The answer is to raise third-party capital, leaving liquid funds free for day-to-day operations. A piece published by the London School of Economics echoes this, noting the need to "Leverage private sector investment through a clear and predictable policy framework based on a national growth, innovation and skills strategy[iv]."
Report: Boosting growth and productivity in the United Kingdom through investments in the sustainable economy (January 2024) by Dimitri Zenghelis, Esin Serin, Nicholas Stern, Anna Valero, John Van Reenen, and Bob Ward