Why batteries both thrill and terrify the U.S. utility industry

http://www.bloomberg.com/news/print/2014-12-05/musk-battery-works-fill-utilities-with-fear-and-promise.html

by dotluis • 12 years ago

159 190 12 years ago

DanKlinton• 12 years ago

This Elon Musk guy sounds more and more like Tony Stark from Iron Man :)

falcor84• 12 years ago

Musk was indeed was an inspiration for the movies (and did a cameo on Iron Man 2) http://content.time.com/time/specials/packages/article/0,288...

gohrt2• 12 years ago

It seemed to me that Iron Man (comic) was an inspiration for Elon Musk's persona.

JoeAltmaier4• 12 years ago

Rooftop solar would have a very hard time supplying the same current feed your power company has. A few back-to-nature Californians may be satisfied with the battery-solar combo straw man in this article; most of us want our TV and microwave too.

taf2• 12 years ago

Really - I am not so sure... my brother in CA tells me after installing solar panels on his home his bill from the power company went from 3 digits to $4 per month. He isn't really a back-to-nature Californian either...

JoeAltmaier4• 12 years ago

Maybe we need 200 Amps from the power company for peak demand (frozen pizza + ball game + blender) but don't really pull much most of the time. Batteries limit not peak but total draw over the day. Hm.

mabbo• 12 years ago

The threat isn't that people don't need any power from the electric company, it's that people need very little of it. Demand dropping to 5% of your usual business model might as well be demand dropping to 0%.

sethhochberg• 12 years ago

Especially when you're dealing with physical infrastructure (like power lines) that has relatively fixed upkeep costs regardless of demand.

JoeAltmaier4• 12 years ago

Some of that drop can be beneficial to the power company. They are always on the edge of capacity, because building more capacity is very (billions) expensive, and at first you don't need all of it, so the marginal cost of expansion is huge. Deploying solar across the area could postpone the need for generator expansion, and save money for current customers.

tomjen3• 12 years ago

But in that case you can downsize a lot, because you only need to produce 10% of the normal electricity, and then charge, say, twice the amount your normally charge for the usage, perhaps reducing it to 8% or so.

That is still a higher rate of return than you would normally get, which makes it a better investment.

reportingsjr• 12 years ago

The batteries that Tesla uses can far, far surpass what a power company would be willing to provide to a residential unit.

The most powerful model s on the road right now has a ~310kW motor in it. That is an order of magnitude above what most house circuit breakers are rated for (200A-300A, 24kW to 36kW). There are even small RC batteries out there that can push 150A+ for a few seconds on their own.

kefka2• 12 years ago

Why are they so scary? They're just a whole bunch of 18650's, with integrated cooling chambers and nice chargers.

I just picked up a pack of 10 from ali express for $14. The charger was $10 and can charge 2 batteries in about 1/2 hour. The American markets don't see them unless you crack open dead laptop batteries and test.

mullingitover• 12 years ago

I've seen plenty of 18650s outside of laptops. They're extremely popular in the electronic cigarette scene.

defective• 12 years ago

Yep, and we inherited them from the flashlight enthusiasts.

jarrettc• 12 years ago

The article suggests that solar panels could be an "existential threat" to power companies. For those of you who are familiar with the math of solar panels, how realistic is that prediction? How much of a normal home's energy needs could be supplied by solar panels, assuming the panels covered the entire surface area of the roof? How much is the ROI on solar panels likely to improve in the foreseeable future? (I've heard estimates of 5-8% annual return for 2014.)

djrogers5• 12 years ago

I installed a 10kw system ~15 months ago on my 3600sq ft house. Average electricity costs was ~$6k/year before the panels, the first year on solar to total cost for the year was $300.

That $300 worth of electricity for the year is before I've been able to talk the wife in to replacing our incandescent bulbs, swapped out our old pool pump, etc etc - I could easily get that down to below 0 with a small investment in bulbs. So in my case at least, it was trivially easy to get to a net-zero usage.

A few $$ notes - the system cost $37k, I got 11.1k of that in a tax credit from the feds, so my net cost was 26k. I'm saving 5.7k/yr, which means my break even point for the system is 5 years. In 5 freaking years I'm making money from my solar panels! And I don't have to write a $500 check to PG&E every month. It's a beautiful thing...

BTW - the above numbers (plus my severe aversion to debt) are why I'm so against solar leases. If we had a solar lease, we'd still be stuck with monthly payments, would have trouble selling our house, and would be stuck for 20 years.

Pxtl• 12 years ago

Where you located? Are we talking Texas or Michigan?

chdir• 12 years ago

How many units does $500 fetch where you live? Would be curious to know a breakdown of the bigger portion of the pie in those units.

mrfusion2• 12 years ago

$6K/year sounds really high no? My neighbor pays $100-150/month for a 3200 sqft house.

hga5• 12 years ago

Where do you live?

Where I live, in SW Missouri, capital and maintenance costs might be higher due to weather (e.g. high winds, hail), and it would be useful during the summer---which the electric company would be generally thankful for, less $$$ peaking power needed---but much less so in fall and winter when it's frequently overcast.

