a-service-request
Solar and battery storage provide meaningful resilience during severe weather. Winter Storm Fern proved that. But performance during extended outages comes down to informed usage.
Monitor your system. Prioritize essential loads. Conserve energy when the grid is down. This approach turns backup power from a short-term convenience into long-term reliability.
