Solgen Energy

How Solar Works

At Solgen Energy, we believe in the power of the sun and we want everyone to understand how it works, so they too can benefit from the power of photovoltaic electricity.

1. Photovoltaic (PV) modules generate DC power from the sun.
2. Inverter – converts DC power into 240V (AC) power for use by standard appliances and grid connection.
3. The building uses the solar power generated, any excess power is supplied back into the grid.
4. Bi-directional meter – measures electricity produced and consumed

Solar Photovoltaic

Solar Photovoltaic (PV) panels on the roofs of homes and businesses capture the sun’s energy to generate electricity cleanly and quietly. Light energy is converted directly into electricity by transferring sunlight photon energy into electrical energy. This conversion takes place within cells of specially fabricated semiconductor crystals.

Solar generates electricity when it is needed most – during the day and on hot sunny days when electricity demand is at its peak driven by air-conditioners.

Importantly, electricity is generated at the point of demand - where people live and work. Having solar panels is like having a mini power station on your roof to power appliances such as fridges, air-conditioners and televisions. This lightens the load on our electricity infrastructure - the expensive network of poles and wires that transmits electricity from the nation’s large, centralised coal-fired stations to where it’s needed.

Solar power is a zero-emission electricity source. One megawatt hour of solar-derived electricity avoids approximately one tonne of CO2.

Connecting to the Grid

Solgen Energy’s photovoltaic systems are interconnected to the electricity grid, so that customers can get energy from their utility when the PV system isn’t providing all of their facility’s electricity needs.

Different types of solar technologies

There are two mainstream solar electric technologies available on the market: Crystalline and Amorphous.

In general terms crystalline silicon modules provide higher power to area solutions than thin film amorphous technologies, however thin film technology is more cost effective.  Figure 1 illustrates the main types of solar cells available on the market.

Figure 1 – Solar Cell Types

Multi-crystalline or poly-crystalline cell

Poly or multi crystalline cells are made from wafers of silicon cut from a multi-crystal square cast ingot of silicon.  Poly cells are smaller than mono cells, slightly less efficient, however have a cost advantage over mono-crystalline cells.  These types of cells are the most commonly available modules used domestically worldwide.  The cells are recognised by a blue flaked appearance of the cell, which is typically under glass.

In crystalline solar technology, the roughly 0.3 mm thick wafers made of the semiconductor material silicon are further processed to ensure that sunlight hitting them can be converted directly into solar power.

SCHOTT solar uses a patented process for manufacturing the wafers known as the EFG process. This process differs from the conventional method in that the thin silicon wafers are not sawn by wire saws from a block but are drawn directly as silicon film from a silicon furnace. To ensure process stability, the silicon film is produced in the form of an octagonal hollow pipe. In the EFG process, the silicon film already has the required thickness of roughly 0.3 mm. The last step in the process is to separate the wafers from the surface shell of this hollow pipe using a laser.

Since the wire is about as thick as the wafer itself the conventional wire sawing process leads to material losses of up to 50%. In the EFG process, however, only about 10% of the silicon material is cut away, and some of this can be recycled. This makes EFG considerably lighter on resource use and more efficient than other processes.

Mono-crystalline or mono cell

The name refers to the cell construction being from single (mono) crystal silicon.  Mono crystalline cells are formed by cutting wafers of silicon from a large circular single crystal ingot of silicon.  These wafers are then processed and used in round, half-round or trimmed square cells which are positioned under glass.  The glass is usually framed in aluminium to allow easy mounting.

Amorphous Solar Technology

Thin filmed solar cells can be applied as an active semiconductor film to low cost substrates such as glass, plastic or steel. Amorphous silicon, one of the thin film technologies, is made by depositing silicon onto a glass backing substrate from a reactive gas such as silane (SiH4).  The silicon is called “amorphous” because it has a non-crystalline structure that is similar to glass found in windows and bottles.

These cells are developed by depositing silicon onto a backing material, usually glass or steel.  Amorphous cells can be made flexible for use on curved surfaces and are used extensively in calculators, watches, toys and similar small solar applications.

The SCHOTT Solar ASI material (ASI stands for amorphous silicon) has a thickness of less than 1 micrometer. This means that only approximately one gram of semiconductor per square meter of substrate is needed to coat a pane of glass. SCHOTT Solar ASI® glass is manufactured at Putzbrunn near München. Here, amorphous silicon is deposited on glass panels. For this, plasma is created in a high-vacuum reactor and from this silicon can be deposited on the surface of the glass. A fine laser is used to structure the silicon in such a way as to produce a large number of tiny solar cells. Transparent conductor pathways conduct electrons to the module’s cables. Several modules are connected in series and linked to the inverter. The direct current produced is converted here into 60 Hertz 230 volt alternating current and fed into the power grid.

The table below provides a summary of the main differences between crystalline and amorphous technologies.

Crystalline	Amorphous
Higher power to area ratio (smaller array for same output)	Lower power to area ratio (larger array for same output)
Higher cost of technology	Lower cost of technology
Lower cost of installation	Higher cost of installation (array is larger, therefore more labour and materials required for the installation)
Requires installation in areas not subject to shading.	Able to operate in greater light range and with partial shading of the array.
More suitable to temperate climates.	Ability to perform well in extreme heat

Solgen Energy’s Approach

Solgen Energy uses SCHOTT solar panels (solar modules).We use technologies that provide the most reliability and value, and then we customise our systems to meet our customers’ financial, power production and facility needs.

For more information on our components, please see our partners.

Planning & installing photovoltaic systems, a guide for installers, architects and engineers.

Learn more about solar

Want to learn more about solar electricity?

There are excellent industry resources that provide a wealth of information about solar energy, and photovoltaic solar specifically. Here, we've identified some of the most applicable sources

Where can I find more information?
The following websites provide further information on solar.

Australian Sustainable Schools Initiative (AuSSI) for energy and water efficiency resources

Greenhouse Challenge Plus for energy audit tools

The Department of Climate Change

The office of the renewable energy regulator for information on Renewable Energy Certificates

The Australian Greenhouse Office

The Australian Government Department of Environment, Water, Heritage and the Arts

Garnuat Climate Change Review for developments on emissions trading