Also, if you live in a place with high electricity rates, like California, the case elsewhere is less compelling. I probably pay on the order of 1/2 of your savings for the total power to handle a building that's almost certainly bigger and thirstier than your's (numbers on request).

crdoconnor• 12 years ago

Hawaii?

pkaye• 12 years ago

Where do you live? Do you use electricity for heating? I'm in California and for a 1500 sf house, it costs us roughly $600 in electricity and $600 is gas per year. This actually an old house with some insulation. I think it would be more efficient for me to improve the insulation and water heater/furnace before even considering solar panels. I wish they would subsidize these other improvements as much as solar panels.

baddox2• 12 years ago

How long are your panels expected to last, and how much maintenance do they require? Is the 5 year break even point pretty much guaranteed, and considering those things?

g8oz• 12 years ago

Wholesale panels are $500 a kW. That's a lot of markup you had to pay. Definitely much room for improvement on margins.

nobodysfool• 12 years ago

Well, one of my friends in Arizona has not necessarily his whole roof covered, but he is able to generate about 90% of his yearly energy usage. The only problem is that he doesn't have batteries installed, so he's selling his electricity to the local power company and buying it back. With batteries and a slightly larger system, he'd meet all his energy needs himself. It's definitely possible. One thing that helps is the hot water heater is solar powered as well.

pwnna• 12 years ago

I believe there was a report from US utility companies saying that solar will severely impact their revenue.

http://www.eei.org/ourissues/finance/Documents/disruptivecha...

abakker10• 12 years ago

Without directly answering the question of total capacity, solar does have a few problems that are unlikely to ever make it an "existential threat" to commercial power generation, especially when done at home.

1. It is highly dependent on the amount of sunlight an area gets. This might seem obvious, but is also problematic in that it is difficult to build the correct capacity for climates that vary significantly over seasons. Solar is well and good in Los Angeles, since the weather is very consistent, and the amount of sunlight doesn't vary hugely over the year. In Seattle though, if you were to install enough capacity to be useful in the winter, you would drastically over-produce in the summer. Over production of solar is currently a problem, and can have significant detrimental impact on the overall power grid. Typically, when it drastically over-produces, it can cause blackouts. This is amplified by the fact that solar produces its maximum amount of output at a time when people don't consume the most electricity. This may eventually be mitigated by better batteries, and alternative power storage systems like Vanadium Flow systems.

2. Solar has a maximum capacity, and will likely always need to be mixed with other "on-demand" power generation systems. At present, these are Coal or NatGas generation stations that can be ramped up to meet spikes in demand. Effectively, these plants allow us to store energy chemically in the gas/coal and burn it on demand. very few renewable energy sources have the ability to be ramped up to greater production over short period of time. Again, this problem could be mitigated by substantial battery installations, where a small amount of excess generation from solar could charge batteries that could be drawn on to deal with spikes in demand.

3. Power transmission is always going to be a problem. Solar is less and less viable the further toward the poles you go. Though we could generate power in the southwest, there are practical limits to how far power can be transmitted over existing lines without too much loss.

In all, though it would be possible for Solar to operate a given house or building with on-site generation. It is very unlikely to threaten the power companies, which give us a low-cost, reliable, and simple solution that is capable of meeting our needs.

gohrt2• 12 years ago

Is it not possible to "turn off" a solar panels? Worst case, you have to throw a tarp over some of your panels for summertime.

djrogers5• 12 years ago

<quote> Typically, when it drastically over-produces, it can cause blackouts. This is amplified by the fact that solar produces its maximum amount of output at a time when people don't consume the most electricity.</quote>

This is a pretty regionalistic viewpoint - in many parts of the world the peak solar production and peak electrical usage are highly correlated due to air conditioning use.

findjashua• 12 years ago

Re #2: is it be possible/feasible for panel owners to sell the extra electricity back to the grid?

maxerickson5• 12 years ago

There's a lot of parameters (load, location, roof size, season), but I think the answer is generally > 100%.

On the other hand, cities don't have the surface area to account for industrial consumption.

ilyanep• 12 years ago

I'm making a lot of assumptions here, as I'm not an expert on solar panels (took a class that touched on them once, but I'm mostly just Googling here):

* Typical efficiency of a consumer solar panel to day is about 12%

* Average of 6 hours of sunlight a day over a year, sunlight providing 120 W/m^2 [1]

* Rooftop of about 80 m^2

Total energy over a year comes out to about 2500 kWh.[2] Apparently the average household energy usage in the US is about 10000 kWh[3], which would imply that you could get about a quarter of your energy from solar.

A few caveats:

* Apparently some places get up to 2200 kWh/m^2 per year of sunlight[4], which would bring your solar panel total to about 21000 kWh a year.

* Not entirely sure how big your average rooftop is.

