Can Standalone Battery Storage Without Solar Cut Energy Bills?

—This article was contributed by Dave Roberts, UK MD at energy storage specialist GivEnergy—

Installations of solar PV panels are on the rise. So too are battery installations. Together, this combination of solar plus battery storage will drastically cut the billpayer’s energy bills and carbon emissions.

But and this is often news to the average billpayer you don’t always need solar to save on energy bills.

While solar PV panels and battery storage is the ideal combination, standalone battery storage can be a viable alternative. (That is, a home battery installed without renewables.) It’s an accessible solution for those who want to save on energy bills but don’t have the means financial, practical, or otherwise to install solar PV panels.

So, how does a standalone battery storage system work, and why is it a game-changer for the future of home energy management?

 

The Relationship Between Batteries and Solar Panels

 

Battery storage coupled with solar is the ideal choice when it comes to cutting bills and carbon emissions. With solar PV you can generate your own renewable energy. The problem is that generation doesn’t always align with when you need electricity the most.

Let’s say the sun is shining brightly during the day when you’re out at work. You’re generating electricity, but there’s nobody home to use it. With battery storage, you can store that clean, free energy. Then, when you get home after work, you can use your stored supply to power your home.

Research published in Applied Energy suggests that without battery storage, a solar installation is just not worth it. The study found that those with standalone solar only used around 30-40% of energy generated. Meanwhile, those with solar PV panels and battery storage reduced imports from the grid by up to 84%.

 

Solar May Need a Battery But a Battery Doesn’t Always Need Solar

 

So, solar works best when paired with battery storage. But the little-known fact remains that you don’t need solar panels to benefit from a battery storage system.

A standalone battery storage system without solar can still help you cut energy bills. The battery will charge when the energy flowing through the wires is cheapest and greenest. (This might be overnight, when the grid is under less strain, or when wind production is particularly high for example.) Then, it will discharge when energy costs spike, helping you dodge peak prices. (And helping flatten demand on the grid, too.)

So, it’s a simple concept: draw from the grid to charge your battery when energy is super-cheap, then switch to battery power to run the home when energy prices peak.

Step 1: Getting The Right Tariff

To reap the benefits of standalone battery storage, you must be on a time of use (TOU) electricity tariff. TOU tariffs offer different electricity prices, depending on the time of day.

• During off-peak hours, prices are cheaper. These usually fall somewhere between 11pm-8am
• During peak hours, prices are more expensive. These usually fall somewhere between 8am-10pm

Some TOU tariffs are also ‘dynamic’. That is, they offer changeable prices per unit of energy depending on conditions. So, for example, prices may depend on the amount of wind power predicted for a particular time.

Either way, your TOU tariff and your home battery will go hand-in-hand to allow you to run your home on cheaper electricity. And, in turn, you can massively reduce your energy bills.

How Much Money Can You Save?

 

Savings on bills depend on a host of factors. These include:

• Battery storage capacity
• Energy prices
• Tariff
• Seasonal variations in energy use

Let’s look at a hypothetical example.

Imagine you’re in the northwest of England on the Octopus Agile tariff. Average off-peak electricity prices during June 2024 were 15.6p per kilowatt hour (kWh). Meanwhile, average peak prices were 29.8p per kWh.

So, if you use your standalone battery storage system effectively, you could be looking at average savings of 14.2p per kWh over a month.

In other words, you could cut your monthly electricity bill by around 50%.

 

Step 2: F a Home Battery Storage System That’s Right For You

 

Sizing the right battery capacity for your home is a key step, regardless of what kind of system you opt for.

You need to figure out how much electricity your home uses, and then, look for a home battery with appropriately sized capacity. When calculating your electricity usage, be sure to pay attention to:

• Seasonal variations
• Use of any high-powered devices (heat pumps, EV chargers, hot tubs, etc.)
• Whether your electricity needs will increase over time (in which case, you may need to add extra battery capacity)

Let’s say you live in a 2-3 bedroom house and use around 2,700kWh of electricity per year, as per the Ofgem average. That works out at an average of around 7.4kWh per day.

But as we know, electricity usage fluctuates depending on the time of year. In winter, you may keep the lights on for longer. If you’re using a heat pump, electricity usage will increase when you heat your home.

Meanwhile, on the hottest days of the year, you may use more electricity when you turn on the AC or use electric fans. Let’s say on one of these days, your electricity usage increases to 10kWh in a single day.

In this case, you may want to look at a battery storage system with a minimum of 10kWh capacity. This means that in theory, your battery capacity can cover your electricity needs, even on days when usage is at its highest.

 

Step 3: Configuring Your Battery To Maximise Savings

 

Most, if not all, battery storage systems come with various charging and discharging settings.

In some cases, your battery’s default setting may be enough. In other cases, however, you may have to change settings manually to maximise savings on bills.

If your TOU tariff offers off-peak rates between 11pm-7am, you could set your battery to charge from the grid during this timeframe. Then, let’s say your peak hours are from 7am-10pm. You may want to set your battery to discharge during this timeframe.

Ultimately, it’s up to you how you manage your home battery based on your electricity tariff and your needs.

 

The Untapped Potential of Standalone Battery Storage Without Solar

 

According to a survey by the Department for Energy Security and Net Zero (DESNZ), uptake of TOU tariffs remains low. As of summer 2022, 71% of households surveyed were on a standard tariff. (I.e., their electricity prices remain the same, regardless of the time of day.)

Meanwhile, just 12% were on a TOU tariff, while 17% didn’t know what type of tariff they were on. Around 32% of those surveyed said that switching wouldn’t save enough money. Meanwhile, 34% said they didn’t want to think about when to use electricity.

In short, most of those surveyed didn’t want the inconvenience of shifting electricity usage, which is understandable. Most of us don’t want to do laundry, watch TV, use the dishwasher, etc. at 3am.

That’s where standalone battery storage could help. By storing cheaper off-peak energy to use during more expensive peak hours, you can have it both ways. Cheaper electricity, without the inconvenience.

 

Battery Storage With Solar PV Vs Standalone Battery Storage: Which is Right For You?

 

Assuming you have the necessary financial and practical means, installing solar PV panels with battery storage is the ideal option.

Benefits of solar PV plus battery storage include:

• Ability to generate and store renewable energy
• Reduce imports from the grid

However, without the means to install solar financial, practical, or otherwise standalone battery storage could be the next best option. Benefits of standalone battery storage include:

• Cheaper upfront cost than solar – helping to lower entry barriers to energy freedom
• Practicality – good for those without the space to install solar panels, such as those in flats without access to roof space

Remember that you can retrofit a solar installation to your battery storage system. So, if you begin with a standalone battery system, you can always add a solar installation later.

 

Considerations When Installing a Home Battery Storage System

 

Think of a home battery as a long-term investment. Invest well and you’ll get a good ROI. Invest badly and your payback time will be lengthened.

So, here are a few things you need to consider:

• Upfront cost, including installation
• Payback period i.e. how long before you save enough on bills to cover the upfront cost
• Electricity usage
• Cost of electricity (if you plan on drawing from the grid with a standalone)
• Solar PV capacity (if you plan on adding a solar installation)

 

TL; DR:

• Solar PV plus battery storage is the ideal setup for cutting bills and carbon emissions
• Standalone battery storage offers a lower cost and more practical alternative
• Standalone battery storage can help you reduce energy bills if you’re on a TOU tariff