Restrict amount of Energy bought at wholsale market.

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Restrict amount of Energy bought at wholsale market.

Michael
Hello everyone,

we´re a student team of the university of augsburg and are trying to develop a broker for several research reasons.
As we are quite unexperienced with such projects, we do hard with coding. So we started with changing the Sample Broker.

Here´s the Problem:
We need to limit the amount of energy a broker can buy, so that one broker can´t supply 100% of demand and some customers have to choose worse tarifs. We suppose to have to change the MarketManagerService - class, but have no idea how to limit the cumulative amount of energy bought with the severel orders for one timeslot. Are there any methods we just haven´t seen yet, or do we have to implement this on our own?

We are grateful for any help!

Michael
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Re: Restrict amount of Energy bought at wholsale market.

grampajohn
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Hello, Michael -

powerTACatFIMuniaugsburg wrote
Here´s the Problem:
We need to limit the amount of energy a broker can buy, so that one broker can´t supply 100% of demand and some customers have to choose worse tarifs. We suppose to have to change the MarketManagerService - class, but have no idea how to limit the cumulative amount of energy bought with the severel orders for one timeslot. Are there any methods we just haven´t seen yet, or do we have to implement this on our own?
I'm not sure why you don't want one broker to supply 100% of demand. In a one-broker game, (against the default broker), you would certainly expect your broker to supply 100% of demand.

Perhaps you are confused about the recent change that's intended to prevent a single broker from cornering the wholesale market? The energy supply in the wholesale market is, on average, 2-3 times the total demand. In the highest peak-demand cases we have seen, it is still something like 150% of total (net) demand. So the restriction on broker market position is with respect to the wholesale market, not the retail tariff market.

So my recommendation is that you focus on predicting customer demand for your current (or anticipated) portfolio over a horizon up to 24h, and design a trading strategy that ends up with a minimum-cost market position that matches the expected net demand (consumption - production) within your portfolio. That would require predicting market prices over the horizon, and buying/selling as your predictions change. Note that your wholesale market orders need not specify a price, if you are more interested in buying or selling a specific quantity than you are in getting a particular price.

Does this help?

John
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Re: Restrict amount of Energy bought at wholsale market.

Michael
Hello John,

thank you for your fast respond.

We have implemented two brokers competing against each other, and want to handicap one of them.
We are trying to implement a pricing modell inspired by the Paris Metro Pricing, so we need two tarfis (we decided to implement two brokers instead of one broker with two tarifs) with the same parameter setting, except the price. As for both tarifs the cumulative energy for alle transcriptions of one tarif is limited, some of the consumers should have to sign up to the more expensive tarif, as they can´t be deliverd by the cheaper one.

So your idea of setting the maxprice willing to pay at the wholesalemarket sounds good to me, i´ll find out the necessary parameter to reach our expected demand. However, as the prices aren´t constant, we will have some fluctation of capacity. There is no possibility to limit the capacity of one broker to a given value?

Greetings,
Michael
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grampajohn
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powerTACatFIMuniaugsburg wrote
We have implemented two brokers competing against each other, and want to handicap one of them.
We are trying to implement a pricing modell inspired by the Paris Metro Pricing, so we need two tarfis (we decided to implement two brokers instead of one broker with two tarifs) with the same parameter setting, except the price. As for both tarifs the cumulative energy for alle transcriptions of one tarif is limited, some of the consumers should have to sign up to the more expensive tarif, as they can´t be deliverd by the cheaper one.

So your idea of setting the maxprice willing to pay at the wholesalemarket sounds good to me, i´ll find out the necessary parameter to reach our expected demand. However, as the prices aren´t constant, we will have some fluctation of capacity. There is no possibility to limit the capacity of one broker to a given value?
There is currently no way to specifically limit the number of subscriptions to a particular tariff, but there is an easy way to limit the period of time over which customers can subscribe to a tariff, by specifying the expiration date/time. This is explained briefly in Section 3.1 of the game specification. If you review Section 4.1 of the game specification, you will see that customers have an "inertia" that limits the probability of evaluating tariffs in any given timeslot. Inertia is very low at the start of a game, but rises rapidly over the first day or two. New tariffs are published every 6 hours, and most (probably all) customers only evaluate tariffs every 6 hours. So if you set the expiration of your tariff to 13 hours in the future, it will only be open to new subscriptions for two evaluation cycles. If you don't get enough subscriptions during that interval, you can issue another with identical terms for another 13 hours, and so on. This should give you a decent level of control over subscription volume.

Does this help?

John
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Re: Restrict amount of Energy bought at wholsale market.

Michael
We actually want to limit not the subcriptions but capacity of the broker, as it would be interesting to simulate how customers react on a lack of service. Therefore it is necessary that the opportunity to change tarifs exists for the customers.

Could it be possible that the price-limitation for offers at the wholesale market doesn´t work? The standard setting is, that offers go up to a maxprice of 70€/mWh, but simulation shows transactions up to around 300€/mWH.

Thanks and greetings,

Michael
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Re: Restrict amount of Energy bought at wholsale market.

grampajohn
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Hello, Michael -
powerTACatFIMuniaugsburg wrote
We actually want to limit not the subcriptions but capacity of the broker, as it would be interesting to simulate how customers react on a lack of service. Therefore it is necessary that the opportunity to change tarifs exists for the customers.
Interesting idea. However, the brokers do not control the grid. All customers are connected to the same grid, and power flows when they turn switches on. As a result, brokers cannot limit the supply available to customers. Their responsibility is to balance supply and demand within their customer portfolios. If a brokers fails to buy as much energy as its customers use in a given timeslot, the grid operator (the Distribution Utility) makes up the difference and charges the broker a balancing fee.
Could it be possible that the price-limitation for offers at the wholesale market doesn´t work? The standard setting is, that offers go up to a maxprice of 70€/mWh, but simulation shows transactions up to around 300€/mWH.
Prices in the wholesale market are not limited. The supply curve is roughly quadratic, and the clearing price depends mostly on overall demand. There is a fair amount of randomness in the shape of the supply curve, and broker behavior can affect prices. For example, some brokers have bought up most of the supply, driving prices up, then attempted to re-sell it before its delivery time for higher prices than customer demand would have produced. It's easy to lose a lot of money doing this, and hard to make a profit -- but not impossible.