* Solar panels have been created with efficiency in the 40s of percent[5]

Hopefully I'm not completely off with some of these, but it seems reasonable that a rooftop system can provide most or all of your power in the near future, depending on how sunny it is where you live. If it's not sunny, you might have a lot more problems, though.

[1] According to https://en.wikipedia.org/wiki/Sunlight, the World Meteorological Organization defines sunshine as a state of receiving at least 120 W/m^2

[2] http://www.wolframalpha.com/input/?i=365+days%2Fyear+*+6+hou...

[3] http://www.eia.gov/tools/faqs/faq.cfm?id=97&t=3

[4] http://www.nrel.gov/gis/images/map_pv_national_lo-res.jpg

[5] http://www.sciencedaily.com/releases/2013/09/130923204214.ht...

maxerickson5• 12 years ago

Power is quite a lot higher:

http://en.wikipedia.org/wiki/Insolation#Earth.27s_insolation

(the 250 W/m^2 there is the 24 hour average)

mrbabbage• 12 years ago

This doesn't answer your question about residential solar, but it's a useful primer on economic analysis for utility-scale operations.

http://www.eia.gov/forecasts/aeo/electricity_generation.cfm

The interesting bit here is how wind is already cheaper than any other option save combined cycle natural gas, and wind is on track to surpass natural gas.

kefka2• 12 years ago

I've been interested in the viability of those wind towers. The ground is blanketed with plastic tarp about 10ft above ground. It slowly tapers to vertical (approximates y=10^x curve). In the vertical section, there is a scaffolding with wind turbines.

The idea is that the sun heats up the ground. When the wind starts moving, it goes up the chute, spinning the blades.

It was theorized that a 1mile diameter ground cover + tower would give 500 MW of power.

blacksmith_tb2• 12 years ago

I have a 4.8kW system on my 1700sqft home here in rainy Portland OR and I am net-zero (and that's with everything electric - heating and cooling, water heater, cooking, etc.). But I am also in a certified Passive House, which makes it quite a bit easier...

bjelkeman-again• 12 years ago

Building passive houses makes so much sense. Did you build it yourself or buy it?

clayton21• 12 years ago

To further comment on djrodgers:

His ROI in 5 years but can possibly be less. Depending on the state/market/utility, the owner qualifies for local rebate incentive, homeowner solar water heating rebates, local labor substantability rebates and SRECs. SRECS are energy credits that are similar to forwards contracts that can be traded on an exchange. The federal tax credit (ITC) is 30% of the purchase price but expires in 2017 to 10%. But, forecasted solar cost drop to 2017 would far cover the itc.

abakker10• 12 years ago

I would point out that most ROI models for solar look so good because of very generous subsidies. If subsidies aren't counted, the ROI time is not nearly so good.

Additionally, the Total Cost of Ownership of Solar will be higher in areas where panels/solar systems are prone to damage from weather etc. Wind, Rain, Snow, freeze/thaw, dust can all damage solar arrays, or negatively impact their performance.

If there are batteries involved, those will likely also need to be replaced before the system has initially paid itself off. Even if batteries get cheaper and better every year, the disposal fees for old batteries and their current inability to deal with house-sized loads well can easily add significant cost.

I don't want this to sound like I am anti-solar. I am a big proponent of solar, but there are many problems with the current system. It is a somewhat unfair comparison no matter what, since the energy we buy from fossil fuel generation does not accurately reflect the cost of the pollution it makes or the environmental harm it does.

mikeyouse4• 12 years ago

A big portion of the existential threat to power companies is the possibility of price-spirals.

The cost of maintaining all of the power infrastructure for a region is relatively fixed, especially if people don't disconnect completely when they add renewables. This cost is generally recouped by a small surcharge to every kWh that's provided to customers. The possibility of a spiral arises when customers start purchasing significantly less power from the utility, which means the per-kWh cost for the remaining customers will have to increase. As this cost increases, the ROI of adding solar panels improves, so more people add solar. As more people add solar, the utility must increase prices to the remaining customers.. etc. etc.

There's also pressure on this spiral from solar installers since the 'soft costs' make up the majority of new installations. As more people purchase systems, the per-installation price will decrease due to installers getting bulk discounts for materials, efficiencies (physical and bureaucratic - dealing with permits, etc.) from previous experience, and a bigger base to spread out the costs of their own capital equipment.

Detractors think that utilities are fear-mongering to increase their operating and price flexibility, which would likely result in higher profits in the near-term. I don't think I buy this theory though, looking at my last bill of about $50, $28 was generation and about $25 was transmission & distribution (T&Ds). PG&E bills T&Ds based on system costs / proportional usage, so if I cut my power, my T&Ds would drop to almost 0, increasing the cost on everyone else.

Here's a pretty balanced article about the issue;

http://www.renewableenergyworld.com/rea/news/article/2014/04...

