If you live in an area prone to power outages — like the North Carolina coast during the Atlantic hurricane season — or need peace of mind to power your home or business’s appliances and equipment, you need a backup plan. Two common options are backup generators and stored energy.
Generators vary in size, ranging from small, portable units to whole-home systems. Though they’re known for noisy operation and fuel emissions, they’re rugged and reliable in an emergency, especially if you’re using one for critical items like medical equipment or home well pumps.
Energy storage technologies are different — instead of running on fuel like a generator, these systems capture electricity and store it to release later. Energy storage systems are available in different size options, and some applications may require multiple energy storage units to power everything at once.
Residential Backup Generators
One of the most common generator types for residential and business power backup is the fuel-powered standby generator, also called the whole-house generator. These units connect to your existing electrical panel and trigger on automatically if there’s an electrical outage.
Generators typically operate on diesel, natural gas or liquid propane for fuel. Depending on your property and generator type, you might be able to connect it to a natural gas line to eliminate the need for fuel storage.
Battery Energy Storage Systems
Battery energy storage systems (BESS) store energy from solar or wind power so homes and businesses can later discharge and use that power as needed. The Solar Energy Industries Association estimates that, by 2025, over 29% of all new solar power systems will include or be compatible with battery storage options — that’s a big increase compared to 2021 when less than 11% of solar power users considered or required battery storage.
Most battery storage systems are technologically advanced, relying on built-in computer mechanics and intelligent algorithms to determine what to do with the stored energy — continue storing it in the battery reserves, release it to the property’s power grid or pause energy storage until more is needed. Energy batteries have a lot in common with rechargeable remote control or video game controller batteries, and most manufacturers use lithium-ion because it provides a compact design that holds charge for a long time.
A BESS works with the home’s electrical grid, rooftop solar panels or a combination of the two. Many homeowners pair BESS with solar energy systems, called solar-plus storage, because it:
- Lets them store and generate energy, even when the sun isn’t shining or the electrical grid loses power.
- Maximizes the usage of green energy from a renewable source.
- Provides around-the-clock power, even during peak hours when solar energy systems may not be enough.
- Eliminates the need to connect to a natural gas line or buy, refill or store fuel for generators.
- Adds an extra layer of security and peace of mind, especially for homeowners living in areas prone to power outages or extreme weather conditions.
- Is a cost-effective energy storage solution that lasts a long time.
- Lets users track energy reserves and consumption in real time to make better energy decisions.
Some homes require multiple batteries to store enough energy to power the whole house — a power storage solution professional can help determine how many your space needs.
The Tesla Powerwall
Tesla dominated the residential energy storage system market in 2020, and a large part of that success came from the Tesla Powerwall. Tesla Powerwall systems, a type of battery energy storage compatible with solar inverters, is equally popular among retailers and installers as it is with customers eager to trust the Tesla brand name.
The Tesla Powerwall 2.0 — a more advanced version of the freshman product with higher energy capacities and an integrated inverter unit — saw an increase of 100,000 installations between January and May of 2021.
How It Works
The Tesla Powerwall operates as a standalone unit or alongside compatible solar inverters. Regardless of its application, you can use the battery storage system and monitoring app to store power when energy rates are low and discharge them when rates are higher to save money on your monthly utility costs.
The Powerwall needs a Wi-Fi or Ethernet internet connection or strong cellular connection to stay functional, receive regular usability and security updates and communicate with the Powerwall app to monitor energy levels. Your connection should be ongoing and stable — while the Powerwall can continue operating without an internet or cellular connection, it can only do so using the most recent settings and doesn’t work as a long-term solution.
Once the Powerwall unit is connected to your home, the built-in backup gateway works to detect when your power goes out and quickly disconnects the storage unit from the electrical grid to repower your house. While traditional solar and electric homes without battery storage are often left to the mercy of grid outages, the Powerwall can reinstate full, reliable power in under a second.
You may need multiple Powerwall units, depending on your property size and solar performance. Tesla recommends at least one Powerwall for each 7.6kW AC of solar in the backup circuit.
The Powerwall App
One thing that offers a unique advantage for Tesla Powerwalls versus backup generators is the Powerwall app, which gives homeowners better insight and more control over their power supply. The Powerwall App lets users:
- Monitor solar energy usage and levels in real time.
- Optimize the Powerwall system to rely less on the electric grid.
- Get insights and updates into possible electric outages that may require using your Powerwall.
- Control the Powerwall system wirelessly, from anywhere, including remote access and instant system alerts.
- Customize the system’s charge and discharge schedule to pair and fluctuate with the home’s existing utilities’ time-of-use (TOU) rates.
Tesla Powerwall vs. Backup Generator — Which Is Right for You?
Battery energy storage systems like the Tesla Powerwall and Tesla Powerwall 2.0 offer significant advantages over residential generators — but that doesn’t make them the right fit for everyone. While some homes thrive on battery storage or a backup generator, many people find success with a combination of energy sources and methods.
