While renewable energy from the wind, sun and ocean currents is expanding quickly, storing that energy is still not yet sustainable. But that isn’t stopping people from trying. John Dyer reports.
Cornell University scientists recently created a microbe that uses solar or wind electricity to separate carbon dioxide molecules from the air that can be used in biofuels. The researchers published their work in the Journal of Biological Engineering.
“We think biology plays a significant role in creating a sustainable energy infrastructure,” said study co-author Buz Barstow, a Cornell biologist, in a press release. “Some roles will be supporting roles and some will be major roles, and we’re trying to find all of those places where biology can work.”
New storage methods in US, Australia
Barstow and his colleagues billed their discovery as a new kind of battery that resembles photosynthesis, which worldwide stores about six times as much energy as human civilization uses but still only captures about 1 per cent of the available solar energy. They noted that microbes could also remove carbon dioxide from the air and convert it into bioplastics, then later turn those bioplastics back into carbon that could generate electricity.
“We are suggesting a new approach where we stitch together biological and non-biological electrochemical engineering to create a new method to store energy,” said the study’s lead author, Farshid Salimijazi, a graduate student in Barstow’s lab.
Australians are investing big in so-called “water batteries”, or hydroelectric dams filled with water pumped using electricity when solar and wind power is ample. During cloudy or calm weather, the utility can then use the stored water to produce more electricity filling the gap resulting from the drop-off in renewable generation.
Australian officials recently appropriated $3.5 billion to expand the 1970s-era Snowy Hydro plant, a project of nine power stations, 16 dams and 145 kilometers of tunnels and pipes.
“We are betting the whole company on it,” said Paul Broad, chief executive of state-owned Snowy Hydro, in an interview with the Financial Times. “You can’t have renewables without reliable storage and the best form of storage is water.”
Coal generates 60 per cent of Australia’s electricity, while renewables like solar and wind generate around 20 per cent. Resistance to new coal-fired plants means the country’s power grid will be vulnerable in the coming decades as old plants are closed. Using hydropower as a battery could solve that problem, said experts.
“Australia is one of the first countries heading towards a mainly solar and wind based renewable energy system, so in a sense we are the international pathfinder to move towards a solar and wind future,” Australian National University Andrew Blakers told the British business newspaper. “Snowy Hydro is important because if we don’t put in more energy storage then the electricity system will run into serious trouble by the mid-2020s.”
Germany boasts 220 megawatts of battery storage
Meanwhile, in Germany, where the energy market is in tumult in the wake of Chancellor Angela Merkel’s decision to shut down the country’s nuclear power plants by 2022, traditional battery technology has made leaps and bounds.
Energy Storage News recently reported that Germany-based wind developer Enertrag, Switzerland-based energy storage company Leclanché, and Enel Green Power Germany recently unveiled a 22 megawatt storage system to stabilize the power grid around Cremzow in the German state of Brandenburg.
The $24.58 million system brings the total battery storage in Germany to more than 220 megawatts. Backers of the project said it demonstrates how batteries can be key to power grids without subsidies that are often associated with sustainable energy.
“The Cremzow project demonstrates how storage is increasingly becoming an integral part of renewable energy systems due to its enabling role in making them more reliable, flexible and stable,” Antonio Cammisecra, head of Enel Green Power.
The US Congress recently enacted a series of laws to boost battery research, too, the National Resource Defense Council wrote in a blog post. Those moves come as energy storage in the US is expected to almost double to 712 MW this year compared to 2018.
As experts solve the storage dilemma, wrote PV Magazine, renewable energy is more likely to fulfill the promise its long held for a green future.