EME 810
Solar Resource Assessment and Economics

6.2 Solar Utility, Locale, and Client


Reading Assignment

  • J.R. Brownson, Solar Energy Conversion Systems (SECS), Chapter 16: Project Design.

We are jumping ahead to the elements of project design, so that you will be able to address Learning Activity 6.1. Chapter 16 will help us to prepare for our tasks ahead. You might consider a quick review of Ch. 2 in light of our new perspective on energy economics, and put it into the context of solar utility and the influence of stakeholders.

I want you to now focus on the connections among the client, the affected and diverse stakeholders, and the concept of solar utility. Your goal is nothing so specific as "highest efficiency" or "most power" or "least expensive system." You may be able to assess your client and address mechanisms to provide them with a high solar utility from a project proposal standing.

Solar Utility

A design effort without constraints and boundaries can quickly spiral out of control. Your SECS is dependent on the locale, and the client! How can we efficiently maximize the client's preference for goods derived from the solar resources to help meet client goals in their particular locale? When we speak of solar utility, we are referring to maximizing the preference for solar goods and services in order to provide needed power, heat, light, food, etc.

  • Utility is simply preference among a set of goods and services.
  • In game theory, a utility function is used to quantify the degree of preference across a suite of alternatives, and can explain the impact of uncertainty for a client. [See the Stanford/UBC MOOC for Game Theory on Coursera]

Solar utility can be met from many technologies, it's not just about PV and solar hot water. Sometimes effective shading for a building or space will reduce demand for electricity, which is completely within the scope of a solar energy design team. Maximizing solar utility is definitely not about "efficiency" or "more power" (or more cow bell), because these are systems variables that are all married into the whole balance of energy supply, demand, fiscal wealth, and broader happiness.

One of the systems approaches to increase solar utility for SECSs is by engineering means (e.g., applying what we learned in Lessons 2-4). You need light to produce electricity and heat, right? These strategies increase the amount of light incident on the SECS through general orientation, tracking, and avoiding shading. Note that they are systems solutions, and not "find a more efficient panel."

The second systems approach that we will cover (to increase/maximize solar utility for the client in their given locale) is economic in nature. This approach is concerned with technology costs relative to metrics of financial payback, levelized costs of energy (LCOE), and net present value. For this particular lesson, we are going to focus on the costs of electricity from the grid (which is mainly coal, nuclear, natural gas, and hydroelectric power), and the incentives that are available to our clients in their locale. Both the grid and the incentives available to our clients are locale-based, as with the solar resource above.

Remember, the design team maximizes solar utility by considering the locale and the client needs, then selects a technology (or suite of approaches) that is appropriate.


The term locale in the SECS context implies more than just site or location – it rather represents a set of key parameters that would have critical impact on the system in question. Locale is defined in both time and space (because meteorology implies both time and space). Here are several parameters we can consider to specify locale for a project:

  • Geographic position, address (ϕ, λ),
  • Solar resource (time variations on seasonal, daily, hourly, minute and second scale) and its intermittency (specifically beam-diffuse components),
  • Setting (for example, urban, rural, ecoregion) or immediate surrounding for the project (field, ground, walls, roof), which can create shading and thus have implication in system design
  • Climate regime (recall the Bergeron system of air mass).

This cartoon summarizes this concept in the nutshell. Further, in the following lessons, when you are asked to provide some characterization of the locale, be sure to include some information on the following four key elements.

The word locale surrounded by the words geographical location, climate, solar resource and setting
Figure 6.1. Main elements of locale for a SECS project.
Credit: N. Miller © Penn State University is licensed under CC BY-NC-SA 4.0

Note that locale does not refer to the design elements of the SECS (when we describe the locale, we do not yet have system in place), neither it considers client. Those two things will come into play next. 

Your client (an individual, a corporation, a society?) and your stakeholders

Your "client" is a utility maximizer. They may (or may not) make rational decisions to implement a SECS. Your function in the solar design team is to be their informed advisor. However, your client may also be a whole cohort of people, or a group of stakeholders. Stakeholders are all those affected by the decision to design and install a solar energy conversion system (SECS). These may include the client, the engineers and installers, building managers, the local community members, and so on. Again, a stakeholder can be a client or just an invested individual participating in the system as a whole. One of your jobs is to identify stakeholders and asses the role their multiple perspectives may play in the design process.

Common business language states that the customer is always right. More appropriately, the customer is always the one who decides "go" or "no go" in a solar project. The basic logic of that statement guides the design process. Every SECS is designed with the needs and requirements of a client in mind. No particular system can be used by all clients in all locales regardless of how well the said system is designed. Design requires that we have a close understanding and appreciation of what a client needs. A solar designer may start the design process by posing questions to the client such as: How much power/energy do you need? How many hours of power do you need and what time during the day do you need this power? Is this power needed year round or only during particular seasons? Answers to these questions will ultimately guide the designer and lead to efficient design.

Your design team holds stakeholders to the concept of the Four Es: Everybody Engaging Everything Early (developed by PA design firm 7Group). We want to engage the stakeholders in the integrative design process, and the pre-design process can involve brainstorming events called charrettes.

The design team also needs to educate the client on the different options available to him/her. For example, if a client decides to install photovoltaic panels to provide electricity, the design team will need to inform the client on the various PV technologies, the advantages and disadvantages of each in regard to price and function in different locales, the different options for funding the project through government grants and loans, etc.

As such, your client (and associated stakeholders) and your locale are the two major super parameters that can guide systems design.

Self-check questions:

1. What is solar utility in this context?

Click for answer.

ANSWER: the client’s preference or measure of derived happiness from the set of goods and services derived from solar energy

2. In one short statement, what is the goal of solar energy design and engineering?

Click for answer.

ANSWER: maximize the solar utility of the resource for a client or stakeholders in a given locale

3. What can locale refer to?

Click for answer.

ANSWER: address, place, placement, climate regime, frequency, time horizon

4. What is the spectrum of light from the Sun that we appropriate for SECSs called?

Click for answer.

ANSWER: the shortwave band