Polyera Corporation

Solar panels are created using an array of tuned photovoltaic cells to create electricity from the sunlight incident upon them. At a basic level, photons are absorbed by the solar cell which then converts the energy from the photon into a current. (For more detailed information on how solar cells work, see the section on photovoltaics.)

The need for alternative, sustainable sources of energy is well-known, and solar power has many advantages:

• Availability. The 89 petawatts of sunlight reaching the earth's surface is plentiful - almost 6,000 times more than the 15 terawatts of average power consumed by humans. Additionally, solar electric generation has the highest power density (global mean of 170 W/m²) among renewable energies.

Average solar irradiance, watts per square metre. The small black dots show the area of solar panels needed to generate all of the worlds energy using 8% eff. PVs.

• Eco-Friendliness. Solar power is pollution free during use. Production end wastes and emissions are manageable using existing pollution controls. End-of-use recycling technologies are under development.

• Sustainability. Facilities can operate with little maintenance or intervention after initial setup.

• Flexibility in deployment. Solar electric generation is economically superior where grid connection or fuel transport is difficult, costly or impossible. Examples include satellites, island communities, remote locations, developing countries, and ocean vessels.

• Affordability. Once the initial capital cost of building a solar power plant has been spent, operating costs are extremely low compared to existing power technologies.

Economics

The two biggest factors to evaluate in determining solar-cells' economic viability are the levelized cost of energy (LCOE) and the energy returned on energy invested (EROEI). The LCOE is a measure of how much it costs to produce a killowatt of power at a given level of solar intensity over a given time frame (usually 20 years), taking into account the initial capital outlay, interest rate, maintenance and depreciation. Depending on conditions, this can range between $0.05 - $0.40. The EROEI is a measure of how much energy is produced by the cell, relative to the amount it takes to produce and maintain the cell, taking into account it's operational lifetime. Current levels for traditional solar cells are around 10 to 30.

The single biggest bottleneck to widespread use of solar-cell technology has been materials and installation cost. Printable solar cells can theoretically eliminate this bottleneck, taking advantage of the low-cost, high-throughput printing techniques this technology affords. However, this requires that photovoltaic materials of which these printable solar cells are made make further performance advances (for more information, see the section of photovoltaics).

Applications

There are a wide range of application for these types of solar cells. The initial areas of commercialization will be places where portability and robustness will be of particular benefits - for example, in the military or developing countries where no infrastructure exists. As costs continue to fall, solar is likely to become a major source of power, eventually contributing substantially to the major power grids.

References