If we really did go to the max on wind farms, hydro-power, tidal energy, and the like, would we just be creating some other sort of ecological problem? I’m not talking about directly affecting wildlife, but instead things like messing up the weather, ocean currents, and the like.
Granted we might be reducing carbon emissions, but taking 10’s of terrawatts of power out the natural system must have some effect.
I am wondering if “there’s no free lunch” is going to kick in here.
The question arises as to where all the 10’s of terrawatts go. Actually they are converted from one form of energy into another more useful form and ultimately returned to the natural system from which they came!
And local effects, which seem to be for the better overall.
As far as solar, probably for the better, offsetting the heat island effects that man made structures now create by capturing solar into electricity rather than dispersing it as heat.
Hydro power is already pretty close to maxed out. Like anything else, it does have an environmental impact, but it’s strictly local, and generally considered a lot better than the impact of fossil fuels. Plus, hydro power is really cheap, even compared to coal.
DSeid, it’s not a matter of “rather than” dispersing as heat. spingears has a point, here: Ultimately, all energy ends up getting converted to heat. And that conversion will mostly happen at the location where the energy is used, which will still be mostly in the cities.
Really? All energy ends up as heat? Solar to electricity to motive force for transportation is the same heat released as solar on a blacktop or a tarred roof that then heats the building which is cooled with electricity produced otherwise? Really?
Trees that absorb solar radiation and use it to produce growth and in the process shade the ground, produce the same amount of heat as dark pavement and rooftops?
Sorry, but you are making a mistake here I think. Solar radiation absorbed by rooftops and pavements cause a heat island (pdf) effect. That can raise both local temperatures (by 8 degrees or more) and raise building energy requirements. Shading a rooftop or a pavement with something that either reflects or absorbs the energy and converts it into electricity not only displaces the greenhouse effect of the generation of that electricity production by a non-renewable means, but decreases the local temperature outside and more dramatically the cooling requirement inside. These heat island effects are documented to alter local weather beyond just the temperature.
I stand by my statement that using that solar energy as power rather than letting it heat the local environment can have significant local weather effects, and if done on a large enough scale could even have nonsignificant beneficial climate effects beyond the GHGs displaced by reducing those urban heat island effects, which are expected to worsen with the onset of greater warming overall.
Some energy might not end up as heat within human lifetimes. For example, if we pave over a swamp with solar cells, we’re capturing energy, some of which would have been stored as chemical energy by plants, then sequestered in a peat bog for longer than the human race persists.
Anything to do with electricity is exothermic. End of story.
All forms of the conversion of electrical energy into any other form releases heat.
A generator of any type, coal, nuclear, gas, solar, wind generates both electricity, and waste heat.
Every step of the transmission process, wires, transformers, regulators create waste heat.
Every end point, motors, coffee makers, refrigerators, computers generate waste heat.
Then, to compound it, we generate a great deal of waste heat with our air conditioners, which move it from one place to another, and add their own heat load.
You are really saying that solar energy captured to create electricity that is then used to say power LEDs to produce light, creates the same amount of heat on the planet or even locally as the same amount of sun landing on a blacktop?
Look if what you are saying is that a tree eventually decomposes and produces heat energy in that oxidative process, then fine. And then electricity used to drive reactions that produce chemical bonds create products that someday decay and that that process will, whenever it occurs, have a heat of reaction, then fine. I think the point is trite but fine.
Pertinent to this thread however is the point that capturing that energy and using for other purposes on the way, rather than having it go directly into creating an urban heat island, could have, minimally, beneficial weather effects, and possible beneficial climate effects, theoretically.
Only if the solar collection system captures LESS sunlight than your random roof or sidewalk or tree or patch of dirt or whatever. Which is silly because solar collection sytems are designed on purpose to capture much as possible.
So, first off, you’ve got MORE being collected. And secondly, like Chronos points out its ALL going to get turned back into heat. And most of that likely quite locally.
If anything, solar power systems are going to heat up the world a smidge more than if they didnt exist. Now thats not to say they arent a net positive because they are better than pumping out even more greenhouse gases or are renewable or because it calms down the hippies. But it they will not cool things down just because they exist (unless you have white solar cells or white solar heating panels). They might (depending on many factors) cause a net local cooling because you aren’t ALSO now using fossil fuels or nuclear power in the same area.
It depends. Take a house covered in white shingles. Now cover it in jet black solar panels. Which one is absorbing more solar heat?
Unless you are using solar power to make fuel or charge batteries that you THEN just stick in the ground and forget about, its all pretty much going back in the form of heat in short order.
There are good reasons to use solar (or they are at least possible). It reducing the heat island effect IMO isnt one of them. At best its probably minor, and it may even make things very slightly worse locally (ignoring the whole greenhouse gas aspect).
Case in point. The bulk of the wind generators in the Columbia River Gorge are offline right now. That’s because the Columbia River is flowing at its highest level in years. Bonneville Power has most of the dam gates open and power generation from the dams at full throttle. In short, there is so much excess power generation from water, wind power isn’t needed.
Caveats with this.
[ul]
[li]There are not enough transmission lines out of the Pacific Northwest that the wind generators could use to sell power out of the local area so between them and the dams, the wind generators lose. Even if they could build new transmission lines right now to use the excess energy generation, the same transmission lines could be under-utilized once the water levels decrease. No easy balance.[/li][li]The excess water flowing down the Columbia River is creating havoc with the fish ladders that native fish can’t swim upstream to spawn. So with many species on different life cycles we may not see the environmental damage from all this water for three, to five, or seven years.[/li][li]The private company wind generators are so miffed they cannot operate they are demanding compensation for being shut down.[/li][/ul]
The more the panels take solar radiation and convert it to electricity which displaces electricity being produced by some other means and which would be used in any case, the less solar radiation is converted to heat on a typical (not hypothetical white) roof or parking lot pavement and the less it is heating up the local environment and any structure underneath.
Stretching to see your point, yes, if the solar energy was used locally in addition to other electricity usage, and all the energy was conserved locally (with no light bleeding out, for example, or none being used to produce products that effectively transported energy out of the factory) then yes. But the actual circumstance is not that.
Yes, the heat IS reduced by the fact you produced power from solar and not from something else. But thats the useful POWER you produced. If solar was like 90 percent efficient your point might be true.
But solar panels are not particularly effiecient. The majority of it gets converted to heat, not electricity, right then and there, not electricity or mechanical work. Then, as Chronos has noted, the electricity or mechanical work it does produce ALSO gets turned into heat in short order.
You REALLY want to reduce the heat island effect? Cover everything in cheap mirrors or something really white that reflects most of the energy back into space.
How about another column by the Master? This sort of addresses the wind impact issue.
When I was helping Cecil with this article, I found some other local effects which some speculated would occur, such as changes in ground-level humidity which could impact cropland if windmills were trying to leverage the large, flat areas of the Great Plains.
Energy may be conserved but it’s not an equal amount which is retained within the biosphere. Cecil wrote a column about that subject as well. I think that is the point some are trying to make.