
How solar power forecasting can help maximise your solar panels
By Maeve Upton and James Sweeney, UL
In recent months, Ireland has seen a rapid surge in solar energy production. A new record for grid-scale solar power was set on the March 25th last, reaching 750 Megawatts at a single moment - enough to power about 750,000 homes at once.
But as electricity from solar becomes an increasingly significant component of our energy system, challenges arise in effectively forecasting and managing variability of solar energy production, at both household and national levels.
From RTÉ Radio 1's Morning Ireland, there has been a significant growth in solar capacity in Ireland
Solar panels convert sunlight or solar irradiance, into electricity, which varies throughout the day. The amount of power produced depends on several factors, including the characteristics of the panel and the solar irradiance it receives. There are many different solar panel systems available with varying panel characteristics. If you're considering installing solar panels, check out this guide which covers everything from panel selection to financial incentives.
Solar irradiance is the amount of sunlight reaching the ground and is the biggest drivers of variability in electricity production. During the day, the three main sources of variability are the sun's position, cloud cover and panel temperature.
Position of the sun
The sun follows a predictable daily (diurnal) cycle—rising in the east and setting in the west —and also changes with the seasons. In the northern hemisphere, the sunniest months are typically May and June.
From RTÉ Brainstorm, all you need to know about putting solar panels on your roof
Cloud cover
Cloud cover can block or scatter sunlight, significantly reducing the amount of solar irradiance reaching the surface of the solar panel. Solar power output drops each time a cloud passes over the solar panel. Unlike the sun's position, cloud cover is much harder to predict, especially in Ireland's temperate maritime climate.
Higher temperatures
Higher temperatures can reduce the efficiency of the solar PV panel. Though weather forecasts can quantify this, the effect on solar power output requires local-level estimates.
What is solar power forecasting?
Solar power forecasting is the process of predicting the amount of solar radiation (sunlight) reaching Earth's surface at a specific location and time. This is crucial for managing solar energy production, integrating renewable energy into power grids and ensuring energy system stability.
From RTÉ Radio 1's Morning Ireland, can Ireland reach solar targets set out in Climate Action Plan?
How does it work?
To forecast solar power at a specific time and location, we need three key components: input data (solar PV system such as orientation and weather), astronomical calculations on the sun's position and a model combining them. The input data provides information about weather conditions, while astronomical calculations determine the position of the sun. These elements are combined within a forecasting model to estimate the solar power output.
The input data has three main sources. The most accurate is ground-based measurements from meteorological stations managed by Met Éireann. They record high quality solar irradiance data in real time, but are limited to their 20 stations around Ireland.
An alternative source is reanalysis datasets, which provide estimates of solar irradiance by blending historical weather observations with advanced numerical weather models. While reanalysis data offers consistent and spatially complete coverage, it is not available in real time and typically lags by about five days.
From RTÉ Radio 1's Morning Ireland, Teagasc's Barry Caslin on a renewed push for rooftop solar on farm sheds
The final source is satellite data, which provides valuable observations of solar irradiance and cloud cover. However, these measurements can vary significantly if the instruments are not regularly calibrated and maintained, an effort that requires consistent investment and funding.
In addition to these data sources, astronomical calculations are performed to determine the sun's position in the sky and day length based on the time of year. These calculations are essential for accurately estimating the potential solar irradiance.
Once we've selected our input data and calculated the sun's position, we apply models to convert solar power observed on a horizontal (flat) surface to that received on a tilted surface—matching the orientation and size of the specific solar panel system. This step is crucial for estimating how much power a real system could generate.
If you're curious about what your solar panels could do, check out the GREEN-GRID app. This uses advanced data-driven modelling tools to estimate real-time solar power, giving hourly insights for homeowners across Ireland.
What are the challenges for solar power in Ireland?
While Ireland's progress in solar power adoption is promising, several challenges complicate accurate forecasting and integration into the grid. These challenges highlight the need for better forecasting and more flexible grid systems to ensure that the growing share of renewable energy is fully captured and effectively used.
From a forecasting perspective, models can be highly effective but their accuracy is limited by the quality and resolution of the input data available.On the integration side, one significant challenge is dispatch down, when renewable energy, particularly wind and solar, is reduced or curtailed because the electricity grid cannot accommodate all of the power being generated at a given time. As a result, some renewable energy is available but not used, which can reduce the overall efficiency of the system and delay the full benefits of clean energy investment.
