In order to compile contracts using a different version of solidity, you need to use the useVersion method to get a reference of a different compiler. useVersion takes a string that indicates the JavaScript filename that holds the compiler, and it looks for the file in the /node_modules/solc/bin directory.

solcjs also provides another method called loadRemoteVersion, which takes the compiler filename that matches the filename in the solc-bin/bin directory of the solc-bin repository (https://github.com/ethereum/solc-bin) and downloads and uses it.

Finally, solcjs also provides another method called setupMethods, which is similar to useVersion but can load the compiler from any directory.

Here is an example to demonstrate all three methods:

var solc = require("solc"); 

var solcV047 = solc.useVersion("v0.4.7.commit.822622cf"); 
var output = solcV011.compile("contract t { function g() {} }", 1); 

solc.loadRemoteVersion('soljson-v0.4.5.commit.b318366e', function(err, solcV045) { 
    if (err) { 
        // An error was encountered, display and quit 
    } 

    var output = solcV045.compile("contract t { function g() {} }", 1); 
}); 

var solcV048 = solc.setupMethods(require("/my/local/0.4.8.js")); 
var output = solcV048.compile("contract t { function g() {} }", 1); 

solc.loadRemoteVersion('latest', function(err, latestVersion) { 
    if (err) { 
        // An error was encountered, display and quit 
    } 
    var output = latestVersion.compile("contract t { function g() {} }", 1); 
}); 

To run the preceding code, you need to first download the v0.4.7.commit.822622cf.js file from the solc-bin repository and place it in the node_modules/solc/bin directory. And then you need to download the compiler file of solidity version 0.4.8 and place it somewhere in the filesystem and point the path in the setupMethods call to that directory.