AE 868
Commercial Solar Electric Systems



Lesson 3 Scenario

At the same international solar trade show, you come across an old friend who represents one of the most well known battery manufacturers in the business. In your conversation, you learn that this company has storage solutions specifically for PV applications.

Assuming you have some PV off-grid projects for which you need battery solutions, the representative starts going over the types of lead-acid batteries they offer, such as flooded lead-acid (FLA) and valve-regulated lead-acid (VRLA). They differ by depth of cycle, maintenance requirements, and other features.

You leave the trade show with more datasheets for other batteries. The next day you need to present to your director a report with different battery types and evaluations for the performance of each type. You are also expected to recommend the best match for the application your company is working on.

What do you look for when selecting the battery type? Is it the efficiency, operating temperature ranges, or capacity rate?

How do you connect batteries for that application, in series or parallel or both?

In this lesson, we will discuss topics that lead to answers to all the questions in the scenario above. We will provide PV designers with a basic understanding of batteries to help them choose the best battery to fit their application. Although the majority of PV applications are grid-connected, designers may encounter off-grid PV systems with storage systems if they are involved in that market sector. That said, participating in this lesson will put you in the right direction when selecting the right technology for your application and will help you perform basic assessments for optimal design.

Learning Outcomes

At the successful completion of this lesson, students should be able to:

  • Identify types of electrical energy storage technologies and how they relate to (Energy or Power) responses.
  • Identify battery parameters and specifications including capacity, efficiency, discharge rate, state of charge and depth of discharge.
  • Interpret battery manufacturer datasheets to match PV system requirements.
  • Describe factors that influence the lifetime of a battery, such as temperature and charge and discharge control.

What is due for Lesson 3?

Lesson 3 will take us one week to complete. Please refer to the Calendar in Canvas for specific timeframes and due dates. Specific directions for the assignments below can be found within this lesson and/or in Canvas.

Complete the following Lesson Assignments:

  • Read through the Lesson Content
  • Complete the Required Reading Assignments:
    • Chapter 6, Photovoltaic Systems by James P. Dunlop (text)
  • Look over the Recommended Readings:
  • Take the Lesson 3 Quiz in Canvas
  • Continue working on your Procurement Report (Part B)


If you have lesson specific questions, please feel free to post to the Lesson 3 Questions discussion forum in Canvas. While you are there, feel free to post your own responses if you, too, are able to help a classmate with a question. If you have questions about the overall course or wish to share and discuss any "extra" course related commentary (interesting articles, etc.), please feel free to post to the General Questions and Discussion forum.