Løsninger for lagring av solenergi: Effektiviteten økt med ‘mer enn én størrelsesorden’ i konverteringsgjennombrudd

“The world’s capacity to generate renewable electricity is expanding faster than at any time in the last three decades,” said the International Energy Agency in a report published earlier this year.

This growth, as per the Paris-based autonomous intergovernmental organization, offers “a real chance of achieving” the goal of tripling global capacity, which was set at the COP28 climate change conference, by the end of this decade.

Renewable capacity has grown significantly over the past decade, with solar energy playing a major role in that. In 2023, renewable sources produced 30% of the world’s electricity, and solar PV accounted for three-quarters of the world’s new renewable capacity additions.

This makes sense, given that the cost of solar energy continues to go down, becoming cheaper than coal. Besides offering economic benefits like cost certainty over a long period, solar energy also boosts resiliency and reduces carbon emissions.

However, despite these benefits and the fact that 50% of global final energy consumption is utilized for heating, solar power usage is still low compared to fossil energy sources.

This is because solar power has its unique limitations, including its unavailability at night, while peak energy use tends to come in the evenings. Then, there’s climate change affecting both its demand and supply.

“We need to think about how climate change will impact the energy system as a whole because, unfortunately, no electricity generating system is immune from the impacts of climate change.”

– Romany Webb, deputy director of the Sabin Center for Climate Change Law at the Columbia Climate School

When it comes to climate impact, more frequent heat waves make solar panels less efficient, while increased demand for cooling strains the grid and negatively affects the system. Hurricanes have actually been found to diminish photovoltaic generation between 18% and 60%, while tropical cyclones can bring down solar radiation by 80%. Extreme weather like wind hazards can further damage solar energy infrastructure.

All these limitations mean that efficient solar energy storage can open up a wealth of possibilities.

Effective storage solutions allow for storing surplus power for peak use when the sun goes down. This way, electric loads can be balanced based on demand and supply and allow for consistent energy flow.

Solar power storage also provides protection during disruptive events like wildfires, during which the energy grid becomes vulnerable to outages.

So, what are these storage solutions? Well, they generally belong to three main categories;  battery, mechanical, and thermal. Among these, batteries, especially lithium-ion batteries, are the most common and cost-effective way for solar energy storage.

Researchers, however, are constantly coming up with new innovations. A brand new approach to harvesting and storing solar energy more efficiently involves using underexplored sensitization strategies.

Mer effektiv innhøsting og lagring av solenergi

To address the primary problem of limited global solar energy usage—intermittency of its direct availability—researchers at the universities of Johannes Gutenberg University Mainz (JGU) and the University of Siegen have developed molecular systems for storing solar energy.

In contrast to traditional thermal energy storage systems that store energy only for short periods, molecular solar energy storage systems can store it for an extended period, from several weeks to months. This is because solar energy is stored in the form of chemical bonds here.

The way molecular solar energy storage systems work is that specialized molecules or photoswitches first absorb the solar energy and then release it as heat on demand.

Even this system isn’t without its challenges. The key issue with exciting photoswitches is the compromise between efficient absorption of solar light and energy storage capacity. This limits the overall performance of molecular solar energy storage systems.

So, the research team at Mainz and Siegen conducted a study to overcome this problem using a new approach.

The new class of photoswitches was initially introduced at Siegen that showcased incredible energy storage potential in comparison to traditional lithium-ion batteries.

Most widely used battery chemistry, these batteries involve one or many lithium-ion cells in addition to a circuit board. A lithium-ion cell has electrodes, an anode, a cathode, an electrolyte that conducts electricity, current collectors, and a separator. A photoswitch, meanwhile, is a molecule that changes its structural geometry and chemical properties when exposed to electromagnetic radiation.

The novel photoswitch, while having exceptional energy storage potential, their functionality was limited to activation by ultraviolet (UV) light. UV light has wavelengths of 10-400 nanometers and constitutes only a small portion of the solar spectrum.

So, the latest study proposed an indirect light harvesting technique. This one is similar to how light-harvesting works in photosynthesis. Here, a second compound is incorporated, which is a sensitizer that exhibits great visible light absorption qualities. According to Professor Christoph Kerzig of the JGU Department of Chemistry, who led the study along with PhD student Till Zähringer:

“In this approach, the sensitizer absorbs light and subsequently transfers energy to the photoswitch, which cannot be directly excited under these conditions.”

With this new approach, the research teams have enhanced solar energy storage efficiency by more than an order of magnitude. This major step forward in energy conversion opens potential applications for both household heating solutions and large-scale energy storage.

The Mainz-based research team also conducted thorough spectroscopic analyses to explore the complex system in order to understand the underlying mechanism.

Gaining a detailed comprehension of how the system operates will help “push the light-harvesting limit substantially,” said first author Zähringer, adding that it could also improve light’s conversion efficiency into stored chemical energy.

In operational conditions, each photon that is absorbed is able to trigger a chemical bond formation process. This is seldom observed in photochemical reactions as a result of several energy loss channels.

