But it doesn't need to be _more_ energy than before, just at different times. If you have 5% of your fuel need filled by wind, that's 5% you didn't need to burn. If it can only do 5% because of clouds, then the gas that need to be burned is still 5% less gas than before the wind turbine contributed 5%. Why would there be an INCREASE in gas burning because wind is taking some of the burden?
So now you only need gas on cloudy days. Before, you needed it every day. That's less overall gas.
It doesn't work that way, because gas and renewables are not the only players.
As more wind and solar are built, they displace non-dispatchable power, such as coal, nuclear and 'run of the river' hydropower. These baseload providers cannot operate profitably in a world where sometimes they are needed, and sometimes not.
Say you need 1000GW of power all the time, and another 300GW for peak loads. Before renewables, you might have:
500GW coal
500GW nuclear
0-300GW gas
Now a 100GW of wind power and 100GW of solar are added to the mix.
The gas plant has to run at 1/3 capacity at peak times on windy, sunny days; and at full capacity on calm, cloudy days. All is good; Exactly as you predicted, less gas is burned, with wind and solar offsetting its use. Yay!
So now you add more wind and solar. Let's double the installed capacity. Now on a windy day with little cloud, the gas plant doesn't run at all. But there's 100GW more power than is needed - so someone else has to shut down. But the coal and nuclear plants cannot just shut down - and if they do, and the wind drops or the clouds roll in, then someone is getting a power outage, because they take a long time to start back up once you take them offline.
So you need more gas to cover the gap, while whichever of the baseload plants ramps back up. So now you have:
0-200GW Wind
0-200GW Solar
500GW Coal
500GW Nuclear
0-900GW Gas
And either the coal or the nuclear plant (or both) is running in a very expensive way - stop-start means more maintenance costs - and they are selling far less than their nameplate capacity of electricity, so they are in a double-bind, with less revenue and increased costs. Meanwhile, the gas plant is running at well below its nameplate capacity (which is fine - they only burn gas when they are up and online, so they don't mind so much if they are only at full power on still, overcast afternoons).
At this point, the anti nuclear lobby will point out that the plant is making a huge loss, runs far less frequently than it should, and with a collective cry of 'Fukushima!!'*, will demand that it be decommissioned forthwith.
So now you have:
500GW coal
500-900GW gas
0-200GW wind
0-200GW solar
You are burning far more gas than before, and total CO
2 emissions have gone UP. For the exact same supply of 1000-1300GW.
And that's pretty much exactly what happened in California. Only the actual numbers are different to keep the maths simple.
Notice that a small amount of wind/solar is not a problem, as it just offsets gas burning as long as the contribution stays below the threshold where it starts to displace baseload power. It's larger installed unreliable capacities that cause a problem. Which is why it's taken a while to get to this point, even though wind and solar have been around for a while.
The principle that "If a little is good, a lot must be better" was never a wise approach to life, and this and alcohol consumption are two prime counterexamples.
Of course, if your population are smarter than the Californians, they shut the coal plant; that way carbon dioxide emissions will fall (gas is about half as bad per GWyear as coal); But note that demand for gas still goes up in this scenario. So you might save the environment from climate change, but you are still going to need to tell the people to get fracked.
*Death toll - zero
Quite right.
Some additional points.
Industrial plants pay for their electrical power differently than you or I do. They pay a demand charge and an energy charge. The demand charge is to pay for the cost of the required electrical power infrastructure to deliver the power to the plant. To pay for the capital investment for the generation plant, to pay for the transmission and distribution to the industrial plant. This is usually a charge based on how much peak power the industrial plant draws, usually measured as the maximum power provided by the grid during any 15 minute window measured in the month. The demand charge is based on kW's, kilowatts.
The energy charge basically is to pay for the fuel that goes into the generating plant, the coal, the natural gas, the enriched uranium, etc. The energy charge is based in kWh's, kilowatt hours.
