Solar Generator or Solar Battery Backup: Which Is Better For Your House?

Published 11/6/2023

With 45% of all new generation capacity in the US in 2023 being solar, it’s safe to say that solar is experiencing explosive growth¹. Even the Executive Director of the International Energy Agency, Dr Fatih Birol, feels optimistic about progress on climate change because of solar². But what's behind this surge in solar, and what does this mean for homeowners?

For many US homeowners, solar has become an increasingly attractive option. And for good reason. Not only is it more affordable than retail electricity in most of the country³, but there's also growing policy support to encourage consumer adoption. But perhaps that's not the full story.

A big part of the appeal of solar is the peace of mind that comes with having power, even during a blackout or extreme weather event⁴. Of course, it's not as simple as that. Without a safe and reliable way to store or produce energy, you, too, may find yourself in the dark during a blackout. And that's where solar generators and solar battery backups come in.

But that begs the question: solar generator (also known as portable power stations) or solar battery backup? How do you know which is the right one for you? And which is the best emergency power option? While it may seem like an overwhelming choice, it actually all comes down to a few factors that largely depend on your specific needs and circumstances.

Let's explore solar generators

If you've decided to go the solar generator or portable power station route, there are a few things you need to know. Despite their name, solar generators don't run on fossil fuels. Instead, these rely on solar panels to generate electricity, which the generator's battery then stores for later. This makes them a renewable source of energy⁵. Solar generators are the 'clean' alternative to small portable gasoline-powered generators⁶. They're portable and relatively easy to set up, making them a good option for outdoor activities like camping.

Solar generators work by converting energy from sunlight into electricity. To do this, they are packaged into a system, and they consist of four main components⁷:

Solar panels:

These are made up of photovoltaic (PV) cells that are designed to capture sunlight and convert it into direct current (DC) electricity. Solar panels can vary greatly and come in different sizes and with different wattages, impacting the solar generator's output and charging speed.

Solar battery:

This is the solar generator's energy storage unit. It enables the generator to store solar energy for later use. While there are many different types of solar batteries, lead-acid and lithium-ion⁸ are among the most common. Lithium-ion tends to be a more popular choice because they're lighter and have a longer lifespan. Additionally, with lithium-ion batteries, users have access to most of the stored energy before they need to recharge.

The other important thing to know about solar batteries is that their capacity is measured in ampere-hours (Ah) or watt-hours (Wh). This is a measurement of how much energy can be stored and will indicate how long a generator can operate without sunlight.

Charge controller:

Designed to keep batteries from overcharging⁹, the charge controller or solar regulator is an essential part of a solar generator. It does this by regulating the flow of electricity between the solar panels, battery, and inverter. This way, the charge controller ensures batteries are charged safely and efficiently. It's worth noting that there are different types of charge controllers: pulse width modulation and maximum power point tracking.

Pulse width modulation (PWM):

This acts as an electric switch between the solar panels and the battery. Because they can be switched on and off quickly, it's easier to obtain the desired voltage to charge batteries. As the batteries are charged, the current will gradually be diminished. These controllers are often more affordable and more widely used.

Maximum power point tracking (MPPT):

These tend to be more efficient and extract more power than PWM controllers.

They work by converting a higher output from solar panels to a lower voltage needed for charge batteries. The idea behind MPPT controllers is to extract the maximum voltage from PV cells to charge batteries.

Solar inverter:

This converts the electricity stored in the battery (DC electricity) into AC electricity, the standard form of electricity used for household appliances and devices. Basically, the solar inverter converts stored power into a usable form of electricity. Solar-plus–battery storage systems rely heavily on inverters to operate without support from the grid during outages.

Disadvantages of solar-powered generators for your home

Solar generators are great for charging devices and running small appliances. They can even come in handy for powering a handful of devices during an emergency. Additionally, they're a useful backup power source for camping because they don't require fuel and are portable. But for anyone looking for an uninterrupted, reliable, and renewable power supply for their home, a solar battery is the best choice. Here are a few key disadvantages that anyone considering a solar generator should keep in mind:

First, solar-powered generators rely on sunlight to generate electricity. Cloudy days, nighttime, or locations with limited sunlight will reduce their efficiency and output. This weather dependency may be a notable consideration, especially when contrasting them with larger-scale solar systems with battery backups.

Another drawback to consider is their slow charge time. Unless you're willing to invest in a high-end solar generator, they take time to recharge. Of course, charging time varies and depends on various factors, from system voltage to battery capacity. But if you have a 100-watt solar panel¹⁰, it would take over 9 hours to charge most mid-sized generator batteries.

But more than slow charging times, one of the biggest issues with solar-powered generators is their limited power supply. And while technically, a solar generator could be used to power a home, the reality is much more complicated. It comes down to the size of the generator, the size of the house, and the household energy consumption. Consider that the average US home uses 886 kWh per month¹¹. This is a considerable amount of electricity. Just think about how much capacity you'd need to power an entire house.

But what is a solar battery backup, really?