AnthonyMouse• 12 years ago

It seems like the obvious solution is to make transmission and distribution a flat amount rather than trying to amortize it per KWh.

derekp7• 12 years ago

So if the power companies are worried about people buying less electricity, why do they constantly send out power saving tips, and push things like CF and LED bulbs, etc? Is that only because they are required to by law?

gerbal• 12 years ago

I think it's that power companies depend on a very broad customer base to support their substantial capital investments. When you start removing a small portion of customers the cost of power to everyone else starts going up. And if those customers aren't consistently off-grid, i.e. they still need grid power sometimes, that can actually raise power costs.

Increasing generation capacity to meet demand spikes is expensive, and requires having large, expensive power stations waiting at the ready, just costing money.

dorfsmay• 12 years ago

Kurzweil said their efficiency doubles every two years, and that they would be able to meet 100% of our energy needs by ~ 2030:

http://www.livescience.com/4824-solar-power-rule-20-years-fu...

teraflop• 12 years ago

Kurzweil said their efficiency doubles every two years

According to that article, he said the "use" of solar energy doubles every two years.

Efficiency has been gradually improving, but it's definitely not doubling every two years. Every few decades would be closer; that said, using an exponential curve to model a function that's capped at 100% doesn't really make much sense in the first place.

http://en.wikipedia.org/wiki/File:PVeff(rev141113).jpg

rdl• 12 years ago

Even if this didn't make sense in California (it might), it makes huge sense in Hawaii -- power is $0.30-0.50/KWh, and they're starting to look at higher charges for grid-connected solar users (connection fees), and lower purchase prices for power.

If I could handle peak and steady state loads off-grid there, I'd be very tempted. I was assuming water pumping storage, or scheduling loads, and a diesel or propane generator for extreme peaks (running tools), but this might work too.

amalag• 12 years ago

This was from last year, I don't know if things are still this way there.

http://www.scientificamerican.com/article/a-solar-boom-so-su...

msandford11• 12 years ago

From the article:

...said Ellen Hayes, a PG&E spokeswoman. “Having a solar panel that isn’t connected to the grid is like having a computer that’s not connected to the Internet.”

Patently false. It's a great way for them to rationalize their continued existence. But as rooftop solar takes off and the "smart grid" fails to materialize I suspect that you're going to start to see federated neighborhood grids running at 48VDC.

Anything less than 50V isn't regulated by the NEC which is why you're supposed to hire an electrician for new or major upgrades to your house wiring but nobody cares if you put in low voltage pathway lighting, doorbells, networking, etc.

That means that although you'll have to buy thick copper wires, people can wire themselves up with their neighbors LEGALLY to share power. That's a big deal. It doesn't take all that many people to be connected to substantially smooth out fluctuations. Most A/C doesn't run all the time, it's only supposed to be about 15 minutes out of every hour. So if I and four neighbors team up then we might need 5kW of solar panels between us instead of 5kW each. At least if it's somewhere sort-of temperate where A/C isn't crucial at night.

The power electronics to make this happen are getting cheaper by the day. Sure it means having to talk to your neighbors and some retrofitting, but that's doable. And with a lot of new equipment having VFDs in them from the factory (refrigerators, mini splits, even a lot of A/C compressors) it means that the cost of converting them drops even more.

mrfusion2• 12 years ago

I might be mistaken but I think 5KW can power your whole AC and a few other appliances, no?

watty2• 12 years ago

Yes, most of the time. My small house routinely exceeds 5 kW though.

kevin_thibedeau• 12 years ago

The NEC doesn't do any regulating nor do they have any authority. They write standards that states may or may not adopt and use for their own enforcement. That's why Romex is illegal in Illinois and New York has it's own code.

msandford11• 12 years ago

You're right, of course. But given how many people/counties/cities/etc just accept NEC recommendations, it's functionally equivalent for a huge portion of the US.

jessaustin4• 12 years ago

In a single building DC could work. Thick wires are expensive (and always will be), so in a neighborhood it's probably best to just go ahead and hire an electrician if you need one. EDIT: actually I believe the cutoff at 50V isn't because it's safe to be shocked by current below that, but because phone line voltage is 48V and the NEC doesn't want to step on the phone company's toes.

I've done a fair amount of line-voltage house/business wiring myself, and I've never taken any electrician's tests, but then again this hasn't been in highly unionized/severe inspection locations.

mey• 12 years ago

You can kill yourself with a single 9 volts in theory http://www.darwinawards.com/darwin/darwin1999-50.html

bravo22• 12 years ago

Correct. It is total power delivered. You can still short 48V wires and start a fire with high enough current.

msandford11• 12 years ago

Yes thick wires are expensive, but there are plenty of places where houses are only 50 feet apart.

That means your round-trip run is only 100 feet so you can look at this chart (http://en.wikipedia.org/wiki/American_wire_gauge#Tables_of_A...) and divide the Ohm/kfoot by 10. If you used 4 gauge that would be 0.24 ohm/kfoot or 24 milliohms per 100 feet. 24 milliohms on 100 amps is 2.4 volts of droop or a 5% loss. Not awesome, but as an engineer, acceptable.

The 4 gauge is available in quantity for less than $1/ft. 1 gauge is available for about $2/ft neither of those prices are all that daunting.

