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ID:
113451
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Publication |
2012.
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Summary/Abstract |
We examine the economic feasibility of using dedicated DC circuits to operate lighting in commercial buildings. We compare light-emitting diodes (LEDs) and fluorescents that are powered by either a central DC power supply or traditional AC grid electricity, with and without solar photovoltaics (PV) and battery back-up. Using DOE performance targets for LEDs and solar PV, we find that by 2012 LEDs have the lowest levelized annualized cost (LAC). If a DC voltage standard were developed, so that each LED fixture's driver could be eliminated, LACs could decrease, on average, by 5% compared to AC LEDs with a driver in each fixture. DC circuits in grid-connected PV-powered LED lighting systems can lower the total unsubsidized capital costs by 4-21% and LACs by 2-21% compared to AC grid-connected PV LEDs. Grid-connected PV LEDs may match the LAC of grid-powered fluorescents by 2013. This outcome depends more on manufacturers' ability to produce LEDs that follow DOE's lamp production cost and efficacy targets, than on reducing power electronics costs for DC building circuits and voltage standardization. Further work is needed to better understand potential safety risks with DC distribution and to remove design, installation, permitting, and regulatory barriers.
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2 |
ID:
128334
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Publication |
2014.
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Summary/Abstract |
In order to reduce greenhouse gas emissions in the United States by an order of magnitude, a portfolio of mitigation strategies is needed. Currently, many utilities pursue energy efficiency programs. We study a case where utilities could choose whether to allocate their energy efficiency budget to either end-use efficiency or vehicle electrification as a means to reduce CO2 emissions. We build a decision space that displays the conditions under which utilities should pursue either strategy. To build such decision space, assumptions are needed on how consumers respond to electric vehicle incentives, and what would be the baseline vehicle selected by consumers if no incentives were in place. Since these two aspects are highly uncertain, we treat them parametrically: if consumers are replacing a conventional vehicle with a PHEV, utility incentive programs to induce PHEV adoption appear to be cost-effective for a wide range of efficiency program costs and grid emissions factors.
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