Solar will supply almost all growth in U.S. electricity generation through 2025

Original Article ↗ Hacker News Discussion ↗

Solar power’s rapidly falling costs mean it is expected to supply nearly all growth in U.S. electricity generation through 2025, but commenters stress that replacing traditional “baseload” plants with variable renewables is a long, complex transition. They highlight the need for complementary resources like wind, grid-scale and residential storage, flexible demand (EV charging, water heating, HVAC), and better market pricing to handle daily and seasonal variability. There is also skepticism toward official forecasts that have historically underpredicted solar growth, along with concern over China’s dominance of the solar supply chain and the economic tradeoffs with nuclear and fossil generation.

Grid variability, “baseload,” and demand shifting

  • Several posters argue “baseload” is an outdated planning concept; better to think in variability timescales (seconds → seasonal) and match resources/storage to each.
  • Others caution that the transition away from traditional baseload is slow and shrinking reserve margins are already causing reliability concerns in parts of the US.
  • There is broad agreement that very cheap solar shifts the optimization: adjust demand to periods of abundance rather than treat demand as fixed.

Time-of-use pricing, home batteries, and economics

  • Where time-of-use (ToU) or hourly pricing exists, people often shift dishwashers, laundry, hot water, and EV charging to cheap hours; elsewhere, flat rates give no incentive.
  • Some utilities tried residential smart meters + ToU and found limited behavioral change relative to program cost.
  • Home batteries for arbitrage often have long payback periods based on user napkin math; economics depend heavily on local rate spreads and incentives.
  • Debate whether grid‑scale storage will generally beat home‑scale economics, versus retail prices and fixed grid costs making rooftop + battery attractive.

Solar growth forecasts and modeling skepticism

  • Multiple comments note EIA/IEA have historically underpredicted solar deployment “comically” for decades, so current projections are treated by some as a floor, not a best guess.
  • Others argue these agencies are generally credible and may have adjusted methods; whether the bias is fixed is contested.

Solar vs wind, seasons, and storage

  • Many stress that solar and wind are complementary: wind often better in winter and at night; their anti‑correlation reduces storage needs.
  • High‑latitude posters point out severe winter mismatch: very low solar output when heating demand peaks, especially in overcast, very cold regions; they see solar as marginal there and emphasize wind, geothermal, nuclear, imports, or hydrogen.
  • Others counter that most of the world’s population is not in such extreme latitudes, and in many places summer AC dominates demand and aligns well with solar.

Household & EV flexibility and control challenges

  • Major flexible loads cited: HVAC, water heating, EV charging, and home batteries; whole buildings can act as “thermal batteries.”
  • People report real behavior changes once they have rooftop solar (running loads in daytime) and EVs (charging when cheap).
  • Technical frustrations remain: “too smart” thermostats, lack of robust standards for safe failover, and dependence on cloud APIs for critical functions.

Costs, storage vs nuclear, and grid economics

  • Several cost numbers are shared (utility PV module $/W, battery $/kWh, hydro wholesale prices), with the claim that new solar is already cheaper than existing hydro and far cheaper than new nuclear on a levelized basis.
  • A sharp dispute arises over storage: one commenter asserts storage is ~100× more expensive than nuclear; others provide rough project-level calculations suggesting solar + batteries can already rival or beat new nuclear for firm power.
  • Exact cost comparisons are labeled complex and uncertain due to financing, lifetime, technology learning curves, and scalability limits.

Land use, geopolitics, and policy

  • Some worry about industrializing farmland/wild land with solar; others note the US already devotes vast acreage to corn ethanol and that rooftops/parking lots and marginal land offer large potential.
  • Concerns are raised about China’s dominance of the solar supply chain; countered by noting domestic-manufacturing policy efforts and the fact that once panels are installed, fuel imports are unnecessary.

Climate timelines and transition pace

  • One thread laments late action and the challenge of replacing legacy infrastructure by ~2050; another argues information and politics limit how fast transitions can realistically occur.
  • Others are more optimistic, citing exponential trends in solar and batteries and predicting most of the transition could happen by the mid‑2030s if current trajectories continue.