WACC the Dog: The Effect of Financing Costs on the Levelized Cost of Solar PV Power

The photovoltaic (PV) power industry has grown rapidly in recent years, and associated with that growh has been a decline in costs. There are indications that PV has already reached cost-parity with power off the grid in some markets and projections that it will attain such grid parity in many more markets over the coming decade. Analysts have suggested that the growth in PV has come at an unnecessariy high price, with unnecessarily high subsidies. However, the factors influencing the cost of PV, and the subsidies required to sustain its construction, include more than just the strength of the sun. While differences in costs of such factors as initial capital spending, operation and maintenance, and decommissioning are hard to ascertain, it is possible to account for the cost of capital, on a counry-by-country basis. In this paper, we therefore map the cost of solar PV globally, accountng for both the quality of the solar resource and the cost of capital in order to differentiate levelized cost of electricity (LCOE) from PV. Our results suggest that northern countries may not be an unwise location to subsidize PV construction, and further suggest that efforts to expand PV installation in developing countries may benefit greatly from policies designed to make low cost finance more widely avaiable

Serratia marcescens internalization and replication in human bladder epithelial cells

BACKGROUND: Serratia marcescens, a frequent agent of catheterization-associated bacteriuria, strongly adheres to human bladder epithelial cells in culture. The epithelium normally provides a barrier between lumal organisms and the interstitium; the tight adhesion of bacteria to the epithelial cells can lead to internalization and subsequent lysis. However, internalisation was not shown yet for S. marcescens strains. METHODS: Elektronmicroscopy and the common gentamycin protection assay was used to assess intracellular bacteria. Via site directed mutagenesis, an hemolytic negative isogenic Serratia strain was generated to point out the importance of hemolysin production. RESULTS: We identified an important bacterial factor mediating the internalization of S. marcescens, and lysis of epithelial cells, as the secreted cytolysin ShlA. Microtubule filaments and actin filaments were shown to be involved in internalization. However, cytolysis of eukaryotic cells by ShlA was an interfering factor, and therefore hemolytic-negative mutants were used in subsequent experiments. Isogenic hemolysin-negative mutant strains were still adhesive, but were no longer cytotoxic, did not disrupt the cell culture monolayer, and were no longer internalized by HEp-2 and RT112 bladder epithelial cells under the conditions used for the wild-type strain. After wild-type S. marcescens became intracellular, the infected epithelial cells were lysed by extended vacuolation induced by ShlA. In late stages of vacuolation, highly motile S. marcescens cells were observed in the vacuoles. S. marcescens was also able to replicate in cultured HEp-2 cells, and replication was not dependent on hemolysin production. CONCLUSION: The results reported here showed that the pore-forming toxin ShlA triggers microtubule-dependent invasion and is the main factor inducing lysis of the epithelial cells to release the bacteria, and therefore plays a major role in the development of S. marcescens infections

Are we there yet? Improving solar PV economics and power planning in developing countries: The case of Kenya

Despite the rapid decline in the cost of solar photovoltaic (PV) systems in the past five years, even recent academic research suggests that the cost of generating PV electricity remains too high for PV to make a meaningful contribution to the generation of grid electricity in developing countries. This assessment is reflected in the views of policymakers throughout Africa, who often consider PV as a technology suited only to remote locations and small-scale applications. This paper therefore analyzes whether, in contrast to conventional wisdom, PV is already competitive with other generation technologies. Analytically, the paper is based on a levelized cost of electricity (LCOE) model to calculate the cost of PV electricity in Kenya, which serves as a case study. Based on actual technology costs and Kenya's solar resource, the LCOE from PV is estimated at USD 0.21/kWh for the year 2011, with scenario results ranging from USD 0.17.0.30/kWh. This suggests that the LCOE of grid-connected PV systems may already be below that of the most expensive conventional power plants, i.e. medium-speed diesel generators and gas turbines, which account for a large share of Kenya's current power mix. This finding implies that researchers and policymakers may be mistaken in perceiving solar PV as a costly niche technology, rather than a feasible option for the expansion of power generation in developing countries

WACC the dog: The effect of financing costs on the levelized cost of solar PV power

The adoption of solar photovoltaic (PV) technologies has expanded rapidly in recent years, leading to suggestions that this growth, which occurred mostly in high-latitude countries with often low levels of sunshine, may have come at an unnecessarily high price. However, the factors influencing the cost of solar PV, and the subsidies required to sustain its uptake, include more than just the level of sunshine. While cross-country differences in technology costs are hard to ascertain, it is possible to account for the cost of capital on a country-by-country basis. In this paper, we therefore map the cost of solar PV globally, accounting for differences in both the solar resource and the financing cost in order to calculate the levelized cost of electricity (LCOE) from solar PV systems in 143 countries. In contrast to the work of other researchers who typically treat financing costs as uniform across countries, our results suggest that the LCOE of solar PV systems in northern countries may in fact be lower than in equatorial countries, and high latitude countries may thus not have been an unwise location to subsidize the adoption of solar PV technologies in the past. Our results further suggest that efforts to expand PV installation in equatorial developing countries may benefit greatly from policies designed to make low cost finance more widely available, which underlines on-going efforts to "de-risk" low carbon investments

Diffusion of solar energy technologies in rural Africa: Trends in Kenya and the LUAV experience in Uganda

The diffusion of Modern Energy Technologies Africa has been found to be very low especially for solar energy systems. The installed solar PV capacity in Africa is a major issue of concern globally. This low trend in technology adoption is of interest because Africa enjoys some of the best solar radiation levels in the world averaging between 4 – 6 kWh/m2/day for most of the year. It was initially speculated that the low uptake of solar technology was associated with the continent’s high poverty levels and limitations in technical capacity as well as awareness; nevertheless, the introduction of Mobile Telephony Technology (MTT) has cast some doubt on those speculations due to the rapid assimilation and diffusion of the technology in several African countries. The paper elaborates on the approach taken by a successful MET business model known as the Lighting-up-a-village (LUAV), designed by an energy company, Barefoot Power (BFP), in Uganda. This model has been used to distribute micro solar home systems in rural Uganda and exhibited a rapid uptake rate that resulted in the establishment of 18 LUAV projects in a span of 12 months. Through the LUAV program, more than 3000 households took up the technology securing their own independent power generation hub. The success factors noted in the LUAV business model were identified and highlighted so as to present recommendations on the key factors that can possibly drive a rapid adoption of METs