I found the solution using a different plugin for localStorage. http://amplifyjs.com/api/request/ I used their request method in particular. This is the solution:
amplify.request.define("model","ajax",{
url:"server/data.php",
dataType:"json",
type:"POST",
cache:"persist"
});
amplify.request("model",function(data){
model = ko.mapping.toJS(data);
ko.applyBindings(new LightsViewModel(model));
});
While it makes the initial request a little bit slower, the page loads up extremely fast afterwards.