Introduction

In the beginning, traditional integrators played an important role in the supply, installation and operations of battery systems. The supply chain was confusing and fragmented. Traditional integrators provided a one-stop-shop with proprietary equipment, software and services. Over time the supply chain for equipment became easier to navigate. Similar to solar, the role of a traditional integrator has diminished because savvy buyers now purchase equipment direct from the OEMs (self-procurement). Along with the emergence of third-party Energy Management System (EMS) companies, a massive shift towards self-procurement has unfolded.

Reasons for Self-Procurement

1. Cost: Traditional integrators add a sizeable margin to the equipment and EPC cost. On a 100 MW / 400 MWh project, integrators add 15% margin (up to 25% margin on smaller projects).
2. Supply Chain and Price Fluctuations: Buyers should have the ability to purchase cost-competitive equipment on a project-by-project basis as pricing and supply fluctuate.
3. Visibility into Risk Exposure: Traditional integrators just pass through the OEM warranties and guarantees. Once LD caps are hit, many integrators reduce support or walk away altogether.
4. Availability: Buyers have become aware that most downtime is caused by inverters and battery thermal management. Instead of purchasing expensive performance guarantees (based on total equipment cost), it is more cost efficient to mitigate this risk by oversizing or purchasing spare parts.
5. Future Flexibility: Integrators that install proprietary equipment and controls can hinder (or even prohibit) the ability to retrofit the EMS. Buyers prefer equipment that can be repurposed and retrofitted in case the original EMS underperforms or becomes insolvent.

Challenges of Self-Procurement

1. Multiple Negotiations and Agreements: Buyers need to separately procure, negotiate and contract the equipment, EPC, EMS and operations. This requires staffing and experience.
2. First Rodeo: New buyers with tight CODs and small projects may fail to get the attention from OEMs and EPCs unless small projects are aggregated into a portfolio.

How Fractal EMS Enables Self-Procurement

1. Competitive Procurement and Contract Support: Fractal consultants can assist Buyers with sizing the equipment, technoeconomic analysis and procurement via RFPs.
2. Universal Controls: There is an ever-growing list of new batteries vendors, Fractal EMS can provide universal controls, reporting and HMI to monitor and operate a fleet of different equipment.
3. Equipment Deficiencies: Some battery OEMs may have excellent pricing, but they may have deficiencies in protections, BMS capabilities (SOC accuracy, p-limiting, etc.), balancing algorithms, and cybersecurity (easy to hack). Fractal provides industry leading controls that compensate for these deficiencies.
4. Warranty Protection: Each OEM has stringent requirements for data to facilitate warranty claims. Fractal EMS provides databases, dashboards, KPIs and alerts to track warranty and off-taker requirements.
5. Technology Expertise: Fractal EMS has deep experience from integrating over ten batteries OEMs and over ten inverter OEMs.
6. Cybersecurity: Fractal EMS implements best practices from NERC/CIP, NIST 800 and ISO 27001.
7. Ongoing Technical Support: Fractal’s 24×7 Remote Operations Center is just a phone call away for inquiries, issues, or troubleshooting of all BESS equipment (inverters, batteries, thermal management, etc.).
8. Features and Customization: Fractal can fulfill owners’ requests for custom features, dashboards and KPIs that may not be available through a traditional integrator’s HMI.
9. Future Augmentations: Fractal EMS is built to facilitate augmentations (AC or DC) by integrating new equipment with the existing equipment.

The Energy Management System (EMS) is the project’s operating system, it is the software that is responsible for controls (charging and discharging), optimization (revenue and health) and safety (electrical and fire).  The EMS coordinates the inverters, BMS, breakers and fire system. But what happens when it does not work well?

There is a trend in the industry to upgrade or retrofit the EMS because of economic and operational issues. Retrofitting the EMS is a big decision, and it is important to plan out the retrofit sequence properly. “About 20% of our deal flow is retrofits,” said Daniel Crotzer, CEO of Fractal EMS.

BMS vs EMS: What is the Difference?

The battery management system (BMS) is often confused with the EMS. The BMS is a simple system that does two things: 1) place the batteries online/offline 2) keep the batteries safe. When starting a BESS, the EMS will request that the BMS place the batteries online (establish the DC bus). If the BMS senses it is safe, then it will carry out the command. While operating, if the BMS senses parameters that are out of range, then it will request that the EMS reduce power (if parameters are violating fault thresholds, then the BMS will open rack contactors).

Compared to solar SCADA, BESS EMS is significantly more difficult. Some owners have found this out the hard way. The EMS has an outsized responsibility compared to its cost. For projects larger than 100 MWh, the following are two cost metrics:

• CAPEX: the EMS should cost less than 1% of project CAPEX for the following scope:
  • Control equipment and control code
  • RTACs and programming
  • Cybersecurity equipment and configuration
  • Networking equipment and setup
  • HMI/historian server and software (including reports)
• OPEX: the EMS annual software license should cost less than 1% of annual revenue (revenue optimization should also cost less than 1% of revenue)

 Reasons for Retrofits

1. The EMS is underperforming or not working:
   1. Stratified SOCs across battery containers
   2. Inability to read and/or diagnose equipment fault codes
   3. Inability to remotely clear equipment fault codes
   4. Inability to overcome OEM local controller issues (if applicable)
   5. Inability to compensate for BMS deficiencies (P-limiting, SOC thresholds, fire alarm issues, etc.)
2. The integrator has maxed out their liquidated damages (and have probably reduced support)
3. Inability to meet ancillary qualification requirements e.g., Fast Frequency Response
4. Poor DC coupled PV + storage performance
5. Cybersecurity concerns
   1. Failure to meet recommendations of NERC CIP, NIST 800 and ISO 27001
   2. Need for on-site controls and servers (i.e., no cloud commands)
   3. CIFIUS requirements (especially if computer boards and code are foreign)
   4. Cyber risk due to a foreign BMS
   5. EMS is outsourcing or off-shoring software development
6. Lackluster HMI/UI experience, historian, analytics or reporting
7. Lack of fire system integration (some EMS provide similar functionality to a FACP)
8. BESS EMS does not properly integrate with the owner SCADA or EMS
9. Poor customer service or outsourced technical support to foreign country
10. Universal fleet control: as the owner accumulates multiple projects, they realize a universal EMS system is preferred
11. The EMS company is insolvent or no longer supports the EMS
12. The EMS is expensive relative to its features

Process and Timeline to Retrofit

The following is a high level summary of the steps and timeline to perform a retrofit.

1. Research the existing project (1-2 weeks):
   1. Equipment and network topography
   2. Project documentation
   3. Deep dive existing issues
   4. Project scope and desired control modes
2. Provide a 60% drawing set of the new EMS (2-3 weeks)
3. EMS equipment procurement and shipment (4-12 weeks)
4. Removal of old EMS equipment (1-2 days)
5. Installation of Fractal EMS equipment (2-3 days)
6. Fractal EMS integration, development, and testing (4 weeks)
7. Commissioning and Substantial Completion (2 weeks)

The decision to retrofit the EMS often comes down to the following themes:

1. The EMS subscription is expensive (more than 1% of annual revenue).
2. The EMS is causing downtime (EMS availability of less than 99% is detrimental).
3. The EMS has cybersecurity concerns or is not addressing foreign equipment risks (e.g., cyber attack through the BMS).
4. The EMS allows the owner to consolidate software for their operations team while keeping the ability to choose different equipment project to project.