Is renewable energy different to electricity from fossil fuels?
An electron of renewable electricity is exactly the same as an electron of electricity generated by a conventional power station. Thermal coal and nuclear fuel are conventional energy sources for generating electric power. There is no difference in the electricity from conventional power stations or that from a renewable source. Power is fed into the national electricity grid from many different locations. Electricity comes from hydropower, geothermal, fossil fuel, nuclear fuel, wind, and solar. The supply of electricity can depend on the location demand and where power is available.
The electrical power in the grid is the same regardless of its source. It is the power production method that makes a difference to the world. An electricity distribution grid is like an electricity mixing and demand-balancing machine. The grid foreseeably will draw power from all available sources; wherever there is electricity. Those sources may be renewable energy sources like hydropower from rivers and dams of ample water supply. They may as well come from the wind turbines farms and tidal energy pontoons of the seas.
Is all electricity clean power?
The grid electricity may come from conventional power stations. These will use fossil fuels like coal to operate existing thermal power stations, or some use nuclear fissile material. In other locations, residential solar PV panels or acres of mirrors for concentrated-solar thermal systems could be producing electricity. Solar thermal power systems focus a large area of sunlight onto a tall tower. The concentrated area of sunlight provides a concentrated heat source. That concentrated heat will produce molten salt for heating water to steam as in a conventional power plant.
There is a major difference between the exhaust or waste output from the power generation process. A coal-based power plant and a nuclear power plant have waste products. With a renewable electricity supply, there is no waste. A concentrated solar-thermal power plant, similarly to coal and nuclear power, use a steam turbine process to generate their electricity. Burning coal or oil generates heat and massive quantities of greenhouse gases (GHG) emissions. Those emissions cause or contribute to global warming from air pollution. Nuclear fission produces heat with no GHG emissions but waste fissile material is an environmental issue needing further resolution. Renewables produce no GHG or waste materials, but they do have a problem of providing an intermittent and variable supply. In that way the electricity produced is different.
Are there fewer problems with renewables?
There are ways to store energy that make renewables more effective for baseload power supplies. These methods include pumped storage, battery banks and heat storage. The question here is about electricity from renewables versus conventional non-renewables. I will leave the issue of intermittent supply but acknowledge some renewables need additional backup power options.
Generators like hydropower, solar power or wind turbines are renewable power generators. If your power comes from a renewable source, then it is green electricity. Green electricity production has contributed no GHG pollution or added no other waste products to the environment. If you consume electricity from your solar PV panels or a wind turbine there is zero pollution output from it. The electricity from a renewable energy source or from a conventional source is identical. There will be a difference in the environment.