Unless one lives in a utility district with very high electricity prices and one that shows no sign of competing with end-user storage (part of Australia, for example) it's unlikely end-user storage will be a large factor. Utilities can compete with cheaper wind and hydro as well as use their ability to purchase storage at better prices.
Of course utilities can buy cheaper wind hydro and storage than end users no disagreement there. However further down the renewables road, those costs are only a tiny part of utility costs. If a significant bit of the supply is wind which is highly likely given current costs then there will be excess supply causing wholesale market price of electric to becomes tiny marginal costs. Capital costs are effectively paid for (possibly overpaid for if subsidy level is higher than needed) by guaranteed prices of the subsidy system is going to be a much larger share of utility cost base.
(In short, Utility is allowed to and needs to charge for difference between renewables guaranteed selling prices and the tiny market prices, and this becomes large majority of utility's cost in future.)
In addition to subsidy for renewables generation there are also capacity payments eg
More than 49GW of capacity was secured for delivery in 2018-19 at a price of £19.40 per KW.
http://www.bbc.co.uk/news/business-30545091Seems another large payment the utilities have to pay and pass on to us but at least the utilities can buy the energy cheap - largely at marginal costs which are tiny. £19.40 per KW seems like a lot to me though I wouldn't want to start a business in a country where electric might not be available when it was needed so I suppose it is necessary and even at bargain at £11 a year per average household.
Anyway those capacity payments to keep some ff plants available will presumably dwindle as we increase renewables capacity and increase storage capacity?
If renewable subsidy costs dominate what utilities are allowed and need to charge (or at least we build up to such a situation over roughly the next 10 to 20 years) and then suppose storage becomes cheap enough to allow off grid renewables and storage to beat paying such costs. Surely the utility is then in trouble and a trickle of customers leaving could ratchett up the problem making it inevitable the trickle turns to a flood of people going off grid. Those subsidy system guaranteed prices might begin to look rather less guaranteed before we reach that point.
I don't suppose this matters much. For a while the renewables get built and are likely to continue to be used to generate power. After a while however, do those renewable price guarantees starting to look rather less guaranteed cause a slowing in the rate of installation of renewables? I would think probably not provided renewables are cheap enough to compete. So I don't suppose it matters much. Still utility failures seem possible given the way subsidy systems are heaping large liabilities on them (they also get large rights to charge customers supposedly worth as much but if customers considers this too expensive then the asset may not be worth as much as the liability).
Whether such utility failures are bound to happen or just a possibility seems to depend quite a lot on how much of the costs of renewables installed in future are fixed compared to their marginal costs, and the potential for small scale storage to become cheaper than those past fixed costs. That depends quite a bit on general inflation vs deflation with volume, experience and innovation cutting cost of storage. So while I wouldn't say it is bound to happen, current cost structures of current cheapest renewables do seem to make it look quite a possibility. Or maybe you view things differently?
