Solar Energy: Applications, Economics and Public Perception

Abstract

This book discusses the applications, economics, and public perceptions of solar energy conversion systems. The book is divided into fi ve sections: the fi rst section provides an overview of hybrid solar energy systems, the second discusses solar energy and conservation issues, the third focuses on solar energy technology, the fourth section is on the economics of solar energy, and, fi nally, the fi nal section addresses public perceptions of solar energy. In Chapter 1, Chow and colleagues give a broad review of the published academic works on hybrid photovoltaic/thermal (PVT) collector systems, with an emphasis placed on the research and development activities in the last decade. In Chapter 2, Cameronand colleagues examine the synergy between renewable energy generation goals and those for biodiversity conservation in the Mojave Desert of the southwestern USA. They integrate spatial data on biodiversity conservation value, solar energy potential, and land surface slope angle (a key determinant of development feasibility) and found there to be suffi cient area to meet renewable energy goals without developing on lands of relatively high conservation value. Indeed, they found nearly 200,000 ha of lower conservation value land below the most restrictive slope angle (<1%); that area could meet the state of California’s current 33% renewable energy goal 1.8 times over. They found over 740,000 ha below the highest slope angle (<5%)—an area that can meet California’s renewable energy goal seven times over. Their analysis also suggests that the supply of high quality habitat on private land may be insuffi cient to mitigate impacts from future solar projects, so enhancing public land management may need to be considered among the options to offset such impacts. Using the approach presented here, planners could reduce development impacts on areas of higher conservation value, and so reduce trade-offs between converting to a green energy economy and conserving biodiversity. Klinger and colleagues presents proof-of-concept all-carbon solar cells in Chapter 3. These solar cells are made of a photoactive side of predominantly semiconducting nanotubes for photo-conversion and a counter electrode made of a natural mixture of carbon nanotubes or graphite, connected by a liquid electrolyte through a redox reaction. The cells do not require rare source materials such as In or Pt, nor high-grade semiconductor processing equipment. They do not rely on dye for photo-conversion and therefore do not bleach, and are easy to fabricate using a spray-paint technique. They observed that cells with a lower concentration of carbon nanotubes on the active semiconducting electrode perform better than cells with a higher concentration of nanotubes. This effect is contrary to the expectation that a larger number of nanotubes would lead to more photo- conversion and therefore more power generation. The authors attribute this to the presence of metallic nanotubes that provide short for photo-excited electrons, bypassing the load. They demonstrate optimization strategies that improve cell effi ciency by orders of magnitude and conclude that, once it is possible to make semiconducting-only carbon nanotube fi lms that may provide the greatest effi ciency improvement. In Chapter 4, Denholm and Mehos examines the degree to which concentrating solar power (CSP) may be complementary to PV via its use of thermal energy storage. The authors fi rst review the challenges of PV deployment at scale with a focus on the supply/demand coincidence and limits of grid fl exibility. They then perform a series of grid simulations to indicate the general potential of CSP with thermal energy storage (TES) to enable greater use of solar generation, including additional PV.