Energy Conversion

We present a new thin-film solar cell structure in which the traditional transparent conductive oxide electrode (ZnO) is replaced by a transparent conductive coating consisting of a network of bundled single-wall carbon nanotubes. Optical transmission properties of these coatings are presented in relation to their electrical properties (sheet resistance), along with preliminary solar cell results from devices made using CuIn1-xGaxSe2 thinfilm absorber materials. Achieving an energy conversion efficiency of >12% and a quantum efficiency of ~80% demonstrate the feasibility of the concept. A discussion of the device structures will be presented considering the physical properties of the new electrodes comparing current-voltage results from the new solar cell structure and those from standard ZnO/CdS/Cu(In,Ga)Se2/Mo solar cells.

Crop residues are common in rural Ghana due to the predominant role agriculture plays in livelihood activities in these communities. In this paper we investigate the prospects of exploiting agricultural crop residues for rural development in Ghana through bioenergy schemes. A theoretical energy potential of 623.84 PJ per year, which is equivalent to 19,781 MW was estimated using crop production data from the Food and Agricultural Organization of the United Nations and residue-to-product ratios. Ghana has a total installed generation capacity of 4577 MW which is four times less the energy potential of crop residues in the country. Cocoa pod husks were identified as important biomass resources for energy generation as they are currently wasted. To further assess the energy potential of cocoa pod husks, different cocoa pod husks samples were collected across the six cocoa growing regions in Ghana and thermo-chemically characterised using proximate and ultimate analysis. The low levels of nitrogen and sulphur observed, together with the high heating value, suggest that cocoa pod husks and for that matter crop residues are eco-friendly feedstock that can be used to power rural communities in Ghana.

Background Pretreatment is a critical step in the conversion of lignocellulose to fermentable sugars. Although many pretreatment processes are currently under investigation, none of them are entirely satisfactory in regard to effectiveness, cost, or environmental impact. The use of hydrogen peroxide at pH 11.5 (alkaline hydrogen peroxide (AHP)) was shown by Gould and coworkers to be an effective pretreatment of grass stovers and other plant materials in the context of animal nutrition and ethanol production. Our earlier experiments indicated that AHP performed well when compared against two other alkaline pretreatments. Here, we explored several key parameters to test the potential of AHP for further improvement relevant to lignocellulosic ethanol production. Results The effects of biomass loading, hydrogen peroxide loading, residence time, and pH control were tested in combination with subsequent digestion with a commercial enzyme preparation, optimized mixtures of four commercial ...

Description/Abstract The PG&E WaveConnect project was intended to demonstrate the technical and economic viability of wave power in the open ocean adjacent to PG&E's service territory. WaveConnect was conceived as a multi-stage development process ...

Achieving a successful transition to hydrogen-powered vehicles in the US automotive market will require strong and sustained commitment by hydrogen producers, vehicle manufacturers, transporters and retailers, consumers, and governments. The interaction ...

In t his paper the results of feasibility study to generate electrical energy from waves of the Bay of Bengal have been discussed. The wave resource assessment, economic conditions, challenges and the cost estimation for power generation are also described. Calculation of Wave energy and an analysis of energy fluctuation at various months of different consecutive years and it is observed that, April to October waves have travelled with a lot of energy and a considerable amount of energy at November to March in Bay of Bengal at Cox’s Bazar, Chittagong. The energy is wave dominated. Due to availability of generated wave, it is possible to generate Power with full pace from April to October and considerable amount can be generated at rest of the months. In the circumstances of Bangladesh energy source research on renewable is most important to mitigate the increasing power demand and a contribution to reduce global warming. In the circumstances of Bangladesh energy source research on r...