If you lived on the ideal setup where you have neighbors on either side and off the backyard you could wire 6 houses together for less than $1000. Divided 6 ways that's $160 as a one-time cost to be able to be a lot less careful about your power usage. Hell everyone could net-meter with each other and settle up occasionally if someone's consumption got severely out of balance.

The thing that I really like about this (and which perhaps makes me overly optimistic) is that it would spur a lot of neighborhood engagement and re-forming of communities in the suburbs, which is somewhere that's severely lacking in a lot of places. Perhaps that desire is clouding my rationality; I can't say for sure. But I can say that with the population's general mistrust of large institutions growing by the year idea like this are going to look more and more attractive as time goes on.

https://www.google.com/search?q=millennials+distrust+institu...

gambiting• 12 years ago

5kW at 48V is over 100 amperes - absolutely no offence to you personally, but anyone handling this without training and precautions is absolutely stupid, no matter how thick the cables are.

Florin_Andrei• 12 years ago

100 amps deserves to be treated with respect, yes. Just try and break the circuit and you'll see why.

It's basically like a welder. I did some welding a couple weeks ago, right around 100 amps. The output voltage of that machine is probably less than 48 V. Still makes a very pretty arc. :)

ddeck• 12 years ago

While you are correct that 48V is definitely sufficient to cause injury/death in certain circumstances, it's not the current that matters here (e.g. a 1V/5000A supply would have a lower risk of shock).

What will hurt/kill you is the amount of current passing through your body (in particular your heart) and that is determined by the resistance of your body and the potential difference of where it's flowing from/to (I = V/R).

Interestingly, the current required for ill effects is significantly higher for DC vs AC (at lowish frequency) [1]:

  BODILY EFFECT     DIRECT CURRENT (DC)    60 Hz AC     10 kHz AC
  --------------------------------------------------------------- 
  Slight sensation     Men = 1.0 mA         0.4 mA        7 mA 
  felt at hand(s)    Women = 0.6 mA         0.3 mA        5 mA 
  --------------------------------------------------------------- 
  Threshold of         Men = 5.2 mA         1.1 mA       12 mA 
  perception         Women = 3.5 mA         0.7 mA        8 mA 
  --------------------------------------------------------------- 
  Painful, but          Men = 62 mA           9 mA       55 mA 
  voluntary muscle    Women = 41 mA           6 mA       37 mA 
  control maintained                                           
  --------------------------------------------------------------- 
  Painful, unable       Men = 76 mA          16 mA       75 mA 
  to let go of wires  Women = 51 mA        10.5 mA       50 mA 
  --------------------------------------------------------------- 
  Severe pain,          Men = 90 mA          23 mA       94 mA 
  difficulty          Women = 60 mA          15 mA       63 mA 
  breathing                                                    
  --------------------------------------------------------------- 
  Possible heart        Men = 500 mA        100 mA             
  fibrillation        Women = 500 mA        100 mA             
  after 3 seconds                                              
  ---------------------------------------------------------------

The linked article suggests an across the chest current of at little as 17 mA could potentially induce fibrillation. At 48V, this is equivalent to a hand to hand (assuming the second hand is the exit point) resistance of ~2,823 Ohms.

While is this a very low resistance for the body, it's possible with wet hands and a large surface area in contact with the voltage source.

[1] http://www.allaboutcircuits.com/vol_1/chpt_3/4.html

kazinator• 12 years ago

100A out of 48V requires a resistance of 0.48 Ω.

http://en.wikipedia.org/wiki/Electric_shock#Body_resistance

Amps, as such, are not dangerous unless we are talking about a current source. But practical current sources regulate their output to a given current value by varying their voltage (so it's back to voltage again).

That said, 48V is high enough to be dangerous. See Oli Gaser's answer:

http://electronics.stackexchange.com/questions/19103/how-muc...

"You can see that as low as 20V may be dangerous given the right conditions."

msandford11• 12 years ago

None taken, but I'm afraid that you don't seem to know exactly what you're talking about either.

Just because something CAN supply 100 amps doesn't mean it WILL supply 100 amps. I can touch both terminals of my car's battery with my hands and very little happens. That's because V = I * R, V = 12 and R ~= 100k so I = 0.12 milliamps or 120 microamps.

Now of course we're talking about 48V not 12V but that's still less than half a milliamp, unless of course you have both of your hands drenched in saltwater and you grab as much exposed wire as you can, in which case the body's resistance is going to be much less than 100k. But for any reasonable adult it's fairly difficult to kill yourself with 48V.

