The thing with the panels not being usable for self consumption if the grid goes down shouldn't be a binding technical issue but a regulatory one due to feed in regulations / contract though?
Do your panels directly feed into the grid? Is the electricity grid in your county DC based or AC-based?
Whould be interesting to know what the reason is?
Since from in our neck of the woods (germany) the inverter (the device changing the DC electric power into a grid-conform AC at above 95% overall efficiency if its not broken, YMMV depending on specification ect.) can depending on software and technical setup be easily switched over to self consumption (there was even a short period of about 1 year where part of the payment for renewable electricity was diverted to self consumption.).
If the setup is Panel (>possibly inverter) > Grid > house and the grid is rather unstable that whould explain it (sorry if you explained it clear enough for a native speaker, isn't clear for me.).
(Over here its usually Panel>Inverter>House < > Grid with im- and export to the grid dependant on size of the generator and light-conditions as well as possible other renewable or storage options in / near the house and the last 2-3 years also electricity price for the end consumer since its become cheaper due to both rising electricity price rises and cheaper panel end-installation prices.)
In case of a zombie apocalypse taking some private jet /landbased / Seabased vehicle and liberating a storage option with enough capacity to power your home permanantly sounds like a good idea anyways. (trading for it with food or other life sustaining stuff with other survivors while your at it if you are nice which I guess is what you whould do )
Could of cause liberate a walled place with a big solar generator on the roof while you are at it to put your liberated storage option to good use (China, Japan, Germany and Italy might be prime locations for such an endavour Possibly some places in the States as well you might know those far better than I) Easily defensible + more or less reliable power is a rather safe place in comparison. (Sure a few hours of outage each day whouldn't be the biggest worry in such a situation.)
Whouldn't want to rely on a coal or especially a close nuclear station in such a case either though. shutting down a nuclear plant without (or with zombified) workers might not work soon enough before a meltdown occurs (given that a zombie apocalypse isn't exactly likely to induce controlled and selfless behavior possibly even among trained personal. Especially while being munched on by the walking dead. ).
Plus the poor people holding the grid stable (which is no trivial task either) will probably also not be immune to zombification (and the grid thus will shut down first, not last).
The very existance of a grid is the very thing allowing an electricity supply-system based on large fossil-nuclear power-stations on a big national scale at all (and is one of the big luxuries of developed countries).
Not so much for especially solar + Battery (for extreme example see the devices in outer orbit where solar and possibly nuclear are the only current options. With nuclear ruled out for mostly obvious reasons).
The alternative in the real world in many real grid-less (and often poor) places are kerosene lamps and diesel (or other liquid-fuel fed) generators.
The technical comparison between those options and Solar+Battery even for lighting alone is so big it its bordering the absurd (even excluding the health ramifications of burning kerosene in the place people live / learn / sleep / eat / breathe).
(also economically. Grameen Shakti helps people of Bangladesh and other places without a relibale grid install solar home systems which have a ROI of a few month currently and sinking. Even at the hefty micro-credit interest of about 10% they take. Because burning fossil also means burning large ammount of money there.)
Technical comparison from 2 years ago:
In both cases the comparison has further shifted in favor of solar due to the solar + battery + LED option becoming quite a chunk cheaper (Solar +LED) and developing further (battery + mainly LED) with the kerosene option becoming quite a bit more expensive and kerosene possibly harder to come by.
That trend is likely to continue.
Solar+Battery might not be as reliable as perma-firing a generator or burning kerosene each evening (might be even, generators aren't error-proof either and spare-parts may be hard to get, haven't been to 3rd world with firsthand experience, the number of solar-home-systems installed by grameen Shakti and others sure looks convincing). But it sure is cheaper (to the point of enabling normal life beyond toiling for light and food at all) and offers possible utility beyond light in case of kerosene lamp alternative.
People whouldn't apply that option en-masse (over a million) there if it wasn't viable for them (see http://www.gshakti.org/ Solar System for number of installed Solar Home Systems just by this one micro-financeer and development over the years).
On the other side of the spectrum is middle europe where the grid-based power-supply not least thanks to the stable local, federal and national as well as the pan-european grid (both ways each) is so stable in some places its fit enough to be easily and by far the best emergency and back-up option by itself for generators even when looked at by critical institutions (at downtimes of electric power of average 1 hour per Year for the regular end-customers in the large metropolitan regions in the last decade its better then even the best generators individually can offer. Must run-units or not. For critical consumers which are shut down last its at most a few minutes and those are regulated to always have back-up options, not very likely ore desirable for them to have a power-outage any time soon.)
