Portable power station with a solar panel: what the UK sun really gives

In one line: in winter each 100 W of panel gives roughly 0.06–0.14 kWh a day; in summer about 0.35–0.43. A December day in Glasgow gives about half of London's, and London itself gets little more than a third of the 0.67 kWh the same panel averages in a Madrid December (PVGIS, from our Spanish guide). Summer is much more even across the country.

Every station's solar input has three limits worth reading on its UK page before you buy a panel:

• Watts. From 100 W on the Anker SOLIX C300X to 2,600 W on the EcoFlow DELTA Pro 3, per their UK pages. A bigger panel than the input doesn't charge faster; some margin helps, because panels rarely deliver their rated watts.
• Volts. The panel's open-circuit voltage (on its label) must sit inside the input range: 11–55 V on the EcoFlow RIVER 3 Plus, 12–60 V on the BLUETTI Elite 200 V2, two inputs of 30–150 V and 11–60 V on the DELTA Pro 3.
• Connector and number of panels. Jackery's UK page says the Explorer 500 v2 takes up to 200 W of solar: up to two 100 W panels. Makers' own bundles (station and panel together) save the guesswork.

Measured in ideal sun, they compare stations rather than predict your day. From the UK pages:

• EcoFlow RIVER 3 Plus: 0–100 % in as fast as 1.5 hours with 220 W.
• EcoFlow DELTA 3 Plus: full in 70 minutes with 1,000 W of solar.
• Jackery Explorer 500 v2: 2.8 hours with 200 W.
• Jackery Explorer 2000 v2: 5.5 hours with 400 W.
• BLUETTI Elite 100 V2: full in 70 minutes with 1,000 W.
• EcoFlow DELTA Pro 3: to 80 % in 1.5 hours on solar (2,600 W maximum input).

Set against the table: a 200 W panel in London averages 0.25 kWh on a December day. That is most of a 288 Wh station's charge on an average day; a 2,000 Wh station would take about eight such days.

What matters is the daily balance: what you use against what the panel puts back. With the reference figures of our power-cut calculator (and about 240 Wh a day the station uses itself at 10 W):

• Essentials, no fridge (router all day, three LED bulbs, two phone charges): about 685 Wh a day. In July a 200 W panel replaces it in London; in December you'd need about 550 W in London and 1,100 W in Glasgow.
• With the fridge-freezer: about 1,501 Wh a day. Around 400 W of panel in a London July; in December, about 1,250 W, which is a roof, not a folding panel.
• What it won't do: heaters, kettles or an immersion heater. One hour of a 1 kW heater uses more than a 200 W panel gives in a whole UK summer day.

• Camping and summer cuts: a compact station (around 300 Wh) with a 100–220 W panel. Enough for phones, lights and a router, refilled most summer days.
• Home backup with some solar: a 1,000 Wh class station with 400 W or more of panel. Through much of the summer it can keep up with a fridge-freezer; in winter, treat solar as a top-up.
• Long winter cuts: capacity first (2,000 Wh and up), solar second. Also see how long a freezer stays frozen without power.