AI power.

Startup Exowatt is making a product to store heat from the sun and turn the heat into electricity. Sam Altman and VC firm Andreessen Horowitz are among the investors, The Wall Street Journal reports.

Altman is CEO of leading AI developer OpenAI and Exowatt is targeting its modular design to serve the power-hungry data centers crucial for AI. Access to electricity is a priority for AI execs.