Polyera Corporation

Solar panels are made using an array of tuned solar photovoltaic cells to create electricity from sunlight. Photons are absorbed by the solar cells, which convert photon's energy into direct currents. For more information on solar cells, please see our section on photovoltaics.

The need for alternative, sustainable sources of energy has existed for a long time but yet to be fulfilled economically. Solar power is one of the possibilities with advantages listed below:

• Availability. There are 89 petawatts of sunlight reaching earth's surface, ~6,000 times more than the 15 terawatts of energy consumed on average by humans. In addition, solar power has the highest power density (global mean of 170 W/m²) among renewable energies.

Average solar irradiance, watts per square meter. The small black dots show the area of solar panels needed to generate all of the world's energy needed using 8% efficient PVs.

• Eco-Friendliness. Solar power is pollution free to use. Wastes and emissions from production of solar panels are manageable using existing pollution controls, and the end-of-life recycling technologies are under development.

• Sustainability. Solar power facilities can operate with little maintenance or intervention after initial setup.

• Deployment Flexibility. Solar power generation is the most economic where grid connection or fuel transport is difficult, costly or impossible, including satellites, island communities, remote areas, developing countries, and ocean vessels.

• Affordability. Once the initial capital of building it is invested, operating cost of a solar power plant is extremely low, compared with existing power technologies. However, the fully loaded cost of solar electricity has not achieved grid parity yet for most of the applications.

Economics

The two important measures for evaluating solar cells' economic viability are the levelized cost of energy (LCOE) and the energy returned on energy invested (EROEI).

• 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. Current LCOE ranges between $0.05-$0.40.

• 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 EROEI levels for traditional solar cells are between 10 and 30.

The bottleneck to wide-spread use of current solar panels is the high cost for materials and manufacturing. Printed solar cells can potentially eliminate this bottleneck by taking advantage of the printing process of low-cost and high-throughput. However, it also requires that further advances in performance to be made for the OPV materials used in printed solar cells. For more information, please see our Organic Photovoltaics section.

Applications

Commercially there will be many new applications for printed solar cells. The initial focus is in places where portability and robustness are the most critical factors over cost such as for the military operating in areas where no infrastructure exists. As the cost falls, solar power will become a major source of power and contribute substantially to the power grids.

References