Hope it'll be available in Europe. I'd like to store some photovoltaics generated energy "because I can" (still get loltastic money for feeding it into the grid, yay subsidies). Less reliance on the grid is good.
I'm rooting for decentralized power (I'm envisioning battery stores in communites that form local grids) but there's obvious issues to be solved.
It will be interesting to see how this works in California. Everyone I know who has Photovoltaics, also has a switch which is required to disable them the instant the mains power goes down. The battery is still quite useful in that scenario, but it would be even more useful if you could supply your house with power from batteries, after an event results in the grid losing power.
An alternative is to automatically disconnect your home from the grid in that situation, rather than disabling the PV. This is referred to as intentional islanding. (Although I suppose that could be disallowed in some jurisdictions, for no good reason that I can think of. At the very least though, you should be able to manually disconnect once the anti-islanding has kicked in, and then fire the PV and/or battery-powered inverter back up.) Depending on your equipment you may still have to shut down before reconnecting to the grid, once grid power is back up. (Depends on whether your inverter is capable of re-synchronizing with the grid, and again I suppose based on regulations in your jurisdiction.)
This sounds a lot like the ATS (Automatic Transfer Switch) which, is a massive switch that switches from Mains grid to generator during a power outage in some of the buildings I've worked at (And scares the crap out of you if you are in the same room when it switches over - very, very loud).
Some cities already have their own grid-connected electric utility (the cities of Alameda and Santa-clara in the Bay Area, for example). But for a community grid to completely disconnect from the larger grid and still provide reliable service, it would have to recreate some of the redundancy inherent in today's massive complicated grid.
These batteries might help achieve some of this redundancy for an independent community grid, but the total installed battery+generation capacity would have to far exceed peak demand.
Another thing the grid connection gets you is the ability to charge your battery with cheap, but intermittent renewable electricity being generated at distant wind farms.
You also still have the problem of building, financing, and maintaining the local power distribution infrastructure in your community.
How feasible will it be to use 60+kWh of home battery storage for time-shifting arbitrage (not pure arbitrage, but close enough)? Is it yet possible for a consumer to get direct exposure to the spot electricity price for both feed-in and feed-out?
It would be interesting a) What the payback period is on a strategy where you charge when the spot price is low, and discharge when high, and b) How much installed battery capacity would be required to eliminate this arbitrage? i.e. what MWh of installed battery capacity would flatten the 24 hour across-grid demand cycle.
If it works out, wouldn't the utilities do it themselves? Why transmit that power for miles and then transmit it back. And even if they didn't, arbitrage means the price difference between times would fall as more people do it. Peak prices would move closer to night prices as demand equalizes between the two.
It's the opposite though - during the night, you want to use power from the utility, when it's plentiful, and cheap (particularly if you have a TOU contract).
The objective would be charge the battery up at night from the grid, and then use that power during the day + your solar power, when power is expensive.
Once solar becomes widespread enough, the dynamic changes. In Germany, electricity spot prices can be lower around noon because of solar energy. A quick Google search brings up this example: http://cleantechnica.com/2012/03/23/german-solar-bringing-do... (note that this already happened in 2012!)
Spot prices could even go negative, depending on the rules of the market. That's certainly a feature of Australia's National Electricity Market (NEM) which covers the eastern states. The price can drop to a floor of around -$1000/MWh, so at these times the large generators are paying the network for the privilege of keeping their running - which they are generally forced to do, since such a period of negative prices doesn't tend to last long... certainly not long enough to justify shutting a coal-fired turbine down and then the expense of spinning it back up again.
If you have solar panels, daytime power is as cheap as it gets. The cost of daytime power is negative for me, since my home solar array produces more power than I can use.
Net metering is an accounting trick which lets you treat the grid as a big storage battery. My house "charges up" this battery during the day by running the meter backward; then I can "draw down" the battery at night, when my panels are inactive.
If I had a literal storage battery at home, the economics would work exactly the same way: but instead of externalizing the cost of the battery onto the public utility, I'd be paying the cost myself by purchasing the battery.
Very few people have an excess of power from their solar grid - unless they aren't at home (which, come to think of it, is an excellent use case for a home battery). For most people, the home battery is going to be useful from day one by entering a TOU contract with their local utility, and then charging at night, and using the power during the day.
Solar power, on top of that, will be a bonus.
For the summer, California E-6 Residential rates are $.32/kWh during peak times, $0.13/kWh during off peak. If your house is using, say, 4 kW, for 5 hours during peak - then that 20 kWh will cost save you 20 * ($0.32-$0.13) = $3.80/day in power costs, approx $115/month. Do that for 4 months/year ,that's $460/year. With a 5 year life, that battery would need to be less than $2300 to come out even.
My point is that most people would be perfectly happy just to say that they're no longer reliant on burning fossil fuels to power their homes. Life is just too short for me to care about arbing the residential electricity market.
Even if it was powered from the grid, if these were installed everywhere you could have distributed charging mechanisms, which would lower the peak load on the grid, which would mean less peak power required across the board.
That is effectively a form of arbitrage, I suppose. You're charging the battery when electricity is either cheap (middle of the night), or free (from solar on your roof) and then using it in place of expensive day time electricity.
You could argue using battery electricity in stead of bringing in grid electricity is functionally equivalent to selling it to the grid, both in terms of pricing incentives, and the effect on the grid – in the same way that people are discussing being able to switch fridges on and off minute by minute as being equivalent to building grid generators which can be switched on and off on that timescale.
This was my initial thought too, but I had another!
How feasible is it that the majority of households could have a massive home-battery installed in terms of natural resources? It seems like a lot of rare earth materials to build so many big batteries.
