For a few months now the term “energy self-consumption” has began to spread among professionals in the electricity industry, entrepreneurs with business that have high electricity bills and home users in general. The technical media are also helping that development through many items that list the benefits of such self-consumption in terms of energy independence, better forecasting of costs and reduced energy costs.
The causes of the covert explosion that is taking place with this technology can be attributed to, firstly, the sudden penalty that the development of renewable energy has experienced and that has motivated thousands of people employed in this field to have had to drive the emergence of new ways of earning a living with what they know what to do, i.e. installing photovoltaic panels to generate power for different consumption profiles and, secondly, expressly prohibiting energy storage in the famous Royal Decree 1699/2011 published that the government published to try to regulate the sector and has served as a lever to devise new ways to fail to take advantage of it and for the Autonomous Communities to confront the central government in regulatory matters on this topic.
Some self-consumption system classifications begin to appear based on technologies, power generation sources, with or without storage, etc., which can be summarized into two main groups called On-grid and Off-grid, i.e. connected to the grid or isolated. Clearly for an isolated facility to work, self-supply is key and nobody considers doing it without energy storage. Where differences of approach and criteria arise, and where the Royal Decree is crippling technology development, is in facilities connected to the grid.
It is logical that electricity users want to be connected to the traditional grid to guarantee that they will always have power when they need it. It is also reasonable to assume that these users want to receive electricity at the lowest possible cost, i.e. through generating their own renewable energy. The question arises when we talk about what percentage of electricity consumed should come from the grid and how much from self-supply. Clearly, in this disquisition, energy companies and users are struggling to reach an agreement or balance point that, on the other hand, everyone sees it as inevitable in the coming years.
And the chaos in the market begins to emerge. On the one hand new terms are devised such as backup toll, unmetered electricity, fixed consumption terms, etc. and, on the other, new types of facilities are developed based on obsolete decrees and laws that cause technical insecurities and concerns about security that lead nowhere. And this is no way to implement such an important industry in our country and in the world in general.
I am in favor of using energy storage for self-consumption in both grid-connected and isolated facilities. I think it’s simply a tool that allows users and electricity suppliers greater operational efficiency by offering, at the same time, increasing power quality. We can look at it from an economic, environmental or sustainability standpoint, in general, but I really consider it essential to properly develop storage solutions for proper implementation of self-supply in our homes and businesses.
And this is due to the type of consumption profile that we have in homes and in larger facilities such as factories, hotels, shopping centers, farms, etc. We do not have constant consumption throughout the 24 hours in a day and we have to consider two factors in calculating the system: energy and power. Energy storage systems essentially manage to obtain the best solution in system efficiency as they are able to shift energy consumption from peak to off-peak times saving energy when it is in excess and taking it when needed, without the need to add large high-power devices that are extremely expensive.
In terms of amount of energy, there is now talk in some European countries of batteries from 2-3 KWh to 10-12 KWh for self-consumption in homes or residential consumption, values around 50-60 kWh for small businesses and up to 500-1,000 KWh in public buildings, shopping centers, etc. Great power is not being asked for from batteries in these applications and they are usually sized for durations between 15 and 20 years.
If energy self-consumption is well managed, it is a very powerful tool for a sustainable planet. Its proper development requires energy storage technology to develop or, in other words, for universal access to energy to cease being a myth and become a reality.
Joaquín José Chacón Guadalix
Albufera Energy Storage