Energy storage system information

[neczrak]

Hi together,

I'm really glad to found a forum like these, where I can discuss about PV topics.
As I'm thinking of a new energy storage system for my PV system at home, I was wondering if someone knows a page or has any information about the cycle-life of LiFePO4 batteries.
I know that cycle life can't be generalized, but it would great if anyone could provide test data on cycle life or a page where I can find some cycle life test data available, as I need to calculate the maintenance I'll have to expect from these systems

Regards,

necz

[Sunking]

Hard data you are not going to find. Manufactures stretch the numbers but claim 300 to 500 cycles with LiPo cells. Nano Lipo claims to have improved it up to 500 to 700 cycles but no one has experienced those numbers yet. You can get real feed back by visiting RC Plane Forums.

But let me add a couple of thoughts. Lithium is not ready for solar as it is still way to expensive, and no charge controllers on the market for them. A good 5 year 2000 cycle flooded lead acid battery will cost you around 20-cents per watt hour of capacity. A good 2 year LiPo will cost you 50 to 70 cents per watt hour. So in effect considering cycle life and cost LiPo will end up costing you some 6 to 10 times more than FLA.

Lastly LiPo o rany of the Lithium chemistry demands Battery Management System in the form of Balanced Charging. No such thing exist with solar charge controllers because there is no demand what so ever for such a charge controller. Until lithium prices can compete with lead acid that is not going to change.

[bonaire]

There is activity by some vendors in this area but nothing is very mainstream. Watch for products from the partnership of PowerOne and Panasonic into 2014. Tesla has a storage unit installed by SolarCity. Pricey but answers your questions. The company A123, now named B456 after recent bankruptcy, has cells offering 4000-8000 cycles current and future EXT versions. Their intention was to build packs for cell phone towers in mixed climates without need for AC. There are other firms out there with high cycle rates as well, including taxi and bus service electric vehicles in china that have thousands of cycles on them with 90% capacity remaining. There is high hope that lithium blends will replace lead acid in energy storage. LiPoly is not ready for this. Other blends are. My Chevy Volt has a blend of LiPoly based on manganese spinel oxide which should allow thousands of charges as energy storage once it has reached end of life in the car. Companies are getting ready to use the packs in a few years once cars reach 150k miles or more.

[bonaire]

Link seen today.

http://news.investors.com/technology/070313-662513-new-batteries-being-developed-for-power-storage-e-cars.htm?ven=yahoocp,yahoo

[joannakrup]

Screen technology has many eye-catching features: it's numerous, nonpolluting and difficult to wipe out. The amount of sunshine a given area gets will vary, based on the weather and time of day. At night, for example, a solar power board isn't getting enough light to power household equipment. A variety of techniques--some trial, others already feasible--have been suggested to store solar power power.

[russ]

Screen technology has many eye-catching features: it's numerous, nonpolluting and difficult to wipe out. The amount of sunshine a given area gets will vary, based on the weather and time of day. At night, for example, a solar power board isn't getting enough light to power household equipment. A variety of techniques--some trial, others already feasible--have been suggested to store solar power power.

All that BS just to post you link which I just removed? Links not allowed.