That’s been the first huge limiting factor in renewable energy production – how do you store it for the rainy day? In particular, solar. The sun only shines some of the time, so when it’s not shining, how do you get electricity, if you’re not using hydrocarbons, which after all, can burn night and day, 365 days a year? But this problem also appears with wind (which does not blow the same every day) and other renewable energy sources.
Up until recently, and even now, batteries have limits. The bulky sizes, low capacity levels, and degradation of that capacity over time, have all made battery storage the redheaded stepchild of renewable energy. Think of this as a bottleneck for transitioning to other types of power that are not as constant as hydrocarbon-based fuels.
In comes hydrogen. Using hydrogen as energy storage works thusly: let’s say you have a solar panel on your roof. It generates excess electricity than what your daytime use is. So that extra energy would then be used for electrolysis of plain, old, H2O…aka water…separating the H from the O and producing hydrogen and oxygen (well, O2). The oxygen is let go, the hydrogen captured. Electrolysis is an energy-sucking process – it takes energy to break the molecule up. But now, the resultant hydrogen becomes stored energy. Because let’s say it’s 10 pm, there’s no sun, and you turn on a light. The hydrogen fuel cell in your basement – storing the hydrogen in whatever form, gas, liquid, or solid – mixes that H with air. The air has O2, the hydrogen likes to bond with O2, and that marriage of the two elements produces energy – which can be captured and run through your wires as electricity.
That’s the basics…I don’t pretend to remember all the specifics, like regarding any extra electron atoms and where they go. But in the end, all it means is that hydrogen, once made, is an energy storage battery.
Though it sounds really hunky-dory, it might just not be the right solution. First, electrolysis is pretty inefficient. Someone once pointed that out to me, and in researching it, it appears they are right. Any research in the area of electrolysis has to focus on reducing the cost to produce a fuel cell – there’s not much you can do to change physics. There is also high-heat electrolysis, which is still stuck in the lab, and is not yet in production. Even high-heat has a conversion rate of maybe 50% – compared with generating hydrogen from natural gas, which has an 80% efficiency.
There’s another major limiting factor in the use of renewable energy in the first place, which is the efficiency of the energy capture. Current solar panels only capture about 25% of sunlight falling on them for conversion, because only a small range of wavelengths can affect the panel. There’s hope in that department, like with this.
Here’s some of my problems with Finegold’s proposal, bold as it is. It seems he doesn’t understand the difference between energy production and hydrogen, which really would only act like a battery. He has not answered the question of where that energy would be produced (because right now, hydrogen is by far most efficiently produced by natural gas, a hydrocarbon).
Another problem is that I have not seen him address energy use. A much better investment of most of his $100 billion would be an efficiency program that uses regulation and incentives to drive innovation in efficiency. I’ve heard crazy figures like people could reduce their footprint on the earth by up to 90% if only we developed the energy-saving products, processes, and lifestyles that are quite within our technological reach.
This would require standing up to big auto, big industry, and big oil. Get rid of the subsidies for drilling, obviously, but also raise efficiency standards for cars by tens of miles per gallon, in a short time span. We have the current technology, with hybrids and electric cars, just not the will. The Congress just might save GM’s bacon in the meantime, forcing them to be innovative with the rest of the auto industry, since they can’t seem to get off their bottom lines and do it themselves.
It would also mean efficiency standard for things like refrigerators, ceiling fans, air conditioners, TV’s (do they have to suck up all that power when they’re off??). Did you know that your ceiling fan could be more efficient, but that the industry killed any chance of that because the GOP Congress slipped an amendment into a bill that preempted the rights of states to impose higher standards?
The other side of that coin is incentives. Personally, I oppose tax breaks for big business as much as possible, because after the tax break or subsidy has passed its usefulness, big business has the money to lobby to keep it anyway (like property tax breaks on telephone polls for telecom, or the gianormous farm subsidy bill). I would like to see subsidies and tax breaks given to individuals, instead. So let’s say a new fridge that uses 50% less power came out this year, but it costs twice as much? Give the consumer the ability to pay for it with subsidies and tax breaks, instead of subsidizing the company. Same result, the product moves, becomes more popular, goes into mass production, and comes down in price over time. But when the time comes, it’ll probably be easier to lose the subsidy to the consumer than one direct to the business.
Whatever we do, it does have to be bold. $100 billion is completely reasonable. However, I am disappointed in the lack of concentration on reducing our energy use, the rhetoric that appears to replace scientific understanding for buzz words, and the inability to stand up to Big Oil and other industries in order to walk the fastest path away from hydrocarbons. I don’t think Finegold’s admittedly unspecific proposal (all I see is a press release, which is not a proposal, by the way) is the best…or most efficient…way.
