La search for a stable year-round renewable energy source It is no longer just an environmental goal: it is an economic, business, and social necessity. Spain is at a key moment in its energy transition, with record levels of clean energy generation, new certification systems, and ambitious future plans that will shape how electricity is produced and consumed in the coming decades.
At the same time, very reasonable doubts arise: Can we rely solely on renewables without experiencing energy shortages?Which technologies are more stable? What role do storage, interconnections, or certificates like Guarantees of Origin play? We'll break down, using the latest data, how Spain is building a renewable, reliable, and secure electricity system 365 days a year.
Stable renewable energy all year round: much more than installing solar panels and wind turbines
When we talk about stability, it's not enough to say that an energy source is clean; it needs to be can be supplied continuously, reliably and measurably throughout the year. Several elements come into play: the type of technologies (solar, wind, hydroelectric, biomass, geothermal…), storage, the transmission network, international interconnections and market mechanisms such as PPAs and Guarantees of Origin.
In the case of companies, stability also translates into price certainty and environmental traceabilityIt is of little use to enter into a long-term power purchase agreement (PPA) if it cannot then be rigorously demonstrated that the electricity is of renewable origin and that the declared emission reductions are valid against standards such as the GHG Protocol or initiatives such as RE100.
Therefore, today one cannot talk about stable renewable energy without mentioning the Guarantees of Origin (GoOs), the massive deployment of renewables in Spain and macro-projects like La Robla Green, the new objectives of the PNIEC and the revolution of storage and smart grids, which allow variable production to be balanced with real demand at any given time.
Furthermore, official data shows that Spain is no longer simply “testing” renewables: Renewable energy is the central pillar of the electricity systemwith more than half of the annual generation coming from clean sources and a growing presence of technologies capable of providing stability, such as hydropower, biomass or geothermal, supported by batteries and pumped hydro.
PPA 365 and Guarantees of Origin: how to certify year-round renewable
For many organizations, the key is not just consuming renewable electricity, but being able to demonstrate 365 days a year whose electricity consumption is linked to clean generation. This includes the PPA (Power Purchase Agreements) and Guarantees of Origin (GoOs), which function as the renewable “ID” of energy.
A 365 PPA seeks to ensure a continuous supply of electricity at an agreed price, while the Guarantees of Origin certify that this energy comes from renewable sourcesThese GoOs can be contracted along with the PPA itself or independently, to "green" existing electricity consumption and align it with internationally accepted renewable credentials.
Thanks to this system, a company can support their climate goals in different methodologies: Scope 2 emissions accounting of the Greenhouse Gas Protocol (GHG Protocol), the requirements of initiatives such as RE100 or sustainability reports aligned with European and international standards.
Among the most relevant benefits of combining PPA and GoOs are the possibility of comply with Scope 2 emissions reportingaligning the corporate strategy with frameworks such as RE100 and reinforcing the credibility of public sustainability commitments, avoiding the risk of greenwashing thanks to a recognized and traceable certification system.
Spain: record-breaking renewable energy generation and a cleaner system
The latest official data shows a change in scale: Spain ended 2024 with 148.999 GWh from renewablesThis represents an increase of just over 10% compared to the previous year. It is the highest annual figure recorded to date by Red Eléctrica and accounts for no less than 56,8% of the entire national electricity generation mix.
This leap is not due to a single factor: on the one hand, The installed capacity of renewable energy sources has grown significantly.On the other hand, 2024 was accompanied by very favorable weather conditions, especially for hydroelectric and solar photovoltaic power. As a result, hydroelectric production increased by around 35,5% compared to 2023, and photovoltaic production soared by nearly 18,9%, marking its sixth consecutive annual record.
In the distribution by technology, the Wind power has established itself as the main source of generation with a share exceeding 23% of the national total. This is followed by nuclear energy, with around 20%, solar photovoltaics at around 17%, combined cycle gas turbines with slightly more than 13%, and hydroelectric power with a contribution slightly above 13%.
