Solar power in tiers, pocket panel to full off-grid rig, plus cooking and heat without mains power.
Solar — the core (prices keep falling)
Tier 1, pocket (£20-40): 10–28 W folding USB panel + 2× 20,000 mAh power banks. Keeps phones (your survival library), headlamps, radio alive forever.
Tier 2, household-lite (£365-875): 100–200 W rigid panel (£90-250 each) + MPPT charge controller (£70-270 — 20–30% more harvest than cheap PWM) + 12 V 100 Ah LiFePO4 battery (£150-280 now; 3–5,000 cycles, 10× lead-acid lifespan, safe indoors) + 300–500 W pure-sine inverter (£30-65). Runs: the Raspberry Pi survival server 24/7, lights, phone/radio charging, a 12 V fridge in summer.
Tier 2 alt: all-in-one power station (EcoFlow River/Bluetti ~£200-400 + panel) — zero wiring skill needed, grab-and-go.
Sizing rule: daily watt-hours needed ÷ (panel watts × 4 real sun-hours) — then double the panel because clouds. Pi (5 W×24 h=120 Wh) + lights + phones ≈ 300 Wh/day → one 200 W panel + 100 Ah battery covers it with margin.
12 V DC everything where possible (USB/12 V lights, fans, fridge) — inverters waste 10–15%.
Non-solar
Hand-crank/solar FM/DAB radio with USB out (£20-45) — human-powered electricity of last resort + weather/emergency broadcasts.
Thermoelectric camp stove (BioLite, £100-150): charges USB from burning twigs. Gimmicky but genuinely grid-independent.
Cooking without the grid
Rocket stove (£20-130, or FREE from ~24 bricks or a big tin can + 4 small cans): boils water on a handful of twigs — 80–90% less wood than open fire. This is the primary Phase-2/3 cooker; build one this month.
Butane/propane camp stove (£20-40 + canisters): clean indoor-safe-ish Phase-1 cooking. Cheap £15 single-burner butane stoves + a case of canisters = weeks of cooking.
Solar oven (£0 DIY from box + foil + glass, or £100-250 GoSun-type): free fuel, reaches 150–200 °C on clear days — bakes, slow-cooks, pasteurises water.
Haybox/wonder-oven (£0): bring pot to boil 5 min, bury it in a blanket-stuffed box; it finishes cooking rice/beans/stews on retained heat for hours. Halves ALL fuel use — massively underrated.
Dutch oven + cast iron pan (£35-90): cooks on any heat source forever.
Heat & light
Wood stove if you have a chimney; otherwise Calor butane cabinet heater (indoor-rated, with ventilation) (£70-140) — heat ONE room, everyone lives in it; blankets over doorways.
Free heat: south windows open by day/blanketed by night, clear bottle "solar wall" heaters, bodies in one room, sleeping bags rated below your winter temps (£40-80 each) beat any heater for survivability.
Light: LED headlamps (£10-40 EACH person — hands-free is non-negotiable), solar garden stakes (charge outside by day, light rooms at night — £1-2 each), candles + oil lamp with stored lamp oil, glow sticks for kids/marking.