Isn’t there a similar issue with hybrid cars? Yes, electricity is much cleaner, but that electricity has to be produced in the first place, a lot of it by coal.
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I did some energy research earlier this year, and was surprised to learn the most efficient coal-burning plants waste two-thirds of coal’s potential energy. Two-thirds. Time to think outside the box.
I presume you mean plug-in hybrids; hybrids get all their energy from gasoline.
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EPRI and NRDC recently completed a report that evaluates the implications of plug-in hybrids. Short answer: on balance, they are a good thing.
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I cowrote a study in college 15 years ago looking at electric vehicles that found the same thing- for almost all pollutants, electric vehicles were better than the status quo.
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If you think the 30-40% efficiency of a coal plant is bad, check out an internal combustion engine sometime.
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And if you want to get out of the box regarding the 30-40% efficiency for a coal plant, that means figuring out how to violate the 2nd law of thermodynamics. Good luck with that!
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Of course, one smart strategy is to use the waste heat from electricity production for head and/or cooling. This is called cogeneration and/or trigeneration. It is not a new idea; the longwood medical area is powered by MATEP: “Annual consumption by MATEP’s customers totals over 1 billion pounds of steam, 45 million ton-hours of refrigeration and 225 million kiliowatt-hours of electricity.”
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Cogeneration/trigeneration is a good reason to argue for distributed energy; the generation of the heating/cooling needs to be pretty close to the point of consumption.
is that the electricity coming out of a plug is generally a little cleaner comparatively to internal combustion engines and what they spew per mile. Hybrids, of course, are not electric – they just recapture lost energy as the car moves, so that the engine can do less work and shut down.
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Of course, if you had an electric car, solar panels, and net metering, you’d see even less garbage spewed per mile of movement with your car. Eventually, the ideal situation is to get off the grid completely with the right battery technology and really efficient solar panels or a wind mill in your back yard or geothermal or whatever. Then every time you plug your car into your house to get it charged, you’re spewing zero emissions per auto mile.
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The big infrastructure question, it seems to me, is how and with what you power up when on the road…what will the future “gas” stations be powered by?
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I do think electric cars are more likely the best solution for the average family than hydrogen fuel cells. If, and only if, we have decentralized individual power generation.
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You had me until this sentence. Grid is good. The reason is that it reduces the total amount of battery storage needed. As long as net metering exists, there’s no reason for you to store your own energy on site if a neighbor needs the energy now — effectively, your meter “loans” the electricity to your neighbor, and collects when you need more energy than you’re able to generate and your neighbor has a surplus.
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Without the grid, everybody has to have enough battery to store enough energy to weather their worst scenario. With a grid, each user can “borrow” from neighbors — and if all neighbors are needy at the same time, we just fire up a power plant for a while [say, a biomass plant that’s renewable].
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The grid allows us to avoid having to have all those heavy metals in our basement, times 100 million households in tUSA. Each home can still have its own renewable power generation, and if that’s not enough for any particular home, the grid can still be providing green energy.
where that grid gets its energy at night. Unless we find a way to store grid-sized amounts of energy for use in the off hours, we’re still talking the use of hydrocarbons. If there’s one thing we can all agree on, it’s that we gotta phase the hydrocarbons completely out.
Lynne,
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I don’t know that I do agree with you. Before I continue, I should note that I serve on my town’s sustainable energy committee (I helped write the charter for it this year) and am very passionate about the environmental impact of energy use.
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But go here and see how much electricity currently comes from fossil sources. It’s flippin’ huge. And of course home heating and transport is nearly 100% fossil powered.
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While I support aggressive expansion of wind, solar, etc., the fact is that even with massively successful conservation programs, renewables will not be able to fill the gap provided by fossil fuels for decades, at the earliest. I am not being a cynic, I am being realistic.
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Our use of fossil fuels has a lot of negative impacts on the environment, geopolitics, environmental justice, etc. But it’s also provided a lot of the world with a lot of energy at a low price, and that can’t be ignored. If we wean ourselves from fossil fuels and end up spending 4x as much on energy, unfortunately that matters.
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The bottom line is, I can’t say that I agree with the statement “we gotta phase the hydrocarbons completely out”. I strongly agree with “we should rely much less heavily on fossil fuels,” but that’s a much different statement.
where would homeowners get their renewable energy at night?