Another issue is the limited visibility of microgeneration, such as roof-top solar, which is often excluded from official reports. Similarly, embedded generation, which refers to electricity generated and used locally, is not consistently measured, though recent reports suggest improvements are planned.

Try Our AI Features
Explore what Daily8 AI can do for you:
Comments
No comments yet...
Related Articles


RTÉ News
7 days ago
- RTÉ News
Is your cat loud or quiet? It could be in their genes
Analysis: Research suggests cats don't have a single temperament, but rather various traits that prove useful under different domestic conditions By Grace Carroll, Queen's University Belfast If you've ever shared your home with more than one cat, you'll know how different their personalities can be. One might chirp for food, purr loudly on your lap and greet visitors at the door. Another might prefer quiet observation from a distance. So why do some cats become chatty companions while others seem more reserved? A recent study led by wildlife researcher Yume Okamoto and their colleagues at Kyoto University suggests that part of the answer may lie in cat genes. From RTÉ Radio 1's Drivetime, the relationship between humans and cats Cat owners from across Japan were asked to complete a questionnaire about their cat (the Feline Behavioural Assessment and Research Questionnaire), and to take a cheek swab from their pet to provide a DNA sample. The survey included questions about a range of cat behaviour, including purring and vocalisations directed at people. The researchers in the recent Japanese study focused on the cats' androgen receptor (AR) gene, located on the X chromosome. This gene helps regulate the body's response to hormones such as testosterone and contains a section where a DNA sequence is repeated. AR is an essential part of vertebrate biology. The most ancient form of AR appeared in the common ancestor of all jawed vertebrates, over 450 million years ago. AR controls the formation of male reproductive organs, secondary sexual characteristics and reproductive behaviour. The number of these sequences alters how responsive the gene is. Shorter repeats make the receptor more sensitive to androgens. In other species, including humans and dogs, shorter repeats in the AR gene have been linked with increased aggression and extraversion. Among 280 spayed or neutered cats, those with the short AR gene variant purred more often. Males with the variant also scored higher for directed vocalisations such as meowing to be fed or let out. Females with the same genotype, however, were more aggressive towards strangers. Meanwhile, cats with the longer, less active version of the gene tended to be quieter. This variant was more common in pedigree breeds, which are typically bred for docility. Domestication is generally thought to have increased vocal behaviour in cats, so it may seem odd that the version of the gene linked to increased communication and assertiveness is the one also found in wild species such as lynx. But this study doesn't tell a straightforward narrative about how cat domestication selects for sociable traits. Instead, it points to a more complex picture. One where certain ancestral traits like aggression may still be useful, especially in high-stress or resource-scarce domestic environments. From RTÉ Radio 1's Ray D'Arcy Show, should all cats be indoor cats? Some animals spend a lot of time around humans because they are attracted by our resources rather than bred as companion animals or farmed. Urban gulls offer an interesting example of how close proximity to humans doesn't always make animals more docile. In cities, herring and lesser black-backed gulls (both often referred to as seagulls) have become bolder and more aggressive. Researchers at Liverpool John Moores University found that urban gulls were less fearful of humans and more prone to squabbling compared to their rural counterparts. In urban areas, where food is highly contested, being assertive gets results. Gulls are often vilified in the UK press during breeding season as urban villains, swooping down to snatch your lunch or chase pedestrians. This suggests that life alongside humans can sometimes favour more confrontational behaviour. From cats to gulls, life alongside humans doesn't always produce gentler animals The parallels with cats raise broader questions about how environment and genes shape behaviour. Okamoto and colleagues' findings may reflect a trade-off. Traits linked to the short AR variant, such as greater vocalisation or assertiveness, might offer advantages in gaining human attention in uncertain or competitive settings. But these same traits may also manifest as aggression, suggesting that domestication can produce a mix of desirable and challenging traits. It's worth bearing in mind that this kind of variation between individuals is fundamental to the evolution of species. Without variation in behaviour, species would struggle to adapt to changing environments. For cats, this means there may be no single ideal temperament, but rather a range of traits that prove useful under different domestic conditions. From cats to gulls, life alongside humans doesn't always produce gentler animals. Sometimes, a little pushiness pays off.


