Navigate Grid Uncertainties with Confidence
Driven by Expertise: Delivering Timely, High-Quality Services and Solutions.
With over 70 years of combined experience in electric utilities, renewable development, and engineering consulting, our team deeply understands our customers' needs and challenges.
We prioritize timely delivery without compromising quality. Our streamlined processes and dedicated team ensure that we meet your deadlines, helping you achieve your renewable goals promptly and effectively
ZEG provides advanced Hardware-in-the-Loop (HIL) testing services for model validation and real-time studies of large-load, inverter-based, and power-electronics-based systems under realistic grid conditions. HIL testing provides the closest possible representation of real-world system behavior.
Using advanced real-time simulators and industry-standard protection and control interfaces, we replicate real-life operating conditions, disturbances, and fault scenarios to evaluate system behavior, performance limits, and compliance risk. Our HIL services support utilities, OEMs, developers, consultants, and data center operators in identifying issues early, reducing deployment risk, accelerating project timelines with confidence, and improving reliability.
HIL service capabilities include:
- Power electronics controller testing (inverters, STATCOMs, HVDC)
- Power system co-simulation and digital twin development
- Grid connection and impact assessments for IBRs, DERs, data centers, EV charging, and storage
- Real-time simulation using RTDS, Opal-RT, and Typhoon HIL platforms
- DER & microgrid control testing
- Protection system validation (IEC 61850, relay testing)
- Cybersecurity assessment of power system controls
- Digital substation & communications testing
HIL Testing Capabilities
Power Electronics Controller Testing
Validate inverter, STATCOM, and HVDC control systems under realistic grid conditions, including disturbances, faults, and operating edge cases.
Co-Simulation & Digital Twins
Build EMT/RMS co-simulation environments and digital twins to evaluate system interactions, control–protection behavior, and multi-timescale dynamics.
Real-Time Simulation Platforms
Run closed-loop simulation using RTDS, OPAL-RT, and Typhoon HIL to validate controller, protection, and system performance under realistic conditions.
Grid Connection & Impact Assessments
Assess grid impacts for IBRs, DERs, data centres, EV charging, and storage—covering voltage, frequency, system strength, and protection interactions.
Protection System Validation
Test protection and control schemes using IEC 61850 and relay-based systems to verify settings, coordination, and performance across fault scenarios.
DER & Microgrid Control Testing
Evaluate DER and microgrid control behavior in closed-loop environments to confirm stability, ride-through capability, and operating limits.
Digital Substation & Comms Testing
Validate digital substation architectures and communications performance across protection, control, and interoperability workflows.
Cybersecurity Assessment
Assess cybersecurity risks and vulnerabilities in power system control environments, including interfaces, protocols, and operational scenarios.
Proven Results, Backed by Experience – Request Our Statement of Qualifications
Expert services for a greener world, one grid at a time.
ZEG Service Offerings
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Siting and Sizing
We identify optimal locations for energy infrastructure considering regional criteria, grid and market dynamics, and determine the right size to maximize performance.
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NERC/FERC Compliance
Technical analyses supporting MOD-25/26/27/32, PRC-005/019/024/025, VAR-002, FAC-002/008.
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Nodal Market Analytics
In-depth analysis using benchmarked proprietary models to inform strategy and optimize project development.
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Interconnection Application
Guidance through generation and large-load interconnection applications—meeting requirements with proven ZEG-level timeliness and quality.
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Comprehensive Modeling
Standards, methods, and procedures for complex analytics across conventional and emerging technologies, including grid-following/forming inverters, FACTs, and GETs.
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Shadow System Impact Studies
Load flow, transient stability, and sub-synchronous analysis mirroring TO/ISO/RTO assumptions and methodology.
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Electrical Studies
Load flow, short circuit, arc flash, grounding, CYMCAP ampacity; advanced analyses: reactive power, islanding, harmonics, transients, TRV/TOV, Volt/Var optimization.
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Technical Due Diligence
M&A and ISO/RTO decisions: system impact reviews, deliverability, cluster studies, shadow impacts, and cost-allocation assessments.
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Engineering Stamping Services
Certified PE stamps across states—documentation review & approval to meet state-specific requirements and streamline approvals.
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SLD, Site Layouts, String Optimization, Energy Yield
Concept & preliminary layouts (solar, BESS, gas, co-gen, data centers); SLDs, trench plans, feeder schedules, area maps, shading/terrain optimization, yield estimates, irradiance, string optimization, preliminary BOM/CapEx/OpEx.
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Reliability & Economic-Based Transmission Planning
Analyses per applicable regional criteria to identify issues and mitigation for reliability constraints or congested flowgates.
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ISO/RTO Registration, Energization, Commissioning
Interconnection agreement reviews, electrical studies, forms, commissioning tests, data collection, and post-commissioning model validation.
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Detailed Design Packages
30% / 60% / 90% / IFC drawings: grounding/bonding, conduit transitions, trench & crossings, equipment elevations, SLDs—build-ready for permitting & construction.
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Energy Yield & Performance Modeling
PVSyst and 8760 (P50–P99), annual loss reports, voltage drop, feeder sizing, CYMCAP ampacity—supporting financial models and system optimization.
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Hardware-in-the-Loop Testing Services
End-to-end validation for controls, protection, and communications.
- Power Electronics Controller Testing
- Protection System Validation
- DER & Microgrid Control Testing
- Digital Substation & IEC 61850 Testing
- Cybersecurity Assessment of Power Systems
HOW REST® WORKS:
Meet REST®, our comprehensive tool that strategically addresses the industry's key challenges.
Designed to meet current and future standards, REST® provides invaluable support handling critical aspects of energy resource siting such as grid data precision, anticipated transmission capacity, streamlined interconnection processes, and more.
Leverage REST® to:
- Conduct Congestion Analyses
- Assesses Resource and Real-Estate Availability
- Evaluates Anticipated Transmission Capacity
- Determines Grid Data Precision
- Optimizes the Interconnection Process
FAQ's
Since 2022, ZEG has been dedicated to advancing the future of power grid interconnection. We provide tailored consulting services to developers, asset owners, operators, independent power producers, and other key stakeholders, with a focus on building a sustainable, renewable energy grid.
Our team consists of industry veterans with over 70 years of collective experience in power grid consulting, electric utilities, and renewable development. This diverse expertise enables us to deeply understand the unique challenges of our clients and support their decarbonization goals effectively.
ZEG works with a wide range of clients, including developers, asset owners, operators, independent power producers, and other stakeholders in the energy sector. We collaborate closely with both industry leaders and forward-thinking customers committed to driving a sustainable, zero-emission power grid.
At ZEG, we believe that collaboration is key to overcoming the inertia of the industry. We partner with stakeholders to drive a zero-emission, reliable power grid. Our approach is rooted in agility, creativity, and innovation, which are the principles that inspire our mission and services.
Our team brings extensive knowledge and expertise to help our clients achieve their decarbonization goals. We provide customized solutions, strategic advisory services, and innovative tools to support the transition to a renewable, sustainable energy grid. Through our services, we help clients navigate the complexities of the power grid interconnection process.
Yes, ZEG operates across all major North American ISOs/RTOs, including CAISO, ERCOT, ISONE, MISO, PJM, SPP, WECC, and SERC, covering 80% of the U.S. power grid.