Energy Mechanics · Electricity · Solar generation

The fastest-growing
U.S. electricity source

SOLAR · TWh/YR · GW
RELEASE · EIA EPM TABLES 1.1A & 1.17.B
VINTAGE · —
NEXT EPM · —
UTILITY + DISTRIBUTED
STATUS · LOADING
U.S. solar generation is — TWh/year — roughly triple what it was five years ago, and now larger than hydro. Two distinct categories: utility-scale (big-acre farms feeding the wholesale grid) is two-thirds of the total; distributed (mostly rooftop) is the rest. Solar's defining feature isn't peak capacity — it's capacity factor: the average panel only outputs — of its rated nameplate over a year, because the sun isn't always up and rarely directly overhead.
Utility-scale solar Distributed (rooftop) Unused capacity (intermittency) bar length ∝ TWh/year · capacity factor ≈ generation ÷ (capacity × 8,760 h)
TYPE · TWh/YEAR CAPACITY (GW) & CAPACITY FACTOR Utility-scale solar PPA-CONTRACTED FARMS · 1 MW+ — Capacity — GW CF — · best fixed-tilt + single-axis trackers Texas, California, Florida lead. New plants are increasingly co-located with battery storage. Distributed (rooftop + small) RESIDENTIAL + COMMERCIAL · BEHIND-THE-METER — Capacity — GW CF — · suboptimal pitch + shading California ~45% of distributed alone. Net-metering policy is the key driver. TOP GENERATING STATES · TWh/YEAR California — Duck curve birthplace · most distributed Texas — Fastest growing · ERCOT market signals work Florida — Mostly utility-scale · FPL aggressive build-out North Carolina — Duke Energy + early adopter PPA contracts Arizona + Nevada — Best U.S. solar resource · highest capacity factors TOP 5 STATES = — OF U.S. SOLAR · REMAINDER SPREAD ACROSS ~40 STATES
Total solar generation
—
tripled vs 5 yrs ago
—
Total nameplate capacity
—
GW · utility + distributed
Average capacity factor
—
vs ~93% nuclear · ~55% gas CC
Share of U.S. generation
—
of all electricity · all sources
SOURCE · U.S. Energy Information Administration, Electric Power Monthly (Table 1.1.A utility-scale + Table 1.17.B distributed) and Form EIA-860 for nameplate capacity. Capacity factor = generation ÷ (capacity × 8,760 hours/year), where 8,760 hours is the count of hours in a year. Solar's structural CF ceiling is roughly 30% even with perfect tracking — the sun doesn't reach the panel at all between dusk and dawn, and delivers reduced flux at shallow angles. Per-state numbers are EIA EPM Table 1.6.B; the "Arizona + Nevada" row combines two desert states with similar capacity factors. The duck curve — peak solar generation at noon crashing into peak demand at 6pm — is California's defining grid challenge and increasingly Texas's too.
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