Kudos to the people keeping that grid stable here (in spite of not being in favor of fossil nuclear myself grid-stability is not an issue in the system here to be criticized even at 25% gross anual renewable electricity generation/consumption, with large regional differences with some places allready exceeding 60% of yearly gross production currently and one federal state aiming at becoming a whopping 400% renewable electricity generation and export powerhouse in about a decade. And I have good trust in those grid-maintaining people to also cope with 40% or 60% renewables which will financially break the back of the large power generating units which are by and large very old to the point of going down for maintenance often anyways and will have to be replaced in the next decade by something (fossil-nuclear or renewable). At 25% renewables those big plants are allready in dire straits and whould burst the grid if not for the option to export into other European countries (which is usually done). Shutdown often isn't a technical much less an economic option for them since midday peak is fastly turning into midday valley. Flexibility Options whould be nice and are technically possible with gas-fired stations but in the all out raging economic, political and market regulatory-framework battle those options fall by the wayside in spite of probably mid-term neccessites (long-term storage and flexibility options are possibly going to win in a world powered by fluctuating renewable electricity). End of the year after general elections things might clear up. Currently its possibly outgoing current gouvernment + 4 big power supplier-utility oligopoly (well, to be honest its 3 now since one fell into the hands of a federal-county green-working party coaltion right after fokushima thus re-accessing its stance currently with another one possibly falling due to political and economic reasons in the coming month to a year) vs. will of majority of the local electored / parliament / federal house. With lobbyists, companies and media mingling in on various fronts. old generation vs. new since the old players have well and clearly understood that it might be their last stand if they should lose. With no guarantee that even with a first clear victory in this battle ever they might survive long term. Tense times for all involved. As usual in existential conflicts both sides loose badly since solar companies are hanging in the ropes just like some of the old powers that be are. Cell- and Module-Producers from China along with the local people installing renewable generators on their roofs or in their fields here and small-middle local installing companies might very well be the laughing 3rd when the dust settles. Beyond the Chinese everyone will sustain grave wounds economically and psychologicaly.)
On a more serious note: You might want to wait for a few years and look another time for storage options then.
The technical possibilites are manifold but unlike with renewable power generation (where the fluctuating generators of wind and especially solar seem to be the unlikely but clear winners) the storage options haven't reached mass-scale industrial production yet (meaning if all runs well and in five years time the systemic switch to renewables here and in China will run in full swing demand might araise along with mass-production and prices are set to fall till after another 5 years the best options might emerge).
Electricaly induced electrolysis and / or following methanation (+ re-electrification and usage of exess heat from methanation step and re-electrifictaion step, only current long-term storage option which is technically ready also covers heat generation partly. Handily we also have a rather comprehensive methane gas distribution and storage network here which can be filled with either natural gas or hydrocarbons synthesized with the help of renewable electricity making it a likely systemic contender mid-term), natrium-sulfur (might be a good option for stationary applications unlike lithium ion which is (yet) comparably expensive or different lead-based options which have major environmental and direct health ramifications + might not be the cheapest in short order.), redox flow (which is a liquid chemical which can be transported comparably easily from what I understand) and mechanical storage (compressed air, fly whell) , just to name a few (to describe the options as plenty whould be quite an understatement) are all possible and promising candidates.
Main Questions to be answered for you are what time of an outage do you want to cover (short-term, long term,seasonal).
Combining mid-large-scale wind with solar PV alleviates most of the solar / wind (respectively) downtimes (but that is on a systemic scale might not help you localy) to a few days a year.
But if the race for the best generation technology is anything to go by we can't with certainty guess which will come out top (who even of the most visionary thinkers in the renewable energy community as short as 5 years ago whould have thought that solar PV will very likely be the cheapest electricity generation option bar none sometime between the middle and the end of this decade?
Possibly even beating Wind-power at about 2016 and subsidized and! written off! Lignite well into the start to middle of next decade. Since China has decided to markedly up their short term targets for solar prices are bound to fall further possibly even faster than guessed which is the norm since all estimates in the past have been way to conservative, usually by far.
Prices for a KW/h of electricity generated by a newly installed solar PV-plant delivered to the consumer may well be hovering below 5 cent (euro a bit more for dollar-cent) before 2020)
With Wind onshore comparably stagnating in price (high 1-digit percent-range reduction each yer) but on a very low level (development there mostly takes place in size of the generator / tower might change though) since concrete and steel don't get cheaper (unlike solar-grade polysilicate while at the same time experiencing current overproduction of panels in stock.) and probably reaching 6-7 cent till then.
That is with just the evolutionary optimization constantly seen in the last 10 years with revolutionary developments in those two fields possible if not likely. (But who knows the future? Predictions have been widely off as I have alluded to, usually to pessimistic with regards to renewable electricity. Power from renewable energy in all its forms may be abundant and even freely available to citizens and companies alike reaching the state of an allmende good by the mid of this century or maybe even in many corners of the globe and possibly beyond. Like many things got with time when society evolved and things turned cheaper / commonplace / taken for granted.)
If you really like to throw money at experimental storage-tech have fun but as a sound economical investment storage doesn't seem viable right now here either (neither much neccessary here short term until about 60-80% electricity share is generated by renewables. Cutting some 1% access power from point of view of the power generator or exporting it like we do with our fossil-nuclear exess energy that can't be turned down fast either are alternatives to storage among others.)
If you are genuinely and highly interested in development of storage options for renewable power even at its current (wildly variying) states IRES (Internetional Renewable Energy Storage Converence and Exibition) 2013 in Berlin, Germany November this year might be of interest to you (@Moderators: feel free to delete that part if its seen as spam. Not sure if it blurs the line since while the conference itself is mostly cost-covering and Eurosolar as organizer is a non-profit organisation by local law, its your forums and you may view it as such...)
That is peek at our little space of land over here (with each other european country having wildly different ideas of how to generate their future electricity. Eager to see which System is set to come out top. My bet is on fluctuating renewables + flexibility + grid + storage with efficiency being a nice idea but not often implemented into practice)
Savor the luxyry of a more or less stable grid / electricity, its something which shouldn't be taken for granted indeed but here and for now it is (YMMV might be different in the states, care to elaborate happy to hear how it is on the other side of the pond.). A power outage over here is a rare and strange occurance indeed (and due to the short time and mandatory backup + tiered shutdown for critical consumers nothing which is worrying anyone besides a few media lunatics which preach the blackout while electricity is flowing outward because we generate way more than we can use and rising.)