BATTERY BOXES Batteries, blackouts and the bits of your estate you’ve forgotten about

Ben Wallace

Ben boasts 16 years in energy asset development, having served at notable firms like Arup, ESB, and Lightsource, and has experience across technologies such as energy storage, biomass, onshore wind, nuclear power, and more. Over the last 6 years at AMP, he’s spearheaded the development of flexible assets, initiating 300MW+ of distributed gas and energy storage across over 60 distinct projects.

Ben here expands on earlier articles about why Battery Box works financially, to this one about why this matters operationally. “it’s part of a much broader conversation about how energy works across a local authorities’ estate.” 

There’s a particular moment we’ve probably all experienced. You’re halfway through something important; Teams call, email, a spreadsheet that’s just about behaving - and suddenly everything goes off. Silence. Darkness. Mild panic. Someone inevitably says, “It’ll be back in a minute.” Now imagine that, but across an entire country.

On 28 April 2025, Spain and Portugal experienced a full-scale blackout that brought transport systems to a halt, disrupted communications, and left entire regions without power for hours. What’s perhaps most striking isn’t that it happened, it’s how it happened. It wasn’t one single

catastrophic failure, rather a chain of issues that escalated in seconds.

The fallout has not been limited to Spain and the UK, and many other European countries are looking to bolster the requirements for essential infrastructure to be more “energy resilient”.

One emerging technology that is excellent at providing that resilience, which also has a low environmental impact compared to the traditional diesel generator, is Battery Energy Storage Systems (BESS).

Which brings me back to a familiar subject for anyone who might recall our Spring 2024 and Spring 2025 ACES Terrier pieces (or indeed any of our Terrier adverts!): the rather unassuming BESS we call a Battery Box.

Battery Box: A quick recap

In earlier issues I spoke about Battery Box in fairly simple terms: let us rent space on your estate, often small parcels that that aren’t of other development value, and in return, you receive a reliable income stream with very little management burden.

That remains entirely true. If anything, as more capacity is needed across the grid, the opportunity for estates to host these assets has become more compelling rather than less. But what’s changed since my first article, is the breadth of value these BESS can deliver beyond rent. 

If the first article was about “why this works financially”, this one is really about “why this matters operationally”.

The shift from income to infrastructure

At its core, a battery is very simple: it stores electricity when it’s available, abundant and low cost, and then exports it when there isn’t enough and its expensive. But once you place that capability on an estate, particularly one with multiple tenants, varying demand profiles and growing pressure from electrification, it starts to do far more than just sit there quietly earning rent; it becomes a tool. And like most useful tools, it tends to solve several problems at once.

When resilience stops being theoretical

For a long time, “power resilience” has been one of those phrases that sits comfortably in strategy documents, but doesn’t necessarily translate into day-to-day decision-making. Events like the Iberian blackout have shifted that perspective. It was the most severe outage of its kind in Europe in decades, and it highlighted how quickly a modern system can unravel when the conditions line up the wrong way. Regulators have been explicit in the response: greater flexibility, faster response assets, and systems that can support the grid at a local level, rather than relying solely on national infrastructure. This is where localised batteries quietly excel.

Placed on an estate, they can support critical loads, smooth out fluctuations in demand and, depending on configuration, provide a layer of backup or support that simply wasn’t there before. For occupiers, particularly those with operational or commercial sensitivity to outages, that’s not just a ‘nice to have’. It’s increasingly part of the conversation around leasing, covenant strength and long-term attractiveness of space. And at Battery Box, we are already speaking to many telecom companies, water companies, and even Electric Vehicle charging companies, on how our systems can help them improve their resilience.

The complexity of energy bills

Reducing your energy bill can be as easy as lowering your consumption, but that only gets you so far and often its not even possible without impacting your business.

The variable cost, i.e. how much you consume, also changes based on when (what time) you consume it. Power prices are generally cheaper at night than during the day. Using a BESS to charge at night, and then use that power during the day, can dramatically lower your costs.

There is also a growing fixed charge on your bill. This is partly driven by your peak demand, which might only be for a few minutes a day, compared to a lower base use. Using BESS you can ‘shave’ that peak demand period, lower your connection capacity, and dramatically cut your fixed costs. This approach can see, on some sites, returns on investment in as little as 3 years.

Electric vehicles: from aspiration to constraint

If there’s one area where the conversation has moved particularly quickly, it’s electric vehicles. A few years ago, EV charging was a mark of progress. Now, for many estates, it’s becoming a logistical challenge.

Connections need upgrading. Demand spikes need managing. Tenants want provision without disruption. It’s not uncommon for the biggest barrier to rolling out additional charging to be the local grid connection itself, which is either constrained, expensive to upgrade, or often both. This is precisely the sort of problem batteries are designed to solve.

Rather than building infrastructure for the single busiest moment of the week (or month), a battery allows that demand to be delivered more intelligently, by charging steadily in the background and delivering power when it’s actually needed. In practical terms, that can mean fewer upgrades, faster deployment, and a smoother experience for occupiers.

Instead of EV infrastructure being something that creates friction, it becomes something that can be scaled sensibly and, in some cases, commercially.

Making solar do what people thought it did in the first place

Solar has been a familiar feature on estates for years now, and rightly so. But anyone who’s spent time looking at the numbers will know that without storage, a significant proportion of the value can be lost, not because the energy isn’t generated, but because it arrives at the wrong time. Sunny afternoons don’t always align with peak demand.

Without a battery, excess generation is typically exported or underutilised. With a battery, it can be held and used when it’s actually needed, dramatically increasing the usefulness of the system. For estates with existing rooftop solar, this is often the missing piece of the puzzle. It turns something that is broadly positive (and good for the ESG report) into something that is far more integrated into the way energy is actually managed on site.

So where does that leave Battery Box?

It would be easy to think of all the above as separate ideas - income, resilience, cost management, EVs, renewables. But in reality, they’re converging. The same piece of infrastructure can contribute, in different ways, to all of them.

That’s really the evolution we’re seeing. When I first wrote about Battery Box, the message was quite simple: this is a relatively low-impact way of generating income from spare land. That’s still a perfectly valid starting point, and for many estates, it remains the primary driver. But increasingly, it’s part of a much broader conversation about how energy works across a local authorities’ estate:

• how it’s used

• when it’s used

• how reliable it is

• and how much control the landlord or occupiers actually have over it.

  
  

The interesting part is that all of this can be introduced without fundamentally changing the look or feel of a site, given the small nature of BESS installations.

A final thought (and a familiar one) 

There’s a tendency in our industry to focus on the visible, like the frontages, the buildings, the spaces people interact with day to day. But increasingly, value is being created (and lost) in the background systems that support those spaces. Energy is one of them. And batteries (unexciting as they may sound!) are becoming one of the simplest ways of taking a bit more control of that system, whether through income, resilience, or operational efficiency.

As I’ve said in previous pieces, it’s often the overlooked corners of an estate that end up offering the most interesting opportunities. This just happens to be one that is growing in relevance rather than fading away.

If it’s something you’d like to explore

If you’ve got parts of an estate that aren’t doing much, or you’re starting to think about EV infrastructure, solar optimisation or resilience more generally, it’s worth having a conversation. Happy to sense check whether it’s relevant, or just talk through how it tends to work in practice. (And I promise to keep the battery chat to a reasonable level.)