Will people still need to be careful? Absolutely. But the idea is that at least at first, it's much easier to get around codes requiring permits and inspections and whatnot that make it much harder for individuals to do without explicit approval of the government (know how to file a permit? great. are you a certified electrician? sorry...). Given that in many places the government owns, regulates or otherwise has a substantial interest in the electrical utility company this at least temporarily would allow people to do this on their own. The laws could always change, but it tends to take a while at which point there might be enough people doing it that it wouldn't get passed.

cmsmith• 12 years ago

It seems good to note that neighborhood power co-ops would smooth out demand fluctuations, but not necessarily supply fluctuations.

toomuchtodo5• 12 years ago

Batteries for the supply slack, hot water heater elements to dump excess power into. Concerned about enough supply? Oversize your systems.

jessaustin4• 12 years ago

There's only so much they can do about demand correlation. Electric stoves, for instance, are likely to be used at the same time by most households. That's one reason why really good batteries would be such a benefit.

ctdonath• 12 years ago

Having a Leaf EV, I'd very much like to have a 2kWh panel not connected to the grid. Selling power back is uninteresting relative to keeping a 30kWh buffer battery topped off, charged during the day while the car's away, and passing the charge to the car in the evening (ideally at 220V, charging the EV within 4 hours). Other than perhaps being physically located in the garage, it would have nothing to do with house wiring.

sfall• 12 years ago

the NEC does cover low voltage systems

infogulch3• 12 years ago

Federated neighborhood grids could further smooth out large demand fluctuations by networking their cycling devices together so they take turns. The biggest power demands like heaters/AC units/refrigerators/water heaters all cycle on and off, and these cycles could be coordinated so that they wouldn't all be on throughout the neighborhood at the same time.

Smart water heaters could also smooth out some excess supply. The water heater would mix cold water with its' stored hot water in different ratios (depending on how much excess electricity there was and therefore how hot the water is) to provide a constant temperature output.

msandford11• 12 years ago

Yeah, at scale this kind of coordination is really, really difficult. With only 10 houses it's pretty easy.

gaius• 12 years ago

This is what you want http://en.wikipedia.org/wiki/Vanadium_redox_battery

The extremely large capacities possible from vanadium redox batteries make them well suited to use in large power storage applications such as helping to average out the production of highly variable generation sources such as wind or solar power, helping generators cope with large surges in demand or leveling out supply/demand at a transmission constrained region.

sliverstorm3• 12 years ago

At ~$5/foot for sufficient gauges, this sounds like a rather expensive project.

msandford11• 12 years ago

It's not $5/ft, see my other post: https://news.ycombinator.com/item?id=8706592

Further, even if it was $5/ft that eventually starts to look good compared to a $20/mo charge to have the privilege of being connected to the power grid. This is a concept that utility companies are actively discussing and implementing: https://www.google.com/search?q=power+grid+monthly+connectio...

If it costs $400 to hook up to a neighbor and it smooths supply/demand enough to where you could forgo the hookup fee you get paid back in less than two years.

Is the $20 number reasonable? Maybe or maybe not. The first article in the results is Arizona where the utility asked for $50/mo and got $5/mo. But I pay $15/mo to be hooked up to natural gas and nobody seems to think that's robbery at least where I live. I suspect that politicians might accept $25/mo or more as reasonable with enough campaign donations.

fnordfnordfnord2• 12 years ago

Yes, on the third day, boost converters, buck converters, and wiring with a higher voltage rating would arrive via UPS and that would be the end of the "safe" low voltage neighborhood grid idea; replaced with the much more efficient high(er)-voltage neighborhood grid.

goatforce5• 12 years ago

...said Ellen Hayes, a PG&E spokeswoman. “Having a solar panel that isn’t connected to the grid is like having a computer that’s not connected to the Internet.”

... "still useful". Is that the rest of the quote?

msandford11• 12 years ago

No, the quote ends. It's hilarious how wrong this lady is. Internet access multiplies the utility of a computer by what, infinity percent? I don't know, but it's a huge freaking number. How much extra utility do you get from having a solar panel grid connected? Maybe 20% to 200% more useful? Certainly not 10x as useful.

http://www.goodreads.com/quotes/21810-it-is-difficult-to-get...

kstrauser• 12 years ago

"Having a solar panel that isn’t connected to the grid is like having a computer that’s not connected to the Internet."

"...it keeps the NSA from spying on you."

There is so much market segmentation potential in that one sentence.

ap22213• 12 years ago

Extrapolating a bit, I'm guessing that she means that it doesn't make much sense for most individual homeowners to manage their own electricity production and storage. Instead what you'll see is more communities adopting Microgrids 'behind the meter'.

It makes sense to be connected because any excess can be sold back to the distribution company at the feed-in-tariff rate. Plus, what happens when a local power system fails?

nullgeo• 12 years ago

Oh how funny, 130 years ago Tesla scared the hell out of some battery company.

bdamm• 12 years ago

Even if individual homes can sustain themselves on solar power, there are many homes and even more businesses that cannot. Even if people are storing power in batteries and charging them up for later use when power is cheap (determined locally) you still need the utility to be that conduit to get the power from the (distributed) sources to the (distributed) consumption.

Can the existing grid handle this kind of workload? Yes, if it is managed well and controls are in place to prevent delivering more power into the network than it can handle.

dmritard96• 12 years ago

The interesting situation is that companies regulated as a utility, presumably because a competitive environment for infrastructure isn't always practical (defacto monopolies) is facing competition hence creating some interesting questions.

nostromo• 12 years ago

Another reason: consumers subsidize industry.