This renewable energy push has a direct impact on the climate: CO₂ equivalent emissions from the electricity sector have fallen to record lowsaround 27 million tons, a decrease of approximately 16-17% compared to the previous year. Overall, roughly 76-77% of all electricity generated in Spain in 2024 was emission-free.
Photovoltaics takes the lead in installed capacity
If we look at the installed capacity, the Solar photovoltaic energy has become the leading technology in the Spanish power generation sectorIn 2024 alone, some 7,3 GW of new renewable power was added, mainly from photovoltaics and wind power, which is the largest figure incorporated in a single year to date.
Of that total, approximately 6 GW correspond to new photovoltaic installations, which have allowed this technology to reach approximately 25,1% of all installed generation capacity in Spain. Wind power has also grown, with around 1,3 GW of additional capacity, reaching a share of approximately 24,9% of the national generation capacity.
The power map has also changed on the side of fossil fuel technologies: the definitive closure of the As Pontes coal-fired power plantIn Galicia, this has meant the removal of approximately 1,4 GW of non-renewable capacity. Thus, by the end of 2024, Spain had nearly 129 GW of total installed capacity, of which around 66% was renewable.
Photovoltaics is currently the fastest-growing renewable energy technology. It is based on panels that convert solar radiation into electricity It can be installed in large plants as well as on residential rooftops, industrial buildings, or parking garages. Its cost has fallen dramatically in the last decade, making it very competitive; see international examples such as the new solar plant in Germany It illustrates the global trend.
Among its advantages are its inexhaustible nature, the ease of scaling from small installations to large parks, and some relatively low operating and maintenance costsAs disadvantages, it depends on the presence of sunlight (it loses production on cloudy days and at night) and requires available space, either on the roof or on the ground.
The typical efficiency of commercial modules is around 15-22%, although technologies exceeding these values are being developed. For photovoltaics to contribute to a stable year-round renewable energy supply, it is crucial to complement it with batteries, pumping, or other forms of storageas well as good network planning.
Wind energy: high power, but limited by the wind
Wind power takes advantage of wind kinetic energy through wind turbines onshore or offshore. Spain is one of the European leaders in this technology, with a well-established wind farm sector that contributes a significant percentage to the annual energy mix, and initiatives such as the following stand out in the European context: Record offshore wind energy auction.
Its great strength is that, in areas with good wind resources, it offers a significant production at competitive costswith efficiencies that typically range between 35 and 50% in modern turbines. However, it is subject to wind variability, which necessitates complementing it with other technologies and energy storage.
The combination of wind and photovoltaic power is particularly interesting because their maximum production does not always coincideThere are times with more wind and less sun, and vice versa. This helps to smooth the renewable energy generation curve throughout the year and reduce dependence on backup fossil fuels.
The key role of hydropower: a very stable renewable energy source
Within the group of renewables, hydroelectric power stands out for its ability to provide stability and manageable power to the systemIn the Iberian Peninsula, hydroelectric production during 2024 was around 34.900 GWh, representing an increase of approximately 35,5% compared to 2023.
Thanks to this increase, hydropower reached approximately 14% of the Iberian Peninsula's electricity generation, gaining several percentage points in the energy mix compared to the previous year and consolidating its position as the fourth largest source of generation across the peninsula. This technology has a clear advantage: It can adjust its production based on demand.within the limits set by the availability of water stored in the reservoirs. Furthermore, there are aid to boost wind and hydroelectric energy in Spain that facilitate investments and improvements in resource management.
Comparative data from 2023 and 2024 show that, except for November and December, the Hydraulic production was higher in virtually every month of the year 2024. The most striking month was April, with a growth close to 159%, while December saw the largest year-on-year drop, with production around 39% lower than in the same month of the previous year.
The experience of this exceptionally wet year leaves an important lesson: hydraulics, well managed and combined with other technologies and with storage, It is one of the great allies for having a stable renewable energy supply all year round.provided that the weather cooperates and adequate water reserves are maintained.
