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Is Storage Necessary For Renewable Energy?
mdsolar writes Physicist and energy expert Amory Lovins, chief scientist at The Rocky Mountain Institute, recently released a video in which he claims that renewable energy can meet all of our energy needs without the need for a fossil fuel or nuclear baseload generation. There's nothing unusual about that — many people have made that claim — but he also suggests that this can be done without a lot of grid-level storage. Instead, Lovins describes a "choreography" between supply and demand, using predictive computer models models to anticipate production and consumption, and intelligent routing to deliver power where it's needed. This "energy dance," combined with advances in energy efficiency, will allow us to meet all of our energy needs without sacrificing reliability.
This guy is clearly no energy expert. He should have consulted an electrical engineer familiar with grid behavior and transmission & distribution engineering before creating this over-simplified explanation. He completely ignores the importance of local load differences, and seems to assume there is a loss-less, instantaneous transfer of energy across the national grid, both transmission and distribution channels, with no limitations.
He also doesn't get that even at a local level things like AC compressors are already averaged out and that delaying the timing of starts really makes almost no difference at the neighborhood level, much less a town level.
Its nice to completely ignore realities like overall cost. Its nice to not realize that industrial areas have a significantly different profile than urban areas, and that rural areas are vastly different. Its nice to call yourself and energy expert and get submitted to slashdot by those that believe you just because they want to, or because you fall in line with their agenda.
Credible experts are people who understand what they know, and what they don't know.
This is about as valid as the claim that "the wind always blows somewhere". Actual power generation data shows that weather is a very large scale phenomenon and the wind most definitely slows to a tiny fraction of its average power over an entire continent.
Stop worrying about the risks of nuclear power and start worrying about the risks of not using nuclear power.
Never worked as an academic physicist, never even completed a degree apparently.
Never worked in the power industry.
Never manufactured EE Equipment.
Nevertheless knows how to power the world?
-- Mike Greaves
Keep saving those AA's. Your gonna need them.
Heh, I laughed at this because one of my ideas is to use old but still viable EV batteries as grid storage devices, and the Model S, with the biggest batteries, uses the Lithium-Ion equivalent of a AA.
If you figure that the battery is retired from the car at 70% capacity and kept as a grid device until it's around 40% capacity this would give you massive storage capacity if only 10% of people drive a Tesla type car.
Of course, this would be a 30 year solution - 5-10 years for the batteries to degrade to the point they're no longer useful in a car, plus 20 years for EVs to actually penetrate the market enough to provide enough batteries.
I don't read AC A human right
I think the biggest mistake of the video, is when Lovins says that renewables are no different from baseload power plants, because baseload plants are down some fraction of the time also. He claims that power companies already compensate for downtime of baseload power plants by just having a few extra power plants. He claims that the same thing could be done with renewables.
That's just all wrong, in my opinion. It's a statistical error. Although baseload power plants are down 10-20% of the time, they are down at random. The downtime of any one plant is not correlated with the downtime of any other. As a result, if you have enough plants, then 10-20% of power generation is offline at any given time, as a result of the law of large numbers. That can be compensated for by building a few extra power plants.
With renewables, their downtime is not random. Their downtime is correlated with that of the other plants. For example, when the sun goes down, all solar panels stop working at the same time in a geographic region. Also, when the wind stops blowing (which can happen over a wide area), all windmills in that region will stop working at the same time. This is a much bigger problem than randomly distributed downtime.
If solar panels had randomly distributed downtime, and were as likely to generate power during winter nights as during summer days, then no storage would be required. We could just build more solar panels. This is because the randomly distributed periods of downtime of the solar panels would "cancel out" each other. However, it does not help to build more solar panels for the night time.
That is why renewables require storage.
The American Physical Society, http://www.aps.org/units/fps/m... Association of Energy Engineers http://www.aeecenter.org/i4a/p... and the Annual Appalachian Energy Summit http://www.news.appstate.edu/2... all seem happy to have Lovins as a Keynote speaker. Guess claims he is not an expert are ignored by these groups.
And yet spreading cr*p is all you do here. How about a link or two instead of ad hominem all the the time?
Lets say the grid operator detects an impending mismatch between supply and demand and they want me to shut down my refrigerator. So now I have to size my refrigerator such that it will 'carry through' such an outage without my food spoiling. That's just another form of storage. But now you've come up with a sneaky way for me to pay for it. And subsidize the renewable energy producers.
Will I get a tax credit for my extra large freezer? My oversized hot water tank? The extra capacity air conditioning unit I put in?
Have gnu, will travel.
> the minimum output of variable sources like wind. If you have enough turbines the wind is always blowing somewhere, and the overall output of the entire fleet never drops below some predictable level.
Not at all true, but it doesn't need to be.
The energy in a fluid , such as air / wind, is proportional to the velocity SQUARED. In other words, if a 10 MPH wind has 100 units of energy, a 30 MPH wind has 625 units. A light breeze of 5 MPH, just 25 units. 40 MPH, 1600 units.
So suppose you build a turbine with a design speed of 25 MPH (625 units). You don't want it to fall apart in higher winds, so the blades, bearings etc need to be big and heavy enough to handle over 1,000 units. That means you'll have friction and other losses of about 25 units. Notice the loss is the same as 5 MPH of wind - you get zero energy production at 5 MPH. At 10 MPH, energy output is negligible. At much above the design speed, the force on the structure quickly becomes much higher than the 625 it's designed for, so the blades are rotated and such to work AGAINST the wind, to avoid having the turbine tower blown over or spin apart. These facts combine to mean turbines produce a useful amount of power only within a narrow range of wind speeds. Unfortunately, the rule power = velocity squared is a fundamental fact of physics. You can't change that by inventing a new type of battery chemistry or something.
If you look at a radar map of the US, you'll see one or two weather systems covering nearly a million square miles moving across the country. Missouri may be on the north end of a system while the southern wind of the system is in central Texas. That's pretty typical that the radar will show one or two systems for the whole country. So it's simply not true that the country as a whole always has "average" weather, that the wind is always 25 over much of the country. The fact is, a windy system will move across the country one week, then the next week heat wave will tour the country.
If you wanted to use wind as your "stable" primary energy source, you'd need a week of storage.
Fortunately not all energy needs to be a stable primary supply. If wind produces good power 10% of the time, you can reduce the use of natural gas generators 10% of the time. That's a good thing! If solar heating heats just your hot water, just 30% of the time, that's a lot of natural gas that doesn't need to be burned.
Since they are often idealists, it's not surprising that advocates of renewable energy always have their eye on renewables as a complete replacement for primary electrical generation, but it's sad because it means we've almost completely missed some great opportunities to make a big difference. Th syn is REALLY good at heating things up. If you've left water in your garden hose in the summer, you know making an effective solar water heater is dead simple - so simple most of us have done it on accident. Yet, most of us heat our water by burning fossil fuels. Why? Because we've ignored the obvious, simple, effective wins as we focus on the holy grail. We've spent tens of billions of dollars on solar electric and a workable solution is always five years and two billion dollars away. For half that money, we could have converted all homes to solar water heating AND mostly solved world hunger with the billions left over.