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It’s not a problem. Wind blows at night. Biomass can be burned at night. Geothermal energy works at night. Tidal power works at night. Hydropower works at night. *
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These are things that don’t work so great for each individual homeowner, but do work for larger installations… making the grid that much more valuable at night.
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We’ve got to phase the hydrocarbons out, but the grid is not a barrier to that mission.
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It’s the only non-hydrocarbon burning form of baseload (GWe) electricity generation. Look at the numbers, it just isn’t physically reasonable to replace the coal and gas fired electricity generation, in this country, in this century, with your list of alternative sources unless you include a very generous portion of nuclear power.
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One, it’s not the only non-hydrocarbon burning form of baseload electricity generation on the GWe scale. Just ask Niagra. Or Hoover. Or Grand Coulee. Et al. Sure, there aren’t many more opportunities to build new large hydro in tUSA, but to claim that nuclear is the only large scale baseload is purely false.
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Two, you ignore the benefits of conservation, which could easily help reduce 20% of the total demand.
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Three, you ignore that in fact wind alone could generate enough power for all of tUS alone. Now, NIMBYism and energy storage problems indicate that this is unlikely, but to say it can’t be done is again, purely false.
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So, consider this: as of 2002, our electricity generation came from the following sources [numbers in quads]
nuke 8.1
hydro 2.5
green 0.9
ngas 5.7
coal 20
oil 0.9
total: 38.2 [rounding]
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So, take 7.6 off the top from efficiency. Let’s get rid of that amount in coal.
nuke 8.1
hydro 2.5
green 0.9
ngas 5.7
coal 12.4
oil 0.9
total: 30.6 [rounding]
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Now, let’s have 30% of demand renewable. That’s easily doable [in 93 years!], and in fact it’s in the process of being legislated to 20% by 2050. 30% of 30.6 is 9.2. Let’s bump green from 0.9 to 9.2, an increase of 8.3… and take that off of coal.
nuke 8.1
hydro 2.5
green 9.2
ngas 5.7
coal 4.1
oil 0.9
total: 30.6 [rounding]
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Let’s have some extra hydro. We can build small dams, but also we’re gaining efficiency in the larger dams. Let’s say we can get a half a quad there.
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nuke 8.1
hydro 3.0
green 9.2
ngas 5.7
coal 3.6
oil 0.9
total: 30.6 [rounding]
So yeah, I’ve got some estimates which you might label as optimistic. That’s fine. You might also point out that we’ve only reduced coal by 82%, not 100%. Fair criticism too. There’s also oil and natural gas still cranking out the carbon. Yup.
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I’ve never said that it can be done without nuclear. But, at this point we can still add wind and biomass and landfill gas right now without the side effects of nuclear waste or risk of disastrous accident. We can also add “negawatts” though efficiency and conservation without those nuclear problems. Let’s do those first. By then, maybe we’ve developed commercially scalable new green techniques, like tidal, solar, whatever. Then, we do those. When we’ve run out of green options, and we’ve still got hydrocarbons, sure… we look at nuclear and hope they’ve got some solutions to their two huge problems.
Ive never studied engineering, but I have always wondered why we can’t harness water movement, like waves, tides, or currents. I have heard you can make a windmill up to 33% more efficient by placing it sideways, and I can imagine that sideways turbine in the water, catching movement from all directions. The water is always moving…
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The trouble I see with my idea already is that it will keep us on the grid, and most people are looking to get off that once and for all.
…I have always wondered why we can’t harness water movement, like waves, tides, or currents…
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…there’s more than a bit of hydro than you might believe. Much of the electricity generated by the Tennessee Valley Authority project is hydro. Several decades ago, there was proposed a rather interesting hydro project in eastern Canada, in an area that had unusually high tides. The problem with hydro is that you have to build devices (dams and such) that will result in sufficient and sustaining pressure heads that the turbines can convert the force of the moving water into electricity. The TVA did that by basically flooding large parts of valleys in Tennessee (dams) and then by releasing the water through turbines (electricity).
You need to get access to the land. One of the difficulties with many proposed projects in the Grand-Nord (northern Quebec) is that the Cree and Inuit claim those lands. The negotiations for access can be complex and time-intensive, which makes them seem less attractive.
Can you imagine installing something like this off the Kennedy compound? You’ll get the next ride with Ted. Shore property is owned by too many fat cats to be used to generate power.
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But we should cut Mr. Finegold some slack. Whatever he’s talking about will be forgotten the day after the election. Both by the voters and by Mr. Finegold. That he has no idea of what he’s talking about, in the long run, doesn’t matter.
