Solar will get too cheap to connect to the power grid
Solar power costs are falling so quickly that, in many places, generating extra electricity is becoming cheaper than expanding or even connecting to the existing grid. Commenters debate how to use this surplus energy—ranging from long-distance HVDC transmission and batteries (including EVs) to desalination, hydrogen production, and other industrial processes—while weighing environmental side effects like brine disposal and the economics of capital‑intensive infrastructure. The conversation also contrasts cheap utility‑scale solar with still‑costly rooftop systems, questions subsidies and net metering, and highlights that grid constraints and storage, not panel prices, are emerging as the main bottlenecks.
Long-Distance Transmission & Grids
- One path for excess solar is exporting power via long-distance high-voltage transmission, as with China’s ultra-high-voltage lines and proposed Australia–Singapore cables.
- HVDC is argued to be sufficient (≈3.5% loss per 1,000 km, less than AC); superconductors seen as unnecessary and currently impractical (brittle, expensive).
- Continental grids could smooth solar across time zones (e.g., US east–west), but large grid expansions are seen as slow, expensive, politically fraught, and security-sensitive.
Desalination and Water from Excess Solar
- Many see solar-powered desalination as a prime “dump load”: deserts near coasts could gain water and new arable/usable land.
- Counterpoints: brine discharge can damage near-shore ecosystems; evidence of concentrated high-salinity plumes and long outflow pipes is cited.
- Others argue global impact is tiny versus natural evaporation, with effects mostly local and mitigable via dilution, mixing with treated sewage, or further processing.
- Capital cost, not energy, dominates desal economics; plants must run near-continuously. Using only midday surplus demands much cheaper plant construction.
Economics of Solar, Storage, and Incentives
- Debate over whether “too cheap” solar leads to underinvestment: some say negative or low midday prices will self-correct and curb new builds; others say once cheap enough, people buy for direct usefulness, not ROI.
- Excess solar can be monetized via arbitrage and flexible loads (batteries, fertilizer production, CO₂ capture, overcooling buildings, water).
- Battery round-trip efficiency is quoted around 80+%; there is confusion and dispute over how capacity factor and efficiency interact at grid scale.
Rooftop vs Utility-Scale Solar
- Utility-scale solar is broadly seen as much cheaper per MWh than rooftop.
- Rooftop is criticized as heavily subsidized via net metering, shifting costs to non-solar customers.
- Others counter that rooftop only needs to beat retail (not wholesale) prices and can already be rational, especially in high-tariff regions; soft costs and policy design (connection fees, export tariffs) are key.
Batteries, EVs, and Off-Grid Trends
- Home batteries are getting cheaper; some expect them to become widely affordable within 5–10 years.
- EVs with large batteries and vehicle-to-home/grid are viewed as emerging storage assets, especially as used EV prices fall.
- In places with unreliable grids (e.g., South Africa), solar + batteries are already widely used to reduce or eliminate grid dependence.
Environmental & Scale Concerns; Skepticism
- Some worry cheap solar will boost total energy use with unclear long-term effects, though others note solar’s lower climate impact vs fossil fuels despite lower albedo.
- There is skepticism about long-range projections that promise “effectively free” energy, likened to past “too cheap to meter” claims, and about the reliability of some official solar deployment statistics.