報告書番号

Y04013

タイトル（和文）

米国のグリーン電力プログラムの設計に関する考察

タイトル（英文）

Study on Green Power Program Design in the Unites States

概要 （図表や脚注は「報告書全文」に掲載しております）

米国の電力会社が実施する家庭用需要家向けのグリーン電力プログラムの設計について検討し、さらに日本で受容性の高いプログラムについて考察した。電力会社が、需要家の電力消費量に関わらず、一定の単位電力量毎(100-200kWh/月)に固定価格で販売する「ブロック型」は、米国のプログラム加入者数上位10社の内5社が実施している。ただし、近年は消費量の100%をグリーン電力とするプログラムの加入者数も増加している。負担額が明確なブロック型は日本でも受容性が高いと考えられるが、米国よりグリーン電力供給源として有力な風力発電のコストは高く、より小さい単位電力量の設定が必要である。100%グリーン電力では、その負担額が高く、日本で多くの需要家が加入する可能性は小さい。グリーン電力がRPS制度の義務達成にも用いられる場合は、より低い負担額の設定が可能だが、プログラムの実施意義自体に対する慎重な議論を要する。

概要 （英文）

The purpose of this paper is to investigate green power program design in the United States and obtain implications useful for Japanese programs. The author focuses on programs in which utilities supply electricity generated from renewable sources to residential customers. The main results are as follows:1) Among the top 10 utilities in the number of participants in the United States, five companies offer "block programs" that supply green power in blocks of energy, such as 100-200kWh/month, for a fixed monthly payment. One of the merits of the block programs is that customers can know the exact payments in advance of their participation. But, recently participants in programs in which utilities meet 100% of customers’ electricity demands from renewables (100% green program) have been on the increase. There is a utility that offers a 100% green fixed payment program.2) Power from wind and landfill gas generation facilities is mainly supplied in the programs that the top 10 utilities offer. Monthly minimum payments for the block programs are approximately 2-4$ (a utility exempts participants from fuel cost adjustments and from environmental costs related to coal power plants, therefore the actual payment is 0.76$ as of February 2005). Although payments for the 100% green programs are generally higher than those for the block programs, participating customers place the highest value on 100% renewables.3) The block program is considered to be acceptable for Japanese customers. But, due to higher generation costs of wind power facilities in Japan than those in the United States, a block in Japan should be set lower than that in the United States. There is a low possibility that the 100% green program acquires a lot of participants due to their higher payments. If green power were supplied from renewables to meet a Renewable Portfolio Standard requirement or utilities used green power certificates issued to self consumption of on-site facilities, premiums of green power programs could be set lower. However, in the former, preferences of customers to programs might be lower and the rights and wrongs would have to be discussed deliberately regarding an achievement of the green power programs.

報告者

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