Toward Cost-Effective Solar Energy Use
Solar Energy - Journal ArticleAuthor: Nathan, Lewis S.
Author Affiliation: Science Magazine
Submitted: Mon, 07/07/2008 - 21:52
Published in: Science Magazine on February, 9th 2007
Copyright Status: Pay to Download Link to source material: Full Article Here Description:
More energy from sunlight strikes the earth in 1 hour than all of the energy consumed by humans in an entire year. In fact, the earth's solar resource dwarfs all other renewable and fossil fuel based energy resources combined. However, solar electricity will not be a material contributor to primary energy generation until cost effective methods for capturing, converting, storing and distributing massive amounts of solar electricity is discovered.
Current silicon based solar modules are not cost competitive. Most shipped PV modules have efficiencies of around 15-20%. At such efficiencies, under standard operating conditions, and at a cost of roughly $600/ m2 (including balance of systems components; inverter, grid connection, etc), the sale price of grid electricity must be between $0.25 and $0.30 per kilowatt-hour (kwh) to recover the initial capital investment over the 30 year lifetime of the system. The current national average, across all sectors, is $0.0898 per kwh (2008).
In this article, the author proposes how advancements in nanotechnology and biotechnology might make solar electricity more cost competitive. Technologies to consider include: PbSe quantum dots (however no current technology exists to transfer the quantized energy out of the quantum dot to an external circuit), roll-to-roll manufacturing of modules using silicon doped inks on conductive filaments such as organic polymers or inorganic particulate solids, high-aspect-ratio nano rods or inorganic CdTe "tetrapods" that allow for photon collection across many band gaps increasing collection efficiency, and dye synthesized solar cells with a random disordered network of inexpensive TiO2 particles surrounded by an absorbed dye fluid (efficiencies are currently around 10%).
Given that the sun goes out locally every night and electrical demand exists throughout the day, advancements in storage capacity must also be met. Solutions could include: pumped water storage (as potential energy), lithium-ion batteries that cost less than lead-acid batteries, a global superconducting DC transmission grid, super capacitors, flywheels, or, most attractively, energy stored as chemical bonds. Modified hydrogenase enzymes that produce H2 from H2O might act as a natural catalyst. The direct electrolysis of water could also serve to produce H2 from H2O, however the current cost of commercial electrolyzers is prohibitive.
Login to post comments
Printer friendly version
Display a printer friendly version of this page. |
