Good garden lighting ideas can completely transform an outdoor space. They will extend your evenings relaxing out on the patio, make tricksy garden paths safer to navigate, and stop you accidentally trampling through your flowerbeds after dark.
And these days, garden solar lights are one of the most popular choices – easy to install, eco-friendly, and wonderfully bill-free (take that energy price hikes).
But here’s the big question: do solar lights need direct sunlight to actually work properly? After all, one common complaint is that they sometimes don’t shine as brightly as expected. We put the question to the experts, who reveal how you can use solar lights in most conditions, and offer their best tips to keep your garden glowing long after sunset.
With over 10 years of experience in product management, Claire has a track record of designing and creating successful products from concept to market, focusing on user experience, data-driven decision-making and team collaboration. Claire thrives on bringing something new and unique to Lights4fun's customers, and takes great satisfaction in the knowledge that these products bring a little bit of sparkle to everyday life.
Alex Bridgman is the CEO of Bridgman, an independent supplier and makers of luxury home and garden furniture. Responsible for managing the company's overall operations, Alex's day-to-day focuses on sustainably driving business development and overseeing the exquisite product design that Bridgman has become renowned for.
Loren Taylor is a seasoned expert in landscaping and gardening, with a keen eye for exterior design. His deep knowledge of plant species, soil conditions, and sustainable gardening practices, combined with a passion for creating harmonious outdoor designs, has made him a sought-after authority in the field. Loren's expertise has been recognized across several notable television networks, including DIY Network, Style Network, and HGTV, where his innovative approach to garden design and landscaping has been featured.
How solar lights work
Let's start with the science bit – but don't worry, we'll keep it simple.
"Solar lights are a brilliant example of sustainable design, turning natural sunlight into a dependable light source after dark," says Claire Bassett, head of product at Lights4fun. "At the heart of the system is a small photovoltaic solar panel, which is made up of layers of semiconducting material – typically silicon. When sunlight hits the panel, photons from the sun’s rays excite the electrons in the semiconductor, creating an electrical current. This process produces direct current electricity."
"During the day, this electricity is directed into a rechargeable battery built into the unit. Once daylight fades and the integrated light sensor detects low ambient light levels, the stored energy is released to power the LED bulb," she continues.
In short, solar lights operate through a simple yet effective cycle: sunlight is captured, stored, and then converted into illumination at night – all without the need for external wiring or electricity. The more sunlight they get, the more juice they store in their rechargeable batteries.
Direct vs. indirect sunlight: what difference can it make?
Where you place your solar lights in terms of the amount of light that's available to them absolutely has a bearing on their performance.
"I’ve been playing around with solar lights in gardens for years, and the type of sunlight they receive makes a huge difference," says Loren Taylor, landscape gardener and owner of Outdoor Fountain Pros. "If your light is placed in direct sunlight, it charges fully and can glow brightly for 10 or 12 hours. If the light receives only indirect sunlight, such as filtered through tree leaves or on a cloudy day, it may only charge halfway. That means it will come on dimmer for just a few hours."
"Performance is intimately tied to placement," agrees Alex, CEO at Bridgman. "In optimal conditions, full, direct sunlight for 6 to 8 hours, a high-quality solar light can fully charge and provide up to 8 to 10 hours of illumination overnight. However, in partial shade or on overcast days, charging efficiency diminishes.
"Indirect sunlight will still contribute to battery replenishment but expect a reduced output: often around 50–70% of the potential charge, which may translate to 4–6 hours of light depending on the model," Alex adds.
"Total shade is even worse. In those spots, the lights might barely turn on at all because the panel is not getting enough energy to fill the battery," says Loren.
Claire Bassett takes us through these scenarios in more detail.
Direct sunlight
"Positioning a solar panel in unobstructed, direct sunlight provides the optimum conditions for charging," says Claire. "On a clear summer’s day in the UK, six to eight hours of direct sunlight is usually sufficient to fully charge a solar light’s battery. This can deliver anywhere between 8-12 hours of illumination, easily lasting from dusk until dawn."
Indirect sunlight
"When a panel is placed in a spot that only receives diffused or partial sunlight – for instance, behind light foliage, on a north-facing wall, or in the shade for part of the day – charging efficiency drops," says Claire. "Under these conditions, you might expect the battery to charge only 50-75% of its full potential. As a result, the light may run for 4-6 hours in the evening, still providing a pleasing glow but not lasting throughout the night."
Total shade
"In locations that receive little or no direct daylight – such as under dense trees or next to high walls – solar panels struggle to generate enough power," Claire explains. "Even though some models can harvest a small amount of ambient light, the charging is typically minimal, meaning illumination could be limited to 1-2 hours, or in some cases not function reliably at all."
What can affect the performance of my solar lights?
When it comes to solar lighting, not all models are created equal. For example, the quality of panel and battery can be the difference between a light that soaks up the sun like a Brit abroad, and one that fades faster than your tan when you get back home.
Here are the key benefits and blockers to be wary of.
Panel quality
"The kind of panel and battery in the light matters a lot," says Loren. "Monocrystalline panels are more efficient than polycrystalline ones, so even when sunlight is weak, they still pull in more energy."
"Monocrystalline panels typically convert 15–20% of sunlight into energy," says George Penny, solar energy expert and founder at The SolarCo. "They tend to perform better in shaded or cloudy conditions but come with a higher price tag."
"Polycrystalline panels sit in the middle," George continues. "They're less efficient (around 13 - 16%) but more affordable, though they don’t handle low light quite as well. Thin-film panels are the least common in garden lights; while they’re cheap and flexible, their efficiency is much lower (7 -10%), which limits their usefulness and are therefore best avoided."
