Renewables. It’s time for some myth-busting.

A more sustainable energy mix not only counteracts the effects of climate change but it also contains the rising costs of the energy sector. Since energy production from renewable sources is not susceptible to changes in commodity prices during the power generation phase, it provides greater stability in the market. Indeed, once the construction of a power plant has been completed, no additional costs related to fuel and its transportation will be incurred. This means that generation costs can be contained and stabilized over time.

Renewable plants do not emit greenhouse gases that cause the greenhouse effect, unlike power plants that use fossil fuels such as coal, oil or gas.

The renewable energy sector will produce 42 million jobs by 2050. This is according to the Global Renewables Outlook from IRENA, the International Renewable Energy Agency. Green jobs concern not only the energy transition, but also agriculture, manufacturing and the circular economy, research and development, public administrations and services.

In a country like Italy, with scarce raw material deposits but rich in natural resources from sun, wind, water and geothermal heat, renewables reduce expenditures on fossil fuel imports and consequently dependence on producing countries.

Renewable energy plants are proving to be valuable safeguards against wildfires thanks mainly to surveillance systems and sensors. In addition, hydroelectric reservoirs are being used to draw water for firefighting.

The presence of renewable plants sometimes brings unexpected benefits, such as using plants with deep roots to prevent soil erosion at EGP sites. This natural and totally sustainable solution is capable of halting erosion: it allows infrastructure and plants to be transformed into powerful CO2 absorbers, using only deep-rooted herbaceous plants, while also promoting biodiversity. This is environmental technology from Prati Armati®, an Italian company.

The energy transition is increasing the need for raw materials. A key role is played by copper, for example, which is among the most widely used materials for energy infrastructure, including renewable energy infrastructure; the same goes for other materials, such as nickel and lithium. According to data from the IEA (International Energy Agency), the reserves we have of raw materials like copper, lithium and nickel – but also of other materials – are sufficient for the energy transition.

For example, it is estimated that the more than 750 million tons of copper reserves that can already be mined today for a low cost, will cover 30 times the average annual demand needed for the energy transition between now and 2030 (estimated to be about 25 million tons per year, 25% higher than today). Consequently, for the next 30 years, the demand for copper can be largely supported by the reserves that have already been identified.

In general, great importance will be placed on both extraction projects that have already been initiated but also on the new investments that will be required in this regard.

The mechanisms of supply and demand should also be taken into account, since as demand increases and prices go up, the search for new raw material reserves and better prices typically intensifies. In addition, when the price of a resource rises excessively, technological development leads to its substitution with other raw materials that are less expensive: batteries are a good example of this, where innovation related to the use of materials moves very fast and we are witnessing continuous technological evolution.

Finally, a key role will also be played by innovative material recycling projects, which will aim to make materials available for the construction of renewable plants. It’s through these projects and new investments that it will be possible to diversify where materials come from so that the production chain becomes more stable and resilient.

The noise of a wind turbine is produced by the friction of air against the blades and the wind turbine support tower.  At a distance of 150 meters from a plant's turbine, the noise level is about 45.3 absolute decibels, and it drops to 36.9 absolute decibels at a distance of 400 meters. The noise level is therefore less intense than that generated at home by an air conditioner or refrigerator, and so, under an operating wind turbine, people can talk without having to raise their voice.   Not only that, when the plant is located near a built-up area, noise can be further reduced by limiting production to medium to high winds. Specifically, all of our wind turbines comply with IEC (International Electrotechnical Commission) 61400/1 standards which include acoustic measurement ranges, and any noise disturbance is further reduced by installing special instruments in the blades (known as Serrators and DinoTails).

Our wind turbines last up to 30 years and consist of about 8,000 components. About 90% of a wind turbine is made of metal, which can be easily recycled. Numerous initiatives are underway to get to the point where even the remaining 10% - mainly in the blades - can be recycled quickly. In particular, we’ve identified several solutions to recycle the wind blades - which, with their average length of 60 meters, make up the main part of the installations - as well as using the wood to build the towers.