Researchers successfully validated the robustness of the system’s practicality by cycling between the energy storage and release state numerous times using solar light, highlighting the system’s potential for real-world applications.

Siste utviklinger innen innhøsting og lagring av solenergi

Given the big role solar plays in the renewable energy mix, it has been the growing focus among researchers, companies, and government initiatives, which are trying to gain a deeper understanding of how it all works and develop better solutions to harvest the energy and its storage.

New research from NC State University has focused on providing a deeper understanding of what occurs in organic cells as sunlight converts to electricity. To visualize the interfaces where light energy converts to electrical charges, researchers developed a novel method, scanning-probe microscopy, and used it to improve solar cell efficiency.

Made of carbon-based polymer materials, organic solar cells have the potential to be used for flexible and lightweight solar applications as well as semi or full-transparent window applications, but they are not as efficient as perovskite or silicon solar technologies at converting light into electricity.

This is because these cells are made of a mixture of two materials; one of them harvests electrons (donor) but then has to interact with the second one to pass them (acceptor), and interfaces between the two are responsible for a voltage loss, hence, limiting organic solar cells efficiency.

The latest study found that both energy differential between constituent donor and acceptor materials, as well as energetic disorder along interfaces, drive voltage loss.

According to co-author Aram Amassian, professor of materials science and engineering at NC State University, selecting materials with minimal energy offsets reduces voltage losses. Solvent and processing parameters that diminish interfacial disorder can further reduce energy losses.

Another recent study took the task of reliably estimating the capacity of household energy storage systems to get an idea of the future deployment of effective residential PV systems.

For this, researchers introduced a scalable capacity estimation technique, which involves three key steps: determining when a storage system is at full capacity and when it is empty and calculating capacity between these two states.

It was then used to measure 21 lithium-ion batteries-based systems in private households in Germany over eight years. The analysis revealed that, on average, the systems lost 2-3% of their capacity annually.

Notably, the method can be used by manufacturers and solar energy companies to estimate the capacity of their energy storage systems. Moreover, researchers published an extensive dataset, which comprises 14 billion data points from over 100 years, that can be used to conduct additional studies or train computational models.

Earlier this year, in June, researchers also developed an innovative light-harvesting system that can “absorb a great deal of light energy in a relatively thin layer,” much like natural light-harvesting systems.

By having a band structure that is similar to inorganic semiconductors, it can absorb light panchromatically across the whale visible range, while using high absorption coefficients of organic dyes allows it to absorb a lot of energy.

The system has four different merocyanine dyes that are folded and stacked closely together, enabling ultra-fast and efficient energy transport within it. The system has been found to be able to convert 38% of the irradiated light energy.

For efficient storage of solar energy and reducing conversion loss, researchers from around the world also came together earlier this year to study the dynamics of photo- and electrochemical transformation to design a better-suited molecule for the desired functions.

The researchers are looking into norbornadiene for this, which is a hydrocarbon isomer having two molecule rings and, when exposed to UV light, results in its conversion to a more highly strained quadricyclane.

Given the pure energy density of the norbornadiene-quadricyclane system is comparable to a lithium-ion battery, if its reversal conversion can be controlled reliably, that can achieve an efficient solar module that is also suitable for storing electricity.

Focusing on hydrocarbon molecules offers a cost-effective method that doesn’t require any rare metals and can be easily recycled or disposed of. All these recent developments in the sector are a testament to the growing focus on increasing solar energy adoption worldwide.

Selskaper som er posisjonert til å dra nytte av fremskrittet

Now, we’ll look into two of the most prominent names that can benefit from or offer such a molecular solar energy storage system. These two names are NextEra Energy, Inc. (NEE ) and Enphase Energy, Inc. (ENPH ), both of which are US-based companies and actively involved in renewable energy.

1. NextEra Energy (NEE )

Kjent for sine investeringer i fornybare energiteknologier, kan NextEra Energy dra nytte av slik teknologi når det gjelder lagringseffektivitet.

Med en markedsverdi på 161 milliarder dollar, handles NextEra-aksjer for tiden til 78,37 $, opp over 29 % så langt i år. Selskapet har en EPS (TTM) på 3,37 og en P/E (TTM) på 23,24, mens det betaler en utbytteavkastning på 2,63 %.

Energistruktur‑selskapet rapporterte nylig resultatene for 3Q24, og avslørte at nettoinntekten steg til 1,85 milliarder dollar, sammenlignet med 1,29 milliarder dollar i Q3 2023. Justert resultat per aksje økte samtidig med 10 % år‑over‑år. Disse resultatene, ifølge administrerende direktør John Ketchum, viser «fortsatt solid finansiell og operasjonell ytelse».

Samtidig hadde NextEra Energy‑eide Florida Power & Light Company (FPL) 1,29 milliarder dollar i nettoinntekt, mens kapitalutgiftene var 2 milliarder dollar, og regulert kapitalbruk økte med 9,5 % år‑over‑år. Når han snakket om sine floridanske kunder som ble påvirket av orkanene Helene og Milton, bemerket Ketchum at FPLs «investeringer i forsterkning og smart‑grid‑teknologi hindret hundretusener av strømbrudd».

