Module 10 — A New Approach to Market Design
Lesson 7 of 10
Forward Requests and Flexible Demand
Learning objectives
By the end of this lesson you should be able to:
- Understand what is meant by a forward request.
- Explain how flexible demand differs from inflexible demand.
- Recognise how flexibility can improve the coordination of electricity systems.
- Appreciate how forward requests support continuous market operation.
- Understand why flexibility allows the market to allocate resources more efficiently.
Introduction
Traditional electricity markets often require participants to decide how much electricity they wish to buy or sell during a particular market interval.
However, many electricity services are naturally flexible.
An electric vehicle may need to finish charging by tomorrow morning rather than immediately.
A battery may be willing to charge at different times during the day.
Some industrial processes can be shifted within a specified time window.
Rather than requesting electricity at one exact moment, participants may instead describe what they require and how much flexibility they are willing to offer.
This idea forms the basis of forward requests.
What is a forward request?
A forward request describes a future electricity requirement together with the constraints that define how it may be delivered.
Instead of requesting electricity at a single instant, participants specify the service they require over a future period.
For example, a request may describe:
- the amount of energy required,
- when the service must be completed,
- the earliest start time,
- the latest completion time,
- the maximum charging or discharge rate,
- any operational constraints.
The market then determines how best to satisfy that request while coordinating it with all other participants.
Inflexible and flexible demand
Not every electricity demand is equally flexible.
Some demand must be supplied immediately.
Examples include:
- lighting,
- medical equipment,
- many household appliances.
Other demand can often be shifted in time without affecting the service received by the consumer.
Examples include:
- electric vehicle charging,
- battery storage,
- water heating,
- refrigeration,
- some industrial processes.
This flexibility creates additional opportunities for coordination.
Flexibility creates choice
If every participant requires electricity at exactly the same moment, the market has relatively few options.
If some participants are flexible, the market gains additional choices.
It may schedule requests:
- earlier,
- later,
- at different power levels,
- alongside available renewable generation,
- during periods of lower network loading.
The greater the flexibility available, the more options exist for coordinating the system.
A simple example
Imagine two electric vehicles each requiring 20 kWh before 7:00 a.m.
The first driver plugs in at 6:00 p.m. and needs the vehicle immediately.
The second driver plugs in at 6:00 p.m. but only requires the vehicle by the following morning.
Both require the same amount of energy.
However, the second request provides the market with much greater flexibility regarding when charging can occur.
This additional flexibility may allow the market to make better use of available generation and network capacity.
Forward requests in a continuous market
Forward requests naturally complement continuous clearing.
Whenever a new request arrives, the market evaluates:
- the current state of the electricity system,
- existing future commitments,
- available flexibility,
- physical network constraints.
The request is then incorporated into the evolving allocation.
Rather than planning only for the present moment, the market continuously updates its understanding of future demand.
Coordinating future demand
Forward requests allow the market to coordinate future demand before electricity is actually consumed.
As new requests arrive, the market develops an increasingly complete picture of expected future resource requirements.
This enables allocation decisions to consider both present operating conditions and future commitments.
The result is a continuously evolving schedule that adapts as additional information becomes available.
Consumer choice
Forward requests do not require every participant to become highly flexible.
Instead, participants choose the level of flexibility they wish to offer.
Some consumers may request immediate service.
Others may allow greater scheduling flexibility.
The market coordinates these different requirements while respecting the constraints specified by each participant.
In this way, flexibility becomes a service chosen by consumers rather than an obligation imposed upon them.
Building on previous lessons
Earlier lessons introduced:
- a continuously maintained system state,
- continuous clearing,
- network-feasible allocation,
- distributed pricing,
- fairness over time.
Forward requests provide the information needed for these mechanisms to coordinate demand across both space and time.
Rather than reacting only to current conditions, the market can also consider future opportunities and constraints.
A systems perspective
Forward requests transform the market from a system that reacts to electricity demand into one that actively coordinates future resource use.
Participants communicate not only how much electricity they require, but also when they are willing to receive it and under what conditions.
This additional information allows the market to make more informed allocation decisions while preserving consumer choice.
A key insight
Forward requests allow participants to describe future electricity requirements together with their operational flexibility.
By coordinating these requests continuously as they arrive, the market gains greater freedom to allocate resources efficiently while respecting consumer preferences and physical network constraints.
Key takeaways
- A forward request describes a future electricity requirement rather than an immediate purchase.
- Flexible demand allows electricity consumption to be scheduled within specified constraints.
- Greater flexibility increases the options available for coordinating the electricity system.
- Continuous clearing naturally supports the ongoing coordination of future requests.
- Consumers retain control by specifying the flexibility they are willing to provide.
- Forward requests enable the market to coordinate both present and future resource requirements.
Looking ahead
Forward requests describe what participants require and when they are willing to receive it.
The next lesson examines how these requests can be satisfied using different energy, capacity and reliability products, allowing consumers to choose services that best match their individual requirements.