Once you have prepared the essentials of food, water, shelter, and self-defense you should prepare to generate your own power. Don’t waste your time with hydro or wind power, unless you have ideal conditions–very high fall height for water, and very high, uncomfortable winds. Otherwise, they are rarely cost-effective compared to the constantly dropping solar prices.
A properly sized solar system will generate power in a slow, steady stream all day but you have to capture and store that power for use at night, during cloudy days and for high power draw projects using batteries. Battery banks are expensive and, depending on the type of battery you choose, can be a very frustrating part of the system. Solar panels easily last decades with hardly any maintenance, but the typical lead acid battery banks require frequent water level maintenance and the extremely heavy batteries need to be replaced after just 5 to 10 years. Fortunately, there are better, lighter battery options out there.
At the time of this writing, the best off-grid battery option is the Lithium Iron Phosphate or Lithium Ferrous Phosphate (LFP) batteries from SimpliPhi Power. At first glance these batteries look incredibly expensive at $1,000 to $3,000 apiece which seems like 10 times the cost of an equivalent voltage and amp-hour rated lead acid battery (such as the Trojan T-105, a popular deep cycle golf cart battery)—until you compare them to their lifecycle cost. As I wrote last week, lead acid batteries lose life cycle capacity faster when they are deeply discharged. Even so-called “deep discharge” batteries are most efficient when only discharged by 20%. The T-105 golf cart batteries get about 3,000 cycles at this depth of discharge and then they need to be hauled out and disposed of. Compare this to the LFP batteries from SimpliPhi which are rated for 10,000 cycles all the way down to 80% discharge. AltEStore.com (which sells both batteries) did the math and found the LFP batteries were almost 10% cheaper over their life span.
So not only are the LFP batteries cheaper in the long run but they are lighter, smaller, recharge faster, release power faster and don’t need to be ventilated. That means they can be stored anywhere, including a crawlspace. They won’t overheat, unlike other lithium-iron-cobalt based battery technologies, and SimpliPhi’s batteries come with embedded circuitry to avoid over-charge, over-discharge, shorts, or unbalanced cells. Also, a built-in 80 amp breaker eliminates any risk of over-current and provides a convenient on-off switch to that battery. But the biggest advantage is that they require no maintenance. You will never have to check the water level and rarely, if ever, replace the batteries. The only drawback is they can’t be linked in series for higher voltage systems—48V is the highest unit right now. The cheapest prices I have found are at the Alt-E Store and at Northern Arizona Wind and Sun.
There are other battery products out there, but none of them compare to SimpliPhi at this time. Tesla’s Powerwall 2 is impressive, but they are Lithium-iron-cobalt which isn’t as safe and they aren’t designed for off-grid use at this time. Their website says this aspect is “coming soon” which is a common promise from Tesla that could mean anything from “soon” to “much later” or “never.” Other manufacturers of Lithium Ferrous Phosphate batteries so far have failed to provide the same number of cycles and depth of discharge. ReLion, for instance, shows their slightly cheaper batteries losing up to 40% capacity after 10,000 cycles at 80% depth of discharge. SimpliPhi warranties their batteries for at least 80% remaining capacity after 10 years or 10,000 cycles.
We expect further improvements in the world of batteries in the future, with continued dropping prices, but if you are installing a backup power system in the near future, the LFP batteries from SimpliPhi are currently your best option.
No comments:
Post a Comment