A study by the Canadian Wind Energy Association indicates that out of 10,000 accidents involving birds, less than one is caused by wind turbines. In any case, in terms of design, a minimum blade height of 25 meters above the ground has been established, which reduces the probability of impact.

Where active control methods are not sufficient, in the presence of birdlife or during migratory periods, turbines are promptly stopped to eliminate the risk of impacts. We collaborate with environmental and dedicated species conservation groups to remedy this potential problem. This joint activity reduces the impact of collisions through knowledge of wildlife behavior and helps preserve bird and bat populations. For example, at the Gibson Bay wind farm in South Africa, through the installation of special acoustic deterrent sensors, we created a barrier effect around the turbine that prevents bats from approaching the wind blades, reducing accidents by more than 80%. In Spain, we’ve launched an extensive testing campaign with day and/or night vision cameras, microphones and radar in order to identify useful ways to protect birds and bats and to continue to improve compatibility with local ecosystems and habitats. 

The electrical and magnetic impact of our wind turbines is below the limits set by law, both in the turbine and in the electrical connection systems. The electric fields generated are nullified by the ''shielding'' effect produced by the metal conduits and the soil above the cables, which are normally buried at a depth of about 1.8 meters.

Compared to the average wind available in Europe, especially in the North Sea, Italy has lower wind speeds. Mountainous areas, coasts, and islands are the windiest areas and therefore where wind farms have higher efficiency. Despite the lower wind speed, it is possible to transform wind energy into electricity using higher class turbines. For medium to high winds, class I-II turbines are installed. For low winds, as is the case with most Italian wind farms, class III-IV turbines are installed. In addition to differences in construction that allow them to better capture the less wind that’s available yet produce the same amount of power, class III-IV turbines have a larger diameter rotor than lower class turbines. According to Terna data, in 2022, there were nearly 12 GW of wind turbines in operation in Italy, mainly in the south and the islands. In addition, the National Integrated Energy and Climate Plan (NIPEC) envisions about 20 GW of wind power capacity by 2030 through initiatives to refurbish existing turbines and develop new capacity.

Wind power does not use rare earths except in marginal amounts, and only in offshore plants, installed at sea. 

When operating at full capacity, a geothermal power plant produces negligible or inaudible noise, at most comparable to that of a vacuum cleaner (in the case of large plants).

In Tuscany, the presence of our geothermal plants has been a driving force for tourism development in the area, helping to enhance the area's beautiful landscapes. UNESCO has approved the expansion of the Metalliferous Hills Geopark, which also includes our infrastructures, such as the demonstration well, the Larderello Geothermal Museums and the Sasso Pisano Fumarole Park.

All Italian geothermal power plants are equipped with an emission purification system - Abatement of Mercury and Hydrogen Sulfide emissions: in Italian the acronym is AMIS - to remove mercury and hydrogen sulfide naturally present in the geothermal fluid (hydrogen sulfide is spontaneously emitted from the ground in geothermal areas). The AMIS plants, using the abatement technology developed and patented by Enel, have contributed to a substantial decrease in environmental impact by reducing the presence of these toxic substances in the air, and they are subject to a strict regime of surveillance by the relevant authorities in terms of performance and operation.

It has also been shown that emissions from Italian geothermal plants replace the natural emissions that are normally produced in a more distributed way from the ground. This was made possible by comparing the extensive historical production data against evidence previously recorded in virgin areas.

Steam extracted from underground is condensed during the power generation cycle and transforms into water, which is then injected into the naturally occurring geothermal reservoir deep underground. No additional water other than that generated by steam condensation is used in the power plants. The reservoirs from which the steam is drawn and into which water is injected are located several kilometers deep, completely separated from the surface aquifers: for this reason, there is no possibility of contamination and/or reduction in the availability of water potentially intended for human use; in fact, vapors and deep fluids characterized by high salinity are used.

Hydroelectric plants do not consume water. They only pass it through turbines to produce electricity, then return it to the waterway without having altered its quality in any way.

Because of the regulation of stream flow that is done to build the facilities and because of the reservoirs' storage capacity, hydropower infrastructure can actually help manage extreme weather events, prevent flooding, and reclaim marshy areas. In addition, dams on rivers trap floating branches and fallen trees, keeping waterways free of obstacles. Finally, a hydroelectric plant has the advantage of being able to regulate water flow (and thus electricity production) as needed.

