Photovoltaic solar self-consumption

The definition of self-consumption is one that understands as such the consumption by one or several consumers of electrical energy from generation facilities close to those of consumption and associated with them..


Photovoltaic solar self-consumption is already a dynamic reality in most developed countries. In Spain they are beginning to make installations for self-consumption of all measures since their benefits are tangible in all their dimensions: savings, return on investment, a greater degree of energy emancipation, and of course, the great environmental benefits that this entails.


There are many hoaxes and information poisoning that have been spread about photovoltaic solar self-consumption: The Sun tax, million-dollar fines for those who opted for this system, legal impediments of all kinds, unaffordable costs, etc, etc.


The truth is that today, a self-consumption installation is perfectly legalizable and has no extra costs or additional taxes, with a payback period ( return on investment) of between 8 and 10 years (depending on the contractual circumstances of the supply), and a useful life (if there is no energy accumulation) of between 25 and 30 years; The real examples of self-consumption installations that we have already carried out will serve as examples from Soma Electricity.

Summary of the new regulations for Photovoltaic Self-consumption
(Royal Decree 244/2019)

There are many novelties and improvements presented by this new Royal Decree. Let’s discuss the most important:

What does photovoltaic solar self-consumption consist of?

Given the confusion that often occurs, we remind you that this type of photovoltaic installations correspond to the installations carried out in homes and industries with connection to the electrical network.


Solar installations isolated from the electricity grid are not called photovoltaic self-consumption, nor are photovoltaic installations whose sole objective is the sale of energy.


The objective of photovoltaic self-consumption is to consume the energy generated directly and thus save on the electricity bill.

Autoconsumo solar fotovoltaico

Is this a Net Balance?

This RD does not refer specifically to the term Net Balance, however, it does use the concept “simplified compensation of surpluses</ b> “. The difference basically lies in the fact that, in the Net Balance, the excess energy from our solar panels will be accounted for and compensated watt by watt, that is, for each watt discharged into the network, one watt can be recovered from the electrical network when needed. In the system proposed in this RD, this compensation will not be watt by watt, but rather an economic compensation per watt discharged that will be deducted from the electricity bill. As we will see later, this price to be deducted from the electricity bill will depend on the electricity supplier.


In summary, the system proposed by this RD resembles a net balance in which, instead of to compensate kilowatts, a balance will be received for each kilowatt discharged into the network and this balance will be deducted from the electricity bill, but at a much lower price than the purchase price, with which we can conclude that it is not a net balance, in the one that is exchanged watt x watt at the same purchase price.

What kind of self-consumption are there?

Two modes of photovoltaic solar self-consumption are established: without surplus and with surplus.


Self-consumption without surplus. These facilities will need anti-discharge equipment to ensure that no energy is discharged into the grid. Its administrative processing is minimal.


Self-consumption with surpluses. They are those installations that at certain times are going to send solar energy to the electrical network, for example, a house or industry without activity in central hours of the day. Within this modality we distinguish two important blocks:


Modality with surpluses eligible for compensation. In this modality, the electricity supplier will compensate the energy poured into the network in our electricity bill. Homes and industries with installed power of less than 100 kW will be able to take advantage of this modality, undoubtedly the most relevant in the RD.


Mode with surpluses not subject to simplified compensation. These installations are those, in principle greater than 100 KW, whose surpluses are going to be turned over to the network, but under a sale regime, not compensation. The price of the discharged energy will be that provided by the legislation on electricity generating facilities.

Can homes qualify for consumption compensation? How much is received for the energy discharged?

Yes, all homes can benefit from the self-consumption model with surplus compensation And it is the most recommendable since most of them are installations of less than 15 Kw, it will not be necessary to request an access point from the electricity supplier.


Regarding the compensation received, this will depend on two cases:


  • If our supply contract is covered by regulated market prices (PVPC Tariffs) with a reference supplier, the financial compensation received for self-consumption will be the average daily price of the energy purchased at the hour in which we discharge. That is to say, if in our facility the surplus is discharged at 11 a.m. and at that time the average daily price of energy is 9 cts, the compensation that we will see reflected in the invoice will be that corresponding to the amount of kilowatts discharged by the average price per kilowatt, in this example 9 cts.


  • In cases where our supply contract is not on the regulated market, but is on the free market , the price at which the kilowatt will be compensated will be negotiated between the marketer and the consumer.
Autoconsumo solar fotovoltaico

In practice, it is most likely that in a few months we will begin to see offers in the market from electricity companies that will offer, as in telephony, different compensation options for consumptions. In any case, it seems that the price of the compensated kw will depend on the time or tariff period in which it is discharged

Can industries take advantage of consumption compensation? What will be the value of the compensated energy?

Yes, all industries whose self-consumption photovoltaic installations are less than 100 Kw may benefit from the </span >self-consumption with surplus compensation. Since the majority of them are installations greater than 15 Kw, they will have to carry out the procedures for access and connection to the electrical network to be able to carry out the discharge, so in cases in which the surpluses are very scarce, it may be advisable to take advantage of the modality of self-consumption without surplus and in this way no enter into procedures with the electricity supplier.


