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).  Overall, the cost of an EMS is an insignificant part of the total system cost, however, the performance and capabilities of the EMS can have an outsized effect on project availability.

There are several EMS companies in the energy storage market, other than cost, the following differentiators should be considered prior to selecting a BESS and/or Solar EMS.

On Premise vs. Cloud Solution. Fractal EMS is an on-site solution with cloud data backup (air gapped). On-site controls are a requirement for large projects with NERC CIP policies.

Renewable Energy Integration. Very few BESS EMS providers also offer solar controls. Some offer just a dashboard in lieu of actual controls. In addition to BESS controls, Fractal EMS also offers solar-only controls, as well as AC and DC coupled PV+S.

Controller Capabilities. Some EMS companies cannot communicate with multiple container BMS behind a single inverter (they need a BMS aggregator to create a single connection). Fractal EMS can handle multiple connections and P/Q commands (e.g., 13 devices: 1 solar inverter, 6 DC converters, and 6 BMS).

Cyber Security Capabilities. EMS providers can have various VPN options, security frameworks and standards. Fractal EMS follows best practices from NIST 800-53, ISO 27001 and NERC/CIP and has in-house cyber security and IT expertise. Fractal EMS is also NERC CIP medium compliant in our remote 24/7 monitoring center.

Controller Hardware. Fractal EMS controllers are built to run real-time controls for power plants and have a mean time between failure of 40 years. Some EMS companies use cheap industrial PCs or use virtual machines running on one server (single point of failure).

Controller Installation Flexibility. Fractal EMS equipment is rated for at least -40 C to 70C. This means the equipment can be housed in field network enclosures (FNE), normally without thermal management.

Commissioning Time. Some EMS providers commission on time, some do not. This can create exposure to LDs for the contracting party, and missed market revenues. Fractal EMS has an excellent track record for commissioning projects on time.

Master Plant Controls. Some EMS providers also provide a Master Plant Controller (MPC) on top of hybrid (PV+S or Wind+S) projects. MPC is essential when there is more than one resource ID sharing an interconnection. Fractal EMS can provide a MPC that coordinates between solar, wind and/or BESS while maintaining interconnection requirements.

Point of Origin. The EMS provider may use equipment manufactured domestically or manufactured abroad. The point of origin for equipment may introduce cyber security concerns. Fractal EMS main equipment (controllers, network switches, SCADA devices, and servers) are domestically sourced.

Response Time. Response time varies across EMS companies. Controls latency (including metering and communication latency) can hinder participation in specific wholesale market applications that require fast response. Fractal EMS will identify and then issue a power command to the inverters in 49 ms. Fractal EMS has successful passed qualification and has assets under operations providing ERCOT FFR, CAISO Regulation, PJM RegD and AEMO FCAS.

Networking. Not all EMS providers can provide networking. Networking influences response time, availability and cyber security, thus it goes hand-in-hand with the EMS. Fractal EMS networking is performed in-house. Fractal designs, installs, tests, and commissions the network to include firewalls, VPNs, VLANs, and modems (including cellular backup).

SCADA Integration. Not all EMS providers can program SCADA (RTAC programming and SCADA layer integration via RTU – substation configuration and integration is especially difficult). Fractal EMS uses RTACs which serve as a protocol gateway to establish telemetry with entities outside of the EMS network. Fractal EMS RTAC programming is performed in-house.

Monitoring. Some EMS provides say they provide monitoring but they only monitor their controllers and Web Interface, not the entire BESS. Some providers off-shore monitoring and technical support to a third-party. Fractal EMS has options for business hours and 24/7 monitoring. Fractal EMS monitors the entire project, while providing round the clock technical support and troubleshooting from experience operators out of our Austin, Texas facility. The Fractal EMS remote operations center is NERC CIP compliant.

Domestic Content. Some EMS controllers use chips or printed circuit boards (PCBAs) manufactured in countries on the Foreign Entity of Concern (FOEC) list (e.g., China, Russia, and Iran). Fractal only uses chips from the USA or Europe. EMS can be complimented with Fractal’s U.S. made Battery Management System (BMS) with advanced chip technology to increase cybersecurity and create the ability to perform remote updates.

Availability / Uptime. Some EMS companies start the clock on “notification of downtime” and some start the clock at the downtime event. Fractal EMS provides a base 98% Availability Guarantee starting from the downtime event. As an option, this guarantee can increase to 99.5%.

Speed of Integration with New Suppliers. The number of man-hours required to integrate with new make/models of batteries and PCSs significantly varies across EMS providers. Most vendors take 2-3 months to integrate with a new equipment vendor. Fractal EMS takes 2-3 weeks.

Data Capture and Retention. The periodicity of data capture (1-10 sec) and data retention (1-5 years) can vary drastically across EMS providers. Fractal EMS captures all data once per second (with the ability to capture 20 parameters at 100 times per second). Fractal EMS stores the data for a minimum of 5 years.

Remote O&M. Does the EMS provider offer operations and monitoring (or are they outsourcing it)? To achieve high uptime, it is critical to have experience engineers troubleshoot and restore the BESS. Some EMS providers charge for monitoring but they are only monitoring their devices and software, not the entire plant. Fractal EMS has a remote operations center (ROC) located in Austin, TX and monitors the entire asset. The ROC is staffed by former Navy Nuclear engineers. The Fractal EMS staff has 12 years of O&M experience (including preventative and corrective maintenance).

Bid Optimization. Some EMS providers provide bid optimization and scheduling services to support wholesale market participation. There are significant variations in commercial terms, cost and effectiveness (50 to 90% of perfect) across market players. Fractal Optimization service has outperformed other players in the market across competitive trials. The service includes RT and DAM forecasts, optimized offer curves, settlement summaries and weekly performance reports.

Software Team and Capabilities. Some EMS providers outsource software development overseas or have limited in-house capabilities which can introduce vulnerabilities or limit development progress. Fractal’s EMS software team is in-house. This enables fast response when an issue is discovered.

Historian. Ease of access and ability to visualize data can vary across EMS providers. Fractal EMS provides an on-site and off-site historian to enable troubleshooting and analytics. The off-site historian is for storage of warranty data.

HMI Features. The HMI experience (features and usability) varies across EMS providers. Some owners may need robust reporting, analytics and dashboards. Fractal EMS has industry leading dashboards, reporting and analytics. Plus, all these features are accessible with one login.

Company Resources. Some EMS providers may not have enough headcount or redundancy to support several concurrent projects. Fractal EMS has multiple teams that can integrate concurrent projects.

BMS Deficiencies. Some BMS lack protections, features, and/or p-limiting capabilities. Fractal has experience building BMS, hence Fractal EMS can add missing BMS features.

Pricing. Most EMS providers are priced similarly (the typical difference is about one day of Delay LDs). Fractal EMS provides straight forward pricing with a history of on-time COD.

If you are experience commissioning / operational issues, or would like a demo, please contact us at info@fractalems.com.

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.