Your questions, honestly answered

South-facing is ideal, but south-west and south-east work well. You need a pitch between 20–50 degrees and no significant shading from chimneys, trees or neighbouring buildings. East-west split arrays are viable. The best way to find out is a free survey — I can connect you with my installer who will assess your roof at no cost.

For a system like mine (8 panels + 10.3kWh battery + installation), expect to pay £8,000–£9,000 with a reputable installer. Panels-only typically run £4,000–£6,000. My go-to recommendations are GoodWe ESA for value, Tesla Powerwall 3 for premium, and EcoFlow Ocean 2 for the best warranty (15 years).

Based on my real saving rate of around £79/month on an £8,500 system — roughly 9 years. Add Axle VPP income (£144/yr) and it shortens. After payback you have 20+ years of heavily subsidised electricity. Panels carry a 30-year performance warranty.

Panels alone still save money — any solar you generate instead of buying is a saving. But without a battery you only benefit when the sun is shining. A battery stores surplus and discharges in the evenings. On Octopus Agile, a battery lets you charge cheaply overnight. The combination is much more powerful.

Agile is a half-hourly tariff from Octopus Energy that tracks the wholesale market. Prices vary from negative (they pay you) to 35p+ at peak times. With a battery and Predbat, you charge when cheap (often 5–8p overnight) and discharge during expensive evening peaks. My average effective rate is around 12p vs 28p on a standard tariff. Not with Octopus yet? Join via my referral link share.octopus.energy/flax-shell-473 and we both get £50 credit — then switch to Agile free from your account.

Predbat is a free Home Assistant add-on that automates your battery charging and discharging based on forecast solar generation and Octopus Agile prices. It reads the next 48 hours of prices, checks the weather forecast, and plans every charge slot automatically. Completely hands-off once configured.

A VPP aggregates thousands of home batteries to help balance the National Grid. When the grid is stressed, all connected batteries export at the same time — and you get paid. I use Axle Energy's VPP with my Fox ESS battery. They pay £1 per kWh during events (typically 4 per month) — roughly £144/year, completely passive.

Yes — use Axle's Events-Only Mode. Axle only touches your battery during grid events (~4 times/month). The rest of the time Predbat runs as normal. After an event, Predbat refills the battery on cheap overnight Agile rates. Setup takes 15 minutes — sign up with my referral link at vpp.axle.energy/landing?ref=R-NGTUFBIZ and we both get a welcome bonus.

Yes — better than most people expect. Cardiff gets around 1,600 sunshine hours per year. My south-facing setup in Whitchurch generated an estimated 4,100+ kWh in 17 months. Pair it with a battery and smart tariff and the numbers stack up well.

I used AIKO 455W N-Type ABC panels — full black, 23.3% efficiency, which is class-leading for residential. N-Type ABC cells degrade slower than standard PERC (≤0.35%/yr from year 2). They carry a 30-year performance warranty and in 30 years still produce 88.85% of rated output.

Fox ESS AIO H3 with 10.3kWh. 17 months in, zero hardware issues. But I'd be honest: I wouldn't recommend Fox to most customers. The app is poor and customer care is non-existent in the UK. For new installs I recommend GoodWe ESA (best all-rounder), Tesla Powerwall 3 (best support), or EcoFlow Ocean 2 (best warranty).

Generally yes. Studies suggest solar adds 1–4% to property value. A battery system and smart tariff is increasingly seen as a premium feature. There's no stamp duty or CGT on solar installations.

SEG requires energy suppliers to pay you for electricity you export to the grid. I'm on roughly 15p/kWh. With a battery you export less (you store it instead), but any surplus still gets paid. Over 17 months I've earned around £174 in export payments.

Fill in the form on my get a quote page. I'll look at your roof, usage, and budget and put together a proper system design — panel count, inverter sizing, battery spec, tariff recommendation. All free, no obligation.