Yes, it is right.

Advantages of using renewable plant:

1) By the use renewable plant, we can avoid the disadvantages of nuclear and thermal power. like, nuclear power plant requires very much secure place,bad effect of radiations, long constructing time and very high construction cost, and many more. in the same way thermal power plant has disadvantages, like, waste materials and fossil fuels are expensive and growing in slow rate and create pollution in environment which create bad effects for human as well as animals and plants.

2)   cost of renewable plants are  less expensive as compare to non-renewable plants.

3) use of renewable plants is good for environmental.

Disadvantages of using renewable energy plants:

1) wind energy and solar energy depends on weather. if weather is very rainy then solar energy will be dim, and if weather is very hot and no wind is over there then wind turbines will be failed to produce its required energy.

Currently No, renewable sources are not stable and large enough and also not so economic in some cases. The most issue about renewable sources is how to store electricity generated by them. If this problem is solved in an economic way, renewable energies will be much more useful than they are now.

How ever the future world may not have an other choice except renewable energies but currently it is still soon to eliminate fossil based an nuclear power plants.

In majority cases, the thermal and nuclear power plants are meant to meet the constant/base loads. The fundamental disadvantage of renewable sources is intermittancy of power availability. Unless the problem is sorted, your question has a no as answer.

Look at what is going on in Germany right now. They are doing exactly what you said.

I am NOT going to make a judgement.....

But, if you press me, I would say 'It is a bad policy'..

Now, electricity prices in Germany are going higher and higher and that causes the ding on their economy!!

Advantages of Renewable Energy

1. Renewable energy is, well, renewable: This means it has infinity of sustainability and we will never run out of it. Other sources of energy like coal, oil and gas are limited and will run out some day. 

2. Environmental Benefits: It is clean and results in little to no greenhouse and net carbon emissions. It will not deplete our natural resources and have minimal, if any, negative impacts on the environment, with no waste products of Co2 and other, more toxic take with different sources of energy.

3. Reliable Energy Source: Our dependence on fossil fuels has increased considerably in last few decades. The result is that our national security continues to be threatened by our dependence on fossil fuels which are vulnerable to political instabilities,  trade disputes, wars, and high prices. This impacts more than just our national energy policy. Also, solar and wind plants are distributed over large geographical area and weather disruptions in one area won’t cut off power to an entire region.

4. Economic Benefits: Renewable energy is also cheaper and more economically sound than other sources of generated energy. It is estimated that as a result of renewable energy manufacturing, hundreds of thousands of stable jobs will be created. Thousands of jobs have already been created in numerous European countries like the United Kingdom and Germany, who have adopted measures to manufacture renewable energy. 

Disadvantages of Renewable Energy

1. Reliability of Supply: One shortcoming is that renewable energy relies heavily upon the weather for sources of supply: rain, wind, and sunshine. In the event of weather that doesn’t produce these kinds of climate conditions renewable energy sources lack the capacity to make energy. Since it may be difficult the generate the necessary energy due to the unpredictable weather patterns, we may need to reduce the amount of energy we use.

2. Difficult to Generate in Large Quantity: Another disadvantage of renewable energy is that it is difficult to generate large amount of energy as those produced by coal powered plants. This means that either we need to set up more such facilities to match up with the growing demand or look out for ways to reduce our energy consumption.

3. Large Capital Cost: Initial investments are quite high in case of building renewable energy plants. These plants require upfront investments to build, have high maintenance expenses and require careful planning and implementation.

4. Large Tracts of Land Required: To meet up with the large quantities of electricity produced byfossil fuels, large amount of solar panels and wind farms need to be set up. For this, large tracts of land is required to produce energy quantities competitive with fossil fuel burning.

I found something interesting related to this topic.

http://www.forbes.com/sites/christopherhelman/2014/04/24/solar-is-booming-but-will-never-replace-coal/

http://cleantechnica.com/2008/03/27/solar-thermal-electricity-can-it-replace-coal-gas-and-oil/

Thanks Anurag,

The second reference cited by you is really a blow to the conservative belief that the renewables cannot meet the base loads and that the cost of renewable energy is  not affordable. 

And yes, as the article says, the policy makers are still underestimating the renewable energy sources. 

https://www.pscc-central.org/uploads/tx_ethpublications/223.pdf

https://www.nrel.gov/docs/fy17osti/66745.pdf

Yes, it is. But there are some problems to install renewable plant instead of all thermal and nuclear power plant. The main problems are uncertainty to produce power, installation cost, and small quantity.

With State of the art it is not possible due to long energy payback period in renewable energy technology. But renewable energy sources are the best option where grid connectivity, availability and transportation is very limited.