Simply because of the overt Shakespeare reference.
Unless of course I lived on or used the land that would be flooded. If you are planning a vacation out west, check out the Glen Canyon dam This dam decimated some of the most beautiful land in America.
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Why is nuclear power never mentioned as an alternative? It solves an awful lot of problems in regard to decreasing greenhouse gas emissions. It does create its own set of problems but if your goal is to decrease greenhouse emissions, nuclear power should be the first place you look.
Nuclear power isn’t off the table, but it’s not the easiest/safest/cleanest source.
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It’s not the easiest because the engineering and construction takes many years, lots of regulations, etc.
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It’s not the safest because, well, a wind turbine failure or solar failure might kill a few people and result in a small amount of very localized pollution. A nuclear accident, even if it’s just spilled radioactive water after an earthquake for example, is much more dangerous.
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It’s not the cleanest because (1) you have to mine the uranium, and (2) you’ve got that nasty waste.
If the choice were simply between nuclear and coal, I’d argue that nuclear is the way to go. But, so long as there are [cheap!] opportunities for renewable energy in the form of wind, biomass, geothermal, et al [not to mention efficiency gains — negawatts], there’s just no reason to go nuclear just yet…
I agree, excellent stuff Lynne.
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A buddy of mine sent me a link about a company harnessing waves and tides.
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http://www.oceanpowe…
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I read a story on cnn.com the other day about major office towers in NYC using 800 gallon tanks of ice to lower AC costs. They blow off the cold air during the day to reduce use of the grid. Then they use cheaper electricity at night, when demand is also much lower, to refreeze.
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For large scale applications, they say it works. You just have to have a big building to cool, with room for 800 gallong tanks somewhere and the will to do it. Article said it’s catching on in NYC,though. Becuase it makes sen$e.
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I believe it was stomv here who also told me about a similar method where water is allowed to flow through a damn and generate during the day. And then pumped back up above the damn when electricity is cheaper. That cycle is cheaper than just using electricity all day and reduces demand during peak hours.
the ice – AC trick isn’t more energy efficient — it’s less energy efficient, by definition. Damn second law of thermodynamics.
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However, it is economically efficient because the price to generate electricity during the day is far higher than at night, since the demand at night is lower and therefore only the most efficient power plants are used.
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So, the ice trick uses more total electricity, but reduces the amount of electricity used during the day. Net effect? It depends — it could reduce or increase carbon emissions, depending on circumstance.
the dam: that’s exactly right. What’s elegant about it in the long run is that it allows the power grid to balance unpredictable renewable energy sources [wind, but also solar in the long run] with this hydro — when the wind is blowing fierce, you “save” some of that electricity by pumping water up the hill. When the wind dies down, you “cash out” that saved electricity. This allows the power grid to know they’ll have a steady supply of electricity for customer demands, which makes the usefulness of wind turbines and other intermittent renewable energy sources higher, since they can be counted on to produce [in conjunction with the dam] when needed, not merely when the wind is blowing.
…in this discussion. I know full well what the 2d law is, and I’ve had to do battle with the anti-evilutionists over it on other message boards. The earth is not a closed system, and that is the point of the 2d law–entropy increases in a closed system.
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Example: you are able to get refrigeration in a space (a reduction in entropy in a refrigerator or a room) because of an increase in entropy at the power source.
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On the general subject matter of the comment, it seems somewhat ironic that buildings would be basically going back to the “ice-dominated” regime of cooling that was evident in the 1920s and possibly before. Any thoughts, as to the retrogradation of the technology?
It’s my understanding that the 2nd law absolutely is relevant to the explanation that cooling water to make ice cubes and letting those ice cubes melt [hours later, after keeping them cool in the mean time] to cool air must be less efficient than simply cooling the air in the first place.
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Using ice cubes requires at least two iterations of temperature differences between systems in contact with each other, and in each one heat [energy] loss occurs, no?
Re-hashing an old technology isn’t a bad thing — I mean, any time we discover that an inclined plane or a wheel is useful for a technology, we don’t think of ourselves as pre-historic retrogrades, do we?
…the 2d law is a differential equation; nothing more, nothing less. Read Feynman’s The Nature of Physical Law
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On your main theme, you’re correct. It is less efficient in the long run to cool the water, which will later be used to cool the air in the building. But in the short run, it might be more efficient to cool the water between midnight and 3AM, using power from the “peaking” power plants that would otherwise be dormant, than to have everyone merely cool the air at 3PM.
