HA Sustainable Infrastructure Capital (HASI) is a specialty finance company that provides capital to developers, owners, and operators of clean energy infrastructure across the U.S. HASI does not develop or operate projects itself — it steps in as a capital provider at a late, de-risked stage when assets are near or at commercial operation. HASI's portfolio spans three markets: behind-the-meter assets (~52%), which includes distributed solar, storage, and energy efficiency upgrades; grid-connected assets (~34%), covering utility-scale solar, wind, and battery storage; and fuels, transport, and nature (~14%), which includes renewable natural gas and fleet decarbonization. HASI earns returns through interest income on debt investments, equity income from project-level equity stakes, gain on sale from securitizations, and recurring fees from managing off-balance-sheet assets. The core earnings driver is the spread between its portfolio yield and cost of debt. A key part of the model is capital efficiency: HASI co-invests alongside KKR in a ~$3B vehicle, earning both investment returns and management fees on KKR's capital, allowing HASI to deploy more capital per dollar of equity. HASI targets a payout ratio below 50% by 2028, retaining more earnings to reinvest rather than issuing equity. HASI manages over $16B in assets and has built programmatic relationships with many of the largest U.S. clean energy developers over 30 years, originating most deals through repeat clients rather than one-off transactions.