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Tesla Energy

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Re: Tesla Energy

#221

Post by matt4077 »

eru wrote: post #201
toomuchtodo wrote: post #110

Earlier quoted context omitted.

> utilities would quickly erase any peak-vs-non-peak arbitrage opportunities. Probably right around the same time they're no longer necessary, as the cost of distribute solar continues to plummet. Its actually truly amazing how quickly the price continues to drop for panels each year.

Depends on country. I doubt you could ever run, say, Germany or Britain on locally produced solar power.

There also wind... But solar already provides quite a substantial contribution in Germany. See this live chart: https://www.energy-charts.de/power.htm.

Considering the rate at which solar power is getting cheaper, I'd say a solar power based economy is within reach.

Re: Tesla Energy

#222

Post by roel_v »

IanCal wrote: post #212
roel_v wrote: post #197

Earlier quoted context omitted.

" 4kW seems to be the maximum potential drain from the battery. That wouldn't power an oven… let alone anything else at the same time." 4kW is enough to power an entire home continuously, without thinking about energy use, even a large one with a home office with several people working in it + washing machine + oven + electrical stove at the same time . I have the data to prove it, too - 10 second interval power cons…

> I never had a load of more than 3.5kW Different issues over the pond, my kettle can draw 3kW :) Since so many of my countryfolk have something similar, this actually causes our energy production quite severe issues when popular TV shows finish. Often a 200-400 MW spike but at the end of the 1990 world cup semi final penalty shootout against Germany, there was a spike of 2.8GW. An interesting example of some of the…

"Different issues over the pond"

Well depending on which pond you're talking about, we're actually on the same side :)

" my kettle can draw 3kW :)"

True, you have some special circumstances in your country. You'd still be better off with a boiling water tap, the cost of which (even when amortized over only a few years) is the same as using a kettle (when accounting for all costs - lost energy, water, installation costs etc). So for somebody implementing this in the UK, they'd have to budget for an additional 1500 pound up front cost - which has the potential to turn into a cost saver after 5-10 years (probably closer to 5, depending on how fast energy costs will rise - which I think is fair to expect will be at a higher-than-linear rate).

Re: Tesla Energy

#223

Post by mauricemir »

miratrix wrote: post #181
ChuckMcM wrote: post #138

Nice, that came in lower than I was expecting. I was thinking $5K for the 7kWh unit. Of course that is the "installers" price so who knows what those folks will consider the 'retail' price. My wife still has her solar installer certification so we could presumably get one that way. It also makes for a really interesting opportunity for grid tied solar inverters. Now you want the inverter to power the house first, the…

On the grid tied solar inverter front - the spec sheet says the battery voltage is 350~450 V, so we're looking at 108 lithium ion cells (25 x 18650 cells?) at 400 VDC nominal. This is quite different from typical lead acid battery pack voltage of 12, 24, or 48VDC that's used for battery backup storage, so a lot of existing solar battery storage infrastructure may not even work... this means that people may need to bu…

Yes talk to telco Engineers from the power side of the biz and they will have war stories about accidents and close misses with the Central Offices (Exchanges) DC power.

High Voltage/Amperage DC is quiet different to AC power and i suspect that building/wiring codes are going to need to be updated if this local storage takes off.

Re: Tesla Energy

#224

Post by yen223 »

GigabyteCoin wrote: post #206
eru wrote: post #202

Earlier quoted context omitted.

> That, and the factory is in the USA. I would assume shipping something that large and heavy would add to the cost in Australia. Put it on a boat. Shouldn't cost more than shipping inside the US.

You still need to ship it inside the US to the boat dock, and then pay to put it on a boat, and then pay to ship it from the australian dock to the homeowner.

Freight costs are so cheap they're essentially negligible. There's a reason why it's cost-effective to make stuff in China, and ship it all the way across the Pacific to the US, instead of just making them in the US.

Re: Tesla Energy

#225

Post by gutnor »

epistasis wrote: post #95
kmod wrote: post #91

Earlier quoted context omitted.

If what you say is true, then with better economies of scale and longer investment horizons, utilities would quickly erase any peak-vs-non-peak arbitrage opportunities.

Different entities have different risk profiles, and utilities are extremely conservative. It will probably be profitable to load shift for several years before utilities start to do it on their own. And even then, it may take quite some time before there's enough battery capacity for all the fluctuations to even out.

Utilities with electricity production are more conservative because they have technical limitation due to the infrastructure they run.

However, there is a bunch of companies that buy and sell electricity on the open market, so they have a direct financial interest to play with this arbitrage.

