Energy Consumption and Self-Consumption: Your Complete Guide to Smarter Energy Use

Understanding how much electricity you use is an important first step towards managing your energy more efficiently. But energy consumption and self-consumption are not the same thing. Energy consumption refers to the amount of energy used by your home or business. Electricity self-consumption, on the other hand, means using electricity produced by a generation installation associated with your supply, commonly a solar photovoltaic system, instead of obtaining all your electricity from the grid.

This distinction is important: self-consumption does not automatically reduce the amount of electricity you use. It changes where part of that electricity comes from. Combining energy efficiency with self-consumption can help you reduce unnecessary consumption, make better use of locally generated renewable electricity and reduce the amount of electricity you need to import from the grid.

In this guide, we explain energy consumption, electricity self-consumption, collective self-consumption, surplus electricity and energy storage, and how these concepts work together. 

 

What Is Energy Consumption?

 

Energy consumption is the amount of energy used by a home, building, business or process over a given period. In a home, electricity consumption can come from lighting, appliances, air conditioning, electric heating, water heating, cooking, electronic devices and other equipment.

Electricity consumption is normally measured in kilowatt-hours (kWh). Understanding your consumption involves more than simply looking at the final amount on your electricity bill. It is useful to know how much electricity you use, when you use it and which appliances or systems account for that consumption.

These consumption patterns become particularly important if you have a self-consumption installation because the time at which electricity is used can determine how much of your own generation you can consume directly.

 

Energy Consumption vs Self-Consumption: What’s the Difference?

 

Although the terms are related, they describe different things.

• Energy consumption tells you how much energy you use.
• Self-consumption tells you how much electricity generated by an associated production installation you use yourself.

Imagine, for example, that a home requires electricity during the day while its solar panels are producing electricity. Part of that demand can be covered directly by the solar installation. If the home needs more electricity than the panels are producing at that moment, the remaining electricity can be obtained from the grid.

The household may therefore consume the same total amount of electricity as before while importing less electricity from the grid. This is why reducing energy consumption and increasing self-consumption are different objectives.

Energy efficiency can reduce the amount of energy you need. Self-consumption can reduce the amount of electricity you need to obtain from the grid when your own generation is available 

Used together, the two strategies can complement each other.

 

Understanding Self-Consumption: What Does It Really Mean?

 

In Spain, electricity self-consumption refers to electricity consumed by one or more consumers from generation installations located close to and associated with their consumption points.

Solar photovoltaic installations are one of the most familiar examples. When your installation is generating electricity, that energy can be used to meet your electricity demand at that moment.

If production is lower than consumption, the grid can supply the difference in a grid-connected installation.

If production is higher than consumption, what happens to the surplus depends on the configuration and arrangements associated with the installation.

Self-consumption therefore does not necessarily mean becoming independent from the electricity grid. Many self-consumption installations remain connected to the grid and use it whenever local generation is insufficient.

 

How Does Electricity Self-Consumption Work?

 

A simple solar self-consumption system can be understood through three situations. When your installation is producing electricity and your home or business is consuming electricity at the same time, part or all of that demand can be covered directly by your own generation.

If you need more electricity than the installation is producing, the additional electricity is obtained from the grid. If the installation produces more than you are consuming, there is surplus electricity.

Depending on the type and configuration of the installation, that surplus can be prevented from entering the grid, exported to the grid or managed according to the economic arrangement applicable to the supply.

A physical battery can also be incorporated into some installations to store electricity and use it later. This makes the relationship between generation and consumption profiles particularly important. The more of your electricity demand that coincides with your own generation, the more electricity you may be able to consume directly.

 

Self-Consumption With and Without Surplus Electricity

 

Not all self-consumption installations manage surplus electricity in the same way. In Spain, self-consumption can operate without surplus, where the appropriate system prevents excess electricity from being injected into the grid. It can also operate with surplus, allowing electricity that is generated but not consumed at that moment to be exported to the grid.

Depending on the applicable self-consumption arrangement and the conditions that are met, surplus electricity may be subject to an economic compensation mechanism or another arrangement. This is different from directly consuming your own solar electricity.

Direct self-consumption occurs when the electricity is generated and consumed at the same time. Surplus electricity is the electricity that your installation generates but you do not consume at that moment. Understanding this distinction makes it much easier to interpret your self-consumption data and electricity bill.