Cheers -

John

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Re: Restrict amount of Energy bought at wholsale market.

Michael
Hello John,

your explanations helped a lot to understand what happens behind. We have to rethink our model now - in the existing form it won´t be possible to simulate in powerTAC.

Thanks a lot!

Greetings,
Michael
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Re: Restrict amount of Energy bought at wholsale market.

Michael
Hello John,

i have one more question concerning the market transactions.
Is my interpretation of regular trading and balancing fees right, if you look at the image?
The maxprice willing to pay were 70 €/MWh.
Why do the balancing fees (or the left side, if these are other transactions) have such a discrete structure?
I don´t expect any linearity, but the fees seem to have quite random values.

Greetings,
Michael

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Re: Restrict amount of Energy bought at wholsale market.

grampajohn
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Hello again, Michael -
powerTACatFIMuniaugsburg wrote
I have one more question concerning the market transactions.
Is my interpretation of regular trading and balancing fees right, if you look at the image?
The maxprice willing to pay were 70 €/MWh.
Why do the balancing fees (or the left side, if these are other transactions) have such a discrete structure?
I don´t expect any linearity, but the fees seem to have quite random values.
Balancing fees are a function of overall imbalance and a broker's individual contribution to the imbalance. The main reason for the volatility in the cost is the volatility of the overall imbalance. Since imbalance is the net of (consumption + exports) and (production + imports), random errors in broker predictions of consumption and production within their customer portfolios can have a big impact on imbalance. Also, energy prices in the balancing market are substantially higher than in the wholesale market, and are strongly affected by the size of the imbalance. Note that a broker is always better off being having an individual imbalance with the opposite sign from the overall imbalance, because they are actually contributing to the solution. For that reason, balancing fees can be positive. Partly for that reason, and partly because brokers both buy and sell in the wholesale market, I don't understand why you labeled the graph the way you did.

Does this help?

John
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Michael
Okay i got your point, i understood how the fees work.

But i have no idea why the shown transactions, falsely named as distribution fee, appear.
I have limited the price to 70 €/MWh, so i don´t expect any market transactions of my broker ("low" in the graph) for higher prices. But there are transactions up to around 300 €/MWh. So where do they come from?
There is a cut in the graph, it is kind of continuous from 0 to -70 as expected. That should be the regular market transactions, matched by offer and call.
But can you explain me the transactions i see for higher prices (-70 to -300 €/MWh)?
Or rather: are it the transactions for the fees, and i just made the mistake, that there could be other transactions for the fees outeside the labeled area. So just the labeling was wrong?

Thanks a lot!

Michael
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grampajohn
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powerTACatFIMuniaugsburg wrote
But i have no idea why the shown transactions, falsely named as distribution fee, appear.
I have limited the price to 70 €/MWh, so i don´t expect any market transactions of my broker ("low" in the graph) for higher prices. But there are transactions up to around 300 €/MWh. So where do they come from?
There is a cut in the graph, it is kind of continuous from 0 to -70 as expected. That should be the regular market transactions, matched by offer and call.
But can you explain me the transactions i see for higher prices (-70 to -300 €/MWh)?
Or rather: are it the transactions for the fees, and i just made the mistake, that there could be other transactions for the fees outeside the labeled area. So just the labeling was wrong?
I'm afraid I really could not tell you what's happening here without looking at the server logs. Unfortunately, I would not have time to do that for the next 3-4 days, but I would be willing to spend some time on it after that. You would need to point me to the logs from the game that produced this plot.

Cheers -

John

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Re: Restrict amount of Energy bought at wholsale market.

Michael
Hello again, John

i´m very interested to a explanation of this transactions.
If it´s easier for you: just run a simulation with the Sample Broker on your own, there should appear the transactions.

If it turned out that it are indeed the distribution fees, i wonder why they are listed under "wholesale market transactions".

If i can help you with my server logs, just let me know.

Greetings,

Michael
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Re: Restrict amount of Energy bought at wholsale market.

grampajohn
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Hello, Michael
powerTACatFIMuniaugsburg wrote
i´m very interested to a explanation of this transactions.
If it´s easier for you: just run a simulation with the Sample Broker on your own, there should appear the transactions.

If it turned out that it are indeed the distribution fees, i wonder why they are listed under "wholesale market transactions".

If i can help you with my server logs, just let me know.
I am not sure I understand your question. If it is why these transactions show up on a display in the old visualizer under "wholesale market transactions" I cannot tell you. That visualizer is badly out of date, and I have felt for some time that some of the displays are mis-labeled and hard to understand. We are no longer maintaining it. A completely new visualizer is being used for the tournament; it is still a bit spare and we are working on additional displays for it. In the meantime, You might be better off analyzing games using the log-analysis tool. There are a number of example scripts under powertac-tools/logtool-examples, along with some python and r code that applies these scripts over multiple games, and works with the data extracted by them.

Best regards -

John
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Re: Restrict amount of Energy bought at wholsale market.

Michael
Hello John,


so i´ll concentrate on analyzing the server-logs.
As exams get closer here in Germany, i have to pause till August. Maybe the new visualizer is ready then ;)

Thanks for your help so far!

Greetings,

Michael

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