Table of Contents
Residential solar power is booming.
In 2022, electricity produced using solar energy exceeded electricity generated by coal for the first time in US history.
Switching to renewable energy sources like solar is crucial to combat the growing global climate emergency.
If you’re a homeowner, capturing the sun’s energy has many more immediate benefits, such as:
- Slashing (or eliminating) electricity bills
- Increasing the value of your home
- Decreased reliance on the grid and aging infrastructure (or complete energy independence)
- Reliable home backup power during blackouts
Increased demand for residential solar power systems has significantly sped up innovation and reduced costs.
The recently enacted Federal Solar Tax Credit has added more fuel to the fire.
In 2019, Generac — established in 1959 and a leading US manufacturer of fossil fuel generators — launched its first residential solar generator: PWRCell.
Two years earlier, EcoFlow was founded as an innovative solar-first manufacturer and has already won numerous awards and Best-Of listings from authorities like Red Dot and WireCutter.
In 2023, EcoFlow launched its Whole Home Generator — a direct competitor to Generac’s PWRCell solar power system.
When matched up head-to-head, which residential solar power solution wins the fight?
The grizzled fossil fuel veteran?
Or the upstart solar power brand that’s changing the portable off-grid solar power industry?
Read on to find out who comes out on top in the battle between Generac’s PWRCell and Ecoflow’s Whole Home Generator.
What Sets the Generac Power Cell Apart?
Generac is a newcomer to solar power, but it’s one of the most established residential and commercial fossil-fuel-powered backup generator manufacturers in the US.
Its PWRCell residential solar system has received mostly positive reviews from the media since its release in 2019.
However, according to CNET: “Many customers have left complaints on Generac’s Better Business Bureau page about products breaking after a couple of years of use, with some customers even referring to Generac as “Junkerac.”
Let’s take a look at some of PWRCell’s key features.
Following that, we’ll examine EcoFlow’s Whole Home Generator and sum the products up in a head-to-head comparison table.
AC Output
One of PWRCell’s strengths is its Inverter’s high AC output capacity.
A portable power station or other balance of the system’s maximum AC output determines the total wattage of appliances you can operate simultaneously.
If the sum total of the devices and appliances you want to use at the same time exceeds an inverter’s AC output, you’ll have to make some hard choices about what you want to run and when.
Another crucial factor to keep in mind is that many appliances — including refrigerators, washing machines, HVAC systems, etc. — are driven by motors. Motor-driven appliances typically require more starting watts than running watts.
Ensure that the solar generator you choose can deliver enough surge power to start up high-wattage appliances.
Somewhat confusingly, Generac lists its surge power output as the AC output capacity for its PWRCell offerings. This can be misleading. Surge power (starting watts) is a short burst of electricity the inverter delivers to start an appliance. It’s different from operating AC output (running watts) because the inverter can’t provide surge power over extended periods of time (more than a few seconds).
With that in mind, let’s look at Generac’s AC output by PWRCell configuration.
| PWRCell Configuration | Operating AC Output (Running Watts) | Surge Power AC Output (Starting Watts) |
| M3 (3 x Battery Modules) | 3.4kW | 4.5kW |
| M4 (4 x Battery Modules) | 4.5kW | 6kW |
| M5 (5 x Battery Modules) | 5.6kW | 7.5kW |
| M6 (6 x Battery Modules) | 6.7kW | 9kW |
Expandable Solar Battery Capacity
Another positive aspect of PWRCell is its modular design and expandability.
Its modular system consists of multiple 3kWh Generac Solar Batteries, which must reside in Generac’s Battery Cabinet.
A minimum of 3 x 3kWh Generac Solar Batteries is required for the system to operate (9kWh total).
Each Battery Cabinet can house up to 9 x kWh Generac Solar Batteries (18kWh). If that’s not enough storage capacity, you can chain 2 x Battery Cabinets together for 36kWh of total storage capacity.
Note that both Generac’s Solar Batteries and Battery Cabinet are only compatible with the company’s Inverter.
Extended Warranty (With a Caveat)
At first glance, Generac’s PWRCell comes with a much more impressive warranty than EcoFlow’s Whole Home Generator — ten years vs. five.
Here’s another example of why reading the fine print is crucial.
Generac’s solar battery warranty ends once 7.56mWh of electricity cycles through each module.
The average American household uses 10,632 kWh of electricity annually, or 10.632mWh. The minimum number of PWRCell solar battery modules is three.
3 x 7.56mWh = 22.68mWh
22.68mWh / 10.632mWh =
If you use PWRCell to run your house fully off-grid, your warranty could expire in just over two years.
If you use more electricity than the average American household, your warranty could end much sooner.
Additionally, depending on how the inverter distributes the power load, the warranty on one module in your Battery Cabinet may expire before the others.