Since there is no regulated electricity market insolar installations greater than 10 Kw, the price of the compensated energy will be negotiated between the electricity supplier and the photovoltaic producer. As we said in the previous point, it is to be expected that marketers will emerge with specific offers of compensation for excess energy.

Can I save 100% of the electric bill?

No, the electricity bill is made up of some costs assigned to the Power Term and others assigned to the Energy Term. The costs of the power term are fixed and depend on the contracted and consumed power, so they will not be compensated, although due to the power provided by solar energy it is possible that in some cases this term can be reduced.</ span>


The costs of the energy term could be – at least hypothetically – fully compensated.</ span>


Let’s imagine, for example, that in an industry 100 kWh are consumed daily, and we pay an average price of 9 Cts. so we pay monthly in active energy 270 euros. If we carry out a self-consumption photovoltaic installation that produces 200 Kwh/day (approximately a 40 Kwh installation, about 120 solar panels) and we assume that self-consumption is 60% (that is, 60% of the energy comes directly from the panels installed in the industry) we would have to pour 140 Kwh/day or 4200 Kwh/month into the network. If for this excess energy, hypothetically, we accumulate an average balance of 4 cts per Kwh, the accumulated balance would be 5.6 euros per day, 168 euros per month. The direct savings, 60% would be 60 Kwh/day or 1800 Kwh/month. This direct self-consumption will deduct 162 euros directly from the bill. If we add the accumulator balance for surplus energy, the accumulated balance: 168 euros, added to direct savings: 162 euros, add up to 330 euros per month. Therefore, in this case, 100% of the active energy term would be saved.

What price will be assigned to the surplus kilowatts?

This balance per Kwh discharged will be determined by the different offers from the marketers, however, everything makes us think that the value granted to the energy discharged may be equal to or very close to the pool price of the energy, that is, the price of energy in the wholesale market that is fixed hour by hour. This heat in solar hours is usually, depending on various factors, between 4 Cts/Kwh and 5.5 Cts/Kwh.

Is there any power limit for the size of self-consumption facilities?

None, the solar energy installations for self-consumption they can be any size. For users who choose self-consumption with compensation, it may be interesting to use the largest possible area, this must be studied on a case-by-case basis.

Can the excess energy discharged in one month be accumulated for the following month?

In principle, the compensation will be made in the billing period, that is, month by month, leaving the door open to negotiation with the marketer regarding consumption compensation. However, it is to be expected that, with the majority of marketers, consumption compensation occurs only month by month, and surpluses not compensated in one month cannot be accumulated for the following month.

Autoconsumo solar fotovoltaico

Can the roof be transferred to an external company and receive income from the generated solar production?

Yes, in fact, this is one of the most interesting services that we offer at SOMA Electricity for industrial installations of more than 30 kW.


The thing is very simple, an external company makes the investment, performs the installation and is in charge of maintenance. The owner of the roof will self-consume the energy generated and the savings generated by photovoltaic energy are shared between the user and the company that owns the solar installation. RD 244/2019 allows the owner of the solar plant and the consumer to be different.

Can self-consumption solar installations be shared?

Yes, the RD contemplates shared solar self-consumption. For example, an industrial estate or a community of neighbors can carry out a collective installation and benefit from the savings obtained. The system by which the savings obtained or the photovoltaic production are distributed will be decided between the co-owners.


In this sense, mechanisms are already being developed to quantify the savings obtained by each user of the collective solar installation.

How are surplus photovoltaic discharged into the grid discounted from the electricity bill?

Energy compensation in solar installations not included in the regulated market (less than 10 Kw and contract with a reference) and less than 100 Kw, the compensation of excesses will be carried out by means of a balance compensation in economic terms. This economic compensation will be reflected by the electricity supplier in the monthly bill and the price to be compensated for the energy discharged will be determined by the price of the energy at the time the discharge is made. Ultimately, it will be the retailers that will offer a price to be offset on the bill for this excess energy and the user will be able to choose between staying or changing the electric company based on the offers received for their consumption and excess energy.</span >


Summarizing, the compensation of excess energy will be carried out by means of balance compensation in economic terms. This economic compensation will be reflected in the monthly electric bill.

How is the processing done?

All self-consumption modalities involve notifying the retailer of the existence of a installation of photovoltaic solar self-consumption. In the case of installations without discharge, it is not necessary to have permits for access and connection by the electrical network, which facilitates the procedures. It will only be necessary to deliver to the competent body of the autonomous community the certificate of installation, technical report and/or corresponding technical project in each case.

In the modality with surpluses for installations of more than 15 Kw (mainly industries) it will be necessary to carry out the access procedures and connection to the electrical network. The initiation of these procedures is carried out at the request of the Autonomous Community (within 10 days from the presentation of the documentation), and the electric company is obliged to respond to the user of the installation within 5 days.

