EPC Efficiency: How the Right EPC Ensures Battery Storage Projects Stay on Time and on Budget

Battery energy storage systems (BESS) offer one great advantage for clean energy projects: flexibility. They can either operate independently, or pair seamlessly with solar and wind assets. They strengthen grid resilience, improve project economics, and maximize the impact of renewable energy. 

But getting these projects delivered on time and within budget requires deep experience. Even small details—like selecting the right wire gauge or material—can impact performance, compliance, and commissioning timelines. That’s why finding the right EPC partner can make all the difference between an on-budget, on-time project and one with expensive delays. 

What Causes BESS Project Delays and Cost Overruns?

Some delays, like extreme weather, are unavoidable. However, the right EPC partner will prevent many common issues early on. Here are several common risk factors that the right EPC can predict and mitigate:

• Long-lead components: Specialized equipment like main power transformers, switchgear or MV transformers can have very long lead times. If not accounted for in the original plan, such procurement delays can derail entire project schedules.

• Permitting slowdowns: Navigating approvals from utilities, ISOs, and local agencies (like fire departments) takes time. Without a clear process, these steps can drag on and cause costly hold-ups.

• Poor coordination: Late-stage design changes or weak communication between EPCs and OEMs often lead to scope creep, misaligned schedules, and unexpected costs.

• Documentation mismatches: When spec sheets, drawings, and manuals aren’t updated in sync, gaps between documentation and what’s actually installed can result in errors and rework.

How Experienced EPCs Keep Projects on Track

Experienced EPCs know how to anticipate and navigate challenges with strategies including:

• Schedule alignment: A knowledgeable EPC understands timelines for each utility’s approvals and permitting requirements, building them into the master schedule from day one. For instance, our team’s familiarity with ERCOT commissioning timelines, which differs from projects connected to the national grid, allows us to put together a realistic schedule for the project for each region.

• Code compliance: Familiarity with local codes and standards means fewer surprises during review. Strong EPCs also facilitate communication between fire departments and owners early in the process, to ensure compliance with fire safety regulations like NFPA 855.

• OEM coordination: Project Owners involve multiple BESS Equipment vendors at the development/early design stage. A seasoned EPC has a good understanding of design and construction requirements that varies with each OEM and therefore, provides higher costing confidence, mitigating risk of design variations, and coordinating deliveries with OEM logistics companies to ensure seamless process.

• Site logistics: An EPC that expertly manages site availability – for instance, by providing the unique environment needed for testing and commissioning with temporary power generators – can prevent last-minute surprises or delays.

  
  

Strong EPCs also build testing and commissioning protocols into the schedule from the start, not as an afterthought. Combined with rigorous QA/QC practices, this approach catches issues early, reduces rework, and helps maintain budget and delivery targets.

What to Ask Your BESS EPC

When EPCs are involved early in the project lifecycle, they can help manage long lead times, support procurement strategy, and optimize BESS placement for space and cost efficiency. Early coordination also allows the EPC to identify value engineering opportunities that reduce overall system costs without compromising performance.

Here’s what to ask your EPC partner to determine whether they’re a good fit for your project: 

• Have you worked with this storage technology (PCS, EMS, BESS container) before? 

• What experience do you have with the specific utility interconnection process and regional ISO? 

• Can you show a track record of past storage projects delivered on time and on budget in similar conditions? 

• Can you show me details of past BESS projects?

• Do you have internal teams, such as an in-house engineering team, in-house safety and quality team, and in-house supply chain team, or are these roles subcontracted? 

• What is the field experience of the project management team? 

How We Keep Projects On Time and In Budget

At CS Energy, we’re proud to be an industry-leading EPC with over 725 MWh of completed energy storage projects in multiple states. To move projects forward while staying within budget and on schedule, we: 

• Act quickly and responsively, engaging in projects early and adapting nimbly to feedback 

• Remain highly transparent and communicative throughout the course of a project 

• Employ in-house teams with deep engineering expertise so that we can offer cost and timing outlines confidently

This focus allows us to deliver projects with the highest standards of safety, quality, and social responsibility to best serve our clients, employees, and communities. We’re committed to upholding this track record of success as we expand the battery storage capacity across the country.

Looking to streamline your next solar or battery storage project?

Connect with our EPC team to learn how we deliver high-performance BESS solutions—on time, on budget, and built to last.