SolarCity will install a bank of Tesla Motors Li-ion batteries for grid backup and load shifting. This would be financed over the course of the loan (typically 20 years), not all at once. http://www.solarcity.com/residential/energy-storage.aspx
Check out this Hak5 rig of van with PV and batteries: http://www.youtube.com/watch?v=tWmCpt2KXOs
From this, it is not hard to imagine if one scaled this setup one could be off the grid now.
There were several PV and battery setups there which worked pretty well. Obviously you need to be careful with the amount of power that you use, but it can run computers, TV and lighting with a reasonable setup.
There was a computer lab at one installation which had one desktop machine acting as a server and about 15 thin clients to keep the power usage low.
The only difference to them is that you draw less power than you used to. Sure, it would benefit them to learn your habits so they can manage steady power delivery at scale, but they don't get a say in your solar rollout. They don't get to prevent it. They don't get to be skeptical (or if they are, they can't act on it).
The person I'm replying to seemed to say that the engineers at utilities are skeptical of this technology and honestly I don't understand how they're relevant, since utilities aren't rolling out the technology, maintaining the technology, etc.
That is not the only difference; the pattern of your load changes too.
With 100% grid-supplied power, changes in load are driven by slow-moving, predictable systems like sunrise/sunset, weather, and seasons.
If you are running your own solar array, though, you will vary your grid load on much shorter time scales unless you invest in a big battery pack to smooth out the variations in insolation from clouds and storms. And even the normal daily variation will be stronger, since when it gets dark you'll not only be increasing your load (turning on lights, TV, cooking, etc), you'll also be losing your local generation.
The current electric grid is not built to handle such large changes in load on such short timeframes.
If you are running your own solar array, though, you will vary your grid load on much shorter time scales
I'm not so sure that these latter variations are significantly less predictable than what you mention in the former paragraph. Isn't the output of a solar array dependent on the insolation? Isn't the insolation dependent on the cloud cover? Can't you predict the cloud cover in any single place simply by taking advantage of real-time meteo satellite data? A similar feedback could be established for wind power. Given enough data, I'm reasonably certain that models could be established that would allow you to predict how the solar and wind power generation distribution is going to change in the next hour(s) so that you could prepare for it.
The issue is that the supply side and supporting infrastructure is built for an entirely different system where power leaves the power plants and goes through the grid to consumers. Now people are adding solar panels which generate a ton of electricity during the day (when everyone is largely at work/school) that must then be fed back into the grid, opposite the direction of normal flow.
Power is sold to the electric company at a much lower rate than the power that is bought from the electric company.
So you might buy power for 27c/kwh and sell it for 3c/kwh.
I figured what you generated went directly to your storage system, you drew from your storage system OR the grid, or some third part intelligently drew from the grid or your system as necessary.
Is it functionally impossible to have solar panels that don't "run the meter backwards?" Because I can see how that would threaten the infrastructure that wasn't designed for it.
I mean, I see places like Apple generating all their electricity on location for their new planned office and using the grid as backup. Is Apple sending their excess power back to the utility? Totally different scale, I'm well aware, but just curious.
In almost all grid-tied scenarios though, you want to sell the power back to the utility. I'm not familiar with commerical operations, as they would fall under power purchase agreements (PPAs), but with residential installations your meter quite literally does spin backwards or a separate meter is used to determine how much power you've sent back to the grid. This is dependent on how the utility compensates you for the power you generate (spin the meter back if its a credit or the same price as what your purchase it from them at, separate meter if the pricing paid to you is different than the retail rate).
As the article states, we don't have the issues in the US that Germany has yet, because Germany produces so much more solar energy than in the US. At some point though, questions will need to be answered about who is going to pay for the spinning capacity (likely natural gas generators) that isn't used except for those rare times when the wind isn't blowing, the sun isn't shinning, and you can't drag enough power in from another geographic region over HVDC transmission lines.
That doesn't sound like a bad problem to have.
Fukushima showed us how hard it is to turn a nuke on and off quickly, but I would think most hydrocarbon burning and other generation systems could be throttled according to demand.
If you really have a problem with too much energy, well, smelt some aluminum or electrolyze water or something.
http://www.caiso.com/docs/2003/09/08/2003090815135425649.pdf
The poster isn't saying they're producing energy, just that they must be ready to do so at any time.
The cheapest storage battery is simple lead acid figure a quarter per watthour installed. Or a KWh is $250. But with a 100% charge/discharge cycle the battery will be dead and need replacing in about 10 or so cycles. To get up to 1000 or so cycles (which is only 3 yrs daily cycles) means you only get to use about 10% of the capacity. Lets round up because rectifier/inverter gear, and buildings, and operators and their stuff, are not free. So you can guess about $3/watt of storage as an absolute best case, but probably more realistically a turn key battery storage facility would cost more like $4 and would depreciate fully in about half a decade.
Hydro turnkey is about $1/watt plus or minus massive corruption (what is the dollar value of the hetch hetchy valley of yosemite national park, etc?) Coal plants sell turnkey for a bit over $2/watt, natgas is arguably the most expensive around $6/watt. All of those last like 50 years, so divide those costs by about 10 to compare with a battery bank that only lasts at best 5 years.
Spinning capacity (well, sorta, in case of natgas) is around 10 times cheaper per KWH than batteries. You have to remember that power companies don't really care about pushing an agenda, more or less. There is no conspiracy, they just want to sell KWH. If they could install a battery bank instead of a natgas peaking plant, and keep huge profits, they most certainly would.
There are some interesting math problems too. If each stored utility grade battery costs $2500/KHW and the total overall worldwide battery industry is about $50B, that means if we abandon all other forms of battery use in the world and get rid of all laptops, cellphones, etc, we could build nothing but lead acid batteries at a pitiful rate of ... drum roll ... 20 megawatt hours of utility grade storage per year. Now since the batteries are scrap in 5 years, that means if in a Manhattan style worldwide project we focus the entire industry on utility grade storage, we can never store more than 100 megawatt-hours worldwide. Which if you assume a daily charge discharge cycle is about 10 MW continuous or about the capacity of ONE small gas turbine system. So its not as simple as going down to "batteries plus" and picking up a battery large enough to UPS a nuke plant.
http://juneauempire.com/state/2011-04-17/fairbanks-battery-b...
http://www.gvea.com/energy/bess
They chose Ni-Cad (presumably for good reason).
Edit: Some numbers:
It's about 5 megawatt hours (varies somewhat based on draw, could stretch it to 6.5 MW-h for 15 minute runtime, less at higher draws).
Cost $35 million, so ~$7000 per KW-h of capacity.
Planning authorized in 1993, online in 2003.
Expected battery life of 20 years (maybe 30).
So a project that didn't seem to take up the entire manufacturing capacity of the battery industry managed to bring up 0.5 megawatt hours per year, with a lifetime of 20 years, half of your prediction of capacity production capacity (but at much higher cost than you started from).
Instead we keep hearing the old "Wind and solar will never work because base load" garbage.
http://library.abb.com/GLOBAL/SCOT/scot271.nsf/VerityDisplay...
"An economically and ecologically more viable alternative to ‘spinning reserve’ – gas turbines kept running in case of an emergency – is battery back-up."