Ch. 1 - Introduction to Photovoltaic Systems

The policies are being aimed at reducing dependency on fossil fuel energy, mandating efficient energy use, and encouraging the development of renewable energy resources. The primary ways federal, state, and local governments encourage renewable energy, including PV, is through incentives and quotas.

How are government policies being used to encourage development of renewable energy technologies?

Installers are the most visible level of the PV industry to the consumers, so it is vital that installers be professional and qualified individuals. Sales and quality PV system installations are essential for the success and acceptable of PV technology.

How is installer training vital to the continued growth of the PV industry?

Integrator

A business that designs, builds, and installs complete PV systems for particular applications by matching components from various manufacturers.

Utility

A company that produces and/or distributes electricity to consumers in a certain region or state.

Solar Energy Collection

A device designed to absorb solar radiation and convert it to another form, usually heat or electricity.

Balance-of-system (BOS) Component

An electrical or structural component, aside from a major component, that is required to complete a PV system.

Photovoltaic (PV) System

An electrical system consisting of a PV module array and other electrical components needed to convert solar energy into electricity usable by loads.

Dist of US Electricity Consumption, Vol by Price

Explain

PV Industry Fig 1-14. Like most industries, the PV industry has several levels of business. These levels can include a variety of enterprises: large and small, domestic and foreign, and public and private.

Explain

The Grid

The utility's network of conductors, substations, and equipment that distributes electricity from its central generation point to the consumer.

Load

A piece of equipment that consumes energy.

Flat Plate Collector Fig 1-19 A flat-plate collector is a solar energy collector that absorbs solar energy on a flat surface without concentrating it, and can utilize solar radiation directly from the sun as well as diffuse radiation that is reflected or scattered by clouds and other surfaces. Flat-plate collectors may be installed in a fixed orientation or on a sun-tracking mount. Nearly all commercial and residential solar energy installations use flat-plate collectors.

A solar energy collector that absorbs solar energy on a flat surface without concentrating it, and can utilize solar radiation directly from the sun as well as diffuse radiation that is reflected or scattered by clouds and other surfaces.

Concentrating Collector Fig 1-20. A concentrating collector is a solar energy collector that enhances solar energy by focusing it on a smaller area through reflective surfaces or lenses. The high-intensity sunlight is focused onto high-efficiency solar cells or working fluids that transfer thermal energy. Since concentrating collectors utilize only radiation directly from the sun, they must continually track the sun. Concentrating collectors have increased efficiency and reduced size because of the ability to channel more solar radiation onto the desired surface.

A solar energy collector that enhances solar energy by focusing it on a smaller area through reflective surfaces or lenses.

Photovoltaics

A solar energy technology that uses the unique properties of certain semiconductors to directly convert solar radiation into electricity.

Concentrating Solar Power (CSP) Fig 1-23. Concentrating solar power (CSP) is a technology that uses mirrors and lenses to reflect and concentrate solar radiation from a large area onto a small area. The energy is then used to heat working fluids or materials that will be used to produce electricity. These systems are complex to build, so they are only feasible for utility-scale power plants. The three main styles of CSP plants include trough collectors, dish collectors, and power towers.

A technology that uses mirrors and/or lenses to reflect and concentrate solar radiation from a large area onto a small area.

Authority Having Jurisdiction (AHJ)

An organization, office, or individual designated by local government with legal powers to administer, interpret, and enforce building codes.

If an alternate power source is very expensive, such as utility connection to a remote location, then a PV system can save money. A PV system also produces environmentally friend energy, is very flexible and adaptable, and can offer energy independence. However, the system's initial cost can be high and it may require a large surface area to produce a significant amount of power. The available solar resource may affect the feasibility of the system. There is also a lack of knowledge among some potential system owners, installers, and local officials that could impede a successful system installation.

Compare the advantages and disadvantages of installing PV systems.

Space: designed for high efficiency and low weight, with cost being less important. Portable: Relatively small and can handle only modest loads; should be light weight for ease of transport. Will require batteries. Supplemental-Power Applications: Can be used to supply power to any utility-connected building or structure. The applications are all similar, except that the sytems vary in size.

Compare the design priorities of PV systems for space, portable, and supplemental-power applications.

PV System Fig 1-1. A photovoltaic (PV) system is an electrical system consisting of a PV module array and other electrical components needed to convert solar energy into electricity usable by loads. These components can be arranged in many ways to design PV systems for different situations, but the most common configuration is a utility-connected system, which is found on commercial and residential buildings. These PV systems may or may not include battery storage. The array is usually mounted on a rooftop or nearby on the ground.

Explain

Flat Plate Collector: A solar energy collector that absorbs solar energy on a flat surface without concentrating it, and can utilize solar radiation directly from the sun as well as diffuse radiation that is reflected or scattered by clouds and other surfaces. Note: Nearly all commercial an residential solar energy installations use flat-plate collectors. Concentrating Collector: A solar energy collector that enhances solar energy by focusing it on a smaller area through reflective surfaces or lenses.

Explain the two main technologies that can convert solar radiation into electricity.

Telephone Systems

The first common Earth-based applications using PV cells were in ___ and radio transmitters.

-Relatively simple in design -May not have moving parts. -Can locate close to populated areas because they do not involve hazardous materials or cause any air, water, or noise pollution. -Can easily expanded incrementally as demand increases, as long as space allows.

What are some advantages to using PV technology to build utility-scale power plants?

A business that designs, builds, and installs complete PV systems for particular applications by matching components from various manufacturers. Integrators work with homeowners, businesses, organizations, contractors, and utilities to design, install, monitor, and maintain PV systems. They also work with architects and builders to create aesthetically pleasing buildings using PV systems that meet local codes, standards, and regulations.

What is the role of the integrator?

Concentrating collectors gather solar irradiation from a large area and focus it down to a small area for energy conversion

Why are concentrating collectors more efficient than flat-plate collectors?

Distributed Generation Fig 1-3. Distributed generation is a system in which many smaller power-generating systems create electrical power near the point of consumption. The electricity may travel only a few feet to the loads, which avoids the losses from long transmission lines. Distributed generation systems can include PV systems, wind turbines, engine generators, or other relatively small-scale power systems. A distributed generation system may serve as the only source of power for the consumer (a stand-alone system), or as backup or supplemental power for a utility grid connection. If consumers are connected to the utility grid, excess power can be distributed to the grid if it is not needed by the on-site loads.

___ generation is a system in which many smaller power-generating systems create electrical power near the point of consumption.

Edmund Becquerel

___ is credited with discovering the photovoltaic effect in 1839.

Utility Interactive

___ systems are the fastest growing segment of the PV system market.