Problem with renewable energy?

S

Starkey

New member
I think I've found a problem with renewable energy. I've probably just misunderstood, could someone explain it to me?

Lets take wind power for example: Wind turbines do no generate energy constantly; it isn't always windy enough.
So doesn't this mean that power plants (like nuclear, oil etc..) must keep producing the same amount of energy, just in case it stops being windy, so there aren't power cuts? We don't have an efficient way of storing this energy yet. So doesn't this an equal amount of energy is created be wind energy as is earthed into the ground, and wasted?
I don't understand; surly this means wind turbines are bad for the environment, as a great deal of energy is needed to create them, and any energy they generate is earthed anyway.
I really hope I'm wrong, can somebody please show me how.
 
You're right.

This is a problem with some renewable sources. The amount of energy you produce by solar cells will depend on how overcast or bright it happens to be at a particular time. The amount of energy you produce with wind turbines depends on how windy the day happens to be.

It is possible to store the energy. You can take excess power generated on the 'good days' to pump water to a high reservoir. On the bad days you let that water flow to a lower reservoir and generate hydroelectric power.

But, in principle, you're absolutely correct. We will need a continuous source of power that can still operate in the event that renewable sources fail to meet the needs.
 
A modern wind turbine produces electricity 70-85% of the time, but it generates different outputs dependent on wind speed. Over the course of a year, it will generate about 30% of the theoretical maximum output. This is known as its load factor. The load factor of conventional power stations is on average 50%.

The space occupied by wind generators is far larger than just the base of the generator. The actual footprint includes a safety zone around each generator and is at least 5 acres. When all is said and done, wind generation will occupy land areas of over 50 Acres Per Megawatt of power output. At the most 60,000 acres would be required to produce the same power output as a large, 1.2 gigawatt, conventional power plant which occupies less than 200 acres of land. That means that wind turbines would use about 300 times the amount of land as conventional power plants. Estimates vary a great deal, and depend partly on who is doing the estimating. At present, onshore wind is more economical than development offshore. Furthermore, offshore wind farms take longer to develop, as the sea is inherently a more hostile environment.
The modern electrical power grid is designed and managed to operate 99.9% of the time with less than a 2% variance in voltage, regardless of the load swings placed on the system. On a typical day, a major city will increase load demand on its power plants by more than a million kilowatts, it will happen within a couple of hours, and it has to happen with perfection.
To accomplish this engineering feat, every generator (and there are many) involved with the grid must operate in harmony with the others. Large steam driven power plants provide base load, or the large, steady portion of the electrical load that is most predictable. Smaller generators, often gas turbines, can be started with the flick of a switch to pick up load increases.

The two essential components of all generators on the power grid are dispatch ability and reliability. Wind power, as it is applied today, offers neither.

Dispatchability means that generators can be started when operators need them, any time day or night, regardless of weather conditions. Wind power isn’t completely dispatchable; it can’t be started unless the wind is blowing.

Reliability means that a generator will, virtually every time it’s fired up, produce constant, controllable power exactly as required by the power plant operator. Wind power also fails the reliability test because, even when the wind is blowing, it rarely blows at a constant speed. Wind tends to blow in gusts with an ebb and flow that makes wind generated power difficult to control.

One of the problem is that at best renewables won't be able to handle the "worlds" energy demands until the year 2050 (personally I don't know how they predict this as could you imagine someone 50 years ago predicting accurately what today would be like) but if you keep nuclear and remewables we can reach the C02 goals by 2035. This is one of the big debates at the moment about getting rid of nuclear which emits no greenhouse gases (it produce 6s6g/kwh at the most when you include mining, construction and decommissioning of the plan and is comparable to renewables).


Wind Pros:
Wind is free (Don't get excited,not free for the consumer)
Good source for farms with water pumping demands.
Perfect for rural areas

Wind Cons:
The demand is three times the amount of installed generation.
Can only be in windy areas
Require many towers and are limited to small generators.
Very dependent on climate.
Can affect birds if not designed right.

Solar Pros:
Sunlight is free
Very little pollution

Solar Cons:
Can only be in sunny areas.
Special mirrors are required and they can affect the environment.
A lot of land is needed for the small amount of energy generated.

If you want further and more detailed information go to:
http://nuclearradiophobia.blogspot.com/p/other-energy-sources-below-is-death.html
 
When the turbines are generating, the other sources can cut back on their production of electrical power. When they are not, the other sources have to take up the slack. It's that simple... in concept.

Both the turbines and the other, non renewable sources of power, are hooked up to the same power grids that cross the nation to give you electricity to see this answer. So the trick, the complex engineering feat, is to regulate the renewable and non renewable sources; so that there is no interruption to your computer screen.

In the case of those fickle turbines, the power grid managers must be able to anticipate when or if the winds will stop blowing; so the other sources will have to take over the job. And they must also keep track of the demand for power; it's a matter of supply and demand. If the winds stop blowing while you're asleep at night and your computer is off, there may not be sufficient demand in those wee hours to warrant stoking up another coal burning generator for example.

My point is this. Just because the turbines stop doing their thing, that doesn't necessarily mean non renewable sources have to be lit off. So their use, the turbines, does not add to the pollution issue.
 
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