The warranty on the EcoFlow DELTA Pro and Ecoflow Smart Extra batteries is five years, even with daily off-grid use. There is no restriction on how much electricity cycles through the solar battery during the warranty period.
With Li-ion solar batteries, it’s crucial to account for any restrictions on cycle life. Unlike lead acid batteries, Li-ion batteries like NMC and LiFePO4 don’t degrade over time — they diminish in performance with use.
On and Off-Grid Capability
Generac’s PWRCell is intended to be used on-grid as a backup power source. Unlike EcoFlow’s Whole Home Generator, It is not sold primarily as an off-grid electricity solution.
However, with an expandable storage capacity of up to 18kWh (36kWh with 2 x Battery Cabinets chained together), Generac’s PWRCell can store and generate more than enough electricity for the average home.
Generac’s PWRCell Inverter offers five modes that control power distribution: Clean Backup, Priority Backup, Self Supply, Grid Tie, and Sell. Of the five modes, only one — Self Supply — is the only one that takes you fully off-grid.
The other four modes depend on being grid-tied and offer various options for when the system accesses on-grid electricity.
Net Metering
PWRCell is intended primarily for grid-tied applications. If you live in a state or municipality that offers net metering, Generac’s PWRCell inverter enables you to sell electricity in excess of what you consume back to the grid. It even provides a Sell Mode if your primary use for PWRCell is not to use your system’s electricity but to sell it back to the utility grid.
EcoFlow Solar Solution: A Green Revolution in Home Energy
EcoFlow doesn’t have the lengthy history as a fossil-fuel generator manufacturer that Generac does, but that has its advantages.
Founded as a solar-first company by battery and PV industry veterans in 2017, EcoFlow’s first portable power station — EcoFlow DELTA Pro — broke Kickstarter’s record for the most funded tech project of all time by over $4M in 2021.
Unlike Generac, EcoFlow designs and manufactures its own range of rigid, portable, and flexible solar panels. Using proprietary technology, EcoFlow’s monocrystalline PV panels achieve industry-leading efficiency of 22-23%.
With solar panels, efficiency measures the amount of sunlight a panel can convert into electricity. Cheaper polycrystalline and thin-film PV panels typically have efficiency ratings ranging from 5 – 15%.
Efficiency is a crucial metric to consider when purchasing a residential solar panel array. The higher the efficiency, the more electricity your PV panel array will produce while taking up less space.
The solar batteries in EcoFlow’s Whole Home Generator solutions are significantly more eco-friendly than in Generac’s PWRCell and come with other advantages like longer cycle life and faster recharge times.
Since launching EcoFlow DELTA Pro, EcoFlow has gone from strength to strength. EcoFlow DELTA Pro won the first of the company’s many prestigious Red Dot Design Awards.
Read on to find out more about the advantages of going with a solar power company that puts innovation and the green revolution first.
Energy Independence
Unlike Generac’s PWRCell, EcoFlow’s Whole Home Generator was designed with off-grid power in mind from the ground up.
On-grid solar has its advantages. But it still leaves you dependent on aging infrastructure and the utility grid. You can combine solar batteries with an on-grid system to provide home backup in an emergency.
Still, there are benefits to going fully off-grid.
You can enjoy personal energy independence by switching to a clean, renewable energy source like solar.
No more relying on fossil fuels to produce your on-grid electricity, worrying about rising energy costs, or relying on overworked infrastructure during extreme weather events.
And you can significantly reduce your carbon footprint.
More Efficient (and Eco-Friendly) Solar Battery Chemistry
Lithium iron phosphate batteries (LFP/LiFePO4) are a newer subset of the lithium-ion (Li-ion) batteries you find in virtually all modern rechargeable electrical applications — from smartphones to Electric Vehicles (EVs).
Lithium nickel manganese cobalt batteries are also an advanced version of traditional Li-on chemistry.
EcoFlow uses LFP batteries in virtually all its products. Generac’s PWRCell utilizes NMC.
Both battery chemistries offer significant improvements over older Li-ion — and especially lead-acid and nickel-cadmium — batteries.
However, LFP solar batteries have significant advantages over NMC:
- More Sustainable, Humanitarian, and Eco-Friendly: Unlike NMC, LiFePO4 batteries contain no cobalt or nickel. Over 70% of the world’s cobalt comes from the Democratic Republic of Congo, where it is mined under extremely cruel conditions by pregnant mothers and children as young as six.
Mining cobalt and nickel also exacts more of a toll on the environment than extracting the necessary materials for LFP batteries like iron (ferrous phosphate).
Lastly, the heavy metals in NMC make eco-friendly disposal or recycling significantly more challenging than the green end-of-life protocol for LFP batteries.
