Geothermal is good howver it needs to be in regions were there is previous history or current history of volcanic activities they are very expensive to construct as well with minimal green house effect.
Solar is good definately cheap and all you need is the sun and you have power. however my understanding of solar is you would need a large field of panels to power a city so the wasted land with these panel sitting on them turns me off.
Wind power is very good especially in coastal areas, but you will find you would need huge wind farms to be able to power cities or even contribute reasonably to the national grid.
Hydro- electric is very good, it does however require the land to be valley like and have a gorge present to work effectively but it is the most popular and can power up the entire grid by itself very efficient.
Biomass hmmm, not to keen on bio mass green house gas emissions use of methane to produce power to extract biomass energy is expensive.
How about Nuclear i think though it is dangerous it is the best because of the amount energy it can produce. The smaller nuclear power stations used on US NAVY ships are refuelled or re- serviced once every 20 years how good is that. Good luck