In the UK, another reader has calculated the best case scenario was profitability in about 10 years. (his numbers ring true to me, I calculated recently that there was no reason to take an economy 7 contract for my electricity usage using similar data) That's a lot of time even in the utility market. So if batteries not attached to solar panel are going to be profitable (in the UK), that would be a future generation.

Re: Tesla Energy

#226

Post by doublerebel »

mryan wrote: post #140
digitalzombie wrote: post #112

How hacker friendly is this? I'm not crazy enough to do anything fancy. But I would like to build some metric system to see the data and usages. If I can some how hack it so that it keep track of which devices uses the Tesla battery the most.

I highly doubt that will be possible. Actually I think it is entirely impossible, but I'm trying to future-proof my statement :-) The battery system will just know how much power is currently being used. It will have no way to identify which devices are currently drawing power. For that, you'd need something like this on each outlet: http://www.amazon.com/P3-P4400-Electricity-Usage-Monitor/dp/... Maybe future smart h…

It may be possible to use non-intrusive load monitoring to determine the devices. However, I'm not aware of any products on the market using this tech.

http://en.m.wikipedia.org/wiki/Nonintrusive_load_monitoring

Re: Tesla Energy

#227

Post by roel_v »

jacobolus wrote: post #211
roel_v wrote: post #200

Earlier quoted context omitted.

"and can only provide 2kW output." only 2kW? 2kW is enough to power any residential, single-family house for 95-98% of the time; you only need (a little bit) more than that at very short (few minutes) peak intervals - when heating up an oven, or some cycles of doing laundry. A second unit would provide that headroom, and otherwise (when the extra $5k for a second unit is prohibitive) you could still draw from the gri…

I use incandescent lights. They produce a much more pleasant spectrum than “white” CFLs or LEDs.

LED's are available in various color temperatures, including 2700K (commonly referred to as 'warm white' which is basically the temperature of incandescent). It's true that the dollar-bin Chinese LED's have all sorts of bad characteristics that used to be associated with all things LED - pale color, bad spread, bad (or no) dimming capabilities, etc.

It's 2015 though - take a 20$ Philips Master LED for example (I decided upon those for myself so I looked into them more heavily; I have about 20 in use now, with another few boxes in my basement awaiting installation). The GU10 socket halogen-replacement version is available in 3 temperatures and 3 spread bundles, has a 20k burn hour rating (vs 1-2k for incandescent!) and can be dimmed very well using a 50$ leading edge electronic dimmer.

I'm no tree hugger - even purely economical (apart from the convenience of not having to replace lamps every year), in 2015 it doesn't make any economic sense to buy incandescent (in those places where it's possible to buy them at all...) for all purposes where the light is used on a 'regular' basis (more than an hour a day or so).

Of course it does require an initial 'investment'. But one that would be spread over 1 or 2 years - the normal replacement cycle of incandescent bulbs. Throwing out working incandescent bulbs to replace them with LED is not rational either, of course.

Re: Tesla Energy

#228

Post by ZeroGravitas »

colinsidoti wrote: post #51

One thing that might go overlooked: Load shifting could, in theory, lower electric bills such that there's ROI without solar panels. --- Edit for why: On-demand power is expensive. "Spinning up" additional power during the day is more expensive than having certain types of power generation running all the time. In theory, pumping power into a battery at night during non-peak hours will cost less than consuming direct…

Can grid arbitrage and time-shifting solar co-exist? Some clever software might be able to predict your energy demand (e.g. based on seasons and past usage patterns) and your likely solar output (this time based on seasons and weather forecasts) and make the maximum use out of the battery.

I'm also wondering if the same software is going to be rolled out to Tesla's cars so that they act like Tesla Energy when plugged in overnight.

Re: Tesla Energy

#230

Post by raverbashing »

miratrix wrote: post #181
ChuckMcM wrote: post #138

Nice, that came in lower than I was expecting. I was thinking $5K for the 7kWh unit. Of course that is the "installers" price so who knows what those folks will consider the 'retail' price. My wife still has her solar installer certification so we could presumably get one that way. It also makes for a really interesting opportunity for grid tied solar inverters. Now you want the inverter to power the house first, the…

On the grid tied solar inverter front - the spec sheet says the battery voltage is 350~450 V, so we're looking at 108 lithium ion cells (25 x 18650 cells?) at 400 VDC nominal. This is quite different from typical lead acid battery pack voltage of 12, 24, or 48VDC that's used for battery backup storage, so a lot of existing solar battery storage infrastructure may not even work... this means that people may need to bu…

Yes, it would be interesting to know if there's an advantage of connecting so many cells in series

Most systems limit themselves to something like 48v as you said (I think 48v is the threshold of "being dangerous")

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