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Plunging Battery Prices Expected To Spur Renewable Energy Adoption

Posted by Soulskill on from the lower-charge-per-charge dept.

Lucas123 writes: Lithium-ion (Li-on) and flow battery prices are expected to drop by as much as 60% by 2020, making them far more affordable for storing power from distributed renewable energy systems, such as wind and solar, according to a recent report by Australia's Renewable Energy Agency (ARENA). The 130-page report (PDF) shows that Li-on batteries will drop from $550 per kilowatt hour (kWh) in 2014 to $200 per kWh by 2020; and flow battery prices will drop from $680 per kWh to $350 per kWh during the same time. Flow batteries and Li-ion batteries work well with intermittent energy sources such as solar panels and wind turbines because of their ability to be idle for long periods without losing a charge. Both battery technologies offer unique advantages in that they can easily be scaled to suit many applications and have high cycle efficiency, the ARENA report noted. Li-ion batteries more easily suit consumer market. Flow batteries, which are less adaptable for consumer use because they're typically too large, scale more easily because all that's needed to grow storage capacity is more electrolyte liquid; the hardware remains the same.

7 of 130 comments (clear)

  1. Still a bad value by Anonymous Coward · · Score: 3, Interesting

    Lead acid 6 v golf cart battery with over 100 Ah of usable capacity, or 0.6 kWh of storage (ie: 200+ Ah actual capacity, you never drain a lead acid battery flat) : $90. Deep cycle (because it's for powering golf carts) means you actually CAN drain 50% or more of it without damaging the battery at all.

    That's $150 per kWh, and you can hop on over to Sam's Club and buy one or more of them tonight.

    If you have the space to deal with them, which if you're using them for home you likely do, lead acid battery tech is going to beat out lithium ion for a long time yet (past 2020 apparently!)

    1. Re:Still a bad value by cunniff · · Score: 5, Interesting

      Lead is cheap but you get what you pay for.

      First, lead-acid has a shelf life even if you do not discharge the battery - the lead plates sulfate over time, reducing capacity. It is only partially reversible by occasional special charge/discharge cycles. This shelf life is something like 3-5 years, depending on how much capacity you are willing to lose.

      Second, lead-acid self-discharges. This means, unless you use the battery very close in time to when you charge it, you've wasted some of the energy you put into it. Trickle-charging only makes this worse, since you will always be dropping energy into the battery without getting most of it out.

      Third, lead-acid discharge voltages are strongly impacted by the current at which you discharge them - look up the Peukert exponent for the golf cart batteries you were quoting - it will be over 1.2, and probably higher, meaning that high current discharge will drain the battery much faster than expected.

      Finally, even deep cycle lead-acid batteries are slowly degraded even by the 50% discharge you quote. It only takes a few hundred cycles for capacity to be diminished by double-digit percentages. This is caused by plate erosion.

      Existing lithium cells don't have a known shelf-life (they probably have one, but we don't know what it is) - it could be 10 years or more. They have expected 80% discharge cycle counts of *thousands* rather than hundreds. And their Peukert exponent is very close to 1.00 since they don't have the same variable internal resistance characteristics of lead-acid.

      I have first-hand experience of this - I have used all three of deep-cycle flooded, deep-cycle sealed (AGM), and now Lithium Iron Phosphate (LiFePO4) cells in my home-built electric vehicle conversions. My lead-acid shelf lives were right along with that 3-5 year expectations. The LiFePO4 cells are going on 2 years now with no measurable decrease in capacity.

    2. Re:Still a bad value by thinkwaitfast · · Score: 2, Interesting

      Existing lithium cells don't have a known shelf-life

      My laptop would beg to differ.

  2. Re: Yay for price drop by slack_justyb · · Score: 4, Interesting

    From the document, the major rationale for the expected price drop would be from an abundant supply of product. Not due to some new process that makes the product cheaper to build. So a lot of this is educated guessing. One that there are lot of new production coming on line for batteries. That's a true statement. Two, all of these new players will create a vast supply of batteries. That's a logical outcome that's typically true but not always. Three, this huge supply will drive prices down. Again that's the typical market assumption but it's not always a sure thing. So it is a one thing leads to another kind of paper. I don't disagree with some of the assumptions made, and the numbers seem conservative enough to not be in the realm of outlandish. So a pretty safe paper in terms of speculation, but not exactly hard truth so take with usual grain of salt here.

  3. Re:It's already happened; we're at $250/kWh now. by thinkwaitfast · · Score: 2, Interesting

    I was looking at lipo's last night. Still over 4x the cost of lead acid. I got my batteries @ ~$100/kwh. That's roughly the cost at a few places I've looked: walmart, costco, golf cart and auto repair shops. And that's with lifespan et al factored in.

  4. Spontaneous combustion by QuietLagoon · · Score: 1, Interesting
    Yeah, I want a pile of those in my basement....

    .
    The money I save via the solar panels, I'll probably lose due to the higher fire insurance premiums.

    Why lithium batteries keep catching fire

    ...Lithium batteries are widely used because of their high energy density: in other words, their ability to store a lot of energy in a lightweight, compact form. But they have a tendency to cause expensive machinery to go up in smoke....

  5. ROBOTS!!! by EmperorOfCanada · · Score: 3, Interesting

    When I am building robots my battery choices very much are the limiting factor in my designs and the final capabilities of the robot. I can go for big lumbering beasts with piles of lead acid. Or I can break the bank with enough lipo to keep a laptop factory running for a week. Or I can pair my design down until it is simply a toy. Other options are to make it sound like a garden tool and put some kind of gasoline motor in.

    But if I had a reasonably priced source of reasonably power dense batteries then my robots would improve proportionally. For this doesn't just increase the power available to my existing designs but it also reduces the overall costs of a robot. For instance the more efficient the motor or cost computer module, generally the higher the cost. But it would be great if I could slap in any old small motherboard, and use run of the mill DC motors instead of ultra cool brushless.

    Then whole other motor systems become possible. Linear motors, pneumatic systems, hydraulic systems, etc.

    So a revolution in batteries would precipitate a revolution in robots; real robots doing real jobs in the real world.