Smarter operations and faster decisions in Energy: enabled by a cloud-based historian

Introduction: data modernization challenges and on-premises solutions in the power industry

In the power industry, modernizing data infrastructure is especially challenging due to strict cybersecurity mandates, data residency rules, and the need for real-time reliability.

Furthermore, energy systems are inherently hybrid. They rely on a distributed patchwork of OEMs, protocols, and on-premises infrastructure, often in remote or isolated locations. These realities have led asset owners and operators to anchor their data strategies in legacy on-premises data historians, most commonly OSIsoft PI (now AVEVA PI).

Although PI has served the industry well for decades, its on-premises architecture now poses challenges for scalability, integration, and cost-efficiency in today’s cloud-first environment. Many energy companies are finding that:

It is inflexible, closed: Data is difficult and costly to move out of the on-premises PI ecosystem, limiting access to cloud tools, third-party analytics, or integration with modern applications such as artificial intelligence/machine learning (AI/ML) frameworks.

It lacks scalability: Technology relies on tightly coupled, on-premises architecture, needing manual configuration for new data sources.

It is increasingly expensive: With little competition, PI can impose steep, unpredictable costs, such as a recent revenue model overhaul that increased price by 25-50%.

In an era demanding more insight-driven, agile, and cost-effective solutions, on-premises historians such as PI have become a bottleneck.

The cloud-based historian purpose-built for energy

Nexalis is a cloud-native data platform built to replace legacy on-premises historians in the energy industry. It provides the same foundational functionality—real-time ingestion, secure storage, and data standardization—but with the scale, flexibility, and openness of the cloud.

1. The solution

In short, the Nexalis Platform connects to data sources through its Nexalis Agent—which is adaptable to the industry’s wide variety of protocols (for example DNP3, OPC, Modbus)—and sends the data to the Nexalis Cloud (observe Deployment Options for the Nexalis Cloud in the following figure). Here, data is centralized, standardized with AI, and made available in both structured and raw formats. The platform supports both hot and cold data use cases, offering sub-second refresh rates to the cloud, as well as multi-year historical access. Nexalis uses HAQM Web Services (AWS) services such as HAQM S3, HAQM Elastic Compute Cloud (HAQM EC2), and AWS Identity and Access Management (IAM) through a carefully architected design tailored for industrial data management.

Figure 1. Nexalis platform: high level architecture

2. Cybersecure, designed for Energy

To address the unique security concerns of the industry that maintains our power supply, Nexalis differentiates itself by not needing users to hand over their data infrastructure to a vendor-controlled environment. Instead, the platform offers flexible deployment options for the Nexalis Cloud, providing full alignment with the user’s internal policies, cloud governance standards, and resource constraints. Deployment options for the cloud environment include the following:

Regardless of the deployment model chosen, all data is always ingested into client-dedicated environments, with fine-grained access policies controlled by the client.

Core AWS security features used by Nexalis include the following:

• HAQM S3 and HAQM EC2 for highly scalable, encrypted storage and compute
• IAM for granular access control
• Delta Sharing (through Databricks) for secure, governed data sharing
• HAQM Virtual Private Cloud (HAQM VPC) deployment model, allowing Nexalis Cloud to run within the client’s AWS environment
• Compliance-ready architecture, aligned with ISO 27001, SOC 2, NERC CIP, and more

3. Streamlined implementation and maintenance

As well as security concerns, the implementation and maintenance of a data historian often pose the most significant operational challenges. Data-producing energy assets are in remote places, with minimal IT infrastructure onsite, and involve a variety of site-level data complexities. This includes inconsistent data tag structures and variable site connectivity. On-premises historians handle this by forcing operators to deploy complex software stacks locally and need high-touch IT support to maintain integrations and long-term reliability.

Nexalis fundamentally streamlines this landscape. Its Extract, Load, Transform (ELT) architecture means that raw data is collected at the edge without needing preprocessing or transformation on-premises. This shifts the bulk of data handling to the cloud, dramatically reducing the complexity and resource load at the site level. The Nexalis Agent is lightweight, easily deployed on a local virtual machine or industrial PC and updated remotely. When it’s installed, AI-driven data mapping in the Nexalis Cloud eliminates manual configuration and allows for rapid onboarding, even when assets use varying data models.

Therefore, from initial credential access to standardized, accessible data in the cloud, Nexalis can onboard assets across hundreds of megawatts in under an hour. Traditional solutions such as PI can take weeks or months to reach the same point.

4. Powerful data standardization

An ELT architecture means users retain full control over how data can be modeled and structured once in the cloud. By default (but modifiable by users), Nexalis applies an IEC 61850-based standardization framework, unlocking the normalization of data across hundreds of OEMs into a consistent, hierarchical format. The result is a single, reliable source of truth—where every inverter, turbine, or battery reports with the same semantics, no matter the vendor. This consistency is essential for energy operators looking to scale analytics, automate reporting, or run generative AI models.

A modern model for data enablement

Legacy systems bundle data historian, visualization, and analytics tools into a single vendor-controlled stack. This turnkey model was once the industry standard because it provided directness, but today it’s limiting—locking data into closed ecosystems, slowing innovation, and preventing companies from accessing new technology as needs evolve.

Nexalis takes a modular approach. It serves as the data foundation, while clients get to choose (or build) the applications for analytics that use the data. This strategy frees users from vendor lock-in, allowing them to adopt or swap analytics tools without reworking the underlying data infrastructure, and making sure that they only pay for tools that add value. Furthermore, decoupling data enablement from applications means clients have a vendor—Nexalis—focusing exclusively on data connectivity and standardization, unlocking optimized onboarding solutions yet-to-be-built by traditional, turnkey vendors.

Some examples of best-in-class applications that Nexalis integrates with are as follows:

NarrativeWave: for asset performance monitoring
Seeq: for time-series advanced analytics and enterprise monitoring
APERIO: for operational data quality
AWS AI/ML and generative AI tools: for forecasting, anomaly detection, and intelligent automation (for example HAQM SageMaker, HAQM QuickSight, HAQM Q)

On average, the end-to-end replacement of PI with Nexalis and an accompanying analytics vendor yields 50-75% savings for the user, as shown in the following figure. All of this is possible because Nexalis delivers data in a clean, structured, cloud-accessible format, enabling innovation without complexity. Decoupling data infrastructure from applications allows Nexalis to deliver future-proof connectivity, enabling faster onboarding and integrations that traditional platforms weren’t designed to support.

Figure 2. PI and Nexalis: feature comparison

Core AWS components used by Nexalis

1. HAQM EC2

Provides scalability and flexibility for Nexalis cloud workload demands (for example ingestion, transformation jobs).

2. HAQM S3

Central to data storage within Nexalis. Stores raw, structured, and standardized datasets, with fine-grained access control.

3. HAQM CloudWatch

Provides monitoring and observability across all services and performance indicators.

4. IAM

Makes sure of secure and role-based access control across all Nexalis-managed resources and client data.

5. HAQM Virtual Private Cloud (HAQM VPC) and Networking Services

Used to isolate and secure Nexalis infrastructure, enabling hybrid or private connectivity when needed.

Conclusion

The energy industry is evolving quickly, and it needs data systems with the agility to keep up and accelerate progress. Nexalis offers a modern, cloud-based alternative to legacy historians, built to streamline data onboarding, reduce complexity, and unlock real-time insights across operations. Returning data control to the user allows Nexalis to enable faster decision-making and the long-term flexibility needed to manage multi-gigawatt operations. For companies ready to move beyond outdated systems, Nexalis provides a scalable, secure, and future-ready solution. To learn more about cloud-based data historian, go to Nexalis.