Services
Energy Storage Solutions
Battery energy storage systems (BESS) have become a critical part of the electricity system, especially when it comes to the integration of renewable energy, and providing grid stability, among other services. Application possibilities are expanding as competition increases. The value of energy storage is especially relevant when comparing it to alternative investments in the additional infrastructure of distribution system operators (DSOs) and transmission system operators (TSOs).
Enertis Applus+ has been in the global energy storage business since 2018, with an accumulated experience of 15 GWh of installed power.
By combining engineering services for battery materials selection with guidance on manufacturing steps/risks, regulatory impacts, growth strategies, and connections to a network of bankable storage providers and integrators, we assure long-term performance predictability, protect client profits, and lower overall client risk.
A full range of our BESS services are described below:
Development
- PV+BESS modeling for various Independent System Operator (ISO) markets and use cases.
- Site adequacy and capacity verification.
- Creation of the initial site layouts to support early permitting efforts.
- Interconnection application support.
- M&A technical due diligence.
- Bankability reports for BESS equipment suppliers.
Pre-construction
- Fully independent engineering reports for financing.
- Equipment management and EPC request for proposal (RFP) preparation and management.
- Owner’s engineering for all stages of design review prior to mobilization.
- Development of 30% design layouts after equipment is finalized to support EPC pricing efforts.
- Additional BESS modeling to compare results from development stage.
Construction
- Construction monitoring, technical submittal, RFI, and change order.
- Review, tracking, and approval.
- Contractual milestones verification for either the developer or financial lender.
- Quality control inspections of BESS containers at factory and upon on-site arrival.
Commisioning
- Review and management of commissioning and documentation between EPC, equipment suppliers, and owner.
- Capacity testing and round-trip efficiency test validation.
- On-site troubleshooting with BESS supplier, EPC, and owner.
Operations
- Technical analysis and troubleshooting for equipment performance trends relative to equipment agreements or Long-Term Service Agreements (LTSAs).
- Periodic performance review and evaluation of augmentation strategy.
Highlighted projects

Creek Portfolio
Country: US
Capacity: Over 280MW PV, with approx 400 MWh of Energy Storage, in total
Service(s): Owner’s Engineering
Client(s): Carolina Solar Energy
This portfolio is composed of five PV Projects, featuring 50-60 MW PV per site and an average of 100MWh of long-duration Energy Storage (ESS) at 4 of the total sites.
Enertis Applus+ is grateful to work as Owner’s Engineer, while Carolina Solar Energy and the project entities successfully developed and advanced this portfolio. Interconnection Applications (IA) were completed and approved by the affected utilities for PV + ESS operation at all 5 locations. Enertis Applus+ worked closely with Carolina Solar Energy Commercial and Engineering professionals to establish the Basis of Design documents, engineering, PV+ ESS energy modeling, and provide other support and advice to the projects.

Slate Project
Country: California, US
Capacity: 300 MWac solar + 140.25 MW / 561 MWh storage
Service(s): Independent Engineering for PV System
Client(s): Confidential
Enertis Applus+ acted as Independent Engineer in the Slate project, located in Kings County, California. It is expected to be one of the largest projects in the U.S. In January of 2021, Recurrent Energy completed the sale of the Slate Project to Goldman Sachs Renewable Power LLC.