changing process heat to renewables will be costly
Just off the top of my head I can immediately think of multiple examples.
Without stating anything that would reveal the company names, since some of this isn't intended to be in the public domain, basic details:
Large scale manufacturing of a basic consumer product.
Existing heat source = coal.
Alternatives exampled = electricity, natural gas.
Outcome = staying with coal.
Hot water supply to a large hotel in a capital city CBD.
Existing heat source = mains natural gas.
Alternatives examined = electricity, fuel oil, LPG.
Outcome = new boiler burning #2 fuel oil installed.
Note: #2 oil is comparable to diesel. Not to be confused with #6 fuel oil that's thick black stuff.
Large scale manufacturing of a finished consumer product.
Existing heat source = coal. Historically also used light fuel oil (diesel).
Alternatives examined = electricity, natural gas, oil
Outcome = new natural gas boiler installed. Key reason was reduction of labour requirements since labour to work the coal boiler, which included having to transport coal around the site in small loads due to constrained site layout and lack of rail access, was a more significant cost than the fuel itself. New boiler avoids that problem.
Large scale manufacturing of a finished consumer product.
Existing heat source = Heavy fuel oil (#6 oil)
Alternatives examined = electricity, natural gas
Outcome = simple conversion of existing boiler to gas with no other changes.
Metallic mineral processing.
Existing heat source = coal, gas. Historically also used heavy fuel oil #6
Alternatives exampled = hydrogen, full use of gas, retain existing arrangement
Outcome = going fully to natural gas (no coal). Due to the nature of the process only the highest grade of coal, anthracite, is suitable and that's become extremely expensive to obtain - an all-gas approach is cheaper.
Bulk agricultural commodity processing.
Existing heat source = ordinary black coal for heat, grid electricity for power
Alternatives exampled = many
Outcome = new gas-fired co-generation plant installed producing both electricity and process heat.
Basic manufacturing of a bulk commodity
Existing heat source = coal. Has also historically used heavy fuel oil.
Alternatives examined = many (coal, oil, gas, hydrogen, wood, wastes, electricity etc)
Outcome = mix of coal, wood and flammable waste from an unrelated nearby industry.
So many changes but mostly not to non-fossil sources.
I've been deliberately vague to avoid revealing company names but they're all substantial operations in Australia and many are either well known companies or where most would be familiar with the product. All are located in Australia.