You or I pay for our electrical power based on just the total amount of electrical energy we consume. We only pay an energy charge, so the costs of the infrastructure to generate and distribute the power to us has to be lumped into the energy charge. This is reasonable for the traditional electrical power scenario that we have had up to today. But the renewables knock this into a chocked hat.
If I put solar panels on my roof, I reduce my consumption of electrical energy, but I still need the full amount of electrical power from the grid that I needed before the solar panels went up because of night, clouds, etc. But since my monthly consumption of power is down I am paying less than I did before for the infrastructure for generating and distributing the power that I need for standby power. (The same thing applies to energy conservation, too.)
Spread across the whole power grid this inflicts serious pain on the utility. In the US the utilities are for the most part profit seeking corporations. These companies are guaranteed a rate of return on their investment in the power system infrastructure to generate and to distribute electrical power. It is correct to say that these profit seeking companies care only about the demand portion of the equation, the energy component is a pass through for the utility.
This means that as more solar and wind comes on line the energy charge that you and I pay has to go up, because the demand charge for the infrastructure is now paid for through lower consumption.
As the consumption charge goes up it becomes more attractive to add more solar panels and windmills. The result of more solar panels and windmills is higher consumption charges. This is called "positive feedback", and like the horrible sound produced when a microphone picks up its own amplified signal from its own speaker it is bad and unstable.
It is the same thing that occurs even if it is the utility that puts in the solar plant, the energy consumption in the traditional generators goes down but the utility is guaranteed a profit based on their total investment which doesn't go down, so the consumption charge for residential customers has to go up, while at the same time the consumption charges for the largest industrial customers will go down, because these people support the infrastructure costs through the separate demand charge that they pay.
In fact the situation is even worse when the utility builds the solar plant because it increases the investment made by the utility and it increases their guaranteed profit. This increases the consumption charges residences pay and the demand charge that industry pays.
And this dynamic of added investment in wind and solar by the utility increasing the overall cost of power will actually become worse if the utility adds batteries to increase the effective amount of solar and wind generated power. We will still need need the full amount of carbon emitting back up power that we have now and we will use it less meaning that the energy charge when we do has to go through the roof.
The only reasonable solution, in fact the only solution, is to build base power generating plants that emit no carbon and to close down the coal and eventually the base generating natural gas ones, to get them out of the utilities' rate base.
And this is why we should be building more nuclear power plants.
It is also reason #435 why it makes no sense to generate and to distribute electrical power using a multitude of profit making, monopoly private companies. None of the things that we want from a power grid is provided better by a profit making company than it would be from a publicly owned utility. And by publicly owned I mean by the government.
The government has two undeniable advantages that we need to take advantage of here. They have an unlimited amount of money and the ability to sustain continuous losses in the pursuit of a greater public good, in this case the good of not destroying the planet's ability to sustain life as we know it. Think of this as a war.
Every leap forward by humans in the past has been characterized by three factors, collective action, a new cheaper source of power and improved communication. We have in place #1 and #3, we only need #2, and we know what that will be, more efficient gen #4 and #5 nuclear reactors and fast and slow fusion reactors to provide the fission reactors fuel and to burn their waste.
Conservatives have quite possibly done us a favor by behaving like children about the need to reduce the carbon emissions into the atmosphere. They have provided us with yet another reason that we should ignore them, the same lesson that we learned after the gilded age and then forgot only to be taught it again by the Great Depression, only to forget it again, which we should have remembered after the Great Recession, W. Bush's parting gift to us, which we seemingly didn't. In an age when every little thing is blamed on the government, the government does fail and this failure to regulate the banks and Wall Street from doing what they always do, amp up the markets to the point of mindlessly stupid instability, because of an insane belief in the ability of the market and its components to self-regulate, this insane belief by the government and by conservatives isn't blamed for massive financial crisis and the resulting recession.
Unfortunately we will have to deal with some childish behavior by liberals, their fear of nuclear power, but we already ignore them, don't we?
Don't you think that this could be worked around if we could convince Apple to design the next generation of nuclear power plants?
While conservatives deny the existence of the problem, liberals deny the solution to the problem,