Lithium isn't considered a rare earth element, although it is relatively rare compared to, say, lead.
From Wikipedia: However, according to a 2011 study conducted at Lawrence Berkeley National Laboratory and the University of California Berkeley, the currently estimated reserve base of lithium should not be a limiting factor for large-scale battery production for electric vehicles, as the study estimated that on the order of 1 billion 40 kWh Li-based batteries could be built with current reserves.[85] Another 2011 study by researchers from the University of Michigan and Ford Motor Company found that there are sufficient lithium resources to support global demand until 2100, including the lithium required for the potential widespread use of hybrid electric, plug-in hybrid electric and battery electric vehicles. The study estimated global lithium reserves at 39 million tons, and total demand for lithium during the 90-year period analyzed at 12–20 million tons, depending on the scenarios regarding economic growth and recycling rates.[1]
Of course, lithium isn't the only element we can use to make batteries.
Note, I'm not making a claim one way or the other on the feasibility, just stating that resources don't appear to be a limiting factor for the next ~life-time.
It seems like a lot of rare earth materials to build so many big batteries.
Lithium-ion cells actually don't necessarily require any rare earth metals at all. For instance, the batteries Tesla currently uses for their cars are made up of lithium, nickel, cobalt, aluminum, and carbon, none of which qualify as rare earth elements.
There is a LOT of lithium in the world and that's just near the surface - you can always dig down.
But at that scale you don't have to use lithium anyway. When it comes to grid or off-grid storage, you don't need the best energy density as cost per watt-hour is probably the most important factor and there are already other chemistries on the market that will work just fine with many more on the way. Sodium or Aluminium based batteries seem particularly promising.
It seems like the success of this has to come down to some kind of quality-of-life value-add that is only realizable in homes.
Like how Tesla Model S's get their owners access to luxury, HOV lanes, and public environmental bragging rights (presumably the buyers of a $100k car aren't trying to save money on gas).
Otherwise, like some have noted, why wouldn't the utilities themselves do the storage and avoid the round-trip power transmission losses?
The thing is, in the US, power outages are pretty rare and fixed pretty quickly, so bridging outages doesn't seem like a major selling point. If the customer really is the homeowner, I'm still wondering what the big life-value-add is. It's not like home battery storage market has a luxury segment that can be initially targeted as the Model S is in the car market. And
And I don't think that Elon is targeting geeks who want to set up power arbitrage schemes in their homes.
In South Africa we're having rolling blackouts called "load shedding" because we don't have enough power. Exactly why is a long and obviously controversial story, but in short: Mega projects that were supposed to fill in the gaps are being delayed, maintenance on existing infrastructure was delayed in the hope that the new projects would come online in time, but that's now causing cascading failures and maintenance cannot be avoided any longer, causing even more outages..
So we don't have grid power 24/7 anymore and our electricity prices (that used to be some of the cheapest in the world) are now skyrocketing. So I would imagine that many many people here might be in the market for something like this at the right price.
2.5 hours is extremely lucky, in my experience. Normally at least 4 hours and often more like 6 - 8. One of my friends has been without electricity for the past 5 days!
Totally agree that there is a big market here for the Tesla home batteries, depending on the cost vs capacity. I am definitely in the market.
I've actually been looking into playing with some LiFePO4 batteries and trying to see how big of a UPS you can build for, say, R5000 or R10000. LiFe batteries have longer lifetimes, are safer (less likely to catch fire or explode), are less finicky about how they get charged (more like lead-acid), seem to be potentially a bit cheaper, easier to use in multi-cell configurations (cell-balancing issue related), etc. You can also source or sink more current, so faster to charge/discharge. Downside is 14% less energy density which is why they don't get used in laptops or smartphones and (in Tesla's case) sometimes also not in cars. But that's not much of a downside for (off-)grid storage..
Pretty sure there's a gap in the market there just waiting for someone to jump into. And once you already have a giant battery it is probably that much easier to convince yourself of covering your roof in solar panels, getting a gas stove and disconnecting yourself from the grid entirely :)
Many homes have natural gas powered generators that automatically kick in when the power fails, as it often does (trees fall on the wires). Typical outage times are 4 to 8 hours.
A system like this costs 5-10 grand.
I wonder if these home batteries would be a less expensive alternative.
We'll have to wait for the numbers. Cost/KWh and lifetime number of charge/discharge cycles are the numbers that matter. For fixed applications, energy density isn't critical, as it is for mobile and cars.
If the big wind power people start buying these, it's real.
I was planning on using this year's unexpected tax refund to go solar. However, I've been waiting all month for the announcement specifics/pricing before making a move.
I'm curious to see what (if anything) these batteries will do for users that isn't already handled by a UPS.
Not that a cheaper, more energy dense UPS isn't already a win but the article keeps focusing on the fact that the product is a battery, not what it will actually be used for.
I wonder if these eventually would become be hydrogen based eventually. (or already are..)
No matter whether Tesla is actually working on home batteries, i see a need for anyone invested in green energy. They could do greener than LiPo ofcourse.
I think there are some advantages. No gas fuel, no noise, maybe less maintenance. Insurance vs. a genset should be different. I'm assuming you hook these up with a bypass switch, so you effectively have a whole home online UPS; this would eliminate brownouts and dirty/noisy power. I wonder if there's a power factor advantage on the utility side as well.
Yes, but do you think there would be any benefit in it there being less variability? Right now a utility deals with a bunch of random stuff drawing power, presumably at different factors. I don't know what the right language is to describe this, what I was thinking is that if everyone effectively had a big UPS then that variability would be seen by the UPS, and the power company would see a more uniform draw.
Very interested in the announcement, pricing etc.