Look up your local utility rates for high demand users. (These usually include things like factories or data centers.)

They pay a lot less for energy than you do at home -- even though the power plant doesn't care if the electricity is used for your hair dryer or smelting aluminum.

If the consumer goes solar, industry will suddenly have to pay their fair share of the bill.

hga5• 12 years ago

You're ignoring all the ways it's cheaper to provide service to big, compact consumers like factories or data centers, vs. a big branching distribution network, more transformers and metering and billing costs. And then there's math is not optional details like power factor (https://en.wikipedia.org/wiki/Power_factor), although I don't know how they play out for these different sorts of consumers, but it's important to realize the grid past power plants is anything but simple and passively operated.

Plus factories can negotiate schedules of when they're pulling X amount of power, and most of them can shut down during extreme peak demand. It costs power companies a lot to avoid brownouts and blackouts during those worst periods of a year, and most of us home consumers don't have a firm deal to conserve during them.

The biggest devil in the details of all of this is what comes after whatever is producing power, solar cells or conventional power plants, baseline and peaking. That is, after all, what this topic is about.

maratd3• 12 years ago

I experienced the exact opposite with PSE&G in NJ. I had both a residence and an office in the same municipality. I was paying a higher rate per kWh at the office. Almost twice as much. When I asked them about it, they said it was because I was at an address marked as a business.

I think this depends heavily on state-level regulation of the utility and market conditions for your segment.

mikeyouse4• 12 years ago

To be fair, you're talking about a third distinction in the eyes of utilities. They typical tier pricing by residential, commercial and industrial. It's not uncommon for commercial power to be more expensive than residential, but it's extremely uncommon for industrial power to cost more.

grecy• 12 years ago

This is materializing in Australia right now.

My parents just put 5kW of solar on their roof, and are still tied to the grid, selling some back for a tiny fraction of what they buy it for at night.

The government has now mandated that everyone on the grid must pay an "access" fee every month, even if they use nothing, and they are limiting how many people in any neighborhood can go solar and sell power back to the grid.

It's no secret the government are doing this to protect their friends in the coal and electricity industry.

TrainedMonkey• 12 years ago

So what would happen, if government did not mandate that? Some people would go completely off grid, this would raise prices for everyone else. In some communities it would not be economical for electric company to operate at all[0]. Moreover they can't just leave this over to the cities because rich communities would go off grid and raise prices for others in the area. While I am sure there is "friendship" angle you are coming from is real issue is far more complex than that and there is no simple solution.

[0] And given utility status of electrical companies they are mandated by the government to do so anyways.

JoeAltmaier4• 12 years ago

Another issue is sunlight. Most folks own land but not the right for sunlight to fall on it. Someone next door can shade your roof with their large solar collector; now you HAVE to connect to the grid. Such disputes will interfere with the smooth deployment of roof-mounted solar energy panels.

elihu• 12 years ago

What is the price of a residential battery? Let's say you need 10 kilowatt hours to last from sunset to dawn (you might need more some nights, but if you're still on the grid, 10 kwh might be enough most of the time, which is what matters).

The Tesla model S has a 60 or 85 kwh battery. I don't know what the cost of the battery alone is, but it's probably pretty expensive. For fixed residential, you wouldn't need to use the most energy dense cells available, so it might be cheaper.

Wikipedia has a price per kwh comparison, showing lead acid considerably cheaper, though that might not be up-to-date with the price Solar City and Tesla pay for Lithium Ion cells.

If lead-acid is $250 per kilowatt hour, that puts a 10 kwh battery at $2500. Not too bad, but if they only last six years or so, that's a pretty big part of the ongoing cost of maintaining the system. How does lithium ion compare on price and longevity?

http://en.wikipedia.org/wiki/Electric_vehicle_battery

jared3142• 12 years ago

The Tesla model S has a 60 or 85 kwh battery. I don't know what the cost of the battery alone is, but it's probably pretty expensive.

As of 2013, the 60 and 80 kwh batteries are approximately $10k and $12k respectively. [1]

[1] http://www.teslamotors.com/blog/2013-model-s-price-increase

ChuckMcM5• 12 years ago

This is something I've been considering of late. I was an 'early adopter' for Solar and have had 5kW of panels on my roof for 14 years now. Initially we were on a 'watt for watt' type rate schedule with a flat true up at the end of the year (basically net usage would be billed every 12 months). This was a good deal for me, and a bad deal for PG&E apparently. Over the years they have morphed that into something much more in their favor and with the help of "smart" meters have factored in various timing aspects which all work toward increasing how much I pay PG&E even though I am using about the same amount of power that I was before.

The only answer then is to go 'all in' and just cut them out of the equation. But battery maintenance is a huge challenge with lead-acid packs, a fire risk with lithium ones. I'd love to have a locally owned and operated 'storage depot' where I could shove my excess power to the depot, and pull power when I needed it (like being grid tied) but consolidate and amortize the cost of maintaining the power storage component across a bunch of customers.

