How to Connect Solar Panels to Battery Storage

Solar photovoltaic (PV) panels and on-site battery storage have enjoyed explosive growth over the years as more homeowners and businesses grow to appreciate the benefits of maximizing your system when you connect solar panels to battery storage

This article explores these benefits. It also outlines:

  • How to connect solar panels to battery storage
  • Why you should hire a professional (versus doing it yourself)
  • What a typical installation costs (with incentives if necessary)
  • How to troubleshoot issues once your system goes online

But first, some background.

Understanding the Limitations of Solar Power

Whether as a homeowner or business owner, going solar is one of the simplest ways to reduce your monthly utility bills. Rather than pay for grid electricity, you’re able to make and consume your power on-site. Your solar installation also offers environmental benefits since PV panels rely on pure sunshine instead of energy generated from dirty fossil fuels.

However, these benefits only emerge under particular conditions.

For starters, it’s imperative that you monitor, clean, and maintain your PV system regularly. And if necessary, you may even need to occasionally upgrade your existing solar system.

In addition, guaranteed utility bill savings are only possible during the day – when the sun is shining. At night, you must switch over to grid electricity. Utility rates have historically been cheapest at night. But the growing popularity of solar power has pushed peak hours much later into the day. And this shift makes it harder to generate substantial savings if you have heavy energy needs after dark.

Similar issues exist on overcast days. Your solar panels will still generate energy (which is why you may sometimes develop a suntan on cloudy days). But the electricity generated may not be enough to power all of your appliances. And your PV system will automatically switch to grid power during these times.

State-level incentives like net energy metering can help boost some of these savings. Under these programs, you’re allowed to sell excess solar electricity back to the utility company in exchange for credits. The entire energy grid acts as “virtual” storage for your daytime solar power with this approach. However, most utility providers base their credits on wholesale prices instead of retail pay rates. As such, the potential savings under net energy metering are limited.

To reclaim some of these “lost” savings, more solar customers have started turning to on-site battery storage solutions.

Why Use Batteries to Store Solar Power?

Although there are many different ways to pair batteries and solar together, most configurations allow you to do some variation of the following:

  • When the sun is shining during the day, your panels feed excess solar power into the batteries.
  • At night (or on overcast days), the stored solar energy in your batteries can be used to power your home or business.

Note that you only need to purchase electricity from the utility company when your batteries are empty, AND your panels aren’t receiving enough sunshine – either because it is nighttime or too cloudy.

The beauty of this approach is that you can time when you take electricity from the grid. And this allows you to avoid peak rates, demand charges, and time-of-use (ToU) pricing to generate even more significant savings than you could from relying exclusively on solar PV panels.

Better still, it’s technically possible to decouple from the grid entirely if your home or business has enough solar and storage capacity. This approach offers true energy independence, with absolutely no more utility bills, rate increases, or tariffs.

However, increased utility bill savings are only the most recent benefit from the solar + battery revolution. This combination has long been used by:

  • Remote properties that are too far from the utility grid. Combining solar and storage is a more attractive alternative to continued reliance on dirty, noisy, and expensive diesel generators.
  • Critical services that need 24/7 power. Medical facilities, military installations, and data centers fall into this broad category.

There’s also a final group – i.e., those who live in areas with frequent blackouts. Pairing battery storage and solar PV panels provide emergency backup power when the electricity grid goes down. However, this requires using the correct type of inverter since many older inverter technologies are designed to automatically shut down your PV system if there is a grid outage. This “anti-islanding” safety feature is designed to prevent solar electricity from going into the grid as utility workers repair downed power lines in the field.

If your solar inverter comes with this anti-islanding safety feature, you’ll need to either switch inverters or install batteries if you want reliable daytime power. This strategy is becoming increasingly common in California and Texas – both of which have been plagued by significant grid outages. However, blackouts will likely become more widespread as extreme weather conditions disrupt normal grid operations.

How to Connect Solar Panels to Battery Storage

Pairing the on-site batteries with solar PV panels ultimately comes down to connecting the correct wires and components. Many installations require a charge controller to help bridge the gap between the PV panels and batteries. This charge controller is a voltage and current regulator designed to prevent your solar batteries from overcharging.

However, the actual installation process is rarely this straightforward. That’s because every solar battery manufacturer uses slightly different protocols and specifications – similar to how you can’t use an Android charger with an iPhone. In addition, some manufacturers specify that only licensed service dealers can install their components. Hiring someone outside of the Tesla Powerwall network, for example, could potentially void your warranty.

It also matters if there is an existing PV system – and whether it was initially designed to accommodate solar batteries at some later date. Storage-ready solar inverters are becoming increasingly standard with newer installs. However, this compatibility isn’t always a given when working with older PV systems. And you may need to explore one of the following options to prepare your solar installation for battery storage.