So many dams have created bodies of water that form beautiful lakes, frequented by birds and other animals, and also allow tourist use of the land, for hiking and fishing. The presence of plants and reservoirs become concrete examples of attractive tourist routes that combine nature and technology. Some hydroelectric power plants built in the early 20th century are also important works of architecture, inspired by the canons of Art Nouveau or Futurism.

The materials are considered critical when their availability is limited and especially affected by geopolitical and economic factors. And that is why they are monitored by the EU, which keeps the official list of them that is constantly updated. Today, lithium-ion batteries, which are available for industrial uses, come in two types, with the difference being the materials used for the cathode (one of the two "poles" of the cells): in one case nickel/manganese/cobalt (NMC), and, in the other lithium-iron-phosphate (LFP).

The former (NMCs) have higher energy density, i.e., higher capacity for the same volume and weight, making them more suitable for electric mobility. In stationary uses, on the other hand, i.e., when space and weight are less of an issue, LFPs "win," partly because technological development makes them increasingly compact and high-performance.

So the issue is: Which batteries we are talking about? At EGP plants under development and under construction, NMCs are not used, as they can pose supply problems in terms of nickel, manganese, and cobalt. Instead, we use LFPs which, from the supply point of view, are not critical because they depend on less rare materials. Lithium itself is a common material that’s produced on a large scale at numerous stable locations around the world (the leading producer is Australia), and reserves are considered to be particularly abundant. The only “virtuous” exception, for EGP, is the “Second Life” project, in which we use electric vehicle (NMC) batteries as a storage system to stabilize the local grid at the Melilla plant (in Spain).

Whereas lithium batteries are an effective and affordable solution for energy storage in various fields, innovation is also moving quickly when it comes to batteries, and there are several alternatives to lithium being studied that use other materials, such as vanadium, sodium, iron and zinc. There are also energy storage systems based on innovative technologies such as gravitational storage or gas compression systems, or even thermal storage systems based on the use of heat-storing stones, or the use of sand and similar materials. And there are some examples of these innovative systems in various countries: in Spain, a system using vanadium flow batteries has been installed at the Son Orlandis solar plant; in Italy, a sustainable storage system based on fragmented rocks capable of storing heat at around 500° was inaugurated at the Santa Barbara site in Tuscany in late 2022; and in Texas, USA, an innovative energy storage system based on gravitational technology using recycled material from decommissioned wind turbines is being built.

While it is true that currently the battery production chain is mainly concentrated in Asian countries, policies have emerged in Europe to integrate production on the continent.

Specifically, the European Union is funding-through the IPCEI (Important Project of Common European Interest) scheme-the European Battery Innovation, a project aimed at supporting a European battery supply chain and its technologies, making it ecofriendly and competitive and allowing in the medium term to rebalance the concentration of production in Asia. Central to the project is the circular approach to production, for the development of innovative components (electrodes, cells and modules), thus coming to integrate end-of-life management and recycling of batteries, resulting in greatly reducing-with the use of these secondary raw materials-the need for and dependence on those critical materials that are the basis of the existing oligopoly.

Enel participates in some initiatives under the European project, through the IPCEI program specifically in the development of optimization software for the management of storage plants and in the development of battery recycling technologies. 

Batteries can be recycled and there are several projects that can recover and reintroduce some of the materials of which they are composed, such as lithium and cobalt, into the production cycle.For example, in Spain, at the Compostilla power plant, an industrial-scale pilot plant will be set up for the end-of-life management of batteries and the recycling of the so-called black mass (a compound found in batteries containing nickel, manganese, cobalt and lithium) through a process of discharging, dismantling, crushing, sorting of materials, and the subsequent reintroduction into production cycles of new batteries. 

In some cases, batteries can even be reused “as is.” For example, at Melilla, a Spanish enclave in Morocco, with the “Second Life” project, used batteries from Nissan electric vehicles are reassembled into a stationary storage system that stores energy from the thermal power plant or the grid for use at times when demand is higher.