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Guide — portable power
Solar generators for home backup: sizing & selection guide
Home backup is the job that sells solar generators — and the job most often mis-sized. Buyers anchor on the biggest number on the box (watts) and discover at the first long outage that capacity was the binding constraint, or buy capacity for a week and learn their fridge's compressor will not start on the inverter they chose. This guide sizes both numbers from a load list, then maps the result onto the documented station range.
Watts run the moment; watt-hours run the night
Rated power (W) is the ceiling on what can run at once. Capacity (Wh) is the fuel tank. A 2,000 W station with 1,024 Wh (the S1 in this catalogue) can drive heavy loads briefly; a 1,500 W / 1,488 Wh station (the S015) drives lighter loads far longer. Neither is "better" — the load list decides. Motors and compressors add a third consideration: surge. Their start-up draw can be several times the running watts, so the peak of the load list, not its average, must fit under the rated power with headroom.
A worked home load list
| Load | Running watts | Hours/day | Watt-hours |
|---|---|---|---|
| LED lighting (5 points) | 50 | 5 | 250 |
| Router + phones/laptops | 60 | 8 | 480 |
| TV + decoder | 120 | 4 | 480 |
| Fridge (compressor cycles ≈50%) | 120 | ≈12 of 24 | ≈1,400 |
| Fan | 60 | 6 | 360 |
| Total | ≈410 W simultaneous (excl. fridge surge) | ≈2,970 Wh/day |
Apply the planning rule — treat about 85% of nameplate capacity as usable — and the daily need of roughly 2,970 Wh becomes a nameplate target near 3,500 Wh. In the documented range, only the 5,040 Wh flagships (S5-N, S5-E, W5) cover that target outright; the 3,072 Wh pair (S3, W3) yields about 2,610 usable Wh, short of this list unless the solar array returns a meaningful share each day. Drop the fridge (≈1,400 Wh of the day) and the same home needs only ≈1,850 Wh of nameplate capacity — comfortably inside the 2,232 Wh S024. This is why the load list comes first: one appliance moves the answer by two model classes.
The recharge half of the system
A generator that cannot recharge is a battery with a deadline. With the catalogue's Solar Sun 220 panel (220 W, 20.5 V), daily harvest in four peak-sun hours is roughly 880 Wh before losses — enough to sustain the lighting-and-devices layer indefinitely, but only a fraction of a fridge-inclusive budget. Whole-home cycling needs a multi-panel array; the honest way to present a home programme is therefore by layers: solar-sustained essentials, grid- or array-recharged bulk.
Selection checklist
- Load list written down, with surge loads flagged — before looking at models.
- Simultaneous watts ≤ rated power with headroom; daily Wh ≤ 85% of capacity.
- Recharge plan sized with the same arithmetic as the discharge plan.
- Ports, socket standards, solar input window and battery data confirmed per model at quote stage — the catalogue publishes rated power and capacity for every model, and the system details are confirmed for the exact pairing.
The model table and pairing logic are on the solar generators page, the method is generalised in the buying guide, and the outage-lighting layer that pairs with any generator is covered in lights for power outages.
Single station or staged programme?
Households size once; programmes size in stages. A distributor building a home-backup category typically launches with the layer most households can justify — lighting, communications and entertainment on a mid-band station — and lets the fridge-inclusive tier follow as the premium offer, because the load-list conversation is easier after the first purchase has taught the customer their own consumption. The documented range supports the staging: the same platform logic runs from 512 Wh to 5,040 Wh, so a household can start at the S03 Pro or S012 and step up within the same range without reopening the brand decision. For worksite and small-commercial buyers the staging runs the other way — size for the full load list immediately, because a half-sized station on a site is not a partial solution but a failed one.
Reading a station specification like an engineer
Two numbers are published for every station in this catalogue — rated power and capacity — and they are the two that matter for the first pass. Everything after them is confirmation work: which sockets and how many, the solar input window against the intended panel, the battery data behind the capacity figure, and the protection behaviour under overload. Buyers should treat any station offered without the two headline numbers as unpriced risk, and any station whose seller cannot discuss the confirmation list as a retail gadget rather than a backup system. The catalogue's approach — publish the pair, confirm the system per order — is the honest middle: the sizing method in this guide runs entirely on the published pair, and the order closes on the confirmed details.
Where sizing exercises go wrong
Three errors account for nearly every mis-sized home system. The first is sizing to the nameplate of the largest appliance rather than its duty cycle — the fridge that 'draws 800 W' on its plate may average a tenth of that across a day, and sizing capacity to the plate buys a station two classes too large. The second is ignoring surge entirely and discovering it at the first compressor start. The third is the recharge afterthought: a station sized beautifully for discharge and paired with a panel that returns a fifth of the daily budget, converting a backup system into a countdown timer. The load-list method prevents all three by construction — averages for capacity, peaks for power, and a recharge line in the same table as the loads.
After the purchase: living with the system
A sized system still has to be lived with, and two habits protect the investment. The first is the monthly drill: run the home on the station for an hour, in daylight, on a calm day — the drill verifies the station, the transfer routine and the household's memory of both, and it surfaces problems while they are still errands rather than emergencies. The second is storage discipline: a station held for backup should live at a partial, healthy charge rather than forgotten at empty or pinned at full, and its drill doubles as the check. Neither habit costs money. Both are the difference between a backup system and a backup hope, and resellers who print them in the carton own the category's best reviews.
Sizing, in the end, is a form of honesty: about what the home actually runs, what an outage actually lasts, and what a panel can actually return on a grey week. The load list forces all three into the open while the decision is still cheap. Buyers who do the arithmetic once tend to become the category's advocates — their systems work on the night that matters, quietly, which is the only review a backup product ever really gets.