Solar energy is now the cheapest source of power, study

Scope of the claim (“cheapest”)

• Several commenters note solar has had the lowest raw generation cost for years; this paper’s novelty is mainly that in the UK, solar-plus-battery is now modeled as cheaper than gas/coal.
• Others point out the paper focuses on levelized cost of electricity (LCOE), which includes construction but not full-system integration (e.g. seasonal backup, grid upgrades).
• Some argue that saying “cheapest” without specifying firmness/availability is misleading; solar+4h storage is not directly comparable to 24/7 gas or nuclear.

Firm power, storage, and seasonality

• Strong debate over whether cheap PV + batteries can actually provide reliable 24/7/365 power in high-latitude places like the UK, where seasonal mismatch is large.
• Paper’s own hydrogen/seasonal-storage numbers are criticized as still “an order of magnitude” too expensive.
• Many note that no source runs 100% and grids already rely on portfolios (gas, hydro, interties) and planning; “baseload” is called a misleading concept by some.
• Others insist that the cost of backup gas plants and grid firming should be attributed, at least in part, to solar.

Storage technologies and trajectories

• Lithium-ion battery prices reportedly down ~89% since 2010; utility-scale storage auctions in China cited around ~$50/kWh for full systems.
• Sodium-ion is highlighted as a coming low-cost chemistry; some skepticism remains due to lifetime and replacement cycles.
• Multiple alternatives discussed: pumped hydro (effective but site-limited and sometimes environmentally disruptive), compressed air, lifted weights, hydrogen/methane, and new high-temperature thermal storage in “dirt” claimed to be extremely cheap per kWh for long-duration/seasonal use.

Transmission, interconnection, and “hypergrids”

• Long-distance HVDC is seen as key to smoothing intermittency (single-digit % losses per 1000 km mentioned), with examples of existing and proposed interconnectors (Nordics–EU, Spain–Morocco, Africa–Europe).
• Others caution that AC grids today have significant constraints, congestion, and sag limits; actual prices often diverge sharply between regions despite interconnection.

Land use and environmental impacts

• One thread insists land cost is “the most important factor” and is ignored for solar; numerous replies counter that studies and real projects do include land, and it’s usually a small share of total cost.
• Rooftops, parking lots, canals, agrivoltaics, and golf courses are cited as ways to avoid “new” land use and to co-locate generation with load.
• A side-discussion claims panels contain “all sorts of heavy metals”; others rebut that mainstream utility PV is doped silicon with tiny amounts of relatively benign elements, plus some concern about lead in older designs. Recycling and decommissioning costs are claimed to be manageable but not fully detailed.

Utility-scale vs rooftop solar and equity

• Utility solar is generally described as much cheaper per MWh than residential rooftop, especially in the US, where rooftop costs are inflated by tariffs, permitting, and sales overhead.
• Several argue rooftop subsidies and net metering at retail rates effectively shift grid and T&D costs onto non-solar (often poorer) customers, calling it a “reverse Robin Hood” if not reformed.
• Others respond that rooftop cuts distribution needs, uses already-developed land, and is financed mainly by homeowners via tax credits; they favor continuing support, especially for new builds.
• There’s disagreement over whether public money should preferentially subsidize utility-scale projects and storage rather than rooftop.

Market dynamics, cannibalization, and utility incentives

• “Solar cannibalization” is discussed: rapid build-out drives midday wholesale prices toward zero or negative, squeezing solar project revenues.
• Some see this as a healthy signal that drives storage deployment and shifts demand (e.g. smart water heaters, EV charging); others worry it undermines investment and slows decarbonization if not managed.
• Regulated utilities in many regions earn returns on capital, not on lowering power prices, so cheaper generation does not automatically mean cheaper bills; flat connection charges and policy choices are key.
• Anti-solar local politics (e.g. rural resistance to solar farms) and utility-friendly regulation (net metering rollbacks, interconnection fees) are seen as major non-technical barriers.

Household economics and partial grid defection

• Anecdotes show rooftop solar payback ranging from “no-brainer” (~8 years) to marginal, depending heavily on local tariffs, sun, and financing.
• Home batteries at current prices are borderline in many markets but expected to become common as costs fall (e.g. 100 kWh per house, EVs with V2H).
• Several note that as more households self-supply 80–90% of their energy, remaining grid kWh could get much more expensive because fixed grid costs are spread over fewer units, potentially driving further storage/grid-defection feedback loops.

Role of other technologies (wind, nuclear, gas)

• Wind is widely seen as complementary (night/winter in many regions); solar+wind+storage touted as a strong combo.
• Nuclear is defended as 24/7, compact, and clean but criticized as too expensive, slow to build, inflexible for load-following, and a potential single point of failure; regulation vs uncontrollable construction costs are debated.
• Gas remains important as flexible backup today; some want its full externalities (health, climate) internalized in cost comparisons.

Overall sentiment

• Broad agreement that PV module and battery costs have plunged faster than expected and will keep reshaping grids.
• Optimists emphasize that “solar + storage is further along than you think” and point to real-world price reductions in high-renewables regions.
• Skeptics focus on firming, seasonal storage, grid upgrade costs, and equity of current rooftop subsidy schemes, arguing that “cheapest” needs much tighter qualification.