I don't fully understand the technical and economic aspect of the issue. Since a long time many in the forum had been saying that nuclear power or major hydroelectric power projects are absolutely necessary for the base load. Solar and other renewable sources are for like secondary roles. Can we say now that solar power projects can work as base load providers?
There have been many opinions expressed on this forum for a long time regarding baseload power and the indispensability of nuclear and large hydro - (and everything else
. Here is my take, informed by recent cost data and grid requirements..
No, solar + batteries alone cannot yet replace nuclear or large hydro as true baseload for India.
But yes, they can now provide “firm” power for many hours, enough to displace a large fraction of coal and gas—and that’s a big shift.
What has changed is degree, not category.
-- Keep reading if interested in technical aspects any my thoughts -- ignore if not --
Traditionally "Baseload meant: Power available 24×7, Season-independent, Weather-independent, With very high reliability (weeks to months)
Nuclear and large hydro meet this definition. Solar and wind do not, by physics alone.
Now we use a more precise term- :"
Firm or dispatchable capacity, measured in hours of guaranteed supply.
That distinction matters.
Falling BESS costs actually enable (At ~₹2.1–2.8/kWh for storage energy, Solar (~₹2.5/kWh) + BESS (~₹2–3/kWh) - Firmed solar cost: ~₹4.5–5.5/kWh (for ~6–8 hours)
This allows: , evening peak coverage, daily load smoothing, coal peaking replacement - e.g., 8–10 hrs/day
But it does not solve: Multi-day cloud cover, monsoon season variability etc..
For those, storage duration must be days to weeks, not hours.
Why nuclear and large hydro are still structurally necessary
- Batteries scale in energy, not time
- cycles/day economics = short-duration storage
(covering 2–3 cloudy days would require 10–20× more batteries)
That is still prohibitively expensive and material-intensive
No amount of lithium batteries can replace seasonal energy yet.
- The old view: “Renewables are secondary, unreliable add-ons.”
The new reality: "Solar + storage can now replace a large part of coal’s role, but not its entire function.
India needs all four.
- Instant/peaking.- Batteries
- Daily firming - Solar + BESS
- Seasonal baseload - Nuclear, large hydro
- Long-duration storage (future) - Pumped hydro, hydrogen, SMRs
Falling BESS costs mean solar can now deliver firm power for many hours, replacing coal for daily balancing and peak demand—but true baseload still requires nuclear and large hydro to cover seasonal and multi-day reliability. The energy transition is now an engineering optimization problem, not an ideological one.
Even in a so-called “100% renewable” Indian power system, grid physics and economics imply - in my opinion - a need for roughly 50–80 GW of nuclear power (and possibly ~100 GW for comfort) to provide firm, seasonal, weather-independent electricity..