Storage: the great driver of renewable stability
For a system based primarily on renewables to function stably, it is not enough to generate a lot of clean energy during sunny or windy times; it is essential to be able to store electricity and return it to the grid when neededThis is where battery storage and pumped hydro come into play, among other emerging solutions such as green hydrogen.
Spain has already begun to reflect these technologies in official electricity system reports, incorporating specific storage indicators. According to Red Eléctrica, the country currently has a installed storage capacity of approximately 3.356 MWwhich have allowed the integration of approximately 8.666 GWh of stored energy during the last year.
Batteries and pumped storage plants play a dual role: they facilitate the integration of large volumes of variable renewable generation and They provide flexibility and stability services to the network.helping to control frequency, manage peak demand and reduce renewable energy spills during periods of low demand.
Looking ahead to 2030, the Integrated National Energy and Climate Plan (PNIEC) sets a very ambitious target: reach approximately 22,5 GW of storagecombining different technologies. For this to materialize, the sector is awaiting clear regulations that will attract investment and accelerate the deployment of battery, pumped storage, and other advanced solutions.
Electricity demand, transmission network and interconnections: stability at system scale
Renewable energy stability depends not only on how much is generated, but also on how Demand evolves and how robust the electricity grid isIn 2024, Spain's electricity demand grew slightly: adjusted for temperature and calendar effects, it was around 1,4% higher than the previous year. In gross terms, it stood at approximately 248.800 GWh, slightly less than 1% above the previous year.
These levels are in line with those of other European countries, where electricity consumption is growing at a moderate pace due to efficiency improvements, industrial changes, and economic conditions. Even so, the PNIEC forecasts that Demand will reach 358 TWh in 2030, around 34% more than at present, driven by the electrification of transport, heating and part of industry.
The Spanish transport network has also continued to be strengthened: in 2024, approximately 487 kilometers of new lines were added, bringing the total length to approximately 45.674 km. The availability rate of this network is around 98% across the national system, with slightly higher figures in the Balearic and Canary Islands.
Added to all this are the electrical interconnections with France and PortugalThese mechanisms allow for the export and import of energy as needed by the system. Spain has now closed the year as a net exporter of electricity for three consecutive years, with a surplus of approximately 10.227 GWh in 2024, thanks in large part to its renewable energy surplus at certain times of the year.
Objectives of the National Integrated Energy and Climate Plan (PNIEC) and renewable growth forecasts
The framework guiding the Spanish energy transition is the National Integrated Energy and Climate PlanThe National Integrated Energy and Climate Plan (PNIEC), recently updated with more ambitious goals, sets a target of around 81% of electricity generation being from renewable sources by 2030 and Spain achieving climate neutrality by 2050.
Regarding the target power output, the aim is to reach approximately 76 GW of photovoltaic solar energy, 62 GW of onshore wind power, nearly 4,8 GW of concentrated solar power (CSP), and about 1,4 GW of biomass electricity by the middle of the next decade. According to the sector, photovoltaics is the technology that will more aligned with the projected growth pathwhile other renewable technologies will need to accelerate their deployment to meet the established targets.
Market forecasts point to very solid growth. According to specialized analyses, it is estimated that the Spain's cumulative renewable capacity could exceed 218 GW by 2035with an annual growth rate close to 9% between 2024 and 2035. During this period, renewable generation would increase from about 131 TWh to more than 313 TWh, with a particularly strong expansion of solar photovoltaics.
According to these projections, photovoltaic capacity could scale from around 21,5 GW in 2021 to approximately 152,8 GW in 2035, while onshore wind power would increase from approximately 28,7 GW to around 56,3 GW over the same period. Furthermore, Offshore wind and green hydrogen are emerging as new pillars of growthsupported by European and national funding.