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What’s the energy trade-off? I don’t know.
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I do know that more than a few office buildings in Munich are cooled by open windows and fans. Maybe we should consider Turkish fountains–they knew how to cool things. (Actually, the Turkish fountains were quite effective, so I am not making a joke.)
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Actually, it might take less energy to produce ice at night than to cool the building during the day. If the daytime temperature is 90 and the nighttime temperature is 70, the heat pump effectiveness can increase by enough to more than make up for the insulation and storage losses. Whether it actually uses more or less energy depends on the details of the implementation. It will also vary from day to day based on the difference between night and day temperatures.
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Using ice to cool a building should be pretty close to 100% efficient, once the ice is inside the building. There is no way for the ice to melt without pulling in all the required heat from the building. Thermal “batteries” tend to waste very little energy. The reason they aren’t used very often is that they have to be huge in order to justify the cost and complexity of adding them to your heating/cooling system.
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It also depends on how the cooling system is designed. If you have huge tanks of ice/cold water and you blow air through them, the heat transfer is almost 100% efficient. If you use the tanks to cool a heat pump, you need to provide a lot more energy. On the other hand, if you are cooling a heat pump, you can store the water at 50-70 degrees (instead of 20-35), which means the night time heat pump doesn’t use as much energy. It is not immediately obvious which design will use less total energy.
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There is no way you can say without knowing the details of the HVAC design whether the nighttime cooling system uses more or less energy than a typical daytime cooling system.
I agree that we might be quibbling on the margins — that the difference might be negligible.
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But: while ice efficiency may be [nearly] 100% when its in the building, that presumes that it enters the building at the instant that you want to start cooling it. Of course, that’s not what happens… even if you could finish making the ice at exactly the right time, if “growing” ice were linear than you’d have an average of a half an ice block sitting around for hours, and you’ve got to keep that cold until its time to start letting it melt. So, since you can’t flash-freeze huge blocks of ice efficiently, instead you lose efficiency to preventing the ice tray from becoming a water tray before its time to start cooling again… and at 70 degree night time temperatures.
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There’s no question that a poorly designed “traditional” HVAC system could easily use more energy than a well designed nighttime cooling system. But… I don’t see the case for a well designed daytime cooling system doing worse than a well designed nighttime system. Maybe only marginally better, but better. Got a source with a more detailed explanation?
from a non-engineer. I use a heat pump. Aren’t there heat pumps that are designed to extract the cooler air beneath the ground for AC purposes? I don’t know what they are called, but isn’t the temperature beneath the ground a constant well below that of the surface? Why don’t I ever hear about this in discussions? Downsides?
You’ve got a great point — and personally, I’d like to see building codes amended so that things like heat pumps are required unless the builder can show that it’s problematic for this particular project.
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The only downside I can think of is the time for payback, which obviously varies on lots of factors. But things like heat pumps are exactly the kinds of things developers skimp on for new home construction [nobody doesn’t buy a home because it lacks a heat pump] to the detriment of all of us.
…isn’t the temperature beneath the ground (surface) a constant well below that of the surface?…
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It is true that the temperatures a few meters below ground are fairly constant, but there is a rather significant difference between a few hundred meters and the surface, hence giving rise to geothermal power generation. Which, I believe, Iceland makes significant use of; Yellowstone Park, too–the geysers. The earth is actually a very hot planet.
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Heat pumps (that I’m aware of) make use of the temperature differential between surface and subsurface to generate electrical power, that may be used to cool the air as in a common air conditioner. They don’t extract cool air from the subsurface.
I spent the money to install a heat pump because it seemed to be the most economical and environmentally friendly choice for heating and cooling my house. It’s certainly far cheaper than oil or gas. For extreme cold, I installed a pellet stove. My heat pump is effective to about 15-20 degrees. Below that, I crank up the pellet stove and the air handler on the heat pump recirculates the heat through the house. I also use an on-demand hot water system. Since I travel frequently, if I’m away, there’s no need to have the water heater using energy needlessly. I just wondered if there was any way to move the cool basement air (subsurface) up through a house for cooling (or, to cool a building in kinda the same way). Not an engineer, and you lost me on thermodynamics, etc.
how about a personal anecdote? my grandpa built a small church in the 1950s, and did indeed cool it by having the incoming air conduit pass under the basement before being released into the sanctuary. this was in the upper midwest, where summers are nasty hot ‘n sticky. such a system will never approach A/C in cooling and removing moisture from the air. however, it did make a difference. it is a nice “in between” type of solution. however, i’m not aware of anyone taking this approach these days.
