Batteries are not cost-effective. The electrical grid must always be balanced. As such, utilities try to find methods of stabilizing the grid without using batteries. Technically this works. However, the economic impact of the guaranteeing a market for subsidized solar and wind power, is another set of hidden subsidies. Ironically, some of these hidden subsidies are going to fossil fuel companies.
To make a complex story short, the grid must always be balanced. If the power source cannot be controlled (like solar), or if the power source is unreliable (like wind), then it is necessary to make up the difference in some other way. The cheapest methods are to remotely turn on and off loads, and to remotely turn on and off generating stations.
The problem with starting and stopping loads is that there are not many loads that can be turned on and off remotely, and still accomplish something useful. Ontario has been experimenting with ways to turn off home air-conditioners during the day. Also, big consumers often get a preferred electricity rate, with the understanding that their electricity is "interruptible". However, there is only so much that this can be pushed. People want a cool house. The price of "interruptible" electricity is a few cents per kWh, which is often below cost.
This brings us to starting and stopping generating stations. A nuclear station takes days to start and stop. A coal station takes on the order of a day to start and stop. A natural gas turbine take about 3 to 6 hours to start. Natural gas (NG) turbines have the ability to run at a "hot-idle", but this is expensive. At "hot-idle" an NG station is still running, it is just not producing power. Hydro power plants (hydro dams) can be started quickly, however unexpected rapid changes in water levels have killed people downstream. As such, very few generating stations can turn on and off as quickly as wind-power changes.
Probably the best way to solve the problem is to have many small power plants, either small hydro-dams or small NG-turbines, and only turn on and off a fraction of those units at any one time. If the grid operator is required to purchase significant amounts of wind-power, then the grid-operator might have to go very far afield to find a sufficiently large enough pool of existing small generating stations that can be started and stopped quickly. In the case of Ontario, Canada, it needed to pay US power plants to not produce electricity to keep the grid balanced. Ontario has a large energy grid, however Ontario was not large enough to deal with wind-power's fluctuations without external help.
In the case of Ontario, which is purchasing solar at 90 cents/kWh and wind at 17 cents/kWh under certain existing contracts, then a "hidden" solar/wind subsidy is going to mines and smelters and fossil fuel producers to keep the grid balanced. This subsidy is cheaper than battery and capacitor banks. However, conservation is far cheaper than many of the above schemes.
Compared to solar/batteries, conservation is the way to go. LED light bulbs almost make sense at current electricity prices. At 90 cents/kWh, converting existing fixtures to LED light bulbs is cheap. Appliances can be moved from electricity to propane or natural gas. Stoves, hot water heaters, furnaces, and even the fridge and air-conditioner can be converted. This is cheaper than paying for battery storage. What little load is left, can then be powered off a roof-top solar / battery system. Conservation is by far the cheapest option.