Raphmedia• 12 years ago

Can you legally do something like use the solar power for your lighting or small appliances and use the company's electricity for your heating? With different sockets and wires?

joshred• 12 years ago

Why wouldn't you be able to?

ChuckMcM5• 12 years ago

Yes, I could do that.

What I can no longer do is come out revenue neutral if I generate exactly the same number of kwH that I consume in a 12 month period.

jared3142• 12 years ago

I'd love to have a locally owned and operated 'storage depot' where I could shove my excess power to the depot,

I don't understand why the utility companies can't convert some of their regional substations to local grid level storage locations, to counter this trend. They have the scale to utilize larger scale banks of batteries, hire people to manage them, and even exploit more dangerous technologies (like the emerging molten salt batteries).

organsnyder3• 12 years ago

Simple: Most established companies don't have the stomach for that kind of innovation. They've been delivering their product for basically the same way for over a century, and their shareholders don't see the upside to changing.

Of course, that leaves them ripe for disruption, but the nature of local monopolies makes that somewhat less likely.

oblio• 12 years ago

One thing to note - while this all sounds very exciting and optimistic, a huge percentage of energy is actually generated by coal fueled plants: http://www.worldcoal.org/resources/coal-statistics/ - 40%.

Let that sink in for a while. More than 1 century after the introduction of gas and oil fueled power plants and more than half a century after the introduction of nuclear power plants, coal is still powering almost half of the world. Perhaps even this PC on which I'm writing this comment.

Don't expect a revolution. Expect an evolution that will take another half a century or more :)

mikeash2• 12 years ago

For a counterpoint, it should be considered that coal would be a lot more expensive if externalities were accounted for. Coal power poisons the atmosphere, the water, and the land, and kills thousands of people each year. If you account for those costs, coal becomes substantially less attractive, but most places allow power producers to avoid paying for a lot of those costs.

That doesn't mean you're wrong, of course. Coal has tremendous inertia, and accounting for externalities is hard. But the ubiquity of coal is partly due to a cheapness which is somewhat illusory, and we'd be better off if we accounted for it properly which would naturally push alternatives harder.

okaybutthen• 12 years ago

Only because right now the economics of coal fueled electric plants are favorable.

Coal based plants will die down as cost per kWh of ocean tide, wind, solar, etc are optimized.

yason• 12 years ago

Since they also make stationary batteries I wonder what would it cost to manufacture small flywheel energy storage units for homes instead.

To an extent, those are used in bigger grids to balance out peak production and peak consumption: they rotate in a vacuum on magnetic bearings and require very little if any maintenance.

Those big boys probably cost a lot but a consumer-grade flywheel which could spin for, say, 24 hours and be slightly less efficient (wrt. input-to-output and friction losses) could still be a big deal to even out daily usage.

jcromartie• 12 years ago

Entropy will increase...

Everything will become increasingly decentralized and democratized thanks to the miniaturization and increasing efficiency of technology. It's all but inevitable. The only thing that can stop it is politics.

jhallenworld• 12 years ago

I learned recently that nearly ideal batteries already exist for the purpose of storing energy from solar: nickel-iron batteries (side note: Edison made more money from selling these batteries than from any other invention). They last a very long time (50 years), are durable (not damaged by full discharge) and can be made from cheap materials. The energy density is not high, but this is probably not a major issue for home energy storage.

marcosdumay2• 12 years ago

Nickel-zinc looks more attractive. What you do need on such application is a fast discharge, and nickel-iron doe not have it.

Now I'm wondering what would it take to create an iron-zinc battery, and how to make it last... Nickel is not a metal you want to waste around.

infogulch3• 12 years ago

I didn't know about NiFe batteries. With a long lifetime, deep discharge durability, and cheap non-toxic construction they look quite promising. Except overall efficiency isn't great, and it looks like they require regular maintenance. Of course, maintenance becomes less of a problem at neighborhood/grid-local scale.

cportela• 12 years ago

Thank you for posting this as the print link. Literally a simple task, but again thanks.

diafygi• 12 years ago

For people who want to learn more about the complexities in this topic, I highly suggest listening to the Energy Gang podcast[1]. A ‎senior editor at Greentech Media, principal lobbyist at a huge energy lobby firm, and the founder of Sun Edison get together once a week to talk about at latest news. I work in the new energy industry, and everyone I know in this industry listens to this podcast.

For example, a few months ago, they talked extensively about how Hawaii's utility is basically falling apart since it can't find a way to compete with solar now that solar is at grid parity, and solar+storage is on the verge of reaching off-grid parity[2]. What happens when half of your customers simply leave? We're about to find out over the next few years.

Also, if you want to learn more about tech entrepreneurship in the solar, I recommend reaching out to the SfunCube[3].

[1] https://www.greentechmedia.com/podcast

[2] https://soundcloud.com/the-energy-gang/can-the-us-government...

[3] http://www.sfuncube.com/

Why batteries both thrill and terrify the U.S. utility industry

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