I don't have a grid connected solar system, but a small battery based system. As stated by Oigoi, a lead acid battery is about 80% efficient and you'll probably lose another 10% if using it via an inverter.
One way of storing excess solar is to 'charge up' the freezer with the 'deepfreeze' button (overrides the thermostat). I've lined the inside of the chest freezer with storage heater bricks, and if I get it down to -24°C it'll stay cold enough without power 'til the next days sun - even at this time of year.
in a similar vein, you can make ice packs during the day to use in the fridge rather than using grid power to keep it cold at night.
I've installed a couple of immersuns for customers and they seem very happy with them (can of course also be used with storage heaters up to 3kw).
if you want to go down the battery-inverter route properly, then you'd need a decent battery (ideally a traction type battery (forklift battery usually works out cheapest)) and a decent inverter (not an ebay chinese job) so you're talking serious money.
if you want to start small you could look out for a 2nd hand UPS (uninterruptible power supply) like this:-
http://www.ebay.co.uk/itm/APC-1400-UPS-with-faulty-batteries-in-cream-/230900355821?pt=UK_Computing_Uninterruptible_Power_Supplies&hash=item35c2bbd2edwhich is an inverter, battery and charger all in one. connect it to a bigger battery (the built in one is only ~17Ah), but bear in mind that it will only run ~500w continuous and with a limit of 1400va it will only start small fridges and freezers (which typically draw 5-7 times their rated current at startup).
Surely it would have been better for government grants to cover the storage of electric within homes to power the grid in a fall down?
Mmm.. well there isn't really a turnkey small scale energy storage solution unless, maybe, if you use lithium batteries and that would cost £££££, and it would still have only 70% efficiency.