Bells and whistles are great, but sometimes the basic model is all that’s needed for energy storage.
When solar customers and power-concerned homeowners aren’t interested in or able to take advantage of load-shifting and demand arbitrage opportunities managed by energy storage systems, there are simpler products available today just for emergency backup. No longer do contractors have to suggest a gas generator or a bank of lead-acid batteries; many companies offer portable and powerful lithium-ion systems that can support customers looking for peace of mind during a blackout.
This category of energy storage is often referred to as “solar generators” and has been mostly marketed to adventurers on the go — those camping, traveling, tailgating and working off-grid. These battery systems have lower capacities than stationary residential systems like the Tesla Powerwall and LG RESU, but they are expandable for specific power needs. They can be charged by portable solar panels or through the grid. Depending on the source of charging electricity, solar generators can be very clean. And best of all, they can be used to back up appliances and loads in the home at a fraction of the price of a stationary system.
Here are a few portable energy storage systems and solar generators that are increasingly being looked at for emergency backup in the home.
Goal Zero Yeti
Likely the most popular portable lithium battery system comes from Goal Zero. The company’s Yeti 6000X Portable Power Station has an initial capacity of 6.071 kWh and uses NMC batteries with a 500-cycle lifespan at 80% depth of discharge (DoD). Yeti 6000X has 2 kW of continuous power and 3.5 kW of surge power. The station has seven output ports, but it can also be connected to a home’s electrical panel to support four essential circuits.
While Yeti 6000X is the company’s most powerful starting unit, Goal Zero offers many setups to accommodate various power needs. Customers just need one Goal Zero power station as a base, and then storage capacity can be expanded through cheaper lead-acid battery add-ons. Because of their size and weight, the lead-acid batteries are stationary, while the lithium power station is portable. The Yeti Tank Expansion Batteries come in a pair for 2.4 kWh of additional power capacity.
Not an especially common setup, Goal Zero can combine lithium and lead-acid battery technologies through its Yeti Link Expansion Module — essentially, a sophisticated battery management system.
“Our expansion tank is a deep cycle, lead-acid battery. This allows you to use the electronics in the Yeti [lithium-based system] but expand the battery,” said Bill Harmon, GM at Goal Zero. “You can add as many [lead-acid batteries] as you want. The customer can just plug them in. Suddenly, you have the portability of the lithium battery and the inexpensive lead-acid batteries sitting at home.”
Harmon told Solar Power World that Goal Zero has recently seen “almost an even split” between customers buying Yeti systems for home backup vs. outdoor recreation, but more than 70% indicate they intend to use the systems for both purposes.
“Our system is for all the people in the country who don’t have $15,000 to spend on an energy storage installation. And then when I’m done, all I have is something permanently installed in my home,” Harmon said. “Yeti is for those who are sensitive to what they’re spending money on.”
The Yeti 6000X is advertised online at …….