by Jason Deign, Solarplaza

Large-scale deployment of electrical energy storage tied to PV plants is just around the corner, Solarplaza has learned.
“When we talk about solar plus storage we talk about the near-term future,” said Philip Hiersemenzel, spokesman for Younicos, one of Europe’s top battery system developers and installers. “I don’t think it’s surprising we haven’t seen it yet, because prices haven’t been where they need to be. But in the very foreseeable future the game will very likely change.”
Luigi Lanuzza, head of Energy Storage Innovative Business Opportunities at Enel Green Power, said: “Energy storage will be key to further increasing the deployment of PV. It enables both increased programmability and grid support in countries where the fast growth of PV has had an impact on the existing grids and the deployment of solar power as main generation resource in rapidly growing economies.”
Recent months have seen increasing interest in combining energy storage with solar plants as battery prices have plummeted. A Deutsche Bank report issued in March 2015 called batteries the “killer app” of solar penetration.

The report predicted mass adoption before 2020, based on a 20% to 30% annual reduction on an assumed a battery cost of USD$1,500 per kWh.

But that was before Tesla launched the Powerwall, which at $3,000 for a 7 kWh unit works out at around $430 per kWh. Industrial systems are already even lower, with Eos Energy Storage, for instance, claiming a cost of $160 per kWh for its Aurora system. The fall in battery prices has already sparked a stampede towards storage alongside residential PV systems in a couple of key solar markets.
In Germany, for example, the storage player Sonnenbatterie has started commercialising a residential solar-plus-battery offering that allows homeowners to buy community-based renewable energy without going through a utility.  And in Australia, the potential for consumer grid defection has led some utilities to take the initiative and start offering their own solar-plus-storage packages. To date, however, deployment of storage alongside utility-scale solar has been limited.
Enel Green Power developed one of the first such plants in September 2015, when it attached a 1 MW, 2 MWh sodium-metal halide battery system from General Electric to a 10 MW PV project in Catania, Italy.
It has also developed an off-grid hybrid power plant in the Chilean village of Ollagüe, which previously relied on electricity from a diesel generator. “Enel Green Power decided to find a solution to limit the use of diesel, which in such remote areas is typically a costly resource due to transportation costs,” said Lanuzza. “The solution was the installation of a standalone system comprised of a 200 kW PV system, a 30 kW vertical-axis wind turbine and a diesel generator as backup, all integrated with a 250 kW, 750 kWh energy storage system.”
Further projects like this look likely as solar firms wake up to the potential of low-cost storage. A number of solar players have already signalled their intention to move in this direction by taking equity stakes in storage companies. The most recent example is Younicos, which saw First Solar join Grupo ECOS and another, undisclosed, strategic investor in a $50 million funding round completed this month.
"Utility-scale storage is an exciting new frontier for grid flexibility and modernisation that can help to facilitate high penetration of renewables," said Raffi Garabedian, First Solar's chief technology officer, in a press release. "As the promise of storage continues to evolve, we are eager to understand how it will broaden our own power plant offerings."
First Solar’s investment in Younicos follows OCI taking a stake in Eos and SunEdison buying Solar Grid Storage earlier this year.
Other PV players with links to storage companies include SunPower Corporation, whose parent Total Energy Ventures is an investor in Sunverge Energy, and SolarCity, whose chairman, Elon Musk, is chief executive at Tesla. The benefit of these tie-ups, noted Hiersemenzel, is that: “You can come out with dispatchable solar. Increasingly, utility-scale solar and storage is going to become a game changer.”

To find out all about the opportunities for combining utility-scale PV with batteries, come along to Monetising Solar + Storage EU on the 3rd of March in Milan, Italy. Register now for your very early bird discount, ending on 31 December 2015.