Consider these key areas when choosing the best power solution for your home:
The electricity grid is a necessary part of life for most, but it’s far from environmentally friendly. Electricity generation relies on fossil fuels and harmful combustible byproducts that jeopardize the health of the planet, wildlife and human population. Electric lines and power generation also significantly impact the land around them, threatening plant and animal life along the way.
Drawing power from the grid, including those times when your solar energy isn’t enough to meet current usage needs, inevitably contributes to harmful eco practices. Solar battery storage greatly reduces this gap by creating a power reserve of solar energy to use as you see fit, minimizing how much you need to tap into the grid. Even factoring the materials required to make this equipment, battery backup still proves itself a far cleaner, greener way to power your home.
Safety and Usability
The solar inverter and battery storage combination is a safer option for power backup. Gas generators emit toxic fumes and pollutants and increase the risk of carbon monoxide poisoning. Portable generators were responsible for more than 900 deaths and thousands of injuries between 2005 and 2017. Carbon monoxide is odorless, colorless and highly dangerous for humans and pets.
Battery backups don’t emit exhaust, fumes or emissions, making it better for your property’s air quality and safer for your family, staff or visitors. Backup batteries are also free of dangerous wires, hot vents or exposed electrical elements that pose a risk for young children and curious pets.
Solar backed by battery storage also offer a more comfortable environment since it operates without making as much noise or vibrations as a generator does.
Cost and Maintenance
The standard Tesla Powerwall costs $7,600 for each unit and necessary hardware, with installation tacking on another $2,000 to $8,000, depending on your property and power needs. The average cost of a whole-house generator in the United States is $15,000, but small and portable units can cost less.
You should also consider these factors when comparing the cost of a backup battery versus a home generator:
- Installation: Upfront purchase and installation costs are the biggest barriers for homeowners seeking battery storage for their energy systems, though some installers accept third-party loans and other financing options to help cover the costs.
- Upkeep: Like all batteries, battery storage systems eventually lose efficiency as they age. The Powerwall battery is guaranteed to retain 70% of its capacity by the end of its 10-year warranty. However, battery backup doesn’t require fuel or any type of ongoing upkeep, reducing ownership costs compared to generators. Generators also require regular testing and occasional performance cycling to keep the internal components working well.
- Fuel: With a gas backup generator, you have to account for the added cost of fuel, fuel delivery, fuel storage and fuel refill fees. Fuel costs could be significantly less if your property connects to a natural gas line, but it’s still a factor to consider.
- Savings: Pairing a battery backup system with a solar inverter reduces electricity consumption and its costs. Your battery backup system can even get you savings without a compatible solar inverter by working around your utility company’s TOU electricity rates. These rates vary throughout the day, so having a battery backup system with energy monitoring lets you adjust energy sources to avoid high costs during peak hours.
- Incentives: Homeowners may see federal tax credits if they invest in a battery backup system — with or without a compatible solar inverter — and some states offer solar-battery incentives.
The Tesla Powerwall can save home and business owners a lot of money. Its battery backup performance currently relies on your local climate conditions and utility rates.
Generator installation may require laying a solid foundation, such as a concrete slab, and having a professional connect the unit to your fuel source with a compatible transfer switch. You’ll also need to make any necessary adjustments to your home to improve ventilation and create plenty of room for fuel storage, if applicable.
Battery backups easily mount to a wall or floor, fitting seamlessly into your home’s exterior. The Tesla Powerwall, in particular, is lauded for its sleek design, and some battery units can be integrated into a wall to be even more discreet. Battery backup units are also water- and dust-resistant.
Tesla Powerwall installation typically takes one day, and a professional handles all the setup for you.
What type of equipment and appliances do you need to keep running if the grid goes down? Battery backups are ideal for smaller applications like keeping the lights on and completing routine household tasks. They aren’t typically strong enough on their own to power more energy-intensive needs like life-saving medical equipment, a sump or well pump or similar. How long a Powerwall lasts depends on a range of factors, but you can “stack” up to 10 units to meet your home’s needs.
Generators can run for up to three weeks or 3,000 hours at a time if they have enough fuel and you’re maintaining the unit properly. They offer enough energy to support more critical loads — just be sure to size your unit correctly to accommodate anticipated usage needs.
Schedule a Tesla Powerwall Consultation With 8MSolar
Battery backup systems and generators offer unique benefits for homeowners, especially when used in combination with solar panels or other alternative energy sources. While gas generators offer reliable, powerful backup support during grid outages, they are costly to maintain and pose a risk to human health and the environment. Battery backup units require an upfront investment for the unit and installation, but ongoing costs are minimal, and the ability to monitor power consumption can save you a lot of money on utility bills while reducing reliance on the grid.
8MSolar is a certified Tesla Powerwall installer, and we’re here to help you decide if these innovative units are the right option for your home’s or business’s solar storage needs. We can even help you pair your battery backup unit with compatible Tesla solar panels for maximum savings and operating efficiency. Contact the team today to schedule your virtual consultation!