From Weeks to Hours, How BW ESS Simplifies Reporting with A Growing BESS Fleet

Key Takeaways

• Emily’s day runs across three fronts: commercial dashboards (performance, penalties, trading strategy) and operational ones (availability, state of charge, alarms), on top of investor reporting and keeping a multi-country fleet compliant.

• Distribution Network Operator (DNO) -imposed outages are a major operating pain point. With no clear outage schedule across the industry, downtime is hard to predict and out of the operator’s control.

• OEM support in the operational phase lags behind construction. Faults that should take a day to diagnose can stretch out while OEM teams overseas analyze data and grant approvals. BESS analytics lets BW ESS triage internally first and steer the OEM in the right direction rather than starting from a blank slate.

• Consistency across a growing portfolio is a core reporting challenge across the industry, in particular, standardizing methodology and format for every asset, so the data looks the same across sites.

• BESS analytics turns reporting from a multi-day task into a couple of hours and gives BW ESS their own visibility into day-to-day battery behavior — making investor reporting credible by letting them reconcile their figures against OEM data rather than relying on guesswork.

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Emily, what brought you to the BESS industry?

I studied maths and economics and quickly realized after university I wanted to be in a nascent and growing industry, where I could actually help steer decisions and shape the way things are done. Somewhere I'd have real responsibility, make quick decisions, and deploy things. Battery storage was perfect for that.

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As Asset Manager at BW ESS, what does a typical day look like? What are your main responsibilities?

I usually start by going through my dashboards, both commercial and operational.

On the commercial side, I'm looking at performance: have we been penalized for anything? Is there anything I need to question the optimizer about? And is the battery following its bids and offers, or is there something operational I should be flagging?

Then I move to the operational dashboard, which often answers that last question. I look at site availability, state of charge, and any alarms or faults, and I try to triage them. Sometimes everything's fine; sometimes it needs more input.

After that, a large part of my role is reporting to internal stakeholders, but also to banks and investors. That's a lot of downloading data, analyzing it, and adding commentary into slides and reports. And a big chunk of my time goes on staying up to speed with new regulations as they come in, making sure our fleet across different countries stays compliant with cyber security requirements, REMIT instructions, and so on.

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‍In general, what are some of the biggest challenges you see with operating BESS?

The first is having to accept DNO-imposed outages. Sometimes, National Grid imposes an outage on the DNO, who imposes it on us. Across the industry, DNOs don't provide a clear schedule of outages, which makes bankability, scheduling, and reporting difficult. Availability is important for tolling agreements especially, and these DNO-imposed outages that are out of our control can have substantial impact on this availability. Due to this, we have to be prepared and proactive.

The second is OEM maturity in the operational phase. Commissioning and construction generally go well, but technical resources for the operational phase aren’t always properly recruited and planned for. If we have a fault, someone has to go to the site, download the data, and run a root cause analysis. That should be a one-day job, but sometimes it means going back to the OEM's team overseas, waiting for them to analyze and get approval before sending anything back to us. It's a lengthy process.

This is where TWAICE helps. We can triage internally first and steer the OEM in the right direction. We can say "we think it's this, can you check," rather than handing them a blank slate.  

The third is regulation. It's changing quickly, and finding service providers who've caught up, at a reasonable price is tough. Cyber security is a good example: there’s a lot of compliance to meet, but few providers who can help, which makes the ones who can quite expensive.

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What particular challenges do you face in your own role?

For me specifically, the big one is reporting across a growing portfolio. As the number of assets grows, it gets harder to keep everything consistent.  

The key thing is standardizing the methodology and keeping the same format for every asset. Every site has its own complexities, but when it comes down to the data, it should look the same.

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How do you do that?

For the reports, I need KPIs like state of health, round-trip efficiency, depth of discharge, average daily cycles, and so on. I log into TWAICE and pull the data from the warranty page, where I can look at a metric and copy it quickly. That's a ten-minute job. Then I create slides where I present the data in graphs and add commentary behind it — any periods of downtime, why they occurred, whether there was a financial implication. Honestly, the commentary is where most of the effort goes, because the heavy lifting — the data crunching and analysis — is already done by TWAICE.

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How exactly is the TWAICE platform helping you with all this?

It’s saving me a significant amount of time. Data accessibility varies by OEM: sometimes the data is accessible through a portal, but sometimes you have to email the OEM and wait, which can take a couple of weeks. Even when the data is in front of me, it's at least a day to copy and paste it into Excel and validate it: checking for missing data, whether the granularity matches last month, whether it looks sensible. TWAICE cuts that down from a few days, or a couple of weeks, to a couple of hours at most.

Beyond time, the biggest thing for me is peace of mind. Some OEMs are quite secretive about what's actually happening behind the scenes. But there's real value in seeing what's happening day to day. Having TWAICE means we can see that ourselves and take any questions forward with the OEM when we need to.

It also gives us confidence with stakeholders. When we did our first annual performance guarantee and round-trip efficiency test, being able to reconcile our own data against the OEM's data was really valuable. We weren't guessing. We could show that the monthly data we report isn't made up; it tracks accurately alongside the actual site data the OEM sees, and against what the warranty and contracts are set against. So: peace of mind and confidence, those are the two big ones.

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Lastly, what trend in the industry are you most excited about?

The move into European markets, mainly. Commercially it's exciting. The European markets are still emergent, which I find particularly exciting. It'll be interesting to analyze those market trends and capture the lucrative ancillary service opportunities before they mature the way the UK has.

The other is battery augmentation. Some of the earlier players are starting to augment sites to longer duration or repower assets after ten or fifteen years to address degradation. It isn't talked about much yet, because the focus tends to be on just getting sites online. The challenge is to come up with a solution that's practical, minimizes downtime, and is safe. I'm excited to learn how this develops.