RTÉ News
25-06-2025
- RTÉ News
Why it can be harder to sleep during the summer
Analysis: Seasonal insomnia means summer sleeping for many of us is a time of tossing, turning and early waking By Timothy Hearn, Anglia Ruskin University As the days stretch long and the sun lingers late into the evening, most of us welcome summer with open arms. Yet for a surprising number of people, this season brings an unwelcome guest: insomnia. For these people, summer is a time of tossing and turning, early waking – or simply not feeling sleepy when they should. Far from just being a nuisance, this seasonal insomnia may chip away at mood, concentration and metabolic health. From RTÉ 2FM Morning with Laura Fox, sleep expert Síne Dunne on getting off to sleep But why does insomnia spike in summer — and more importantly, what can be done about it? The answer lies in the light. Every tissue in the body owns a molecular "clock". However, these clocks take their cue from a central timekeeper – the brain's suprachiasmatic nucleus. This cluster of about 20,000 neurons synchronises the myriad cellular clocks to a near 24-hour cycle. It uses the external light detected by the eyes as a cue, driving the release of two different hormones: melatonin, which makes us sleepy and a pre-dawn surge cortisol to help us wake. In winter, this light cue is short and sharp. But in June and July, daylight can stretch on for 16 or 17 hours in the mid‑latitudes. That extra dose matters because evening light is the most potent signal for pushing the central timekeeper later. In summer melatonin shifts by roughly 30 minutes to an hour later, while dawn light floods bedrooms early and kills the hormone off sooner. From RTÉ Brainstorm, the A to Zzzzz of sleep This can have a big effect on the amount of sleep we get. One study monitored the sleep of 188 participants in the lab on three nights at different times of the year. The researchers found that total sleep was about an hour shorter in summer than winter. Rapid eye movement (REM) sleep — the sleep stage most strongly linked to emotional regulation and the consolidation of emotionally charged memories — accounted for roughly half the sleep loss in summer. The same team later tracked 377 patients over two consecutive years and showed that sleep length and REM sleep began a five‑month decline soon after the last freezing night of spring. Sleep length shrank by an average of 62 minutes, while REM decreased by about 24 minutes. Slow-wave sleep – the phase most critical for tissue repair, immune regulation and the consolidation of factual memories – reached its annual low around the autumn equinox. Both studies took place in a city bathed in artificial light – suggesting that even in modern environments our sleep remains seasonally affected. From RTÉ Radio 1's Drivetime, you may be sleeping well, but are you actually getting rest? Big population surveys echo these findings. Among more than 30,000 middle‑aged Canadians, volunteers interviewed in midsummer said they slept eight minutes less than those interviewed in midwinter. The summer interviewees also reported greater insomnia symptoms in the fortnight after the autumn clock change – suggesting the abrupt time shift exacerbates underlying seasonal misalignment. One study also compared the effect of summer sleep in people living at very different latitudes – such as near the equator, where there's little change in day length in the summer, and near the Arctic circle, where the differences are extreme. The study found that for people living in Tromsø, Norway, their self-reported insomnia and daytime fatigue rose markedly in summer. But for people living in Accra, Ghana (near the equator), these measures barely budged. This show just how strongly daylight – and the amount of daylight hours we experience – can affect our sleep quality. But it isn't the only culprit of poor summertime sleep. Temperature is another factor that can spoil sleep during the summer months. Just before we fall asleep, our core body temperature begins a steep descent of roughly 1°C to help us fall asleep. It reaches its lowest point during the first half of the night. On muggy summer nights this can make falling asleep difficult. Laboratory experiments show that even a rise from 26°C to about 32°C increases wakefulness and reduces both slow-wave and REM sleep. Different people are also more vulnerable to summer insomnia than others. This has to do with your unique "chronotype" – your natural preference to rise early or sleep late. Evening chronotypes – "night owls" – already lean towards later bedtimes. They may stay up even later when it stays bright past ten o'clock. Morning chronotypes, on the other hand, may find themselves waking up even earlier than they normally do because of when the sun rises in the summer. From RTE Radio 1's Drivetime, sleep physiologist Motty Varghese on sleeping 14 hours a day Mood can amplify the effect. Research found people who suffered with mental health issues were more likely to experience difficulty sleeping in summer. Chronic anxiety, alcohol use and certain prescription drugs — notably beta blockers, which suppress melatonin — can all make sleep more elusive in summer. 4 ways to reclaim your summer sleep Happily, there are many ways of fixing the issue. Get some morning sunshine. Try to step outside within an hour of waking up – even if it's just for 15 minutes. This tells the clock that the day has begun and nudges it to finish earlier that evening. Create an artificial dusk. Around two hours before bed, close the curtains, turn off the lights and reduce the intensity of your phone screen's blue light to help your melatonin rise on time. Don't let the dawn light in. Being exposed to the dawn light too early will wake you up. Blackout curtains or a contoured eye-mask can ensure you don't wake before you're rested. Keep things cool. Fans, breathable cotton or linen sheets or a lukewarm shower before bed all help the body to achieve that crucial one-degree drop in core temperature needed to get a good night's sleep. The deeper lesson here from chronobiology is that humans remain, biologically speaking, seasonal animals. While our industrialised lives flatten the calendar, our cells still measure day length and temperature just as plants and migratory birds do. By adapting and aligning our habits with those light signals, we might just be able to recapture some sleep – even during the warmer months.


