Tesla POWERwall

i see off grid land for sale in the santa cruz mountains for cheap. i wonder if this would be a good application for a house there?

 

SolarCity has been installing commercial versions already.

Toyota has install some peak shavers at Japanese dealers make from 'old' hybrid packs. Don't think they have solar power.

 

Hmm. I foresee in my future a wind turbine powering an inverter feeding the Tesla Home Battery System. From there it can feed the wireless charging system on the garage floor for Firebrid wireless charging. When there is no wind and the power is out, we could run on batteries until they are low, then switch over to the Co-verdant Power-out unit installed in the Firebrid. Yeah, that would work!

Bill the Engineer

 

This is a legitimate use for this power pack. I didn't think lithium-ion would be cost competitive with lead-acid for this use, but this website did a cost comparison that shows Li-ion with the cost advantage: Lithium-ion vs Lead-Acid cost analysis - PowerTech Systems PowerTech Systems
But then, their analysis may be biased since they're selling Li-ion.

I'm confused by Tesla's claims for the Powerall. I was under the impression that it included the inverter, but in the specs it says "DC-AC inverter not included". Maybe a DC-DC converter is included, but not the inverter?

 

I think this is great. Many utilities have off peak plans -- even my coop utility in NC....

 

But off peak in my neck of NC is 9PM to about 8AM.

Peak is not the night time nor when the batteries might provide the most benefit to the grid.

Commercial plus residential combine to make the peak rates in my area daytime hours in the summer. In the winter, peak period shifts to be two periods with a gap during the middle of the day and lower again at night. Winter peaks are when commercial properties are just turning everything on and when everyone is just getting home from work.

The difference in peak versus off-peak rates is significant enough I installed a controller to limit my electricity usage on high use appliances like HVACs, water heater, dryer, etc during peak charge hours. This even beyond time sensitive thermostat settings. And I use timers to start appliances in the off-peak hours. I save enough in a year to power my hybrid Prius.

 

Perfect fit for my roof mounted 10KWH solar system.............

 

I heard it would be more expensive with the associated inverter etc.
In any case saying $3000 for 7x the size of a 1 KWHR $3000 NiMW prius batt

 

Without a PV array, you could use this home UPS to peak shave. Charge it up during off peak with lower rates, and then have it power the home during peak rates. That is how these systems are sold to businesses.

Paired with PV it can shift excess production to use during the evening.
Middle of the day, with few or nobody at home, the PV panels charge the battery up before dumping excess onto the grid.
Evening, the battery supplies power as the solar production drops off, and reduce use of grid juice during the return home peak.
Night time, charge it up at off peak rates.
Morning, it provides power to the home from after off peak rates end and until solar production comes up to meet home use.

 

• drinking water?
• sewage?
• vegetation?
• communications?

Bob Wilson

 

"Middle of the day, with few or nobody at home, the PV panels charge the battery up before dumping excess onto the grid."

Mid-day, lots of folks are home. Think retirees. Think stay at home families. Think doing the dishes/wash while the kids are down for their nap. In that case less is dumped to the grid, less is stored. If residential wasn't still using significant electrons, the peak wouldn't be during the day. The economics are still helped by PV panels and batteries (unless you have a plan like mine and limit your peak time use where I'd imagine the effect would be less and the payout much worse).

 

Since my desire is to live off-grid in a close_to_zero carbon lifestyle, I've been wondering how this product would advance my goal.

It really is not needed as a sink for excess power -- my domestic hot water demands fill that niche.
In terms of an energy reservoir it could complement and supply an *EV at night, and run the home on cloudy days.

I would love to see a database similar to PVwatts that shows a distribution of sun-free events of increasing duration per year. E.g., how many times a year does my home have less than 5 sun-hours over a 72 hour period ?

 

From an economic point of view for individuals, that 10 kwh back up system is an awful idea. Its much cheaper to be grid tied pv system and have a diesel generator or a prius to house connection for blackouts. For some businesses though this does make sense to buy multiple systems and they have placed orders.

The 7kwh system that can charge and discharge daily doesn't make economic sense for peak shaving or demand shifting in the US in grid tied systems. It may soon make sense in germany though with much higher electricity cost differentials. It also looks good for off grid systems. The problem is solar city says there are still some technical problems to use it for these purposes. These issues might be resolved next year though, no details about what doesn't work.
Tesla's New Battery Doesn't Work That Well With Solar - Bloomberg Business

Still economics have little to do with eco luxury goods. Tesla is much cheaper than current systems. People just want more than tesla can make, and they are sold out for the next year.
Tesla Powerwall Sold Out Through Mid 2016

 

It makes sense. Lion should have a longer useful like and be able to use a higher percentage of its of its charge. That means you can pay more upfront for a lion system, but make up for it on lower maintenance costs. The new lower prices of batteries and electronics make this possible.

Yes it includes dc-dc, not dc to ac.

 

Get a quote from your local utility to bring the grid to your new home that is say 0.5 mile away and then talk.

Or consider a future where all grid power is TOU -- you know, the rational one.

 

A home battery.

That's a good idea.

Basically allows you to tailor you home power needs into a "Hybrid" situation, going from the Grid or Solar, to the battery as best warranted or needed.

It seems to be a nice, complete, refined product. But ultimately whether it is charging itself off solar panels or charging itself off the grid at low peak times, it's a "home battery" and seems to me to be aimed at those people wanting convenience, but still living on the grid.

Still I think it's a good idea and intriguing. How much more efficient could all our energy use become if every or the majority of of dwellings were equipped with similar devices? It really is kind of the "Hybrid" concept being applied directly to in home energy utilization.

 

Imagine replacing all the suburban HVAC systems with geothermal. I suspect this would dwarf any potential EV adoption gains.

Had an across the street neighbor whose HVAC was 25 years old who did it. The tax benefits were enormous and the entire system including boring two deep shafts cost him maybe $2k more than a conventional high SEER system and his electric bill savings are enormous. The grid benefits too because the geo is most effective when compared to conventional heat pump systems when the temperatures are at the extremes and the load on the grid is the largest. Reduces the load on the grid by a huge amount. And is completely invisible once installed. Quiet too.

Or tank hot-water heaters with point of use systems. I tried to do that when we built our house but couldn't find anyone who could understand the systems (small town). Things have changed now and people are doing it.

 

I'm unclear what the 7kWh PowerWAll has that the 10 kWh does not.
And by extension, why the 10 kWh unit is called 'back-up,' and not meant for daily use.

Addendum:
This, from a post on the Tesla forum:

A few notes from the conf. call that hopefully I captured correctly:

1. Backup unit: Ni Co Al; 60-70 cycles/yr; 1000-1500 cycles lifetime
2. Daily cycler: Ni Mg Co; 365 cycles/yr; 15yr lifetime

 

These are different issues and are additive. When I lived in Palo Alto california, geothermal HVAC would have been a complete waste, but plug-ins made perfect sense. I barry used heat and didn't even have air conditioning. Here in texas on new construction I would certainly do geothermal heat pump, solar, and rain water collection. On existing buildings though its too expensive. Plug-ins make perfect sense here, and plug-ins and geothermal are subsidized. In the midwest plug-ins make less sense but still work. The grid is dirtier and renewables more expensive, efficiency worse in the cold weather. Geothermal heat pumps certainly make more sense in minnesota than california.
+1

Yep good for your neighbor.

If you have an efficient natural gas water heater, there is no reason to replace it. Definitely if you have electric or need to replace your system combining a point of use with a tankless water heater can make sense.