Battery capacity
As you would imagine, the larger the battery capacity, the more energy is stored and therefore the longer and brighter your solar lights will glow. "The rechargeable battery acts as the reservoir of stored energy," says Claire. "Higher-capacity batteries support brighter lights or extended run times, but they also require more daylight hours to fully recharge."
"Many budget lights use NiMH (nickel–metal hydride) batteries, which are affordable and usually range from about 600 to 1200mAh," says George. "Higher-quality models often use lithium-ion or lithium iron phosphate (LiFePO4) batteries, which offer much larger capacities (1,500–3,000mAh or more), last longer, and generally perform better in colder weather."
"When comparing battery capacity of solar light models, it's also worth noting that the most efficient batteries still depend on a solar panel with sufficient surface area to reach their full charge," George explains. "On top of this, it’s useful to identify whether a product enables the battery to be replaced, which may be required in a couple of years to deliver better illumination. Sealed battery designs will prevent users from replacing the battery, limiting the product's longevity."
Panel cleanliness
"You also have to consider dirt and dust," says Loren. "A panel covered in pollen or grime can lose a fifth or even a third of its power, so keeping it clean really pays off. "
Seasonal changes
"No matter how good the technology, solar lights will always perform better in the summer months than in winter," George tells us. "In the height of summer in the UK, particularly in southern regions, solar panels can benefit from long daylight hours, often from around 7am through to 9pm. This can give them close to 14 hours of potential charging time. In Scotland, midsummer days can stretch even longer, sometimes topping 16–17 hours of usable daylight.
"In contrast, during the winter months, the picture is very different. Across much of the UK, daylight is limited to roughly 9am until 4pm – barely seven hours. Further north, such as in Edinburgh or Aberdeen, the shortest days can bring less than six hours of sun. Add to that the frequent cloud cover, rain, or fog typical of British winters, and solar lights often struggle to fully recharge. As a result, they may shine less brightly and for fewer hours at night."
Three of the best solar string lights
These 300 lights can be powered either via frost-resistant polycrystalline solar panels or with USB charging of its replaceable 18650 lithium ion battery. They cost £64.99.
Choose from 100 (£24.99) or 200 (£54.99) LED lights, which are powered by a separate solar panel that can be positioned separately to take advantage of maximum sunlight.
These Shoreham lights, £19.99, are powered by a Mini Leaf high-grade frost-resistant polycrystalline solar panel. Indicator lights for 0%, 25%, 50%, 75% and 100% let you know how much charge your Leaf has left.
Where's the best place to put solar lights?
Choosing the right location for your solar lights is just as (if not more) important as the quality of the solar light itself. Since they rely on harvesting energy from the sun, their performance is directly tied to their placement, sun exposure, and the orientation of your outdoor space.
"South-facing areas receive the most sun, and west-facing spots can also work well if they receive sunlight for part of the day," says Loren.
"A north-facing garden, however, can be more challenging," says Claire. "It often receives only indirect or diffused sunlight, particularly in winter."
"If your garden is mainly shady, you have to be clever," says Loren. "You can try reflecting sunlight onto the panels, perhaps through the use of garden mirrors, trimming back plants, or choosing lights with larger batteries and better panels that can handle weaker sunlight."
"For gardens with limited sun exposure, consider using solar lights that feature an external solar panel connected via a cable," says Alex at Bridgman. "This allows the panel to sit in a sunnier location while the light itself illuminates a shaded area. Solar lighting should work with your garden’s natural rhythm, not against it."
Where not to place solar lights
"You want to avoid areas under dense trees or roofs because the shadows will rob the light of energy," says Loren.
Claire Bassett agrees: "And don't place them next to tall garden fences or walls that cast long shadows across the panel," she advises. "Also avoid areas where garden ornaments, pergolas or overhangs obstruct the sun and close to artificial light sources (such as street lamps), which can confuse the sensor."
How to take care of solar lights
Solar lights are designed to be low-maintenance, but a little care goes a long way in ensuring they perform at their best year after year.
"With minimal effort, your solar lights can provide years of elegant outdoor illumination," says Alex at Bridgman. "Clean the solar panels every few weeks with a soft cloth and warm, soapy water to remove dust, pollen, or bird droppings – all of which will reduce charging efficiency. During the autumn and winter months, regularly brush away fallen leaves or snow."
"Check occasionally for moisture, especially after heavy rain," adds Alex. "Ensure fixtures remain securely anchored and that batteries are in good condition – many are replaceable after 1–2 years of use. If your lights have on/off switches or lighting modes, switch them off during long spells of poor weather to preserve battery life."
"By looking after the panels, batteries, and casings, you can extend the life of your lights and enjoy reliable illumination through every season," says Claire, who has more tips for looking after them through the year:
- Keep panels clean: A quick wipe every month with a soft damp cloth will restore efficiency.
- Check batteries regularly: Rechargeable batteries gradually lose capacity over time. Most will last one to two years before needing replacement. If you notice your lights dimming earlier in the evening, even after a sunny day, it’s often a sign the battery is wearing out.
- Protect in extreme weather: Most outdoor solar lights are designed to withstand rain, but heavy snow or prolonged damp can affect their longevity. In winter, consider moving decorative solar lights - such as lanterns or fairy lights - to a sheltered spot, or store them indoors when not in use.
- Inspect for damage: Regularly check casings, seals, and fixings. Cracked plastic housings can let in moisture, leading to corrosion. If you spot condensation inside the light, it’s best to dry it thoroughly and reseal before further use.
"When all these pieces come together, the lights perform much better than you might expect," says Loren. "That little bit of attention each day pays off with a garden that glows naturally at night."
