It would be possible but still be pretty slow. Soloing speeds up a little after you get Animated Stone at level 32 and even more after Tornado and Lightning Storm but you will still be most effective in teams. Adding damage procs where possible also helps 
FWIW my level 46 Earth/Storm can solo on invincible just fine but I still prefer to team with him when possible.
Octavian Vanguard
@ohmsEU and @ohms 2
Badging character: Bimble on the Union server, Badgehunter.com and City Info Tracker.
Yes, very soloable - mine has soloed quite a lot off and on up until his present level (also 46, oddly enough).
It's a lot easier with Vet. rewards (Nemesis staff was by far my best attack until I got Tornado). Air Superiority will help - I used it a lot in earlier levels, but have respecced out of it now. FWIW, Volcanic Gasses is a very fine home for damage procs - mine has three at present.
By my 50s shall ye know me:
Tundra, DVM, The Late, Neutrino Ghost, Sir Clanksalot, End Of Days, Prof. Migraine
Howler Monkey
Totally off topic, but Sir Clanksalot is a great name for a character. 
Soloing is not fast, but it does get easier as you level, especially 41+.
Don't be afraid to take powers, even just for the time being, as you can always get rid of them later. I had Stone Mastery before, but respecc'd into Fire Mastery recently, and boy does it make soloing quicker and easier! I'll be probably respecc'ing back into Stone later on for concept reasons.
@Under Control
Unfortunately Earth Control doesn't respond all that well to damage enhancements. It really is more of a control-heavy control set (!). Likewise, Storm Summoning will slow your enemies right down but don't expect amazing damage.
If memory serves, I was able to 'solo' at around the 35+ mark, although the difference between soloing and teaming is quite remarkable. Having said that I could just be a crappy controller
As the majority of damage from Earth is smashing and lethal, you'll find few mobs that succumb to your controllery charms quick enough. However, duoing with a Blaster or Scrapper is very doable, especially with AoE-heavy Blasters.
In short: Can you solo? Yes. Will you get to 50 by soloing in the next month? No. Do you care? I'll leave that answer blank.
I always notice Freezing Rain giving a big boost to my teams when a stormy is on them, does it not give you enough when you are soloing?
"Well, they found my diary today.
They were appropriately appalled
at the discovery of the eight victims
They're now putting it all together.
Women wrapped in silk
with one leg missing
Eight legs, one body, silk,
spider, brilliant!"
Lvl 39 Earth/Storm here,even after I got the Pooman at 32 I still found soloing to be very very slow.
Tornado helps a lot but you need to have stone cages in your build to maximise the damage aspect.
Lightning Storm seems to up the damage quite a bit.
I personally made my Earth/Storm 99% purely as a teaming debuff monster (which it is) but boy have I hated the 1% soloing lol.
Now Ill/Rad boy that is a solo class
I wouldn't solo with it. Earth is the 2nd lowest damaging set, so slotting with damage is pretty worthless 
Just keep teaming and watch the XP flow 
I couldn't solo with any def or controller its just not me.
He will honor his words; he will definitely carry out his actions. What he promises he will fulfill. He does not care about his bodily self, putting his life and death aside to come forward for another's troubled besiegement. He does not boast about his ability, or shamelessly extol his own virtues. - Sima Qian.
[ QUOTE ]
I couldn't solo with any def or controller its just not me.
[/ QUOTE ]
im the complete opposite, after playing my troller every other AT just doesnt seem as soloable.
@Damz Find me on the global channel Union Chat. One of the best "chat channels" ingame!
Ive got a lvl 29 earth/storm cont which i love, but hes slotted for teaming, with acc/rech/hold enhancements. I was simply wondering if i did something like slot damage, would it be possible to solo things? And maybe take air sup (i havnt got any vet reward temp powers)
Thanks x