Home Power seems stuck in the old technology of the past, just like coal power plants, with articles on lead-acid batteries in almost every issue. Please at least balance your articles with some information on advanced lithium batteries, which are being used for many applications including utility power regulation and peak time-of-day storage.
“Understanding Batteries” in HP157 missed the mark in many ways. It did not mention the longest-lasting batteries that have been available for many years—nickel-iron—and didn’t mention advanced lithium batteries.
Jim & Elaine, the Solar Stacks • via email
I appreciate your criticism of lead-acid (LA) batteries. Lead pollution from mining, smelting, and recycling accounts for a pervasive risk to human health (see “Exported Battery Recycling” in HP145).
In countries with few enforceable environmental regulations, battery manufacturing and recycling has a high impact on human health and the environment. By comparison, according to the U.S. Environmental Protection Agency, 96% of LA batteries in the United States are recycled. The risk of pollution in modern recycling plants is low because of strict environmental, health, and safety standards, emission monitoring, stack scrubbers, dust control, and waste treatment.
The issues are less with the fundamental technology, and more with global economic and social inequalities. As long as cars have LA batteries, these issues will persist.
More than 1 billion people worldwide lack access to reliable electricity. Most will never see a power line in their community. As cellphones have allowed people in less-developed countries to enjoy the benefits of microenterprise businesses, small, decentralized PV systems using LA batteries provide lighting, communication, and medical services that would otherwise be unobtainable
Lithium batteries are now being used all over the world, but primarily for consumer devices such as cell phones. They are only finding utility applications in some developed countries, and have achieved wide acceptance in none. They are not yet ready for wide acceptance in energy-storage applications for homes.
HP153 included a feature article on lithium-ion (Li-ion) batteries for off-grid systems. The article fairly presents their pros and cons for RE storage—in short, Li-ions are a highly promising technology not yet ready for widespread use: “At present, the lack of battery management system integration in residential RE power conversion equipment is the biggest hurdle.”
Nickel-iron (NiFe) battery technology is more than 100 years old and indeed offers long life and more benign materials than LA. But before spending your money, look into their disadvantages—low charge and discharge efficiency, high self-discharge, and high cost. The only current source for NiFe batteries is China, and only MidNite Classic controllers have settings to accommodate their atypical charge-cycle performance. Common inverters lack settings to properly charge and maintain them.
Few NiFe suppliers serve North America, and these batteries can be up to four times the cost of comparable LA batteries. And, assuming 100% depth of discharge, an equivalent Li-ion pack is six to 10 times the price.
LA batteries have established themselves as the default choice for most applications because of a practical combination of predictable life, ease of maintenance and recycling, wide availability, and reasonable cost. Home Power focuses on today’s practical solutions, warranted, supported, and affordable to as many people as possible.
Allan Sindelar • Positive Energy; positiveenergysolar.com