St. John Tradewinds News

Battery Backup Systems

You are probably familiar with uninterruptible power supply (UPS) systems. When the power goes out unexpectedly, a UPS will keep power running to your computer. It’s an emergency backup system designed so you do not lose data when the power goes out.

Did you know that there are battery backup systems you can use for your house also? Tesla’s Powerwall is one, but it’s an expensive system, and you cannot use solar to help recharge the battery when it runs low (it requires standard 110/220-volt current to recharge).

There is a company called Humless that makes solar-powered generators. When the sun is shining, they store that energy in a battery bank, ready for use when you lose power. Even if WAPA fails on a cloudy day, this generator will still run on its charged batteries. It can be charged with a manual hand crank, too.

Humless makes different sized solar generators, from small computer backup systems to large 12kW whole-house systems. Their smaller portable systems are relatively compact and affordable. For example, the 1500 series comes in two sizes: the 640 watt system, which weighs just 38 lbs, and the 1,300 watt system, which weighs 47 lbs. With two foldable solar panels, these systems cost $1,999 for the 640 watt and $2,559.00 for the 1.3 kW system. Both have a 7-year warranty.

The larger size systems have a 10-year warranty and can be used either off grid (no need for WAPA) or as a battery backup with an automatic transfer switch. A 4.8 kW system weighs 270 lbs and costs $7,759. A 12 kW system weighs 517 lbs and costs $14,559, and this system is expandable if you want to add generating capacity.

One of the great features of these systems is that you can draw down the lithium ion batteries to almost zero power, and they will recharge 100% for more than 2,500 cycles. Unlike with traditional off-grid systems that use lead acid batteries, you don’t have to do any maintenance at all.

Which system is for you? Here’s a quick estimate: If you were to purchase the 1.3 kW 1500 series, you would have 1,300 watts of maximum energy available. That means you could run one 12 watt LED light bulb for 108 hours, or a 100 watt refrigerator for 13 hours. Or, you could run both for 11.6 hours.

The 4.8 kW system will run a 100 watt refrigerator, a 12 watt bulb, and a 600 watt A/C unit for about 6 hours before needing a recharge. And the 12 kW system will run a 100 watt refrigerator, a 12 watt LED, a 600 watt A/C unit, and a 200 watt TV for about 13 hours.

If you currently have a grid-tied solar system, a Humless generator will allow you to still use solar power when WAPA is out. Your panels can be used to charge your generator batteries then.

You do not have to carry or store gas or diesel to refuel these systems. Although the upfront investment is slightly higher than for a fossil fuel-powered generator, over time you will save hundreds of dollars from not having to buy fuel.  Another great thing about these systems is that they are portable, which makes them a good option for renters as well as homeowners, and even for boats. Also, you can use either solar power or 110 current to recharge them.
The best part is, they make NO noise and have NO emissions—both great things for our islands! So the next time WAPA goes out, you don’t have to be left in the dark with food spoiling in your fridge.

Check them out at Island Solar is an authorized dealer for Humless products.

For a greener tomorrow,

Dan Boyd
Lovango Cay

Dan Boyd of Island Solar is a Virgin Islands Energy Office authorized vendor. For more information, call Boyd on his cell phone at 340-626-9685 or by email at