Battery Energy Storage Systems (BESS): Design, Controls and Safety

A BESS is a set of rechargeable batteries with power conversion and control equipment that stores electricity and releases it to the grid or a site when it is needed. The International Energy Agency calls battery storage the fastest growing power technology today, reporting that 108 GW of new battery storage capacity was deployed worldwide in 2025, 40% more than in 2024, and that around 80% of it was utility-scale. This course follows a BESS from the cell to the grid connection, for both grid-scale and commercial systems.

Because lithium iron phosphate (LFP) cells are typically cheaper and better suited to frequent cycling than the chemistries common in electric vehicles, even though they are less energy-dense. According to the International Energy Agency, LFP batteries now account for around 90% of battery storage deployments. The course compares LFP and NMC for stationary use, and you need no battery chemistry background to follow it.

MW is the power a battery can deliver at any moment, while MWh is the energy it holds, and dividing MWh by MW gives its duration in hours. The International Energy Agency reports that most battery projects still cluster around two hours, with a growing number deployed for four hours or more as power systems take on more solar. The course works through MW versus MWh, duration, C-rate and round-trip losses with calculations you can repeat in a spreadsheet.

Electrical engineers, solar engineers and project engineers moving into battery storage, and anyone specifying or reviewing a BESS. Basic electrical theory, including active and reactive power, is assumed.

No. The course explains what you need about lithium-ion cells, LFP and NMC, and ageing from the start.

Yes. It covers UL 9540, the UL 9540A test method including large-scale fire testing, NFPA 855, and explosion control, and works through what real BESS fires have taught the industry.

Both. The principles are the same from a factory battery to a utility plant; the worked examples use both.

Yes. Every module, the notes, the project and the final assessment. The only paid item is the certificate, if you want it.

An EDWartens Certificate of Completion, issued when you pass the final assessment, with a number anyone can verify on our site.

About 4.5 hours of video lessons, plus time for the notes, worked problems and practice questions. Allow about 10 more hours if you do the optional project.

No. EDWartens is not affiliated with UL Solutions or NFPA, and this course does not replace formal training on their standards. It teaches you to read a UL 9540A report and apply the ideas behind NFPA 855, which is a sound grounding before any paid standards course.

No. The lab is optional practice. You can skip it whenever you like, and it never blocks your progress, the final assessment or your certificate.

Yes. Every lab level for this course opens in your browser, free, with nothing to install.

The Battery Energy Storage Systems course has 9 modules. It opens with "What a battery energy storage system is", goes through "Every component, explained", "Power conversion systems", "Sizing, and solar plus storage" and "Learning from BESS fires" and ends with "Final Assessment". The full list with minutes is under "What you learn" on this page.

After the Battery Energy Storage Systems course: Tell MW from MWh and calculate duration, C-rate and round-trip losses; Name every part of a BESS from cell to MV switchgear; Compare LFP and NMC chemistry for stationary storage. These are the practical outcomes the course is written around, and the final assessment of 15 questions checks them.

For the Battery Energy Storage Systems course, software: None required. A spreadsheet for the sizing calculations. Hardware: none. The course itself is free.

Battery Energy Storage Systems is rated intermediate. Intermediate. You should know basic electrical theory: AC and DC, three-phase power, active and reactive power, and what an inverter does. No battery chemistry background is needed. It is written for electrical, solar and power engineers working on battery storage, and takes about 7.5 hours at your own pace.

Skills from the Battery Energy Storage Systems course (for example: tell MW from MWh and calculate duration, C-rate and round-trip losses) are used in roles such as energy engineer, power systems engineer, solar or EV technician and site engineer, and in energy storage engineer work. The course gives you practical evidence of the skill; it does not promise a job, and employers decide on experience and interview.