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| 1 |
ID:
128335
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2014.
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| Summary/Abstract |
The increase of fossil fuel demand raises concerns on availability of resources for future energy demand and on potential environmental impacts. Electric vehicles (EVs) appear as one alternative to shift from fossil fuels to renewable energy resources. This research work analyzes the benefits of the introduction of EVs in a small energy system, the Flores island, Azores, in terms of primary energy and CO2 emissions. Four scenarios were designed considering different penetration rates of EVs (Low and High) and different time of recharging strategies (Fixed and Flexible). The high shares of RES in the electricity production system (60-62%) did not guarantee a significant use of RES for the recharging of EVs (10-40%), as the additional electricity required had to be produced mainly from the diesel generators. The flexible recharging strategies allowed doubling the share of RES in the recharging of the EVs when compared to fixed recharging, and consequently double the impact on the reduction of primary energy consumption and fossil fuels imports. While the reduction of primary energy ranged between 0.2% and 1.1%, for CO2 emissions there was a decrease between 0.3 and 1.7%, proving that EVs can help improve the sustainability of energy systems.
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| 2 |
ID:
109313
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2011.
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| Summary/Abstract |
Energy policies are often related to the global effort in reducing greenhouse gas emissions through increased use of renewable energies in electricity production. The impact of these policies is usually calculated by energy planning tools. However, the modeling methodologies most currently used are not adequate to simulate long-term scenarios while considering the hourly dynamics of supply and demand.
This paper presents an extension of the TIMES energy planning tool for investment decisions in electricity production that considers seasonal, daily and hourly supply and demand dynamics. The inclusion of these dynamics enables the model to produce more accurate results in what concerns the impact of introducing energy efficiency policies and the increased use of renewable energies.
The model was validated in São Miguel (Azores, Portugal) for the years 2006-2009, where a comparison with real data showed that the model can simulate the supply and demand dynamics. Further, the long-term analysis shows that the inclusion of these dynamics contributes to a better assessment of the renewable energy potential, suggests the postponement of investments in new generation capacity, and demonstrates that using fine time resolution modeling is very valuable for the design of effective policy measures under high renewable penetration energy systems.
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| 3 |
ID:
104954
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2011.
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| Summary/Abstract |
An econometric study of the Portuguese residential electricity consumption is presented, with a focus on the influence of dwelling characteristics on consumption. The relationship between the dwelling and household characteristics on per capita residential electricity consumption is estimated at two different scales, involving two distinct databases: the first includes data at the municipality level for 2001, the second is the most recent Portuguese consumer expenditure survey that was collected in 2005 and 2006. The results of the analysis at both scales are consistent and indicate that household and dwelling characteristics have a significant influence on residential electricity consumption. Our results show that in Portugal the direct effect of income on electricity consumption is low and becomes smaller when more relevant control variables are included in the analysis. Future demand of electricity in Portugal will be significantly influenced by trends in socioeconomic factors as well as changes in the building stock. These trends should be taken in consideration in the formulation of policy measures to reduce electricity consumption.
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