Comparing Batteries to Generators

If you are interested in back-up power for your home, you have two practical options: generators or batteries. Generators are the more traditional option and run on natural gas, typically propane or diesel. They are hooked up to the home’s main service panel with a transfer switch. This switch allows for proper electrical distribution and prevents backfeeding (stops any power flowing back to the main grid’s utility lines). Batteries are the newer technology and are composed of lithium, typical lithium-ion or lithium iron phosphate, though other options are available. These batteries are classically paired with solar panels, which recharge the batteries during the day. Comparing the two involves looking at multipe factors, which are explored below.

Ease-of-Use

Batteries are the clear choice when looking at ease. Batteries kick in automatically when the grid goes down and do not require maintenance. While some generators come with automatic transfer switches, the re-fueling of the generator requires constant upkeep. A standard generator has a 10-20 gallon tank which requires re-filling when it runs out or the generator will not run. This means that in addition of the generator, extra steps will be required to keep fuel on standby.  The gas will need to be kept in a safe, dry location and has a shelf life. 

Conversely, the batteries are fueled by the sun via the solar panels. During the day, the solar will first power the active electrical demand in the house and then any excess power will be stored in the batteries. With a large enough solar system, batteries can theoretically last indefinitely, as long as they can be recharged daily and consumption is limited to essentials only. Batteries typically keep their charge at 95-100%, discharging and recharging slightly to ensure they are ready. 

Lastly, generators are noisy and do produce a sound, where batteries are silent. If considering a generator, make sure you (and your neighbors!) are comfortable with the noise required.

Cost

This factor depends on your requirements and specific use case. There is a lot of misinformation about both generators and batteries, especially when it comes to stating how much they can power. A whole home generator from a reputable company will cost between $10,000 and $20,000 at a minimum, before the cost of installation. Anything cheaper will most likely be underpowered or not have enough capacity to power your house. There are many advertisements for portable generators that claim to power your home, but be wary of these and make sure to review the specifications and warranties. Installation can cost anywhere from $2,000 – $5,000 and we always recommend finding a licensed electrician.

Batteries tend to have a higher upfront cost, but much of this can be offset by federal and state incentives. For example, a 30 kWh battery system would cost around $33,714, but is eligible for the Federal Tax Credit and Maryland Battery Tax Credit. A cost breakdown would look similar to this:

Next, consider the secondary costs. Generators are the more mechanically complicated machines, with a spinning motor and many moving parts. This will lead to more maintenance costs. Batteries have no moving parts and typically do not have any maintenace costs. Furthermore, any costs associated with batteries would most likely be covered by the batteries product or workmanship warranties (make sure the batteries are reputable, as well as the company installing them!).

Finally, another cost that needs to be considered is the gas required to run the generator. With the cost of gas rising, this cost and the future cost of gas needs to be factored in.

Environmental Impact

Solar batteries are superior to generators when considering their environmental impact. Firstly, solar batteries harness energy from the sun, a renewable power source, whereas generators rely on fossil fuels, which emit greenhouse gases and contribute to air pollution. Additionally, solar batteries produce electricity without producing any direct emissions, reducing carbon footprint and mitigating environmental damage. Unlike generators, which require ongoing fuel consumption and emit exhaust during operation, batteries have no output besides slight heat, further minimizing environmental disruption.

Conclusion

When it comes to backup power for your home, generators and batteries offer distinct options, each with its own set of considerations. Overall, the choice between generators and batteries depends on individual preferences, usage needs, and environmental considerations. Our two cents? We are a Generac certified installer, but made the switch to batteries a few years ago due to the constant service calls required. 

If you are interested in learning more about batteries for your home, please reach out to us to build your custom estimate!