- Longer Cycle Life (Longevity): The average cycle life of an NMC battery is 2000 – 2500 cycles. Once cycle life is exceeded, NMC batteries diminish in performance swiftly. LFP batteries typically last up to twice as long (up to 10,000 cycles) without any perceptible impact on performance.
Cycle life is a crucial spec for evaluating Li-ion, NMC, and LFP batteries. It indicates the number of full charges/discharges a battery can provide before its capacity and efficiency decline. - Greater Depth of Discharge: The depth of discharge (DoD) for NMC batteries averages around 80%. PWRCell’s recommended DoD is 84%. Depth of discharge indicates the “usable” storage capacity of a battery. Discharging a battery below its recommended DoD can permanently damage the battery pack. If you operate PWRCell within its recommended DoD parameters, usable storage capacity is reduced by 16%.
In real-world terms, that means that the 9kWh of storage provided by the smallest PWRCell system is reduced by 1.44kWh to a usable capacity of 7.56kWh. A maxed-out PWRCell Battery Cabinet nominally provides 18kWh of storage capacity. However, the usable storage capacity without exceeding DoD recommendations is only 15.12kWh — almost 3kWh less than the storage capacity listed in the specs.
By contrast, LiFePO4 (LFP) batteries offer a DoD of 100% - Safety: Unlike traditional Li-Ion NMC batteries, the chemical reactions that fuel LFP batteries don’t produce oxygen. Oxygen production by Li-ion batteries can lead to fire or explosion and the phenomenon known as thermal runaway.
LiFePO4 batteries do not overheat or produce oxygen when operating — even at high temperatures — making them a safer choice.
MultiCharge delivers record-breaking recharge speeds with up to 6500W total input
Lightning-Fast Recharge Times
Thanks to EcoFlow’s proprietary multi charge technology, you can recharge your EcoFlow DELTA Pro from 0-100% in less than two hours with up to 6500W of simultaneous power input.
With the addition of a Smart Extra Battery, you can recharge using 1600W of solar input, 1700W Smart Generator Dual Fuel input, and one of the following options:
- 3000W 240V AC Input
- 3400W EcoFlow Smart Home Panel
- 3400W EV Charger
By offering multiple charging options — and multi charge functionality — EcoFlow’s Whole Home Generator makes achieving personal energy independence easier.
If you choose to recharge using solar only, EcoFlow DELTA Pro can go from 0-100% in about four hours using 4 x 400W rigid solar panels.
Fully Integrated Solar Power Solution
EcoFlow doesn’t just make portable power stations and Power Kits.
It’s also an industry leader in manufacturing high-efficiency monocrystalline solar panels in rigid, portable, and flexible constructions — with rated power options ranging from 60W to 400W.
Generac has decades of experience in manufacturing traditional fossil-fuel-powered generators. But despite launching PWRCell in 2019, it doesn’t make PV panels.
If you opt for a grid-tied residential solar power system from Generac, you’ll have to purchase third-party PV panels for your solar array.
In fact, EcoFlow’s solar panels are compatible with PWRCell — and most other manufacturer’s systems. If you decide to go with on-grid solar, EcoFlow’s PV panels are an excellent choice for your array.
If you opt to go fully off-grid, EcoFlow’s solar panels integrate seamlessly with the company’s portable power stations, Power Kits, and whole home generator systems.
You’ll never have to worry about compatibility issues if you stay within the EcoFlow solar power ecosystem.
Also, in contrast to PWRCell, EcoFlow DELTA Pro contains all balance of system components — including the inverter and solar battery — in one compact, award-winning design. PWRCell consists of multiple discrete components in addition to third-party solar panels.
Automatic Switchover (Uninterruptible Power Supply)
Generac’s PWRCell is intended primarily as a grid-tied residential solar power solution. It’s a given that an on-grid system will have an automatic switchover to utility power (if it’s available).
However, even high-quality off-grid power solutions — like the EcoFlow RIVER 2 series — often have a barely perceptible 30ms delay when switching between on-grid and off-grid electricity.
For most applications, you’ll barely even notice a switchover that short. But if you have sensitive electronics connected to your system — like desktop computers and hard drives — even a 30ms switchover time can be catastrophic.
That’s why data centers use uninterruptible power supplies (UPS) to protect valuable equipment and digital information if the electricity goes out — even for milliseconds. Even a brownout can damage hard drives and computers without battery backup.
EcoFlow’s Whole Home Generator produces true sine wave AC output and automatic switchover when using the EcoFlow Smart Home Panel integrated with your home’s existing electrical wiring. Even if you only use your Whole Home Generator for emergency backup, your sensitive electronics are safe.
Plug and Play Installation
Unlike Generac’s PWRCell, the Whole Home Generator is plug-and-play. Each EcoFlow DELTA Pro contains an entire balance of system in one compact package, including:
If you need additional storage capacity, simply plug in EcoFlow DELTA Smart Extra Batteries with the included cable. Or connect 2 x EcoFlow DELTA Pros together to double AC output to 7.2kWh (14.4kWh surge power) and storage capacity to 7.2kWh with the Double Voltage Hub.
