Solar power continues to shine brightly in the renewable energy sector. In 2018, solar power overtook biomass as the third-most prevalent renewable energy resource in the U.S. and it grows year-over-year. The U.S. Energy Information Administration expects the nation to add 10 GW of solar capacity by the end of 2020, a 32% increase compared to 2018. It is a trend that compounds on itself: as the industry grows, system and installation costs decrease, prompting even more capacity.
In turn, the solar industry is filled with opportunities and new ideas. Some of the most notable of which are in solar energy storage, as the industry innovates new technologies to keep pace with the demand of electric-heavy applications, like electric vehicles (EVs).
Solar storage meets EVs
The solar industry and EVs are soon destined for a major intersection. Research from Bloomberg New Energy Finance expects almost 550 million EVs in the global auto fleet by 2040, with the sea change away from conventional fuels occurring in the 2020s.
EVs need more frequent recharging, meaning EV owners will be plugging their vehicles in at home, work and many other locations — all places that are increasingly harvesting clean energy via solar technologies.
The mainstream engineering challenge is clear: accommodating EV charging demands in both residential and commercial solar energy storage. Current energy storage technologies must advance to supply the necessary voltage and amperage to charge vehicles, without compromising supply for buildings.
Researchers and engineers continue to push the capabilities of legacy technologies such as lithium-ion and lead-acid. But in all likelihood, future solar energy storage requires new, transformative technology and ideas.
Among those are saltwater battery technologies. These function similarly to lead-acid batteries, with ions exchanged between the anode and cathode, but in a saltwater electrolyte rather than sulfuric acid. These batteries have key advantages over lead-acid types, including safer materials that are non-toxic, non-polluting or non-flammable. Additionally, saltwater battery types have a much deeper depth of discharge and no memory effect.
Another novel concept is the use of EVs as distributed storage, called vehicle-to-grid. Vehicles spend the vast majority of their time parked, and idle EVs could provide stored energy back to a macrogrid or microgrid during high demand, or as emergency backup power for a residence.
Coupling renewable generation and storage with burgeoning kinetic-storage technologies has the potential to erase reliance on traditional fuels to meet periods of peak electrical demand. Australian researchers recently identified 530,000 sites worldwide that are ripe for pumped hydro, with the water pumps powered by solar. There is also ongoing research and development into “power towers” — structures that hoist heavy weights to high heights, powered by cheap, clean energy, and then release those weights to drive turbines and supplement power supply.
The future of energy storage
With so many new, competing technologies, ideas and opportunities, how does the solar-plus-storage technology advance across industry and around the world?
The future of solar, storage and EVs will be made possible by engineers meeting the public and private pressures for increased renewable and sustainable technologies.
Fundamental solar industry communication, networking and knowledge sharing happens at events such as the Solar Power International (SPI) and Energy Storage International (ESI) conferences, part of North America Smart Energy Week. Among the many events and programs offered, the SPI Technical Symposium focuses exclusively on the scientific challenges and approaches that will plot the solar roadmap.
This year’s SPI and ESI conferences are September 23-26, at the Salt Palace Convention Center in Salt Lake City. To be a part of developing the solar future, join the largest gathering of solar power, energy storage, smart energy and fuel cell experts, this autumn in Salt Lake City.