by Julian Spector
August 12, 2016

Summer lovin', it happens so fast. One month, Elon Musk proposes his company Tesla get together with his cousin’s company SolarCity. Barely a month later, the boards of Tesla and SolarCity signed off on the proposal, which means they need to ask their shareholders’ permission for the union to become complete.

Greentech Media recently explored the potential fruits of their sunny romance, in particular the benefits that come from providing both solar power and battery storage within the same company. Tesla’s not the only one putting these two together, though. Here’s a roundup of recent pairings of renewable energy and storage around the world. They’re certainly rare, but a lot of firsts are being broken in geographically diverse markets. These path-breaking unions of clean generation with storage will beget new generations of hybrid projects, so stay tuned.

Australia: Solar and storage and wind, oh my!

The hybrid Kennedy Energy Park just got development approval to get to work near the north Queensland town of Hughenden, Australia. When completed, the $120 million project will have nine to 12 wind turbines generating 30 megawatts of capacity, 200,000 single-axis tracking solar modules yielding 20 megawatts of capacity, and about four shipping crates’ worth of lithium-ion batteries rated at 2 megawatts/4 megawatt-hours.

Windlab Limited, one of the companies developing the project, chose the site because of its complementary wind and solar resources. Having both, they argue, will mitigate the intermittency that often attends variable renewable generation.

“Hughenden is almost unique in that it enjoys [some] of the best wind resources in Australia, co-located with [some] of the best solar resources,” Windlab Project Director Geoff Burns said in a statement. “Furthermore, they are highly consistent and complementary; when the sun sets the wind ramps up and continues through to the morning after the sun rises. It is this unique characteristic that will allow Kennedy to provide a near baseload generation profile.”

Construction will commence in early 2017 and should wrap up a year later. Once complete, Kennedy is expected to produce more than what’s needed to power the nearby community; surplus will be sold into the grid. And if it all goes well, Windlab wants to deploy more than 1,000 megawatts in the vicinity of Hughenden. The combination of mutually supportive resources, with storage bridging the gap, make this a project to watch.

Hawaii: Soaking up the island sun -- and then storing it.

Hawaii has the highest electricity prices in the U.S. and a goal of going 100 percent renewable by 2045. Both of those factors raise the value of storage on the islands, and the market has responded. The first sale of a solar-plus-storage power-purchase agreement in Hawaii occurred in early August, included in a set of PPAs sold by EnSync Energy Systems to a subsidiary of American Electric Power.

EnSync develops hybrid solar-plus-storage systems to power commercial and industrial customers -- in this case, universities and condo buildings on Oahu and the Island of Hawaii. The PPA model gives the customer long-term access to clean energy at lower-than-utility rates, for little or no money down.

In this case, the client is AEP Onsite Partners, which AEP describes as its “customer-centric energy asset business.” Early on, there’s a benefit to having well-monied corporations make the first buys. As the model for solar-plus-storage PPAs gains more traction on the islands, we might see customers reaching out to purchase them directly. Given the geographical isolation of the state and the need to import almost all of its conventional energy supply, it’s hard to imagine electricity prices dropping any time soon, which means the economic case for cheaper PPA contracts should remain strong.

India: Developers wanted

The state-owned Solar Energy Corporation of India announced August 9 that it is seeking developers for 100 megawatts of grid-connected solar PV combined with a “large scale battery energy storage system” at the Kadapa Solar Park in Andhra Pradesh state. That solar park is slated to have a capacity of 1,000 megawatts, according to SECI.

The Indian government first started asking for storage to be included with new solar tenders back in February, PV Tech reported. In light of the nation’s grid stability issues, storage became the cost of admission for any developer seeking government solar contracts. India faces the unenviable challenge of cleaning up its electricity generation per the Paris climate agreement while extending power to 18,452 villages that currently lack electricity. The National Solar Mission has driven much of that effort, with a goal of setting up 20 gigawatts of grid-connected and 2 gigawatts of off-grid solar power by 2022.

Research: Natural gas, can storage have this dance?

Intermittent renewables work best when paired with flexible power sources that can ramp up and down with the variations in sun and wind. A new working paper from the National Bureau of Economic Research attempted to quantify that relationship in 26 countries over more than two decades, and found that natural gas has played the role of key partner for the expansion of renewables.

In the sample, which ran from 1990 to 2013, a 1 percent increase in flexible fossil-fuel generation correlated to a 0.88 percent increase in renewable generation over the long term, other things held equal. This doesn’t mean the expanded natural-gas capacity drove the expansion in clean energy, but it suggests an enabling role.

“If you have an electric car, you don’t need a diesel car in your garage sitting there,” lead author Elena Verdolini of the Fondazione Eni Enrico Mattei in Milan and the Euro-Mediterranean Center on Climate Change told The Washington Post. “But in the case of renewables, it’s different, because if you have renewable electricity and that fails, then you need the fast-acting gas sitting in your garage, so to speak.”

You need it, that is, until you have large amounts of rapid response grid-scale storage in your proverbial garage. If storage can grow to fill that fast-acting function, it could become the dancing partner that lets the wind turbines twirl. Unlike natural-gas infrastructure, batteries aren’t known to leak methane into the atmosphere. They face a strong incumbent in natural gas, though, which is currently quite cheap and more familiar to the utilities of the world. As storage prices fall and political pressure builds to decarbonize the grid, batteries could cut in on the role that natural gas has played.