LAB 5: Problem Solving and Risk Assessment with Photovoltaics
Running Time: 2 hours. This lab can also be divided into two labs, the first being 30-45
minutes and the second being 1:15.

Lab Introduction: This lab introduces students to different kinds of solar
photovoltaics and the tradeoffs associated with each. It requires that students learn
how to do basic calculations regarding different aspects of solar pv using Excel.
For students already familiar with Excel and with quantitative skills, these
calculations will be very easy. For students without these skill sets, they will be
rather confusing. The calculations are set up to help these students walk through
the process. The lab assumes both kinds of students (quantitative and nonquantitative) are in the same lab class, and at some points divides students based
on their existing disciplinary training (i.e. the non-quantitative students do more
calculations and the quantitative students do research into the social aspects of
each kind of solar pv). If this is not the case, the lab should be adapted to meet the
needs of your students.

Learning Goals:
1. Engineering design process goal: Evaluating tradeoffs between solar
technologies.
2. Sustainability content goal: Gain a basic understanding of different
photovoltaic technologies, attendant risks and hazards in manufacture and
use.
3. Sustainability content goal: Evaluate the benefits of
decentralized/centralized solar power generation
4. Professional/technical skills: Learn to use Excel to for basic calculations.
5. Quantitative skills: Conduct basic calculations about energy use and
simple power conversions.
6. Quantitative skills: Applying quantitative reasoning to inform decisions.

Activity
1. Step 1: Solar Basics. If this information has not already been covered in
class, you will need to begin this lab with a brief discussion of a few key
points about solar energy. Specifically, you will need to define solar
insolation, pv peak power rating, and different ways of measuring power
(see the lab website).
2. Step 2: Calculations with the whole group: Walk the group through the
calculations in Questions 1, 2, and 3. This should be done slowly with the
goal of preparing the non-quantitative students to build on these
calculations when doing the in class work (or homework, if divided into
two labs) that follows.
3. Step 3: Individual work.
 NOTE: If you want to divide this lab into two, the class should be
divided into Groups A and B as discussed below, but Step 3 should
be done as a homework assignment. For one longer lab, proceed as
described.
4.
5.
6.
7.


a) Divide the class into two groups. Students should be in Group A if
they found the calculations in Step 2 challenging. They should be
in Group B if they found the calculations easy. Self-selection into
groups is fine.
b) Give them 20 minutes to complete the in-class work described on
the lab website. Work should be done individually, with assistance
from the instructor as needed.
Step 4: Calculations on Excel. Divide the class into small groups. These
should not be their normal groups, but rather should as much as possible
have people from both Group A and Group B in each small group. Have
each group download the Solar PV Worksheet and complete Steps A
through I. The purpose of this is three-fold. First, it furthers quantitative
skills (though the calculations are quite easy). Second, it provides
information on each type of solar pv that will be necessary in the steps to
follow. Third, it should be used as an opportunity to teach students the
basics of Excel use (formulas, etc.).
Step 5: Evaluating trade-offs. At this point each group will start taking the
information they have gathered and begin evaluating the trade-offs
between different kinds of solar installations. They should be recording
the group’s responses to the questions on the Solar PV Worksheet, but the
important thing here is to have them start discussing and thinking about
trade-offs and determining the optimal solar PV technology for the UCSC
campus site..
Step 6: Class Discussion. Beginning with the questions on the lab website
(Which solar technology would you pick for installation at UCSC and
where would you put it? How did your group come to this decision? What
trade-offs did you have to make (efficiency vs. cost, etc.)? ), facilitate a
whole group discussion about solar installations, trade-offs, and how such
decisions can/should be made. Help them make explicit the criteria they
were using in deciding on an optimal solar PV technology.
Step 7: Centralized vs. Decentralized Sites for Solar Power Generation.
This step further complicates the debate about optimal PV technologies.
Students will first do a handful of calculations (again on their Worksheet),
then further complicate the issue by researching ecological and political
issues around putting solar panels in the Mojave. The final questions ask
about the democratic potential of centralized vs. decentralized generation.
If time allows, each group should discuss these questions and record their
answers on the Worksheet. If time is running short, a whole class
discussion on these questions is fine.
Written Work: At the end of this lab each person should individually submit or
upload their in-class work from Step 3 (or homework if done as two labs). Each
group should submit or upload their Solar PV Worksheet.
There IS pre-lab homework for Lab 6.