• Aucun résultat trouvé

Smart conversion of residual heat into electricity: the electricity market point of view

N/A
N/A
Protected

Academic year: 2021

Partager "Smart conversion of residual heat into electricity: the electricity market point of view"

Copied!
11
0
0

Texte intégral

(1)

Smart conversion of residual heat into

electricity: the electricity market point of view

Damien Ernst – University of Li`ege Email: dernst@ulg.ac.be

Restwarmterecuperatie - iets voor uw bedrijf ? ArcelorMittal - Gent

(2)

Problem statement

1. You have a (or several) source(s) of residual heat.

2. You have devices for transforming residual heat into electricity.

3. You would like to know how to interact with electricity markets in a smart way so as to maximize the revenues of your sources of

(3)

In this talk, we will:

1. Describe the very basics of electricity markets.

2. Understand the opportunities that exist in primary electricity markets, with or without storage of heat.

(4)
(5)

Primary electricity markets: the basics

 Trading of electrical energy refers to an amount of megawatts-hours to be

delivered over a specific period of time. 15 minutes in Europe.

 Every injection or off-take points are associated with a Balancing Responsible

Party. A BRP is responsible for maintaining quarter-hourly balance between

total injections and total off-takes. Can buy/sell contracts for energy for ensuring this balance.

 BRPs may be unbalanced and have to pay a price for this.

 All of the market participants; including generators, suppliers, traders and

consumers; must notify their expected final position by gate closure.

 The Transmission System Operator (ELIA in Belgium) is the ultimate actor

(6)

No control over the heat available - what to do?

 Sign the right contract with your retailer or sell/buy well your

energy in the primary electricity market.

 Predicting well the amount of electricity produced by your

residual heat has a value (e.g., it helps the BRP to fulfill its role, forward contracts possible, . . .).

 Build you system so as to be able to throw away residual heat or

to use it for other purposes. Downwards modulation of

electricity production has a value (e.g., when the prices for

electricity are negative, for a BRP that has scheduled too much generation, etc.)

(7)

Storing heat for upwards and downwards modulation of

electricity production

 Even if the amount of residual heat produced by your process

cannot be controlled, heat can often be stored.

 Prices for electricity fluctuate over the day:

 By storing heat when prices are low and transforming heat into

electricity when prices are high, it is possible to exploit these price fluctuations to maximize gains.

(8)

What to do to exploit this flexibility?

 Either you try to exploit by yourself this flexibility by trading

yourself electricity in the market. Or, you can sell this flexiblity to a third party (e.g., a retailer or an aggregator). The second solution may be less risky.

 If you exploit this flexibility yourself, build the right

decision-making tools for scheduling your electricity production. Note that for scheduling well the production you need (i) to have an accurate prediction of electricity prices (ii) to have an accurate prediction of the residual heat produced by your

processes (iii) to solve a potentially complex (stochastic)

optimal sequential decision problem. The sequential nature of the problem is related to the fact that the production level for a market period is going to influence the possible production levels for the subsequent market periods.

(9)

Ancillary markets

 Loads and generators can provide services to support electricity networks. Those are known as ancillary services.

 System Operators have created markets for getting access to

these services.

 We discuss two specific types of ancillary services that machines

converting residual heat to electricity could provide: (i) primary reserve and (ii) relieving congestions/solving voltage problems in distribution networks.

(10)

Primary reserve

 Primary reserve is the ancillary service for balancing production

with consumption that acts at the shortest time-scale. This service is provided by generators that detect frequency fluctuations (note: imbalances modify the frequency) and adjust their power

automatically, according to ∆P = −K∆f .

 Machines converting residual heat could also offer such a reserve

but several difficulties remain, such as for examples: individual

machines may not provide enough reserve to be eligible for selling this service (need for aggregators), upwards modulation can only be done if the machine comes with a heat storage device, difficulties to carry out ex-post analyses.

(11)

Relieving congestions in distributions networks

 Many voltage and congestion problems are caused by

distributed generation in distribution networks. An academic example:

HV

MV Bus 1

Bus 3

Bus 2 Bus 4 Bus 5

12/05/13 16:23 Page 1 sur 1 file:///Users/Quentin/Downloads/generator.svg 12/05/13 16:23 Page 1 sur 1 file:///Users/Quentin/Downloads/generator.svg Solar aggregated Wind Residential aggregated Industrial

When Distributed Generation (DG) sources produce a lot of power: (I) overvoltage problem at Bus 4 (II) congestion problem on the MV/HV transformer.

 Modulating in an adequate way the active and the reactive power

of machines converting residual heat into electricity could help

solving these problems. They could therefore offer valuable services to distribution networks. But markets for such valuable services not yet exist.

Références

Documents relatifs

Regarding the study of commercial samples it provides important information: the aspect, color and the place of acquisition of the resin have no correlation to its

The response of the system following a step change in working fluid mass flow rate is then studied by considering input parameters from an OTEC onshore

We can imagine potential model modifications for a more realistic description of the observed spot series, e.g., by changing the annual pattern to account for multiple annual

Before benefiting from this characterization of EPEC solutions one has to cope with two tasks: first, one has to be able to check the constraint qualification represented by the

Based on analyzing the sample of 40 German electricity companies representing 77% of the total market in terms of end consumer sales in kWh, it may be summarized that the

Let us also mention algorithms MEC and MCC, as defined by Shier [13]. MCC is a more general variant of MCS and MEC is a more general variant of MNS: the condition of maximality

Dans le premier cas, le plus simple, lorsque l’utilisateur est centré sur un objet de la base (un restaurant R, un musée M), le portail peut alors lui proposer de visualiser

This section provides the basic equations of radio astronomy with multiple sensor array and describes a partial aperture synthesis strategy which aims to reduce data transfer,