Danish company Vestas Wind Systems is one of the biggest makers of wind turbines in the world, recently surpassing GE’s market share in the US. But as the wind industry becomes more competitive, Vestas appears to be looking for ways to solidify its lead by offering something different. Now, the company says it’s looking into building wind turbines with battery storage onsite.

According to a Bloomberg report, Vestas is working on 10 projects that will add storage to wind installations, and Tesla is collaborating on at least one of those projects. Vestas says the cooperation between the two companies isn’t a formal partnership, and Tesla hasn’t commented on the nature of its work with Vestas. But the efforts to combine wind turbines with battery storage offer a glimpse into how the wind industry might change in the future.

The news about Vestas is just one datapoint in a summer of news about wind and storage projects. In August, offshore wind developer Deepwater Wind announced that it would pair a 144MW offshore wind farm planned for the coast of New Bedford, Massachusetts, with a 40MWh battery storage system from Tesla. Construction on that project is set to end sometime in 2022. According to GreenTechMedia, Spanish wind power company Acciona recently connected two Samsung lithium-ion batteries to a 3-megawatt turbine in Spain, Dong installed a battery on the UK coastline in June to store some offshore wind energy, and Statoil will include a 1MWh lithium-ion battery in its designs for a floating offshore wind farm that will be completed in late 2018.

The idea of onsite batteries isn’t new—GE’s renewables arm introduced short-term batteries integrated with wind turbines in 2013, and Vestas itself experimented with tying storage to wind turbines in 2012. But turbine manufacturers seem to be more willing to branch out of their wheelhouse lately and contact battery specialists instead of pushing to build batteries on their own.

The appeal of batteries seems self-explanatory at first glance: the cost of wind-generated electricity is falling fast, leading energy companies to install wind capacity at record rates in the US as well as in China and the EU. Although government subsidies for renewable energy have played a part in the wind boom, developers are just starting to submit proposals for wind projects that don’t need subsidies to be profitable. But in order for wind to become even more competitive, it needs to make up for one glaring drawback: wind turbines can’t generate electricity on demand.

That’s where batteries come into play. Installations from AES Energy Storage and Tesla have already hit grids in California, but those systems aren’t tied to a specific renewable resource—they store electricity from coal plants and solar panels alike. But proposing a wind farm with onsite storage might make a grid operator consider that proposal a more reliable source of energy.

Still, the limiting factor is the price of storage. A post from the American Wind Energy Association (AWEA) explains why storage hasn’t been a big part of the equation historically.

The reality is that, while several small-scale energy storage demonstration projects have been conducted, the US has been able to add more than 60,000MW of wind power to the grid without adding any commercial-scale energy storage. Similarly, European countries like Denmark, Spain, Ireland, and Germany have successfully integrated very large amounts of wind energy without having to install new energy storage resources. In the US, numerous peer-reviewed studies have concluded that wind energy can provide 20 percent or more of our electricity without any need for energy storage.

That’s because, the AWEA says, flexibility in the form of fast-ramping gas plants or hydroelectricity already exists on most large grids, and “it is almost always much cheaper to use this flexibility than to build new sources of flexibility like energy storage facilities.”

But the economics of storage may be changing, or at least companies forecast enough of a change in the next five years to justify getting their feet wet on special projects like these. According to Lazard’s 2016 Levelized Cost of Storage report, forecasts show capital costs of chemical battery construction getting much cheaper out to 2020, while more traditional methods of storage, like compressed air and pumped storage, essentially stay flat.

And in a statement to Bloomberg on Friday, Vestas said as much, commenting that the impetus for its 10 projects was to find “sustainable energy solutions that can lower the cost of energy.”