By Dan Sanchez
Solar energy is growing at a rapid pace, and with quick growth comes new manufacturers, products and innovations flooding the market. For some installers and homeowners, it may be difficult to determine what new and emerging technologies will be best for long-term reliability and cost. When it comes to the growing segment of energy storage, many companies are scrambling to buy and install the latest technology without understanding the long-term effects some of these new technologies will have on the environment.
One of the hottest technologies for energy storage, lithium-ion batteries, is an excellent method for compact storage. But some of lithium-ion’s environmental, moral and cost concerns have many industries rethinking the viability of a different technology: the 150-year-old flooded lead-acid (FLA) battery.
An environmentally friendly storage solution
Flooded lead-acid battery manufacturers have received a bad rap over the years, due to the fact that the lead and corrosive battery acids used to make FLA batteries could cause environmental problems if they are not properly managed. Most industries and consumers don’t know, however, that FLA batteries are recycled at a rate of 97 to 99%, with the recycled materials all going back into new batteries or other recycled applications creating a closed-loop system. As a result of this safe and secure system, FLA batteries have become the No. 1 recycled product in the world.
According to the Battery Council International (BCI), a trade association formed to promote the interests of the international battery industry, lead recyclers undergo some of the most restrictive emissions regulations. The process of recycling lead has produced new standards with reduced emissions that are far below EPA regulations. The BCI reports that lead contamination in the air has dropped by 99% since 1980. In addition, a recent study released by the BCI suggests that the U.S. lead battery industry enables more than 95,000 jobs for American workers and contributed more than $28 billion in total economic output to the national economy in 2016.
While the solar industry does offer FLA batteries as storage solutions, their cost effectiveness is often overlooked by newer, smaller and lighter technology. Fred Wehmeyer, VP of engineering for U.S. Battery Manufacturing, said that in most cases, flooded lead-acid batteries remain the most cost-effective method for powering electric vehicles and equipment in a variety of industries.
This also holds true to the amount of amp-hour capacity FLA batteries can provide in solar+storage applications. Although lithium battery packs may provide a longer cycle life, Wehmeyer suggested comparing actual amp-hour capacity and battery pack energy (kilowatt-hours). This comparison often shows that the FLA battery pack provides the most cost-effective solution at an overall purchase cost and operational cost per kilowatt-hour.
The need for better battery labeling
One of the problems with the solar industry utilizing both lithium-ion and flooded lead-acid batteries is the increasing amount of contamination within the recycling process. According to the BCI, lithium battery contamination into the lead-acid battery recycling process has been on an increase. When lithium-ion batteries are mistakenly or knowingly added to the recycling stream, an increased risk of fires and explosions can occur during transport, storage, battery breaking and smelting processes of used lead-based batteries.
The U.S. Society of Automotive Engineers (SAE) and the International Electrotechnical Commission (IEC) are proposing to develop standardized labels that are color-coded to allow for better identification between lead-acid and lithium-ion batteries.
“In the end, not only are lithium batteries not currently being recycled, but consumers would have to pay to dispose of spent lithium vehicle batteries,” said Wehmeyer.
In addition, the global race to control cobalt, an ore used to manufacture lithium-ion battery cells, is a cause of concern for many solar industry manufacturers and installers.
Most battery experts agree that lithium-ion definitely has its place and is safe for many uses, including solar+storage. For those wanting to remain environmentally conscious, however, it’s important to look at battery manufacturing and recycling to see what’s truly “green” about the latest solar energy storage systems available.