 

What Is Collective Self-Consumption?

 

Collective self-consumption allows several consumers to be associated with the same electricity generation installation. This can be particularly relevant for apartment buildings, communities of owners, businesses or other groups of consumers that meet the applicable requirements. It does not simply mean that all participants use an undivided pool of electricity whenever they want.

The electricity generated is allocated among the associated consumers according to agreed distribution coefficients. These determine the portion of generation assigned to each participant for the corresponding periods. The allocation criteria are established through an agreement between the participants in accordance with the applicable framework.

Collective self-consumption can therefore make renewable generation accessible in situations where installing an individual generation system for every consumer would not be practical. It also makes understanding consumption profiles particularly useful, as participants can consider how the generated electricity is distributed among the different associated consumers.

 

How Energy Efficiency and Self-Consumption Work Together

 

Self-consumption and energy efficiency can complement each other, but they should not be confused. Energy efficiency focuses on using less energy to obtain the same or an appropriate level of service or comfort.

Examples can include using efficient appliances, avoiding unnecessary standby consumption, improving insulation or operating heating and cooling systems efficiently.

Self-consumption addresses a different question: where does the electricity you use come from? If you reduce unnecessary electricity use, your overall electricity demand can fall.

If you then cover part of the remaining demand with electricity generated by your own associated installation, you can also reduce the amount of electricity you need to import from the grid while generation is available. This is why a sensible energy strategy starts by understanding consumption rather than simply adding more generation.

If you want to explore practical ways to reduce unnecessary electricity use, read our guide to effective ways to save electrical energy at home.

 

How to Increase Your Solar Self-Consumption

 

If you already have a solar installation, increasing self-consumption does not necessarily mean consuming more electricity. The objective is to make better use of the electricity that your system is already generating. One way to do this is to understand your generation and consumption profiles and, where practical, move flexible electricity use to periods when your installation is producing.

For example, some appliances can be programmed to operate during suitable daylight hours rather than at times when the home is relying entirely on grid electricity.

Monitoring tools can help identify when your installation generates the most electricity and when your household or business consumes the most. The goal is not to use electricity unnecessarily simply because solar production is available. Efficiency should still come first. Instead, where an electricity use is necessary and its timing is flexible, aligning it with local generation can increase the proportion of your own electricity that you consume directly.

 

Physical Battery vs Virtual Battery: What’s the Difference?

 

A physical battery and a virtual battery are not the same thing. A physical battery stores electrical energy produced by your installation so that it can potentially be used at another time, depending on the system configuration. For example, solar electricity generated during the day may be physically stored and later used when solar production is lower.

A virtual battery does not physically store electricity. It is a commercial mechanism that can assign an economic value or balance to eligible surplus electricity according to the conditions of the service. How that balance is generated, accumulated and applied depends on the specific contract.

This means a virtual battery cannot supply stored electricity to your home during the night in the way a physical battery can. If your solar panels are not producing and you do not have suitable physical storage or another local source of generation, your grid-connected home will normally obtain the electricity it needs from the grid.

Evergreen Eléctrica offers a virtual battery service for eligible customers. Check the conditions of the service to understand how surplus value is calculated and applied.

 

What Happens to Solar Energy You Don’t Use?

 

When a solar installation generates more electricity than is being consumed at that moment, the difference becomes surplus generation. What happens next depends on the installation.

In a system configured without surplus, appropriate equipment prevents that excess electricity from being exported to the grid.

In a system with surplus, the electricity can be injected into the grid.

Depending on the applicable arrangement, consumers may be able to receive compensation for eligible surplus electricity or manage its economic value through a commercial service. Alternatively, where a suitable physical battery is installed, some electricity can be stored locally for later use.

These options are different and should not be confused. Exporting surplus electricity is not the same as storing it, and receiving economic compensation for exported electricity does not mean that the same physical electricity is being returned to your property later.

 

How to Monitor and Understand Your Energy Consumption

 

Before making decisions about self-consumption, it is useful to understand your electricity demand. Start by looking at how many kWh you consume and how that consumption changes throughout the day, week and year. Smart-meter data and compatible monitoring systems can provide more detailed information about consumption patterns.

