Should I...

1. Develop a consumer facing web app with free access and use supported by ads?

2. Develop a consumer facing Web app with some free features coupled with premium features using a subscription model?

3. Develop a consumer facing web app with no monetization strategy strictly as a portfolio project?

same dilemma I have now lol

If you do not depend on it to make money, I'd avise you on no. 2.

Ads are introsive and the end-user generally doesn't like them, or you'll face an adblock killing part of your ad revenue.

Strickly free, is an option of course, but if you developed something with quality, and if your customers want a few additional features, make them pay for your effort.

Just adding my 2 cents here.

I second @fredrf. To the last point I don't think you should build it only for a portfolio. Figuring out monetizing is experience in itself

to expand @fredrf comment. mvp for free, use some inapp tracking service to see how users are using it, which features are most used, and then, once you have enough data, make a list of several premium features and create a survay for users to see which is most desirable, and then incorporate it in paid plan. these are just basic steps, there should be percise planning and usefull data collection strategy in place from the start.

100% 2. Ads piss people off, and they will barely make you any money. Also, you can throw it in your portfolio regardless of whether or not you charge for some premium features.

Develop it as a free app, once/if it gets traction then you can think of revenue.