Power outages are unpredictable, but your backup power solution shouldn’t be. Whether you’re preparing for frequent outages or just want peace of mind, the two main options for whole-home backup are battery backup systems and standby generators.
Both have their advantages and trade-offs, and the right choice depends on your needs, budget, and priorities.
The Basics: How They Work
Home Battery Backup
Modern home battery systems, like the FranklinWH aPower 2 and Enphase 5P, store electricity from either the grid or solar panels. During an outage, these batteries automatically provide power to your home, allowing you to keep essential appliances running.
If paired with solar, batteries can recharge during the day, making them a sustainable and long-term solution. Unlike generators, which take up to a minute to start up, batteries switch over instantly, often so quickly that you won’t even notice the lights flickering.
Standby Generators
Standby generators, on the other hand, use fossil fuels (natural gas, propane, or diesel) to generate power. These units automatically turn on when the power goes out and can run as long as they have fuel. Generators are typically cheaper upfront than battery systems but require fuel refills, ongoing maintenance, and produce noise and emissions.
Generators can produce a lot of power, and are capable of running more energy-intensive appliances (think HVAC and heat-pump) for longer periods of time. Generators have been commercially available for a long time, so finding someone to service a generator is typically very easy.
Comparing Battery Backup and Standby Generators
Cost
- Batteries: Higher upfront cost ($15,000-$30,000+ before incentives) but can save money over time if you live in an area with time-of-use rates (ToU). Batteries are also eligible for a 30% federal tax credit, which can significantly reduce the initial investment.
- Generators: Lower initial cost ($7,000-$15,000) but require ongoing expenses for fuel and maintenance.
Fuel and Operating Costs
- Batteries: Charge from the grid or solar, with zero ongoing fuel costs.
- Generators: Need constant fuel supply, which can be expensive and challenging during long outages.
Installation & Maintenance
- Batteries: Typically installed by a solar contractor, and can be mounted on a wall or floor. Minimal maintenance required.
- Generators: Installed on a concrete slab by electricians, HVAC professional, or generator companies, and connected to a fuel source. Requires regular maintenance (oil changes, fuel stabilizers, etc.).
Performance and Reliability
- Batteries: Provide silent, instant power. Can be scaled up for more capacity. Batteries are excellent for supplying lower power for extended periods, making them a great choice for keeping essential loads running. While they won’t run a heat pump for five days during a snowstorm, they can keep your critical appliances running for weeks when paired with solar, as long as you monitor charge levels and use power wisely. If you want to run your entire house with no-changes to usage, then batteries are better for short outages (a day or less)
- Standby Generators: Once power goes out, standby generators will crank up, and return power after warming up for ~30 seconds. Run as long as fuel is available. Better suited for extended power outages if you plan on using lots of energy during that time.
Warranties
- Batteries: Solar batteries like Enphase & FranklinWH have warranties up to 15-years, with most brands offering a warranty for at least 10 years.
- Standby Generators: Home generators typically have a 5-year warranty, but some companies like Generac may offer warranty extensions.
Environmental Impact
- Batteries: Zero emissions during operation, making them the greener choice.
- Generators: Emit carbon monoxide and pollutants. Some areas have regulations on generator use due to noise and emissions.
Which One Is Right for You?
We support clean energy, but the right option depends on your specific needs and budget. We also think it’s important to be realistic about what your goals are. If you intend to run very energy intensive loads for extended periods of time, it may be very costly to do that with battery-backup– Alternatively, if you want to run essentials and have solar panels, then battery backup is a great option.
- Choose a Battery If: You want a clean, low-maintenance solution that can integrate with solar, save money on electricity bills, and avoid fuel costs.
- Choose a Standby Generator If: You need a backup solution with lower upfront costs, and your priority is running heavy loads like heat-pumps for long periods of time.
The Future of Home Backup Power
Battery technology has improved significantly, with models like the Enphase 5P and FranklinWH aPower 2 offering higher storage capacity, better efficiency, and improved integration with solar. As grid reliability becomes more uncertain, more homeowners are choosing batteries over traditional generators for long-term energy security.
Want to explore a battery backup system for your home? Virtue Solar can help you find the right solution. Contact us for a free consultation and see how you can power your home efficiently and sustainably!