For many homeowners, a complete solar power system with a backup battery or batteries is a convenient and all-encompassing renewable energy option, especially when you partner with an experienced solar power and storage company like Sunrun. This type of solar system guarantees you reliable energy when you need it most¹².

When choosing to get solar panels installed, you can opt to add one or more rechargeable solar batteries to your system. You can still go solar and save money on your monthly electric bills without a battery; however, without a battery, you’d still experience loss of power in the event of a grid disruption or blackout. Solar panels with a backup battery capture the sun's energy and convert it into electricity, which is then stored in the solar battery for use when required¹³.

Solar battery backup is a seamless way to ensure you have a consistent and dependable power source while reducing your reliance on traditional energy sources. For homeowners, this translates into reduced utility bills and paves the way toward energy independence¹⁴.

Solar battery backups store excess solar energy for later use¹⁵. Essentially, they bridge the gap between energy production and consumption, ensuring a continuous and reliable power supply even when the grid is down. This added layer of energy storage transforms your solar system into a self-sufficient and resilient energy source, allowing you to maintain power for essential appliances and systems when external power sources fail.

While both solar generators and solar batteries have advantages, solar batteries actually help extend solar beyond sunset. They enable you to harness the power of the sun even when it sets¹⁶. This ensures you always have access to a reliable power source regardless of power outages or extreme weather conditions¹⁷.

Other note-worthy advantages of solar battery storage systems are that they:

Store excess electricity
Reduce utility costs
Ensure greater energy independence
Provide backup power during outages and blackouts

Disadvantages of solar battery backups

One of the first things to consider about solar battery backups is the high upfront costs. With many systems costing thousands of dollars¹⁸, it may seem like a stretch for many homeowners. The good news is that companies like Sunrun provide affordable options, including plans with no down payment, enabling you to begin enjoying the benefits of solar and storage right from the start. This is an opportunity to start generating your own solar energy for as little as $0 down¹⁹.

Or if you’re looking to purchase your solar and battery backup system up-front, you may qualify for the 30% federal energy tax credit²⁰. You may also be eligible for a host of other incentives from your local government, utilities, and even credit unions when paying for your system in cash.

As with solar generators, capacity is an important consideration when going with a full home solar system. The key is to choose the right size solar system and battery or batteries for your home and lifestyle. If you go solar with Sunrun, our experts will closely guide you through the process so you can make the perfect choice for your family’s energy needs.

Other factors to consider are battery capabilities, output, and anticipated lifespan. The efficiency and performance of a solar battery can vary based on the technology used, so it's crucial to understand the specific capabilities of the battery system you're considering. Additionally, the anticipated lifespan of the battery should align with your long-term goals and expectations. Then, there's regular maintenance and monitoring, which are essential to ensure the system operates optimally over its lifespan.

Despite these considerations, many homeowners find that the benefits of increased energy independence and the ability to store and use solar energy outweigh the drawbacks of solar battery backup systems.

Solar generators vs. solar battery backup: How do they compare?

Choosing between a solar generator and a solar battery backup system involves careful consideration of numerous factors. And for many homeowners, this decision is more complex. Ultimately, the choice boils down to your individual needs.

	Solar Generators	Solar Batteries
Power Generation	Generates power directly for immediate use or storage in the battery	Primarily focused on energy storage: stores excess energy generated by solar panels.
Portability	Generally portable for on-the-go power	Typically stationary and integrated
Energy Storage	Limited storage capacity	Significant storage capacity for backup
Grid Dependency	Standalone and can only be used off-grid.	Can operate off-grid even during power outages
Installation	No installation needed	Must be professionally installed
Use Cases	Outdoor activities, camping, emergencies	Home backup power during outages, avoiding peak power rates
Cost	More affordable because they are smaller	Higher upfront cost with potential returns
Incentives	No incentives	Federal tax credits and local incentives are available depending on the financing method
Scalability	Limited scalability for increased demand	Can be scaled in by adding more battery capacity
Suitability for Homes	No; suitable for small devices	Suitable for powering homes, especially during power outages

Sunrun is ready to partner with you

Thanks to technology like solar, homeowners like you are in a unique position to take control of your energy future and shape it. And when coupled with solutions like a battery backup system, you gain a resilient and reliable energy source for powering your home that largely bypasses the already strained electrical grid.

Selecting Sunrun as your solar energy partner goes beyond just acquiring solar panels — it signifies your commitment to a more sustainable future. We recognize that navigating the path to solar power may feel overwhelming, which is why we stand by as your unwavering experts, guiding you every step of the way.

Our team of Solar Advisors offers tailored consultations, simplifying the complexities of transitioning to solar energy. Each Sunrun solar system is crafted to suit your home's distinctive energy profile and specific needs. With our industry-leading guarantee, your peace of mind is safeguarded throughout the entire lifespan of your Sunrun solar system, ensuring that you have access to dependable, renewable, and cost-effective energy precisely when you require it most.

Take control over escalating energy expenses and transition to a secure, sustainable, dependable energy future with Sunrun. Your journey towards a brighter tomorrow starts right here.

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