RTÉ News
11-06-2025
- RTÉ News
Is your beard a hygiene risk?
Analysis: Stylish or unsanitary? Here's what the evidence shows about beards and bacteria Human skin is home to billions of microorganisms – mainly bacteria, but also fungi and viruses – and facial hair provides a unique environment for them to thrive. Research shows that beards, in particular, support a dense and diverse microbial population, which has fuelled a persistent belief that they are inherently unhygienic. The Washington Post recently reported that some toilets contain fewer germs than the average beard. But are beards truly a hygiene risk? A closer look at the evidence reveals a nuanced picture. The microbial population on skin varies by location and is influenced by factors such as temperature, pH, humidity and nutrient availability. Beards create a warm, often moist environment where food debris and oils can accumulate – ideal conditions for microbial growth. From RTÉ Brainstorm, the hairy history of beards These microbes thrive not just because of the warm, moist conditions beards provide, but also because of constant exposure to new contaminants and microbes, especially from hands that frequently touch surfaces and the face. Concerns among scientists about beard hygiene date back over 50 years. Early studies showed that facial hair could retain bacteria and bacterial toxins even after washing. This led to the enduring idea that beards act as bacterial reservoirs and could pose an infection risk to others. For healthcare workers, this has made beards a point of controversy, especially in hospitals where pathogen transmission is a concern. However, hospital-based research has shown mixed results. One study found that bearded healthcare workers had higher bacterial loads on their faces than clean-shaven colleagues. Another investigation, looking at whether it would be hygienic to evaluate dogs and humans in the same MRI scanner, found that most men's beards contained significantly more microbes than dog fur, including a greater presence of harmful bacteria. The researchers concluded: "Dogs are no risk to humans if they use the same MRI." However, other studies have challenged the idea that beards increase infection risk. For example, one investigation found no significant difference in bacterial colonisation between bearded and clean-shaven healthcare workers. The same study also reported that bearded doctors were less likely to carry Staphylococcus aureus, a major cause of hospital infections, and that there was no increase in infection rates among patients treated by bearded surgeons wearing surgical masks. From RTÉ 2fm, beards may be trendy, but are they hygienic? Advice from the Grafton Barbers' Conor McAllister on keeping your facial hair on point Beards can sometimes spread skin infections, such as impetigo — a contagious rash often caused by S aureus, which is commonly found in facial hair. In rare cases, parasites like pubic lice – which usually live in the groin area – can also show up in beards, eyebrows or eyelashes, particularly in cases of poor hygiene or close contact with an infected person. The case for good beard hygiene Neglected beards can foster irritation, inflammation and infection. The skin beneath a beard – rich in blood vessels, nerve endings and immune cells – is highly sensitive to microbial and environmental stressors. When sebum, dead skin, food debris and pollutants accumulate, they can irritate the skin and provide fuel for fungal and bacterial growth. Experts strongly recommend washing your beard and face every day. Doing so removes dirt, oils, allergens and dead skin, helping prevent microbial buildup. Dermatologists also advise moisturising to prevent dryness, using a beard comb to clear debris, and trimming to control loose hairs and reduce shedding. These steps help maintain not only hygiene but also beard health and appearance. So, are beards dirty? Like most things, it depends on how well you care for them. With daily hygiene and proper grooming, beards pose little risk and may even be healthier than we once thought.