Do stackable systems take up more space than fixed battery setups?

Space Requirements: Stackable vs Fixed Battery Systems

If you're considering battery storage for your home solar setup, you've probably noticed there are two main approaches: stackable systems that sit on the floor and fixed systems that mount to walls. The short answer is yes, stackable systems typically need more floor space than wall-mounted batteries, but the picture isn't quite as simple as it first appears.

How Much Space Are We Talking About?

A typical stackable battery unit measures roughly 60cm wide by 40cm deep, and you'll need additional clearance around it for ventilation and maintenance access. If you start with one unit and add two more over time, you're looking at a footprint that could easily take up a square metre or more of floor space in your garage or utility room.

Wall-mounted systems, by contrast, use vertical space that's often going unused anyway. A Tesla Powerwall 2, for instance, measures 115cm tall by 75cm wide but only protrudes 15cm from the wall. That's a significant space saving if floor area is at a premium.

The Flexibility Factor

Where stackable systems shine is in their modular nature. You might start with a 5kWh unit costing around £3,000-4,000, then add another identical unit six months later when you buy an electric car. Each additional unit typically costs less per kWh than buying a large system upfront.

Fixed systems like the popular Powerwall or GivEnergy units come as complete packages. If you want 13.5kWh of storage, you buy the whole system for £8,000-12,000. Need more capacity later? You're looking at installing an entirely separate system.

UK Installation Considerations

Most UK homes have limited suitable wall space for battery installation. The wall needs to be structurally sound enough to support 100-150kg, accessible for maintenance, and meet the required clearances from gas metres and other utilities. Many older British homes simply don't have an ideal wall location, making stackable floor-mounted systems more practical.

Under current UK building regulations, both types need to be installed by MCS-certified installers to qualify for Smart Export Guarantee payments. The good news is that stackable systems are often easier to install since they don't require wall mounting brackets or structural assessments.

Pros and Cons Breakdown

Stackable Systems:

• Start small and expand as needed
• Individual units can be replaced if they fail
• Often easier installation process
• Take up valuable floor space
• May look less tidy than wall-mounted options

Fixed/Wall-Mounted Systems:

• Efficient use of wall space
• Often more aesthetically pleasing
• Integrated design can be more reliable
• Difficult to expand capacity later
• Requires suitable wall structure
• Higher upfront costs

Common Mistakes to Avoid

Don't underestimate how much space you'll actually need around stackable units. That 60cm x 40cm footprint becomes much larger when you factor in the recommended 30cm clearance on all sides for ventilation and access.

Many people also forget to consider cable routing. Stackable systems need power cables running to your inverter, and these need to be properly protected and routed - something that's often neater with wall-mounted systems.

Making Your Decision

If you have a suitable wall location and know your storage needs won't change significantly, a wall-mounted system maximises your floor space. But if you're starting your solar journey gradually or your home lacks suitable wall space, stackable systems offer a practical alternative despite needing more room on the ground.

Consider visiting a local solar installer to see both types in person. The space difference becomes much clearer when you can actually walk around the units and imagine them in your own home.