🕶️ Sam Altman’s hot-rock revolution

A new solar-thermal startup is ditching panels and instead heating bricks inside insulated boxes. The stored heat drives a Stirling engine to generate electricity—aiming for one-cent power for AI data centers. Think massive fields of “hot-rock batteries” that can hold heat for up to five days and run continuously.

The company just added $50M to its earlier $70M Series A and claims a 10 million-unit backlog (about 90 GWh of storage). To get costs low enough, it needs to scale manufacturing to 1 million units a year, betting that modular, factory-built hardware will finally give solar-thermal tech the cost curve it never had.

If it works, data centers get cheap, firm, on-site power without waiting for new transmission lines. If it doesn’t, solar PV + lithium-ion will keep dominating.

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LinkedIn is launching AI-powered people search for U.S. Premium users. Instead of clicking through filters, you can now just type something like “find investors with FDA experience.” The search bar even starts with “I’m looking for…” to encourage natural language queries.

Why it matters: this move could reshape how professionals find people for hiring, partnerships, or fundraising. By making advanced search a paid feature, LinkedIn tightens control over talent discovery and business development—putting new pressure on recruiting tools and sales intelligence platforms. It also means users can uncover connections faster through their existing social networks.

The fine print: results aren’t perfect yet—shortcuts like “YC” might not match “Y Combinator.” Some user badges may appear incorrectly, and more search volume could lead to spammy outreach. The next steps include expanding the rollout, improving how LinkedIn understands names and entities, and clarifying whether AI agents or bots can use the feature.