emix — archive

[Edward Cazalet <ed@cazalet.com>]

Excellent Forward Progress but still some issues for me. Line 294: The Resource schema defines how load and generation, specific capabilities of devices and systems to affect power and energy markets, can be described irrespective of the underlying technologies. Rewrite as: The Resource schema describes specific capabilities of devices and systems, irrespective of the underlying technologies affect power and energy markets. My view: the Power Schema must stand on its own providing all of the schema necessary for pure power transactions that to do not reflect resource capabilities. For example retail tariffs, most financial and physical forward wholesale power trading, and TeMIX do not rely on resource capabilities and therefore should not need to use anything the Resource Schema. Line 306 change "exchange" to "exchanged" Line 320 and Table 3-3: The words "or transaction" should be deleted from the description of Item Base. I suggest that the logic supporting the decision NOT to include quantity or price in the product description is questionable for the following reasons: 1. The statement in Item Base confuses multiple prices and quantities for a products that extend over several intervals with multiple prices and quantities that may be associated with a product delivered within a single interval. For example, options have both a strike price and a premium price. Other products may have both a demand and energy price, or an offer curve to an ISO will have a set of price quantity pairs all in each interval. 2. Other elements such as ramp rates may vary by interval and not just price or quantity. One can imagine products with the same price and quantity in each interval of a sequence but where other elements vary, so why treat price an quantity as special. 3. Price and quantity as part of the product description can be overridden in gluons and intervals if they do vary by gluon or interval. Therefore I can see no reason price and quantity are not part of the product description and to do otherwise only creates unnecessary confusion and potentially some unnecessary communication overhead, however minor. Schedule defines a collection of one or more intervals with durations and starting times. One can imagine a product applied to a schedule where nothing varies by interval. For example, for a product for 1 MWh of energy in each of the next 24 hours at the same price, nothing goes in the interval. Or a single interval product by definition has no elements in the interval. While there may be a reason, there is no reason stated to require the placement of the complete product description in Components of the Schedule. In the case of a single interval product, why can't the product description including price and quantity be communicated along with an interval with a duration and starting time based on WS-Calendar conventions? And in the case of multiple intervals where some product description may vary by interval or gluons, why shouldn't the only these elements be required to be in the gluons or intervals although any could be at the choice of the designers? While great strides have been made the simplification of WS-Calendar it still introduces new concepts which we should only use were they are simpler or introduce valuable new interoperation between the grid and customer domains. Line 325 Price Base and Extensions I think price needs to be a standalone element. Prices and price modifiers are very different elements and often used more as a control signal than a market signal. We can have a Price Modifier Base and Extensions for Price Relative and Price Multiplier. Such Modifiers can apply to the price whether communicated in the product description or the market context. Edward G. Cazalet, Ph.D. 101 First Street, Suite 552 Los Altos, CA 94022 650-949-5274 cell: 408-621-2772 ed@cazalet.com www.cazalet.com