You actually don’t pull the air directly out; you use a fluid (water or other) to pull the temperature out. They can do both heating and cooling.
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The downsides that I can think of:
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High capital cost: even though the payback is pretty good, you still have to sign up for an initial outlay of a few thousand dollars. Energy-efficient mortgages and similar financial instruments help with this, but these have not captured the public imagination widely.
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Invasive: You have to drill a bunch of holes in your yard. Not a huge deal (other than the cost- see above) but it’s another complication to have to deal with.
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Site-specific: You need a certain amount of space, for starters.
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It’s weird: Would you install a different kind of heat system if you didn’t know anyone with a similar system? What’s really going to happen? This is a rational issue; there is risk in the unknown.
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Inertia: If one’s heating system works okay, one tends not to replace it, even if a calculation showed significant savings by switching. If it suddenly craps out, you don’t have time to explore a brand-new option; you just get something similar to what you have now, hopefully higher efficiency.
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Other issues: My understanding (someone please correct me if I’m wrong!) is that ground-source heatpumps work well with hot air systems, but not hot water heat, because the hot water runs at a much higher temperature, and that impacts efficiency (there was a time when I could explain to you why this is, but my thermodynamics memory cells are rusted solid). I have hot-water heat, which is otherwise great, but I don’t want to re-fit the entire house in order to work with a ground-source heat pump (talk about $). My understanding is that it’s much more practical with radiant hot water heat b/c of the lower operating temperature. I installed radiant heat in one new room in my house, it is nice, but also rather expensive!
The theoretical maximum efficiency of a heat pump is H/(H-C) where H is the temperature of the hot side and C is the temperature of the cold side (on an absolute temperature scale, such as Kelvin). Ground water is at something like 280-290K. Hot air for heating needs to get up to 300-310K. Hot water for heating is typically at 320-350K. Steam heat is often over 450K. Heat pumps for hot air can theoretically have an effectiveness as high as 30, but it is more likely to be around 3-5. For hot water heating, the effectiveness can’t get above 10 and is more likely to be around 1-2. For steam heating, the theoretical maximum is about 3, but the real number will probably be under 1 (meaning that electric heating would use less energy). When I last checked, oil cost half as much as electricity for an equivalent amount of heating (so the heat pump effectiveness has to be over 2 to save money relative to burning oil).
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One problem with ground water heat pumps is that there is only so much heat in the ground over a given area. If everyone in a city installs a ground water heat pump, the ground water will freeze. The heat flow rate for the earth isn’t high enough to heat everything in a densely populated area. In suburban and rural areas, everyone could install one without causing trouble. In cities, you have to make sure that you don’t have too many neighbors sucking heat out of the ground.
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Regular heat pumps don’t tend to work very well in climates where it is frequently below freezing. The cold side of the heat pump tends to get coated with ice, which acts as an effective insulator and prevents the heat pump from pulling in more heat. They are fairly common in the mid-atlantic region of the country, because it gets cold enough to need heating for several months, but it rarely gets much below freezing, so the heat pumps actually work. Further south, most people use electric resistance heating, because the required heating energy is too low to justify anything more complicated.
… when ground water freezes in sufficient quantities you will get ground heaving, potentially creating structural problems.
I can feel those neurons stirring slightly…
…about hydrogen is that no one area of the world can claim an undue influence over it’s production. There are many production methods and different geographies can use whatever methods make sense for their particular natural resources. Many of these production methods are relatively ‘green’.
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The problem is that, as of right now, the most cost expedient method of production involves the burning of fossil fuels. No doubt that as the price of fossil fuels rises other methods will become cost effective. The question is, should we start an artificially created market (with taxes, incentives, etc.) to boost the development of hydrogen technology in anticipation of this change, or is the risk of spurring more fossil fuel burning in the short term too great for the potential long term benefits.
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The other thing that hydrogen fuel cells help with is that they encourage distributed generation. If you have a fuel cell battery in your building, for example, it makes more sense to include some solar panels or wind or geothermal generation in the building’s design. This distributed production will have a beneficial ripple effect by cutting into point generation, which usually involves fossil fuels.
One of the main selling points…about hydrogen is that no one area of the world can claim an undue influence over it’s production
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It depends on the source of the hydrogen. If the hydrogen comes from water (by electrolysis), that’s pretty much on target, except for the fact that you need a lot of power to generate the electricity to extract the hydrogen. Power from coal or oil. If the hydrogen comes from, say, methane, you still need a lot of power to extract the hydrogen, and you end up with CO_2 residue (methane is CH_4). With hydrogen, you end up by paying for the hydrogen with carbon based energy sources.
