What are six forms of renewable energy? What are the advantages and disadvantages of each?
Biomass, geothermal, wind, tidal, solar, and hydroelectric
Biomass energy : The dilemma is "Food for people or food for energy?". It is good if a country can provide land for biomass production and does not encounter food deficiency.
Geothermal energy: In some areas the geothermal gradient is sufficient enough to exploit to generate electricity. Disadvantage of it is that geothermal liquids contain many different types of minerals and elements. When they are allowed to flow free, they might pollute the environment (for example in Aydin Buharkent Turkey).
Wind energy: When wind is in sufficient velocity, people want to benefit from it by using wind turbines. The disadvantages of it can be listed as: some birds and bats as well as bees die when this turbines are operated, a certain amount of land (a quarter US acre for example) is necessary to erect wind turbines (wind power company has to cut down trees and clear the area), noise pollution, etc.
Tidal power : During high-tide event store sea water and then when it is low-tide people can produce electric by operating specific turbines. The disadvantages of it are that not everywhere you can see this activity, some fish species might be affected, you disturb some coastal areas, etc.
Solar power: PV technology depends on sunshine. Under sunny conditions, mild (in terms of wind) conditions and less dusty (particulate matter) circumstances, photovoltaics can provide electricity. You need free land to build PV arrays. Some people argue that some birds and other avians are negatively affected by such structures.
Hydroelectric (dams): Water is cycled in nature. When you build a dam on suitable places on a river, you can store water and produce electricity by operating turbines. There are some disadvantages of such structures. First, stagnant water bodies do not oxygenate (aerate) easily compared to that in streams (rivers). Therefore, they are delicate to pollution. Moreover, some migrating fish species could not move towards upstream. They are badly affected. Finally, such large dams slow down the rotational velocity of the earth.
There are many issues related to renewable energy indeed. I was warned that I have provided a long answer. So far, that is it.