Talk:Game Design

Sequence of days for timeline
I suggest that we think about the pattern of weekdays/weekends when deciding on which days to simulate. If we skip by a multiple of 7, then every day would be the same day of week; if we skip by 8, we would have a cycle of 5 weekdays and 2 weekend days. If we skip by 12, we would have a cycle of M-Sat-Th-Tu-Sun-Fri-W so weeks would alternate between 4 days and 3 days. Would it be better to just pre-select the days to get something consistent like 4-day weeks with one weekend day? Grampajohn 18:09, November 3, 2010 (UTC)


 * I do like the idea of having a consistent number of week days and weekends periodically. Skip by 8 seems like a good way to do this. The only drawback, compared to skipping by 12 days, is that we will only be able to simulate about 1.3 years instead of 2 years, so we may not capture seasonal dynamics as well. We could also skip by 15 and get the same 5+2 pattern and simulate a longer time overall. But, would only two days per month be too sparse a sample? PReddy 18:19, November 3, 2010 (UTC)
 * A cycle of 12,12,12,13,12,12,12,13,... gives you a 49-day cycle that could run FWMSFWMS...
 * Grampajohn 21:04, November 3, 2010 (UTC)
 * Grampajohn 21:04, November 3, 2010 (UTC)

Blueprints needed for each of the "Major Scenarios"
Once we understand how the game progresses in enough detail to understand how the game works, we need to take each of the scenarios and detail them in enough technical detail to begin writing an implementation. As these are written, the scenarios need to link to the blueprints so we know they are done.

Grampajohn 14:20, November 4, 2010 (UTC)

What is the initial state of the market?
I have heard two proposals for the "initial state" of the market: In the first case, the Broker may need some leadtime, perhaps 24 hours, to retrieve forecasts and build up a market position in the wholesale market before it must serve its load base.
 * 1) All customers are subscribed to "generic" fixed-price tariffs, which are evenly distributed among the competing Brokers. Each Broker must immediately begin serving its portfolio, while it develops and offers new tariffs, and negotiates contracts with larger customers.
 * 2) Brokers begin with no tariffs, but instead the Distribution Utility holds fixed-price tariffs with all customers. This is a typical state for a new retail market - see Joskow's "Lessons Learned" paper for examples. The key is that the "default" tariffs are fairly unattractive.

Grampajohn 23:53, November 7, 2010 (UTC)

RTD and RTC modeling
(JDcosta asks: Is the Execution (shorter time interval) and the Contracting (relatively longer look-ahead time horizon) identifiable with the Real Time Dispatch (RTD) over 5-10 minute interval) and Real Time Commitment (RTC over a 1-3 hr ) in a Real Time (as well as a Day -Ahead scheduling optimized over hourly intervals over a 24 hr period ) Market operation of a market design referenced on (for example) page 1964 of the reading material assigned for today's meetup (Chow et al)? (except perhaps for convolution with a time contraction/dialation operator to adjust for the relative differences in the magnitudes of the time periods involved in the proposed Game Design and the Market Design presented in the paper)

No, we are abstracting away this distinction for the simulation. Because we are concentrating on the distribution side of the market, the only effect of RTD is (potentially) some short-term price variations. However, the simulation is running a one-hour timeslot in 5 seconds, so a resolution of 10 minutes is unrealistic. We treat the one-hour timeslots as discrete quanta, and only balance overall supply and demand over the full timeslot.

Grampajohn 04:04, November 8, 2010 (UTC)

Prices for external balancing
[mdeweerdt:] For a good "mechanism design" we first need to come up with some properties that we would like to the mechanism and the imbalance penalty/fee to have. Do you agree with the following?

Can you think of additional requirements?
 * 1) Brokers should have an incentive to balance, so their profit from any imbalance should not be greater than the penalty.
 * 2) The imbalance penalty should realistically be sufficient to "repair" the imbalance.

For 1, to bound the profit from imbalances, we could consider an excess and a shortage of power separately. A broker with a shortage has sold power he does not have. His profit is the price at which he sold. This price is bounded above by the maximum over all consumers of the private value they have for power. The penalty can thus be taken accordingly. A broker with an excess has bought power but failed to sell it. I don't think we need a penalty here for 1.

For 2, I could ask my colleagues at electrical engineering, if you think it is relevant.

These ideas should now be converted to a dynamic setting, and I believe we could give a short proof on 1.

Mdeweerdt 19:58, November 16, 2010 (UTC)

This is a well-defined problem at the wholesale level
I suggest we model our retail balancing-power market on the wholesale real-time/balancing markets. Basically it works more or less like the futures markets, in which every player capable of responding to imbalance quickly submits bids. Some will be on the demand side, and some on the supply side. For example, a vehicle battery could be used on either side, possibly with different prices. For every broker, there are three different sources of balancing capacity:


 * 1) The broker's own contracted balancing capacity. Presumably, all of this is constrained in one way or another. For example, you can only charge a battery that is not already fully charged. You can only shed loads that are currently drawing power.
 * 2) Other brokers' surplus or deficit.
 * 3) The wholesale market, which couples the local balancing market to the ISO balancing market.

By definition, balancing happens when it's too late to adjust prices and hope that demand or supply changes. So the only way to change supply and demand within a broker's own portfolio is through its contracted balancing capacity. Each unit of a broker's balancing capacity has a price, determined by the applicable tariff. At the same time, the balancing price in the wholesale market will have a fixed marginal price, possibly over a restricted range (you can only adjust output of spinning turbines over a limited range on short notice). If all these units of supply and demand, with associated prices, are treated as bids, it seems that we could treat the balancing problem as a market clearing problem. Sort supply and demand units by price, find the intersection between supply and demand, and that gives the price. All the supply with lower bids, and all the demand with higher bids, is accepted.

Grampajohn 23:19, November 22, 2010 (UTC)

Keeping our theme of a regional energy market where the ultimate balancing entity is the distribution utility, the crucial element is aggregate imbalance of the market. I.e., if the regional market is imbalanced on aggregate that is when truely imbalance cost occur to the distribution utility which then levies the corresponding imbalance fees from the brokers who caused this imbalance. A special sidenote on this aspect is the situation where the aggregate market was imbalanced to one side (e.g., energy shortage) and a single broker was imbalanced (e.g., oversupply): then this broker should not be charged by the distribution utility since he is not causing any harm, actually he is softening the aggregate market imbalance. Chrisflath 20:26, November 23, 2010 (UTC)

No, in fact that broker should be paid. In general, each broker should be able to decide how to best achieve balance, and I suspect that can be done automatically with a standard call market setup during each timeslot, after all supply and demand values are known. Grampajohn 20:40, November 23, 2010 (UTC)