Solar energy has always been abundant.  Over thirteen hundred watts of power strikes the Earth each day from the sun.  The only thing that hasn’t been abundant, at least in the past, are the customers of solar energy.  Until recent times, the prices of the systems have been not only expensive, but inefficient.  Like any technology cost-effectiveness and efficiency come with time and the time of solar power has arrived and will revitalize energy as we know it. 

In the past thirty years, the price of solar has dropped exponentially.  It has been in recent years that the price solar has become competitive thanks in part to state and federal incentives and rebates.  With this price trend, we have also seen the production of photovoltaic systems increase at a rate of fifty percent per year allotting for global capacity to double every eighteen months.  Now we must ask ourselves….can an earlier commercial breakthrough in photovoltaic systems be achieved than what was originally forecasted?  The answer may lay within Moore’s Law.

So how does Moore’s Law fit into the picture?  For those who are not familiar, Moore’s Law stems from the realm of computing.  It states that the number of components that can be placed on a chip doubles every eighteen months in the world of computing.  In other words, you are getting more power, computing power that is, for every dollar you spend.  This capability has essentially doubled every eighteen months and will do so for decades. Now, arguably, solar power has the same potential.  Ideally the result would be cheap, mass distributed power that is more effective than the predecessor technology from which it is derived.  As an example, in 2004, seven dollars a watt was the average installation cost for solar power as compared with solar which was one dollar per watt.  In the past year, solar has reached four or five dollars a watt.  It is in this price range that we find solar walking the line of Moore’s Law.  If we take this price trend and carry it forward six or seven years, we find that the cost of solar will be below two dollars a watt.  It is at this price point that solar becomes competitive with the wind of 2004.

In all, we can expect to see the costs of solar panels to come down as a result of technological improvements, reduction in costs of polysilicon, and economies of scale.  Along the way to grid parity, we cannot forget that we must factor in not only the costs of the equity, but also the efficiency and longevity of the panels and inverters as well as the location.  

• What are photovoltaic cells? Devices that convert sunlight directly into electricity
• What is photovoltaic effect? This occurs when sunlight that hits the silicon and causes the photons to pass-through, be absorbed, or be reflected. 
• What happens if it is absorbed? The energy will be transferred to electrons and a current will be increased
• How big are PV cells?  PV cells are usually 3x3 inches in size and are 180 to 200 um thin. 
• How many PV cells make up a module? About fifty to seventy-two PV cells make up a module. 
• What is a solar array? A series of modules connected together.
• What is the advantage of putting together varying numbers of modules? It allows for varying power needs to be addressed – small and large.
• What is the most common material in PV manufacturing? Silicon
• What else goes into a PV system?  Inverters, mounting systems, electrical materials, and cables
• What is an inverter?  An inverter allows the DC power generated from the PV system to be converted to AC power.

1. Silicon Manufacturing

A blast furnace is used to reduce silicon dioxide to metallurgical grade silicon. The metallurgical silicon then goes through a purification process to obtain high purity silicon.  This high purity silicon is then use to form an ingot and later a silicon wafer.

2. Wafering

A silicon wafer can be either single (mono) crystalline silicon or poly-crystalline silicon. 

What is mono crystalline and what is poly-crystalline?  Mono is more efficient when it comes to creating electricity, but it is also more expensive.  Poly is less efficient at creating electricity, but it is also less expensive.

3. Cell Manufacturing

During the cell manufacturing process, chemicals such as phosphorus are added to the wafer to produce a positive charge carrier (p conducting semiconductor layer) or negative charge carrier (n conducting semiconductor layer) from the silicon.

4. Module Assembly

During the assembly of the module, individual PV cells are linked together and laminated between a piece of glass and a stainless steel backing.   

5. System Integration

The design and erection of a system is usually contingent to the energy needs of the customer.   The array is usually mounted at an angle facing south.

• U.S. solar market grew to $6 billion in 2010 – a 67% increase from 2009
• 956 megawatts (MW) of solar electric installations occurred in 2010 bringing the overall installed capacity to a total of 2.6 gigawatts (GW)
• More than 10 MW of PV was installed over sixteen states in 2010
• Grid-connected PV systems totaled 152,516 in 2010
• Utility PV installations totaled 242 MW as compared to 70 MW in 2009