Companies with regulated price

• Iberdrola Comercialización de Último Recurso, S.A.U.
• Endesa Energía XXI, S.L.U.
• Gas Natural S.U.R. SDG, S.A.
• EDP Comercializadora de Último Recurso, S.A.
• Viesgo Comercializadora de Referencia, S.L.
• CHC Comercializador de Referencia S.L.U.
• Teramelcor, S.L. (in Melilla).
• Empresa de Alumbrado Eléctrico de Ceuta Comercialización de Referencia, S.A. (in Ceuta).

What does it mean to carry out the procedures for access and connection to the electricity grid?

First of all, it is necessary to clarify that these procedures are only mandatory for those installations of more than 15 Kw (that is, , industrial facilities) that want to take advantage of the compensation of surpluses. Nor are they necessary in self-consumption mode without surpluses.


Processing access and connection to the electricity grid requires compliance with the requirements established in the Electricity Sector Law –LSE (Law 24/2013, of December 26).


In essence, these procedures are: submitting the connection project to the electricity distributor, carrying it out within a period of month by the distributor of a Technical Connection Conditions Report (this report has an additional cost), the adaptation, if necessary, of the connection project to the demands of the distributor and, subsequently, the formalization of a Technical Access Contract in which the conditions of this access are detailed.


Access and connection procedures can cause a delay when starting up the photovoltaic installation.

What about installations of more than 100 Kw?

Solar installations of more than 100 Kw will not be eligible for simplified consumption compensation.</ p>

Therefore, they have two options, to take advantage of the photovoltaic solar self-consumption modality without surpluses or to take advantage of self-consumption with surpluses without compensation. In the first case, the process will be very simple and it will not be necessary to carry out the procedures for access and connection to the network. In the second case, the surpluses discharged into the network may be sold in the electricity market according to the conditions established for electricity producers.


Beinga producer of electricity with solar energy it involves, among other things, declaring the benefits obtained from this activity, registering with the IAE under the heading of producer and, in the case of companies, modifying the company bylaws. In addition, self-consumption facilities with surpluses that do not use the surplus compensation modality will have to pay generation taxes and the grid access toll for the surplus energy they sell to the distributor.< /p>

It will be necessary to study in each case the convenience of carrying out this type of installation as self-consumption without surplus or with surplus. It will depend on the volume of excess solar energy and the conditions of connection to the electricity grid.

Will I need another meter or modify the one I have now?

Not at the beginning. In the self-consumption mode without surpluses, it is not necessary to make any changes.


In the self-consumption mode with surplus compensation, only one meter is necessary, which measures both the energy demanded from the electrical network and the surplus discharged. For this it must be a bidirectional counter. Most modern “smart” meters are bi-directional, so you won’t need to change it.


It is possible that in some cases where this bidirectional counter does not exist, it may be necessary to modify it. This meter can be purchased by the user or rented from the electricity distributor. It is also possible that, in some cases, even though the meter is bi-directional, the meter programming needs to be modified to register the excess energy.

What happens if I already have a photovoltaic solar self-consumption installation?

This RD gives a period of 6 months to benefit from some of the types of self-consumption described. In the case of SOMA Electricity customers, these procedures will be carried out by our technical department.


Most of theinstallations of solar panels made to date by our company have been made with devices without pouring. In the event that users wish to take advantage of the consumption compensation regime, it will only be necessary to change the configuration of the anti-spillage devices and make the corresponding communication to the autonomous community and the electricity company.

When will the surplus compensation system be operational?

The RD enters into force the day after its publication, however, the Autonomous Communities are given a period of 3 months to automate the management and communication protocols to the electric company and a period of 4 months to the electric marketers to make the appropriate changes that allow the compensation of surpluses.

What is the power of the installation: photovoltaic peak power or inverter power?

The powers that are included in the Royal Decree and that refer to the different modalities, refer to the power of the inverter, not of the photovoltaic field. In other words, when the RD says that installations of less than 15 Kw do not need to carry out the procedures for access and connection to the grid, what it refers to is the power of the inverter, that is, that the installation can have 16 Kwp in solar panels.

And… the fundamental question that has nothing to do with this RD How much does a photovoltaic self-consumption installation cost?

Everything will depend on whether it is a direct self-consumption or with accumulation; We propose as of today (Nov.2019) some examples of indicative prices for W.

Direct self-consumption without accumulation:

6 kWp    1’147 €/W + IVA

15 kWp   0’861 €/W + IVA

50 kWp   0’768 €/W + IVA

90 kWp   0’720 €/W + IVA

Self-consumption with accumulation:

5 kWp    2’424 €/W + IVA

15 kWp   2 €/W + IVA

25 kWp   1’880 €/W + IVA

50 kWp   1’610 €/W + IVA

Direct self-consumption is usually amortized over a period of 5 years, while with accumulation the term can reach 12 years.