Nå har NextEra Energy Resources, for andre kvartal på rad, lagt til omtrent 3 gigawatt nye fornybare- og lagringsprosjekter i sin pipeline. De kunngjorde også avtaler med to Fortune‑50‑kunder for utvikling av fornybare‑ og lagringsprosjekter, med en total på opptil 10,5 gigawatt innen 2030.

“Den fortsatte sterke ytelsen til våre virksomheter og vår skala, erfaring og teknologi vil gjøre det mulig for oss å utnytte muligheten som økt etterspørsel etter kraft gir til vår sektor.”

– Ketchum, administrerende direktør i NextEra Energy

Sist uke inngikk det ledende renenergiselskapet en avtale om å selge 1,5 milliarder dollar i egne aksjeenheter til store finansinstitusjoner, inkludert Goldman Sachs (GS ), J.P. Morgan og Mizuho. Midlene vil bli brukt til investeringer i AI‑relaterte energi‑ og kraftprosjekter og til å tilbakebetale utestående kommersielle papirer.

Ettersom AI‑mani fører til økende etterspørsel etter kraft fra AI‑datasentre, og selskapet fokuserer på å vokse sin fornybare energivirksomhet, gjennomfører NextEra Energy også studier og har diskusjoner med føderale regulatorer om å gjenåpne Duane Arnold kjernekraftverk i Iowa.

2. Enphase Energy, Inc. (ENPH )

Spesialisert på solinvertere og lagring, kan Enphase Energy også potensielt utvide til å inkludere innovativ molekylær lagring dersom det er kommersielt levedyktig, for å forbedre energiresiliens og effektivitet for sine kunder.

Med en markedsverdi på 11,8 milliarder dollar, handles Enphase-aksjer for tiden til 87,46 $, ned 33,87 % så langt i år. Selskapet har en EPS (TTM) på 0,44 og en P/E (TTM) på 198,82. For Q3 2024 rapporterte det globale energiteknologiselskapet en inntekt på 380,9 millioner dollar og en non‑GAAP bruttofortjeneste på 48,1 %. I denne perioden sendte Enphase mer enn 1,73 millioner mikroinvertere og 172,9 MWh batterier.

Verdens ledende leverandør av mikro‑inverter‑baserte sol‑ og batterisystemer avsluttet kvartalet med 161,6 millioner dollar i fri kontantstrøm, mens kontanter, kontantekvivalenter og omsettelige verdipapirer var 1,77 milliarder dollar.

I denne perioden lanserte Enphase AI‑basert programvare for å optimalisere energibruk ved å integrere sol‑ og forbruksprediksjon med strømpriser, for å hjelpe forbrukerne med å maksimere besparelser.

I oktober begynte selskapet å sende IQ8™‑mikroinvertere for å støtte nyere, høy‑ytelses solpaneler i utvalgte land, utvidet sin støtte for nettverkstjenesteprogrammer (eller virtuelle kraftverk) i utvalgte amerikanske delstater, og lanserte IQ8X‑mikroinvertere med den lengste standard boliggarantien på 25 år i Australia.

I de to månedene før dette lanserte den sitt kraftigste Enphase Energy System til dags dato, kunngjorde en løsning for å utvide eldre net‑energy‑metering (NEM) solenergisystemer i California uten straff, lanserte NACS‑kontakter for IQ‑EV‑ladere, og sendte IQ8‑mikroinvertere for å støtte nyere, høy‑ytelses solmoduler i utvalgte land i hele Europa. Den introduserte også IQ Energy Management for å muliggjøre støtte for dynamiske strømpriser og integrasjon av tredjeparts EV‑ladere og varmepumper i Nederland.

Selskapet forbereder nå lanseringen av 2. generasjons IQ®‑EV‑lader, 3‑fase IQ‑batteri med backup, og IQ®‑Balcony Solar Kit for det europeiske markedet, mens deres fjerde generasjons energisystem, med IQ®‑Meter‑Collar, 10 kWh IQ‑batteri og forbedret IQ®‑Combiner, vil debutere i USA tidlig neste år.

Totalt sett falt Enphases salg i Europa med 15 % fra Q2 på grunn av «videre mykning i europeisk etterspørsel», mens lagerbeholdningen som vendte tilbake til normale nivåer førte til at US‑inntektene økte med 43 % sekvensielt.

Konklusjon

I takt med det globale presset for fornybar energi har solenergi fremstått som en fremtredende aktør som tilbyr en ren og rikelig løsning. Imidlertid påvirkes den globale adopsjonen av kostnad, mer effektive løsninger og mangel på infrastruktur, blant andre faktorer.

Nylige fremskritt, fra molekylær solenergilagring til innovasjoner innen organiske solceller, gir stort potensial for å gjøre solenergi mer effektiv, hjelpe med å møte global etterspørsel etter kraft, selv under ugunstige forhold, og bane vei for en bærekraftig fremtid.

Klikk her for en liste over de beste solenergiaksjene.