Solar Just Got “Offensively Cheap.” Predicting It Didn’t.

The world just got "offensively cheap" solar

That's not my phrase — it's Dave Jones, co-founder of the energy think-tank Ember, describing today's panel prices in a Financial Times feature this week. He's not exaggerating by much. Panels that cost $5–6 a watt in the year 2000 go for around 12 cents a watt now. Global installed solar capacity passed 1.2 terawatts at the end of 2025 — roughly three times the world's entire nuclear fleet.

None of that happened because of one big project. It happened because millions of ordinary roofs — cement factories in Pakistan, supermarkets in South Africa, houses across the Philippines — finally got panels cheap enough to bother with.

The UK got a mention too

Since the end of August, plug-in solar panels have been legal to buy from a UK supermarket or DIY store and plug straight into a socket at home — the same shift this blog has been covering since it happened. Seeing it turn up in the same feature as Pakistan's cement industry and Philippine rooftops is a decent sign of how far this has already gone.

The actual problem isn't the panels

Here's the part that should matter to you, not just utility executives. Most of that FT piece is really about a different problem: nobody can reliably predict what millions of scattered, privately-owned solar panels are about to do. UK Power Networks recently ran a £389,000 study just to estimate how much solar capacity is even connected to its own network. In Australia, a grid engineer described a single cloud front over Perth wiping out something close to a nuclear plant's worth of generation within minutes. South Africa's Eskom is now waiving registration fees on new installs just to get some visibility into what's already out there.

Read enough of that and the message is hard to miss: even the people running entire national grids don't have a reliable forecast for solar output anymore. They're commissioning studies and building machine-learning models just to guess at scale.

So why would you go without one for your own roof?

That's the whole reason Sun Hours exists — not at grid scale, just at yours. Tell it your location and the best day your system's ever had, and you get a 7-day forecast built around your actual panels, not a national average. Free, no account needed.

If national grid operators need dedicated forecasting tools just to guess in aggregate, going without one for the one roof you actually own is leaving something on the table.