Even EcoFlow’s rigid, portable, and flexible solar panels are plug-and-play.
Portable solar panels require no installation. Rigid and flexible solar panels are easily mountable if you’re at all handy — even on a roof.
Smart Home Functionality
EcoFlow DELTA Pro is an integral part of EcoFlow’s Smart Home Ecosystem.
The EcoFlow smartphone app makes monitoring and controlling your Whole Home Generator from anywhere with an internet or Bluetooth connection a breeze.
Take integration to the next level with the EcoFlow Smart Home Panel. Unlike the other components of a Whole Home Generator, the EcoFlow Smart Home Panel requires a licensed electrician for installation. Once connected, the Panel gives you complete remote control and monitoring of up to 10 circuits in your home.
Each circuit can power multiple appliances — relay modules are available in amperages of 15A, 20A, and 30A.
Making an Informed Decision for Your Home
Once you take a deep dive into making a purchase decision for your residential solar power solution, you’ll quickly realize there’s no such thing as a one-size-fits-all solution.
Here are the essential factors to consider when choosing the right balance of system and PV panels for your home.
- Total electricity consumption requirements
- On-grid or off-grid solar
- Federal, state, and local government incentives and tax credits for switching to solar
- Peak sun hours in your location
- Available surface area receiving direct sunlight
- Solar panel efficiency
- Solar payback period
Once you grasp the core concepts outlined above, you’ll be in an excellent position to make an informed solar power solution purchase decision for your home.
Generac PWRCell vs. EcoFlow Whole Home Generator: The Specs
| Specifications | Generac PWRCell | EcoFlow Whole Home Generator |
| Storage Capacity (Minimum) | 9kWh | 3.6kWh |
| Storage Capacity (Maximum) | 36kWh (2 Battery Cabinets at 18kWh each) | 25kWh |
| AC Output (Minimum) | 3.4kW Continuous output (4.5kW Surge) | 3.6kW Continuous output (7.2kW Surge) |
| AC Output (Maximum) | 6.7kW Continuous output (9kW Surge) | 7.2kW Continuous output (14.4 Surge) |
| Solar Charge Capacity (Maximum) | 15kW (38 x 400W PV Panels) | 3.2kW with 2 x EcoFlow DELTA Pro (16 x 400W PV Panels) |
| Charging Options | 2 (Solar/AC) | 6 (Solar/AC/Car Charger/EcoFlow Smart Home Panel/Smart Generator Dual Fuel/EV Charge Station) |
| Battery Chemistry | Lithium Nickel Manganese Cobalt (NMC) | Lithium Iron Phosphate (LFP/LiFePO4) |
| Depth of Discharge | 84% | 100% |
| Fossil Fuel Generator Cross-Compatibility | Yes | Yes (Smart Generator Dual Fuel) |
| Grid Tied/Off-Grid? | Yes | Off-grid only |
| Uninterruptible Power Supply (UPS) | Yes | Yes |
| Expandable? | Yes | Yes |
| Plug and Play Installation? | No | Yes |
| Proprietary Solar Panels? | No | Yes – Rigid, portable, and flexible monocrystalline PV panels (60W – 400W rated power) |
| Warranty (Per Solar Battery or Portable Power Station) | 10 years (or 7.56 MWh throughput per battery module) | 5 years (no cycle life restrictions) |
| App Monitoring and Control? | Yes | Yes |
| Federal Solar Tax Credit Eligibility? | Yes | Yes |
Final Thoughts
Generac’s PWRCell and EcoFlow’s Whole Home Generator are both viable solutions for reducing your reliance on aging electricity grid infrastructure (or eliminating it altogether).
PWRCell is designed primarily for on-grid use. If you’re leaning towards a grid-tied residential solar power system, PWRCell offers multiple options for managing the electricity you generate — including selling back to your utility company if they provide net metering.
EcoFlow’s Whole Home Generators are built for personal energy independence and living off-grid. You can easily integrate your Whole Home Generator with your home’s existing wiring — and take advantage of AC electricity to recharge the system when available.
EcoFlow’s Whole Home Generators offer longer lifespans, more charging options, and better performance than Generac’s PWRCell residential solar power systems.
EcoFlow is a solar-first manufacturer and innovator. Unlike Generac, a fossil fuel generator incumbent, EcoFlow makes its own industry-leading PV panels. You can purchase your entire residential solar power solution from one company and eliminate concerns about quality and compatibility.
Find out more about EcoFlow’s next-level solar Whole Home Generators and portable off-grid electricity solutions,
Check out EcoFlow today!
