Utility Decoupling

とりあえず、自分用メモ。

“Utility Decoupling: Giving Utilities Incentives to Promote Energy Efficiency”

Progressive States Network

September 10th, 2007

Decoupling breaks the link between the utility's ability to recover its agreed-upon fixed costs, including the profit margin, from the actual volume of sales that occur through a rate adjustment mechanism. If a utility promotes less energy use, they are rewarded rather than punished.
Under decoupling, there are a number of ways to compute the rate adjustment, but the basic principle is that if the actual sales are less than what was forecasted, there is a slight upward adjustment in rates to compensate the utility. Adjustments typically would only be between 2-3 percent and some jurisdictions have applied caps on possible adjustments to protect consumers.

Any rate increase per kilowatt hour is usually offset by lower energy use and usually lower overall energy bills due to increased conservation and lower energy consumption. Typical rate changes due to current decoupling is almost imperceptible to consumers. And instead of utilities passing on the costs of building new plants to meet increased energy demand, under decoupling, consumers avoid the costs of new power plant construction and benefit instead from decreased energy consumption.

“The Role of Decoupling Where Energy Efficiency is Required by Law”

The Regulatory Assistance Project

August 2009  

Under decoupling, the rate case process remains the same. However, the prices computed in the case are in place for an initial period and thereafter are relevant only as a reference point. Prices are adjusted periodically to keep revenue at its allowed level, reflecting differences between the forecasted units sold (in the rate case) and actual units sold. In other words, decoupling fixes the revenue the utility collects and lets prices float up or down with actual sales.

... under decoupling, the only way a utility can increase its profits is by reducing costs. A strong incentive to manage costs efficiently is especially welcome today, with ratepayers facing mounting pressure on near-term rates as utilities transition to low-carbon energy sources, advanced metering, and distribution and transmission system upgrades – all of which should ultimately reduce consumer bills.

... neither requirements in law nor third-party administration of programs negate efficiency’s fundamental conflict with the traditional utility business model, where earnings fall disproportionately with declining energy sales.

伝統的なやり方では、電気の料金は、諸々の発電・配電インフラの構築・維持にかかる費用と、需要予測との見合いで決められている。一旦、料金単価が認可されてしまえば、電気会社にとって、収入を上げる方法は、①支出を減らす、②販売量を増やすの二つに絞られる。事業構造上、電気会社は、支出に占める固定費の割合が非常に大きいので、①の方法で収入を上げるのは困難。勢い、（営利企業としての合理的な行動をとる限り）、販売量を増やす方向にインセンティブ（言いかえれば、省エネを進めることへのディスインセンティブ）が働くことになる。

この状況を改善するため、電気会社の「収入」と「販売量」を「切り離す（decoupingする）」というのが、Utility Decouplingの考え方。具体的には、電気会社の収入が一定になるよう、実際に販売された電気の量に応じて、料金単価をフロートさせる。この結果、電気会社は、販売量を増やしたいというインセンティブから解放されることになる。この方法、実際に、カリフォルニアをはじめとするアメリカのいくつかの州で既に採用されていて、成功を収めているとのことである。

いくつか疑問点（非常に粗雑）。

1. 省エネに対するディスインセンティブが消えるのはわかるが、積極姿勢に転換するとまで言えるのか？（或いは、decouplingと、その他の政策（新エネ導入目標など）との合わせ技で対応する ― 「消臭剤＋芳香剤」作戦 ― ということか。）
2. 公定料金の改定はどのくらいの期間ごとに行われる（或いは「行われるべき」）ものなのか？
3. 二期間以上に及ぶ長期の投資計画に対してdecouplingはどう作用するか？（論理的には中立??
4. 日本における導入・検討状況如何。

答えはおいおい調べます。

my room, Washington, DC, Oct 8, 22:47