  • You are adding a second AC-coupled inverter to your existing system. This approach is less popular since there are multiple steps as direct current (DC) electricity gets converted to and from alternating current (AC) power. Because there are transmission losses at each stage, using a second inverter is less efficient in the long run.
  • It is adding a solar inverter that is truly storage ready. This approach delivers higher efficiency rates since there are fewer overall DC/AC conversion steps. However, the setup process is more complex, driving up the total installation cost.

Which to Choose: DIY vs. Professional Solar Storage Installations?

Because most solar battery storage solutions are installed at ground level, you don’t need the ladders, harnesses, and other safety gear required when installing traditional rooftop PV panels. However, you’re still working with high-voltage electricity. And this means using specialized safety gear to prevent accidents, injury, or property damage. Installing batteries requires making exact calculations for matching voltages and currents across all the different components in the larger solar PV installation.

Unless you’re experienced in electrical wiring and circuitry, hiring a professional battery installer is always best. In addition to being a prerequisite for some battery warranties, outsourcing the job to an experienced electrician also delivers better sizing, quality, utility bill savings, and carbon offsets.

How Much Does It Cost to Install Batteries with Solar Power?

Combining solar and storage has never been more affordable than it is today:

  • According to the National Renewable Energy Laboratory (NREL), residential, commercial, and utility-scale PV installation prices fell 64%, 69%, and 82%, respectively – from 2010 to 2020. Even more significant price drops are expected if the US Department of Energy’s Sunshot initiative achieves its 2030 goal of cutting PV costs in half.
  • Solar batteries used to be notoriously expensive. But over the past 30 years, prices have fallen 97% – while efficiency rates and storage capacities have skyrocketed.

Better still, local, state, and federal incentives exist to make solar and storage even more affordable. A prime example is the 26% Federal investment tax credit covering PV systems and solar-tied storage solutions.  

That being said, determining how much to budget for your solar and storage installation is difficult since:

1. Every PV System Is Unique

New installations are often cheaper than retrofits since you can do all the electrical wiring at once. It also matters how many PV panels you have (or plan on adding in the future). Moreover, if your current PV system isn’t already “storage-ready,” you’ll need to upgrade it – which costs more.

2. Every Battery Is Different

Every manufacturer uses slightly different chemicals and processes when designing their battery solutions. For example, lead-acid is cheaper than lithium-ion – at least initially. However, lithium-ion offers higher efficiencies, larger capacities, and longer lifespans – making them the more affordable option over time.

It also matters how much storage capacity you’re installing – i.e., enough to save money or enough to completely go off-grid.

Despite these variables, it’s possible to give broad price ranges. According to SolarReviews, for example, the average cost of a residential lithium-ion solar battery solution is $7,000 to $14,000. Energy Sage offers similar estimates ($10,000 to $20,000).

Should I Connect Solar Panels to Battery Storage?

Not necessarily. Because of the upfront cost, combining solar and storage may not be the best option. Most customers enroll in their state’s net energy metering program and rely on grid power at night and cloudy days. The setup process is more straightforward, and you don’t need to spend an additional $7,000+ to get started.

However, adding batteries to your solar PV system may be worth it if you:

  • Need emergency backup power during grid outages
  • Want to boost your long-term utility bill savings and ROI
  • Can’t connect to the utility grid (due to geography)
  • Want to unplug and become more energy independent

One important thing to keep in mind, however.

Even though PV panels come with 25 years of warranty protection, they still need servicing, repairs, and upgrades. Batteries come with even shorter warranties, typically lasting 5 to 15 years – depending on the manufacturer. These lifespans can be much shorter if the batteries are poorly installed.

This means that over the next 25 years, you will likely need to repair or replace several of the components in your system – including the batteries, panels, and even the inverters. Unfortunately, this can prove challenging in situations where:

  • The original installer is no longer around to fix the issue.
  • The manufacturer has gone out of business and can’t honor its warranty.

Even if you find service technicians, there’s no guarantee that they’ll be familiar with the technology powering your system. This is especially true if yours is an older installation that uses legacy or outdated components.

At 365 Pronto, we have a simple solution to this increasingly common problem. We use AI-powered matching technology that can instantly connect you with the right solar or battery technician for any job:

  • Our algorithm analyzes your installation’s specs, tech, age, size, and location to develop a unique DNA profile for your system.
  • It then uses that profile to search an extensive database of experts in your area who know precisely how to service your installation.

Whether you need to update a router, clean dust-covered modules, or repair a faulty battery, our platform allows you to extract more value from your clean power investment.

Schedule a free demo with us today to learn more about 365 Pronto’s AI-powered solar matching technology.