For example Haber process used for ammonia production, requires a temperature of at least 400 °C to be efficient. This process is accounting for 1–2% of global energy consumption, 3% of global carbon emissions, and 3% to 5% of natural gas consumption.

https://en.wikipedia.org/wiki/Haber_process

Electric resistance heating generated from PV will supply energy only for few hours each day.

Heating storage (also cold storage) in industrial applications is possible and is done, but in many cases you are limited by allowed temperature range of chemical/physical processes. For example you are limited on the lower side by melting temperature of material and on higher side by high temperature corrosion.

Cold storage for electric demand response https://www.enersponse.com/cold-storage

In cement industries models have been developed to flatten the grid's hourly demand curve by minimizing the industrial customer's hourly peak loads and maximizing the shifting of demand to off-peak periods.

https://www.sciencedirect.com/science/article/pii/S030626192...

> For example Haber process used for ammonia production, requires a temperature of at least 400 °C to be efficient.

I should note that this process doesn't require external heat input (except at startup). The reaction is exothermic and the excess heat is used to make steam that either is used to make power or to provide steam to other processes. It does require pressurization, but that's an input of work, not heat.

It would be nice if the process could be run at lower temperature, but we just don't have the catalysts for that.

> Electric resistance heating generated from PV will supply energy only for few hours each day.

Electric resistance heat is very storable and can provide heat 24/7, possibly even 24/7/365 at high latitude with PV.