I came across this when searching also for a way for my family to be able to view energy data. I noticed that I can do this as long as they are only interested in viewing the Apps (and the following link mentions Dashboards) by sending a link that contains the read API key.

I notice that when you open one of the Apps you have created it then appends the API key to the URL. For example: http://emonpi/app/view?name=Time+of+use&apikey=xyz where xyz is the API key. This link can then be shared and it works well. I notice that it appends the write API key but you can change to the read one (click on your user in top-right and select “My Account” to find this) which also works well for me.

I should mention that I am very new to emonpi (just set it up last weekend) so please feel free to correct me if there are any issues with doing this, or any better way.