Solar String Lights for Your Garden: A UK Guide

For solar string lights in the UK, buy a set with a panel on a lead. Then place the panel in the sun, tilted towards the south, and hang the lights where you want the glow. Also choose warm white, a replaceable rechargeable battery and IP65 for anything left outside.

Winter is the hard part, because the sun is low and the days are short. So this guide shows the sums. We choose from published specifications and have not tested these lights, as our page on how we choose explains.

What should you look for in solar string lights?

Our solar garden lights guide picks fairy and string lights for ambience. They suit patios, pergolas and trees. However, it warns that thin wire can be fragile, and it says to look for a decent lead, warm-white LEDs and a panel you can angle.

In practice, five checks cover most sets, although each maker words them differently.

• Panel on a lead: you can put the panel in the sun while the lights hang in the shade.
• Replaceable battery: you can swap a tired cell and keep the set.
• Weather rating: look for IP65 on exposed runs and connectors.
• Warm white: ENERGY STAR places warm white at around 3000K and below.
• A real panel size: look for the panel’s watts on the label, because that decides how much energy you collect.

How much light can a small panel give in a UK winter?

Not much, and the sums show why. First, hours of light equal the panel’s watts divided by the string’s watts, multiplied by the watt-hours that each rated watt of panel collects per day. PVGIS gives that last figure for London.

Here is an example with round numbers. These are not product specs, so check your own label. Take a 1W panel that feeds a 1W string. At 35 degrees facing south, that gives about 4.1 hours of light in June and 1.2 hours in December. However, real sets lose a little energy in the battery and circuit, so treat these as the best case.

Where should you put the panel?

Tilt it steeply towards the south. In December in London, for example, a panel tilted at 60 degrees collects about 3.1 times the energy of a flat panel (1.42 ÷ 0.46). Meanwhile, a panel facing north on an upright wall collects under a tenth of a south-facing one tilted at 35 degrees (0.10 ÷ 1.17).

In June the difference is small, so a flat panel on a shed roof works well enough. In winter, however, a flat panel does badly because the sun stays low. Also keep the panel clear of fences, hedges and eaves, since PVGIS counts terrain shading only. Your own trees and buildings make real figures worse.

If your lights run along a fence, our guide to solar fence lights shows how the fence direction changes the sunlight. That matters because a fence panel may face north.

What battery do solar string lights use?

Check the manual, because makers differ. For example, one retailer’s English-language manual for a solar garden light says the rechargeable battery will eventually need replacing. It says to use only an NiMH rechargeable battery. It also says that removing the battery and charging it in a separate charger at regular intervals can lengthen its life.

The same manual lists a charge time of about 8 to 12 hours in direct sunlight and about 6 hours of light. That is a basic stake light, not a string. Still, it shows how makers state charge time against run time. Never fit a non-rechargeable cell unless the manual allows it.

Which IP rating do string lights need?

Cables and connectors take the weather in a string set, so the rating matters. For an exposed run, we suggest IP65 or better. Our guide to IP ratings for waterproof solar garden lights explains each digit and what the code leaves out.

Check where the lead meets the panel and the battery box, because water can find a way in at any joint. If a set dies early, our guide to fixing solar garden lights that are not working covers what to check.

When do string lights make sense, and when do they not?

String lights suit ambience, not security. They give a soft glow over a patio or pergola. However, for guaranteed all-night light, choose a mains option or a larger panel.

The same panel sums apply to phone chargers, because panel area decides the yield. Our comparison of a solar power bank and a folding solar panel covers panel size for phone charging. For a garden office, a portable power station suits better, and our power station buyer’s guide explains sizing.

Frequently asked questions

Do solar string lights work in winter?

Yes, but for far less time. In London, for example, PVGIS gives a tilted south-facing panel about 1.17Wh per rated watt per day in December, against 4.09 in June. So a bigger panel and a steeper tilt help most.

Can I use any rechargeable battery?

No, because chemistry and size matter. Match both to your manual. That manual allows only NiMH rechargeable batteries in its light.

Where can I read about other solar products?

Our hub on solar garden lighting lists every lighting guide, while other hubs cover wider needs. For phones and torches, see portable solar chargers. To find where your home’s power goes, read about home energy monitors.

Sources

• PVGIS photovoltaic estimates, European Commission Joint Research Centre. PVGIS-SARAH3, 2005 to 2023, London (51.507 N, 0.128 W), 14% system losses. Daily energy per rated watt for June and December on a flat surface, 35 degree and 60 degree south-facing surfaces and a vertical north-facing surface.
• Solar Garden Light 3-pack instruction manual (art. no. 36-5182), Clas Ohlson. Used for NiMH battery guidance, replacement and the stated charge and run times.
• Light Bulb Purchasing Guide, US EPA ENERGY STAR. Used for the Kelvin scale and warm white.
• IEC 60529: Degrees of protection provided by enclosures (IP Code), International Electrotechnical Commission. Used for the scope of the IP code.
• IEC 60529 IP testing summary, ATS. Used for the IP65 definition (IP6X dust-tight, IPX5 water jets).
• Best solar garden lights UK 2026, this site. Source of the string light checklist and the IP65 guidance.