Photovoltaic summary
The solar energy that reaches the earth in about an hour is equal to the annual amount of commercial energy consumed by human beings.
It is estimated that in 2020 Solar electricity can provide electricity to over 1 billion people worldwide. It could also provide more than 2 million jobs in production, installation and maintenance.
It is estimated that the annual market can grow in average 35% from 2005 until 2010 if adequate support mechanisms are adopted by governments. Following this trend solar electricity can be competitive with peak electricity prices by 2010.
It is estimated that the world will produce 524 GW of PV generated electricity in 2030.
Source: European Photovoltaic Industry Association
Polymer solar cells
are a type of solar cell: they produce electricity from sunlight. A relatively novel technology, they have moved from the research lab, and are now commercially available. They are durable and find common application in small devices, such as pocket calculators.
Compared to silicon-based devices, polymer solar cells are lightweight (which is important for small autonomous sensors), disposable, inexpensive to fabricate, flexible, designable on the molecular level, and have little potential for environmental impact, however the energy yield is just slowly reaching levels of a 1/4 of regular silicon solar cells, and construction geometries have not been fully explored. Polymer solar cells also suffer from huge degradation effects: the efficiency is decreased over time due to environmental effects. Good protective coatings are still to be developed.
An open question is to what degree polymer solar cells can commercially compete with silicon solar cells. Although polymer cells are relatively inexpensive to manufacture, the silicon solar cell industry has the important industrial advantage of being able to leverage the general silicon infrastructure developed for the computer industry. This, however, also has the disadvantage that solar cell manufacturers have to compete with the (much larger) computer industry for supplies of high-quality silicon.

Nanocrystal solar cells
or quantum dot solar cells, are solar cells based on nanocrystals.
A layer of nanocrystals is applied to the solar panel. It is cheaper than other solar panels, more flexible, and claims 12% efficiency. (Conventional solar panels convert 9% of the sun's energy into electricity.)
Although the research is still in its infancy, quantum dot-modified photovoltaics may be able to achieve up to 42 percent energy conversion efficiency due to multiple exciton generation.
Photoelectrochemical cells

or PEC's are solar cells and extract electrical energy from light, including visible light. Each cell consists of a semiconducting photoanode and a metal cathode immersed in an electrolyte. Some photoelectrochemical cells simply produce electrical energy, while others produce hydrogen in a process similar to the electrolysis of water.
Key factors to diffusion of PV diffusion:
- Deregulation by the government
- Subsidy system for residential use
- Selling back surplus to the grid
- Cost reduction