Looking at the economics of all this, some very important relationships exist.
Residential has a rather costly load profile due to the evening peak that you mention. Consumption is highly concentrated and not only that, it's concentrated at a time of day that solar isn't much help with and wind often isn't either.
General business is somewhat better since, apart from restaurants etc, it mostly operates either entirely outside the peak (eg anything "9 to 5") or it runs during the peak but also runs during the off-peak (anything open long hours eg supermarkets, petrol stations).
What really helps though is off-peak loads and this is so for a number of reasons.
Take off-peak water heating for example. What's the effect of having it as an electrical load versus not having it (eg using gas water heating instead)? Well there's two things it does and one it doesn't, all of which are beneficial.
1. It raises minimum load on the system, thus enabling the addition of more generating plant that is continuously fully utilised. With the key benefit that means more low cost plant running throughout the day, it effectively transfers some of the intermediate and peak load to base load plant due to that raising of minimum load enabling its economic construction and operation.
2. More electricity sold, so fixed costs are spread over a greater volume = lower cost per unit sold.
3. Adds nothing at all to peak demand, it doesn't require any additional capacity at all. It's just making more use of existing capacity, and enabling a shift from peaking plant to lower cost means of generation.
Eg if we take a system with a peak load of 3500MW, average load of 1500MW and minimum of 900MW then with that arrangement high capital cost, low running cost plant can generate 60% of total supply, meaning the other 40% is necessarily coming from higher cost intermediate and peaking plant. But if we add electric off-peak water heating, and raise the minimum load by 300MW whilst increasing average load by 100MW, then now we can generate 75% of total production from low cost plant, leaving only 25% to come from intermediate and peaking plant. Meanwhile we're now spreading all fixed costs over a 6.66% greater volume so less cost per unit sold.
Industry is similar but not quite. Assuming we're talking about large scale heavy industry with an interruptible (in emergencies only) contract then what does it do?
Well it raises the minimum system load and thus enables more low cost plant to be installed. It does however also raise routine daily peak demand, so it does also mean some more operation of other generating plant too.
It doesn't however require more generation to be built due to the interruptible nature of it. On the rare occasions when it's 45 degrees outside, that's when the factory gets interrupted in order to maintain supply to residential etc. Due to that it also brings another change - the peaking plant is being used more often, it can now be built as intermediate plant instead of actual peaking plant, lowering the cost per unit of output.
Likewise with transmission, the additional investment required to supply major industry is disproportionately low relative to its energy consumption due to being a 24/365 but interruptible load. Its existence thus lowers the overall cost of supply to all consumers on a price per unit basis.
The underlying economics there is much the same as any business. If you need staff then the cheapest option per unit of labour is to employ full time permanent staff and keep them fully utilised. Anything else costs more - overtime, casual, contractors are all more expensive per unit, and needless to say anything that results in your staff sitting around doing nothing is a dead loss financially.
Now if you have a highly variable workload then employing permanent staff is problematic, due to that sitting around issue, so you might decide on a few permanent staff and meeting the peaks with some combination of paid overtime, casual workers and contractors.
Buti if you could find some other paid work to fill the gaps when you're not busy, then what that would enable you to do is employ more permanent staff and keep them fully utilised. And since it's only adding work during the slow periods, it's not adding work during the busy periods, those permanent staff replace the role you previously paid overtime, casuals or contractors to do. End result is you've lowered your labour cost per unit and you've also grown the business in total. Excellent - you've just discovered the business equivalent of off-peak hot water.
Another business concept you might find useful is having some long term contracts for supplying whatever you sell to someone but with the bonus that you get some flexibility as to when you supply it, you can avoid having to do anything for them when you're flat out serving others (like the pre-Christmas rush) as long as this is only under those limited circumstances as per the contract. So you get consistent revenue, but you can shift those staff and equipment to serve others when demand's unusually high, thus avoiding the need to spend money on additional staff or equipment. Excellent - you've just found the business equivalent of a major industrial power contract.
This isn't radical in any way. There's lots of examples of businesses that have a core business that's quite variable then look for ways to put staff and equipment to use during the slow periods. For one obvious example major CBD hotels worked out long ago that the business conference market mostly operates outside the peak tourist season, meaning it's a very nice way to get people into the hotel during the rest of the year when it would otherwise be partly empty. Lots of examples like that in all sorts of businesses where the demand for the core business is variable, so the owners seek to put equipment and staff to use during the quieter days of the week or season of the year.
None of this is rocket science and it's not ideology. It's just fundamental economics that if the demand for the product can be smoothed then that increases capacity utilisation and reduces cost per unit of production. Nothing radical there, lots of businesses have that dynamic so it shouldn't be controversial. Trouble is, you'd be amazed at how many are unable to grasp it.....