Vol.6 No.3 2014
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Research paper : A proposal for setting electric power saving rate to avoid risk of electric power shortage occurrence (I. ARIZONO et al.)−142−Synthesiology - English edition Vol.6 No.3 (2013) We can obtain the electricity shortage outbreak probability in the situation of (0, 1)=(97.0×0.85, 3.0) as the minimum value among three values from the reason mentioned above. From Fig. 3, it is found that the evaluation by the probability inequality is shifted to the Hoeffding probability inequality from the Chebychev probability inequality after =13.63(%).The result about the minimum value is illustrated in Fig. 4. In Fig. 4, the appropriate electric power saving rate for ensuring the value (5.462 %) of the electricity shortage outbreak probability is derived as =14.66(%).When the electricity supply with the conventional electric generating systems decreased by 15 %, 14.55 % of the total electricity supply was lost from the viewpoint of the average. Therefore, it is found that, for the purpose of ensuring the value (5.462 %) of the electricity shortage outbreak probability in a stable condition, the electric power saving rate of 14.66 % exceeding the lost total electric power rate of 14.55 % is required. In other word, it can be interpreted that to decide on the electric power saving rate from the viewpoint of expectation is not necessarily enough. The proposed evaluation system concludes that excessive electric power saving is not necessary from the comparison of 14.66 % and 14.55 %. This is the effect of having considered the information of each variance in the electricity supplies and demand. Based on this effect, we can say that the proposed evaluation system for the electricity shortage outbreak probability has the appropriate security-oriented property. Similar results have been observed under other loss ratios of the electricity supply with the conventional electric generating systems. Therefore, it is understood that the required electric power saving rate can be obtained under the security-oriented property by utilizing the proposed evaluation system for the electricity shortage outbreak probability. Moreover, it is concluded that the proposed evaluation system contributes to the accountability of the electric power saving rate.7 ConclusionAt the moment, the electricity demand-supply balance is in a tight situation. Although renewable energy as a source of electricity supply is anticipated, the electricity supply based on renewable energy contains a lot of uncertainty. In addition, there is also uncertainty in the electricity demand. In view of the present situation, we have considered a system for evaluating the electricity shortage outbreak probability based on the limited information concerning the electricity supply and demand. Concretely, under the uncertainty concerning the electricity demand and supply, an evaluation system for electricity shortage outbreak probability in the worst-case scenario has been proposed by utilizing the probability inequality. Furthermore, the procedure for achieving appropriate accountability for a certain rate in the reduction of the electricity demand has been discussed by using the proposed evaluation system.In deciding on the required electric power saving rate and the construction planning of a new electric generating system based on renewable energy using the proposed evaluation system, the features of the probability inequality should be fully explained. Basically, the information about the electricity supplies e0 and e1, and the electricity demand e2 should be sufficiently disclosed in order to estimate the expectation and variance of them. We desire more information disclosure by the existing electric power companies and the Japanese government. We can, in fact, request for more information disclosure to the electric power companies and the government on the basis of using the proposed evaluation system. Recently, the Kansai Electric Power Company has made an effort to disclose information in order to answer many questions from the local inhabitants.[11] From this information disclosure, it is found that the electricity supply and demand fluctuate every day as assumed in this paper. At the same time, the Kansai Electric Power Company announces the estimation of the electricity demand-supply balance as part of the information disclosure. However, it seems that the estimation of the electricity demand-supply balance by the Kansai Electric Power Company depends only on the expectation of the electricity supply and demand. Therefore, we desire more information disclosure for the purpose of making more useful decisions.In addition, we consider that some new technical innovations in the case of adopting the probability inequality might be required. For example, improvement of forecast precision of the electricity demand directly influences the required electric power saving rate. Therefore, accurate estimation of the expectation and variance based on historical data accumulated in the electric power companies will be an important innovation. Furthermore, considering that the Fig. 4 Evaluation based on proposed system0.05 0.15 0.25 0.10 0.12 0.14 0.16 0.18 (0.1466, 0.0546)0.200.000.100.20Electricity shortage outbreak probability (%)Electric power saving rate γ

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