This is the first of a series of pages intended to give readers from all backgrounds and roles an overview of a solar car's systems, their design, and manufacturing.

The Competition

Competitive solar cars are generally split between two classes:

• Challenger
• Cruiser

These classes are defined by the World Solar Challenge (WSC), which is the forefront international solar car competition held every two years across Australia. There is another competition held every other two years in the USA, the American Solar Challenge (ASC), which is starting to recognize the definitions outlined by WSC and more closely aligning its regulations with those of WSC.

Challenger Class

The Challenger class comprises ultra-lightweight and aerodynamic endurance race cars carrying a single driver, usually in a small cockpit with a canopy. The shape of these cars is designed for maximum efficiency and solar energy collection, usually resulting in a large flat surface to maximize solar array area. This was the original solar car class and remains today the most well-established competition category, containing the majority of solar cars teams around the world. The competition style is a time challenge where the team that reaches the finish line with the least time expired wins.

Midnight Sun has traditionally designed Challenger Class vehicles, but in recent years has shifted to the newer Cruiser class.

Cruiser Class

The Cruiser Class is a fairly new class (started in 2013) that focusses on energy-efficient, practical vehicles designed to carry at least two people. The WSC competition is structured as a "regularity trial" in which teams must reach the finish line within a certain time window but are scored solely on energy consumption and "practicality", which is determined by judges. This is intended to mirror the design goals of consumer passenger vehicles.

As of 2016 the American Solar Challenge does not hold a separate class for Cruiser vehicles but does recognize them and provide special rules for them. It is possible that in the future Cruiser vehicles will have their own competition category in ASC.

Chassis & Body

Building a solar car requires extensive design to be put into the vehicle's chassis and body. These terms are used in automotive engineering and are described below:

Chassis: The structure on which the vehicle's primary components are mounted. In traditional automotive engineering, the chassis provides the majority of the vehicle's structural strength.

Body: The structure (commonly panels) that form the exterior of the vehicle, directing airflow and determining the appearance of the vehicle.

These terms originate from a time when most vehicles had a separate chassis, in the form of a heavy flat steel frame (onto which the engine and suspension were mounted), and body, in the form of metal panels attached together. This type of design is referred to as a "body-on-frame" and is rarely seen today on anything except trucks.

Modern Automotive Frames

In modern vehicles, automotive frame design has evolved to the point where in some cases the chassis and body become much harder to identify as separate entities. Three common design patterns for vehicle frames are:

Unibody: The frame and body are a single integrated piece. This is the most common design used on modern consumer cars. Steel unibodies form most of the body of the vehicle with an integrated steel structure and may have plastic paneling for aerodynamics.

Space frame:The vehicle has a skeletal frame constructed of steel beams or tubes of varying diameter and wall thickness. Non-structural panels are attached to the frame solely for aerodynamic purposes but otherwise provide no additional strength. This design is used on some high-performance consumer cars and smaller, older aircraft. The strict technical definition for a space frame is that the frame is sufficient triangulated such that all forces within the frame are turned into compression or tension, and not flexing.

Monocoque: The body of the car provides all of the strength through distributing loads through its "skin". This is a design typically only seen in F1 motorsports and some high performance motorcycles, where the entire body of the vehicle is formed with a strong shell made of either carbon fibre composites or aluminum panels. It has the advantage of theoretically achieving the greatest strength-to-weight ratio, but is very hard to design because stretched-skin structures are difficult both to simulate and change.