Policies, regulation and incentives: how renewable stability is promoted
This massive deployment of renewables and storage is not happening by inertia: it is backed by a set of specific public policies and regulatory frameworksAmong them are the Renewable Energy Economic Regime (REER), which organizes competitive auctions for new installations, and the Climate Change and Energy Transition Law, which establishes targets for emissions reduction and renewable energy penetration.
The regulation of self-consumptionThis facilitates distributed generation on rooftops and in small installations, allowing individuals, businesses, and energy communities to generate and consume their own electricity. This reduces grid losses, alleviates some of the demand, and contributes to greater system resilience in the face of peak consumption or occasional outages.
However, the sector faces several challenges: delays in connection and construction permitsCapacity limitations at certain network nodes force the dumping of unused renewable energy, and still low levels of interconnection with the rest of Europe, which makes it difficult to make the most of renewable surpluses during periods of high generation.
Even with these obstacles, the incentive framework, the availability of solar and wind resources, and the diversification of gas imports (with little Russian gas and strong LNG capacity) place Spain in a very favorable position to move towards a decarbonized, stable and competitive mix both at the European and global levels.
Will renewables alone provide us with enough energy year-round?
This is the million-dollar question. The answer, in light of the data and recent experience in Spain, is that Yes, it is possible to meet demand with a system based primarily on renewables.But only if several key elements are combined: technological diversity, storage, reinforced networks, interconnections, and flexibility in demand.
On the one hand, technologies such as hydroelectric, biomass or geothermal They offer more stable and manageable production than solar or wind power, which depend more directly on weather conditions. Furthermore, energy storage and smart demand management (for example, shifting consumption to peak renewable generation times) are essential for making the puzzle work on a daily basis.
Data from 12 consecutive months in which Spain has maintained more than 50% of its electricity generation from renewables demonstrate that Renewable stability is not a theory, but a reality in progress.In some periods, the annual renewable share has been around 56-57%, driven by a strong increase in photovoltaics and, in very wet years, by an extraordinary increase in hydropower.
Looking to the immediate future, the big challenge is not so much whether there will be enough renewable energy, but how it will be integrated and managed To avoid network bottlenecks, energy spills, or price imbalances, this requires intensive investment in storage, grid reinforcement, digitalization, and incentives for flexible consumption.
Types of renewable energy and their contribution to stability
To better understand how to achieve a stable year-round supply of renewable energy, it's helpful to review each of the main clean energy technologies and their role in the system. Each has its strengths and limitations, and stability is achieved precisely through these factors. combining their production profiles.
Solar photovoltaic energy: the main protagonist of growth
Photovoltaics is currently the fastest-growing renewable energy technology. It is based on panels that convert solar radiation into electricity It can be installed in large plants, as well as on residential rooftops, industrial buildings, or parking lots. Its cost has fallen dramatically in the last decade, making it very competitive.
Among its advantages are its inexhaustible nature, the ease of scaling from small installations to large parks, and some relatively low operating and maintenance costsAs disadvantages, it depends on the presence of sunlight (it loses production on cloudy days and at night) and requires available space, either on the roof or on the ground.
The typical efficiency of commercial modules is around 15-22%, although technologies exceeding these values are being developed. For photovoltaics to contribute to a stable year-round renewable energy supply, it is crucial to complement it with batteries, pumping, or other forms of storageas well as good network planning.
Hydropower: the most efficient and one of the most stable
The hydroelectric plant is based on the harnessing the energy of moving waterHydropower is generally generated by dams and reservoirs that allow the flow of water to be used to generate electricity. It is one of the most efficient forms of energy, typically reaching 80-90% efficiency in large power plants.
Its main benefits are its continuous production capacity and flexibility To adapt to peak demand, in addition to low operating costs and a long infrastructure lifespan. However, it can have a significant environmental impact on river ecosystems, and its performance depends on water availability, which is closely linked to weather and reservoir levels.
In terms of stability, hydroelectric power is a key component, especially when combined with pumped storage plants that allow energy storage by pumping water to a higher reservoir during off-peak hours or reduced prices and then using it to generate electricity during peak hours.