If you already have a self-consumption installation, generation monitoring can also help you compare when electricity is produced with when you actually use it.

This can reveal whether a large proportion of your electricity demand already coincides with generation or whether some flexible uses could be shifted to different times. It can also help distinguish between three useful concepts: total electricity consumption, electricity supplied by your own generation and electricity imported from the grid.

If you want to understand the financial side of electricity consumption, you can also read our guide on how to calculate electrical energy cost.

 

Is Self-Consumption Worth It?

 

Self-consumption can be beneficial, but there is no universal answer that applies to every home or business. Whether a self-consumption installation makes sense depends on factors such as your electricity consumption, when that consumption occurs, expected generation, available space, characteristics of the property, installation costs and the way surplus electricity will be managed.

A household that can use a significant part of its solar generation while it is being produced will have a different self-consumption profile from a property that is largely empty during daylight hours. Storage can change that relationship, but a physical battery also has its own cost, capacity, efficiency and operating characteristics.

The right approach is therefore to assess consumption and generation together, rather than assuming that installing more generation will automatically produce a better result.

For more information about the broader factors involved, you can read our guide to whether solar energy is worth it in Spain.

 

Frequently Asked Questions About Energy Consumption and Self-Consumption

 

Does self-consumption reduce energy consumption?

Not automatically. Self-consumption changes the source of part of the electricity you use, while energy efficiency reduces the amount of energy you need. A household can consume the same number of kWh while increasing the proportion supplied by its own solar installation. Combining self-consumption with energy-efficiency measures can address both objectives.

Can I have self-consumption without batteries?

Yes. A physical battery is not a requirement for every self-consumption installation. Without a battery, electricity generated while you are consuming can be used directly. Depending on the configuration, surplus electricity can be exported to the grid or prevented from being injected.

What happens when my solar panels are not producing enough electricity?

In a grid-connected system, the electricity grid can supply the difference between your demand and the electricity available from your own generation. At night, for example, a solar photovoltaic installation is not generating electricity. Unless another suitable source or physical storage system is supplying the property, electricity demand will therefore be met from the grid.

What happens to surplus solar electricity?

It depends on the installation configuration. Surplus can be prevented from entering the grid, exported to the grid or, where suitable physical storage is installed, some generation can be stored for later use. Eligible exported surplus may also be subject to compensation or other commercial arrangements depending on the applicable conditions.

Is a virtual battery the same as a physical battery?

No. A physical battery stores electrical energy. A virtual battery is a commercial mechanism for managing an economic balance associated with eligible surplus electricity according to the conditions of the service. And a virtual battery therefore does not physically store solar electricity for use later.

What is collective self-consumption?

Collective self-consumption allows several consumers to be associated with the same generation installation. The electricity generated is allocated among participants according to agreed distribution coefficients and the applicable regulatory framework.

Does self-consumption make you independent from the electricity grid?

Not necessarily. Most grid-connected self-consumption installations can continue to import electricity whenever local generation is insufficient. Achieving electrical independence would require a different system design and should not be assumed simply because a property has solar panels.

Is it better to use solar electricity directly or export it?

There is no universal answer. Directly using electricity while it is being generated increases your self-consumption, while surplus electricity may have an economic value depending on your contract and the applicable arrangement. The best balance depends on your consumption profile, installation and contractual conditions.

 

Conclusion: Smarter Energy Use Starts With Understanding Consumption

 

Understanding energy consumption and self-consumption means recognising that they solve two different parts of the energy equation. Energy efficiency can help reduce the amount of electricity you need. Self-consumption allows part of that electricity demand to be supplied by an associated generation installation when electricity is available.

With solar self-consumption, electricity can be used directly, exported as surplus or, where suitable physical storage is available, stored for later use. Collective self-consumption also allows several consumers to be associated with the same generation installation. The most effective approach is therefore not simply to generate more electricity, but to understand your consumption, avoid unnecessary demand and make better use of the electricity available from your own generation.

At Evergreen Eléctrica, we can help you understand your electricity supply, consumption and the options associated with your contract, including services related to the management of eligible self-consumption surpluses.

Contact Evergreen Eléctrica if you want more information about your electricity supply or the options available for your self-consumption arrangement.

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