Since using freshwater for electrolysis is, well, too freshwater consuming…
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Signed, * Afghanistan * Andorra * Armenia * Austria * Azerbaijan * Belarus * Bhutan * Bolivia * Botswana * Burkina Faso * Burundi * Central African Republic * Chad * Czech Republic * Ethiopia * Hungary * Kazakhstan * Kyrgyzstan * Laos * Lesotho * Liechtenstein * Luxembourg * Republic of Macedonia * Malawi * Mali * Moldova * Mongolia * Nepal * Niger * Paraguay * Rwanda * San Marino * Serbia * Slovakia * Swaziland * Switzerland * Tajikistan * Turkmenistan * Uganda * Uzbekistan * Vatican City * Zambia * Zimbabwe
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P.S. Admittedly, some of us do have freshwater sources in sufficient supply for electrolysis and agriculture and drinking water and industrial uses, but we land-locked countries have to stick together in solidarity!
But the point I’m making is, that it’s not apparent that this is the best method for storing energy in a battery. Unfortunately, everything I’ve read suggests that basically, not a heck of a lot of movement has been made on batteries in the last few decades…that industry has little incentive to innovate. They need a major prodding. But I bet if we did, we’d see a huge jump in battery technology that probably would begin to compare with cost, usefulness, etc of fuel cells. Really, what needs to happen is a breakthrough in shelf life for rechargeable batteries. If that happened, electric cars may well run on that sort instead of fuel cells for all the reasons I outlined.
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If it were discovered you can preserve much more energy using some other form of battery, in most applications (home, auto, etc) especially if we’ve become energy efficient, other sorts of energy storage will probably be fine, if they are discovered to be cheaper and/or have better conversion rates than 25 or 50%. For other applications, like planes, big trucks, etc, that have a much higher need for energy (heavier loads, or more energy to take off and fly), I don’t know if anything less than hydrogen will do.
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I think it’s going to be a multi-pronged attack. I get the sense that hydrogen may never get used across a majority of applications, both for efficiency and for psychological reasons. And between a regular sort of battery, and volatile hydrogen, which is still combustible even if it wasn’t the reason the Hindenburg burned, you might choose a really great battery over a fuel cell for your home or car. The end result is the same – stored energy.
Lynne,
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Sorry to disagree with you again…
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Many industries have huge incentives to innovate with regard to batteries. Right now, cell phones and laptops are driving the innovations, and many can be scaled up to car or house-sized applications.
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The problem is that battery engineering, like solar power engineering, is really, really hard. Storing electricity, and converting light to electricity, are both really tricky things to do due to basic physics and such.
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Both solar panels and batteries have made tremendous strides in terms of performance and performance/cost over the last decade or so. But the problem is fossil fuels are such cheap sources of energy and have such incredible energy density that solar cells and batteries still can’t compete in terms of cost or other performance attributes. They are getting there, slowly. I would love to have a reasonably affordable solar array on my house that fed a house- or neighborhood-based flow battery, but we aren’t there. Yet.
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As for what the best way to store energy is, who knows. Pumped air and water storage work pretty well, but have their own limitations; hydrogen has all sorts of issues discussed here and elsewhere, and batteries are still not that great.
… my main point on this issue is one of volume. If it is decided that we needed to rely on storage systems, sure there are other technologies that are efficient. The problem is one of scale. If you were serious about getting off of hydrocarbons, then you must acknoledge that the energy has to get into a car some how… the only method besides transporting the generation method in the car itself (hybrid) is to store it. The other storage technologies are probably not scaleable to that size.
If you were serious about getting off of hydrocarbons, then you must acknoledge that the energy has to get into a car some how…
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…hydrogen-based autombile fuels will get us off of hydrocarbons, or significantly reduce the production of CO_2. The hydrogen itself needs to be produced somehow, and, according to SciAm, that means combusting fossil fuels. If and when a credible CO_2 sequestration method is developed, there may be a decrease in CO_2 emissions into the atmosphere.
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Going up a bit to stomv @ Thu Aug 02, 2007 at 20:41:54 PM EDT I’m not sure what the significance of the list is, but I’ll agree with your implication that combusting hydrogen would not significantly decrease the supply of fresh water, if only because the combusting of hydrogen produces fresh water. Unfortunately, the products of combustion are in the form of water vapor, which itself is a significant, if not the most significant, greenhouse gas. Fortunately, the water vapor eventually returns to earth in the form of rain, but, while it is lingering in the atmosphere, it also traps heat.
