I'm planning to store wine bottles for several years, but I live in a hot city and don't have any cellar to use.
What other alternatives can I use to store the wine in a good environment?
How hot are we talking? A cool closet on an inside wall of the house should be fine.
But I think the only real answer to this is a dedicated wine fridge with finer temp control. One that you can set to a cellar type temp. You don't want to store your red wine as cold as a normal fridge obviously.
As brewchez suggests, there are a number of "wine cellars" on the market that are essentially mini-fridges that can run at cellar temp. Another option, if you have the room, is to use a Johnson Controls thermostat with a full-size refrigerator as brewers often do for control of fermentation temperature. (here is one example: http://www.midwestsupplies.com/johnson-digital-temperature-controller.html)
You could get a cheap table-top wine fridge.