Biomass and biogas: renewables that can be managed 24 hours a day
Biomass and biogas obtain energy from organic matter from agricultural, forestry, livestock or urban waste, including projects such as the Logrosán biomass plantCombustion, anaerobic digestion, or other processes allow the generation of electricity and heat with a much more controllable production than solar or wind power.
Among its advantages is the possibility of reuse waste and reduce landfillsas well as their ability to operate continuously, regardless of the weather. However, if not managed properly, they can produce emissions, and their sustainability depends heavily on the origin and logistics of the raw materials.
In terms of efficiency, biomass plants typically range from 20-40%. While not the most efficient, their great value in a renewable energy system is that It provides firm and programmable power., very useful for reinforcing the stability of the system and covering times when other renewables produce less.
Geothermal energy: a constant source where the resource allows it
Geothermal energy harnesses the Earth's internal heat to produce electricity or air conditioningIn areas with significant geothermal activity, it can offer a virtually constant source of energy, with high load factors and very high availability; for example, Geothermal energy is accelerating its expansion in specific regions.
Its main strengths are its stable production, reduced visual impact, and small space occupancyOn the other hand, it is only viable in regions with adequate geothermal resources and requires high initial investments, in addition to presenting certain technical risks associated with deep drilling.
The efficiency of geothermal power plants typically ranges from 45 to 60%. Where feasible, it can become a firm base of renewable generation that complements other more variable technologies and contributes to greater system stability.
Why accelerating the transition to renewables is key to a stable and sustainable system
Beyond security of supply, the transition to stable, year-round renewable energy also responds to climate and public health concerns. Energy production using fossil fuels is responsible for a vast majority of GHG emissions. more than 75% of all greenhouse gases and around 90% of CO₂ worldwide.
Science indicates that, to avoid the worst impacts of climate change, we must to reduce global emissions by almost half by 2030 and achieve a net zero balance by 2050. This implies phasing out coal, oil and gas and investing massively in clean energy sources and energy efficiency.
Renewable energy sources also have a direct impact on air quality. Burning fossil fuels is one of the main sources of air pollution, responsible for millions of premature deaths each year and enormous economic costs. Replacing them with technologies like wind, solar, or hydropower is crucial. It drastically reduces harmful particles and gases. that we breathe every day.
From an economic point of view, renewables also fare well: in most regions of the world, They are already the lowest cost option for new electricity generationThe price of solar electricity has plummeted by around 85% in the last decade, while onshore and offshore wind have reduced their costs by around half or more.
Economic impact, employment and opportunity costs
Investing in renewables and related technologies has more than just environmental benefits. Every dollar invested in clean energy It generates approximately three times more employment. than the same investment in fossil fuels, boosting local industries of manufacturing, installation, maintenance and technological services.
Looking ahead to 2030, it is estimated that the transition to net-zero energy systems could involve the disappearance of some 5 million jobs linked to fossil fuelsBut in return, it will create around 14 million new jobs in clean energy. This is in addition to some 16 million more jobs in related sectors, such as electric vehicles, high-efficiency equipment, and hydrogen technologies.
Therefore, the net result would be more than 30 million new jobs associated with the energy transition. However, it will be essential to guarantee a a just transition that leaves no one behind, supporting the most exposed territories and workers with reindustrialization, training and social protection policies.
Regarding the necessary investments, it is estimated that the world spent around $5,9 trillion on subsidies and hidden costs linked to fossil fuels in 2020, while approximately $4 trillion per year would need to be invested in renewables until 2030 to meet climate goals. Although these figures may seem daunting, the savings from reduced pollution and climate damage They could exceed $4,2 trillion annually by 2030.
Everything suggests that building a system based on stable year-round renewable energy, supported by a combination of clean technologies, storage, reinforced grids, certifications such as Guarantees of Origin and more flexible demand, is not only technically possible, but also safer, healthier and economically smarter than continuing to depend on fossil fuels in the coming decades.