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On a side note, and a question for the techies. It is my understanding that one of the primary problems regarding battery technology for autos is the ability to get current out of the batteries rapidly enough to allow the autos to accelerate rapidly in an emergency situation, the I^2R problem (“I” is, of course, current). Has that been addressed recently, so that the batteries can deliver the requisite current? Or is that a “problem left for the student”?
and that needs water. Lots of it I would think.
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So, either use freshwater [which tends to be in short supply] or sea water. The nations I listed don’t have any ocean shoreline. Strange humor, I know.
We have developed high current batteries (you can put the cells in parallel until you have enough current). The real problem with electric cars is charging them. If you want a battery to have a long lifetime, you have to charge it slowly. I don’t think we have developed any batteries that can be charged more than twice as quickly as they are discharged without significantly dropping the lifetime of the battery. Fast-charge batteries will have about one hundred charge/discharge cycles before they won’t hold a charge any more. Which means if you drive to work every day, your battery probably won’t even last a year. The alternative is to charge the battery for 3-5 hours to drive for 7-8 hours. Which is ok for commuting, but won’t work on long road trips.
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The reason hybrids work so well is that the energy is stored chemically. We can easily transfer several hundred kWhr of energy in a few minutes with gasoline. You just can’t do that with electricity. That’s where hydrogen fuel cells become useful. You can have refueling stations that continuously draw power to refill their hydrogen tanks and then transfer the energy to your car in a few minutes. But biodiesel hybrids are probably a better answer. They allow a more gradual transition and don’t have the leakage/explosiveness problems of hydrogen.
…ask one more question.
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Let me ask you this.
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If you want a battery to have a long lifetime, you have to charge it slowly.
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Suppose an infrastructure is developed that would allow batteries to be swapped out at “filling stations” that recharge the batteries slowly. Would that really satisfy some of the problem? I’ve used NiCd batteries and Nickel-metal-hydride rechargeable batteries (the latter are supposed to not have a “memory” problem like the former) but I haven’t noticed much of a difference between the two. A couple of hundred rechargings, with reduced efficiency after each recharging, and that’s about it.
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I’ll defer the hydrogen issue to another time. From what I have read, the hydrogen used in fuel cells is actually “stored” in a kind of matrix that reduces its explosion likelihood. Unlike the Hindenburg. But I don’t know the details.
You could swap out batteries. But if the batteries are easy to swap, they will necessarily be easy to steal. And there will be an incentive for people to use really cheap batteries, because your battery gets swapped out every time you discharge it. Most people don’t know enough about batteries to know if they are getting ripped off with cheap batteries by a swapout station. It is much easier to regulate fuel quality than it is to regulate swap-out battery quality. For one thing, a swapout station can always claim that they were fooled by a recent customer if someone catches them with low-quality batteries.
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There are many varieties of batteries with different characteristics. The main problem most people notice with NiCd batteries is that you have to discharge them fully every time or they crystallize and you won’t be able to discharge them fully in the future. They are still used mostly because they are cheap.
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Most people only ever use small batteries. Even a laptop battery would only power your car for 2-3 minutes. When you start needing a few hundred kWhr of energy storage, energy density really matters. NiCd’s are heavy. Nimh batteries are lighter. Various Lithium based batteries are even lighter. Lead-acid batteries are the heaviest rechargeables, but they are used in most cars because they don’t require intelligent charging circuitry and they put up with a lot of abuse. A good reference on batteries is available at http://batteryuniver…
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The problem with storing hydrogen is that hydrogen is tiny. Most materials have holes that are at least as large as hydrogen molecules. I’m not keeping track of what the new technology is for storing hydrogen, but it will always have a relatively high leakage rate. And whatever you are doing to prevent it from being explosive, it will still blow up when something goes wrong. You can’t build an indestructible fuel tank and people will always get into accidents. Biodiesel is inherently less explosive.
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What if ExxonMobilShellBP owned the batteries? Effectively, you “rent” the battery and return it empty. This isn’t without precedent. Beer kegs and [Cooking] gas canisters are two examples. So, if the filling station owns the batteries, this problem of cheap-os goes away. How to measure how much charge is on the battery they rent you? Same way you measure how much gas goes into your car now — department of weights and measures.
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This might go a long way toward solving the problems listed above…