Energy planning is essential in any electricity system. This planning provides forecasts on energy demand and the resources needed to meet this demand. It also studies the evolution of market conditions to guarantee supply and environmental protection criteria.
The objectives of energy planning are:
- cost reduction
- energy efficiency
- guarantee of electricity supply
- diversity of sources used
- promotion of renewable energies
How is electricity generation planned in Spain?
In Spain there is a clear distinction in terms of the type of power plants and their use to cover energy demand. Thus, power plants are classified according to the use made of them.
There are three main groups where different types of power plants are included.
Basic power plants
The base or main power plants are those that are intended to supply most of the electrical energy.
Its function is to supply electrical energy permanently: the installation is usually in operation for long periods and should not suffer interruptions of the installation.
These types of power plants are characterized by their high power and can be thermal, nuclear, and hydraulic with high generation capacity and even some wind farms.
In the case of nuclear power plants, for example, the technical difficulty of regulating the energy generated makes it difficult to interrupt their operation, so their role in electricity generation can only be reduced to being basic power plants.
Top central stations
Peak power plants start up when the electricity demand is high (peak hours). Therefore, their operation is periodic. Thus, they must be able to start up and regulate themselves in a short time.
Once commissioned, peaking plants work in parallel with base plants to meet peak demand until they are no longer needed.
Peak plants are typically gas turbine thermal, hydro, and any renewable energy plant, as these types of plants can be up and running on short notice.
Backup power plants
Standby power plants are those designed to replace all or part of the basic power plants in the event of shortage or lack of raw materials (water, coal, fuel oil, etc.), or breakdown.
Backup power plants are usually combined cycle thermal power plants, hydroelectric power plants, and renewable energy power plants, due to their rapid response capacity.
Relief centers
Relief stations serve the same purpose as standby stations, with the difference that relief stations are small, self-contained stations that can be transported on trucks, trains, or ships.
They are usually powered by diesel engines.
Demand forecast
Forecasting electricity demand is essential to achieve a dynamic balance between demand and generation, so it is very important to know in advance and as accurately as possible, what will be the consumption of electricity at a given time.
Red Eléctrica Española (REE) has developed an application for demand forecasting whose results are highly accurate. Based on this application, the Programming Department, for forecasts greater than weekly, and CECOEL, with daily and hourly forecasts, update the demand forecasts.
From adjusting the forecasts to actual consumption, CECOEL schedules the power of each generating group following the offers it receives from them continuously, so that together with international energy exchanges, the actual demand balance is achieved, also compensating for possible failures of the generators.
However, due to the real impossibility of exactly and instantly matching demand and generation, the Electricity System has an automatic regulation system, the Peninsular Shared Regulation (RCP), which modifies the power generated within certain margins. CECOEL automatically sends the generation increase or reduction instructions to the Control Centers of the generation companies, which transmit these data to their generators to achieve a balance between consumption and production.
These forecasts are reflected in the so-called demand curves.
