The US Solar Trajectory: From 200 GW to 737.8 GW

On December 31, 2025, GlobalData released its latest analysis projecting the United States will install between 41 GW and 52 GW of new solar capacity annually through 2035, putting the country on course to reach 737.8 GW of cumulative solar photovoltaic capacity by the end of that period. According to the report published in PV Magazine, this would represent a near-quadrupling of installed solar capacity from current levels, driven by IRA incentives, corporate procurement targets, and state-level clean energy mandates.

The projection covers all market segments — utility-scale, commercial & industrial (C&I), and residential — and the analysts emphasize that continued policy support and grid interconnection reform will be critical to sustaining this growth rate.

Translating Solar GW into BESS GWh

For energy storage developers and project financiers, the critical question is: how much battery storage accompanies 737.8 GW of solar?

The answer depends on the solar-to-storage ratio, which varies by market and application. Typical ratios observed across US markets include:

  • Utility-scale solar farms targeting peak shifting: 25-35% (MW BESS / MW solar) at 2-4 hours duration
  • Solar-plus-storage for capacity market qualification: 50-100% at 4 hours
  • C&I hybrid systems with demand charge management: 20-40% at 2-3 hours
  • Behind-the-meter solar + storage for backup and TOU arbitrage: 50-100% at 2-4 hours

Applying a conservative 25% ratio at 4-hour duration to the 737.8 GW target implies roughly 184 GW / 737 GWh of installed battery storage by 2035. At a more aggressive 40% ratio (increasingly common in CAISO and ERCOT), that figure rises to 295 GW / 1,180 GWh.

Key insight: Each GW of solar installed with 25% battery co-location at 4-hour duration requires approximately 40 MWh of battery capacity per 10 MW of solar inverters. At current pack-level battery costs of $80-100/kWh, this represents $3.2-4.0 million in battery CAPEX per 10 MW solar installation.

The LP Optimization Advantage in a 737 GW Market

At these deployment volumes, right-sizing storage capacity becomes a multi-million-dollar decision. Installing too little storage leaves merchant revenue on the table; installing too much destroys project IRR with underutilized assets.

Energy Optima's linear programming (LP) capacity sizing engine solves this optimization problem against 8,760-hour load and price profiles. The algorithm simultaneously:

  • Optimizes battery MW and MWh capacity against hourly merchant prices or PPA structures
  • Accounts for PV clipping recovery when DC-coupled
  • Models battery degradation (calendar + cycle) over the full 25-year project life
  • Iterates on capital cost trade-offs to find the IRR-maximizing configuration

In high-solar-penetration markets like CAISO — where the duck curve regularly produces multi-hour negative pricing — the optimizer naturally sizes storage to absorb midday overgeneration and discharge during the evening ramp. This is the central finding of the GlobalData report: that solar deployment at 737 GW scale fundamentally changes grid economics, and storage sizing must adapt.

Grid Integration at 737 GW

The report also highlights a critical bottleneck: interconnection queue reform and transmission expansion. The US currently has over 1,000 GW of proposed solar, wind, and storage projects waiting in interconnection queues. At 40-50 GW/year of solar alone, queue processing and transmission buildout must accelerate significantly.

For project developers, this means longer development timelines, higher pre-COD carrying costs, and greater sensitivity to commissioning delays in financial models. Energy Optima's financial projection module handles these dynamics through:

  • Customizable construction period phasing with CAPEX draw schedules
  • Delayed COD start date with partial-year revenue scaling
  • Interest during construction (IDC) calculations tied to debt draw timing
  • Sensitivity analysis on tariff and PPA start dates

What Developers Should Do Now

The 737.8 GW target is achievable, but only if project economics pencil at scale. Key actions for developers:

  • Run LP-optimized sizing rather than rule-of-thumb ratios — the optimal solar:BESS ratio varies by ISO, tariff, and project-specific load profile
  • Model degradation carefully — at 4+ cycles per day, cycle aging dominates over calendar aging, and LFP chemistry selection matters
  • Stress-test financial projections against multiple merchant price scenarios using 8,760-hour data
  • Plan for augmentation — if battery SOH triggers augmentation at year 12, the financial model must account for a second CAPEX event