I have posted some things previously over the past few months, in particular here *, outlining how the US could transition to a 25 quad renewables-only economy over the course of the next 50-75 years or so. I'm pretty confident that the scenario I've mapped out is feasible and realistic. Maybe we could go a little higher, and maybe nuclear, NG and coal will deplete downward at a slow enough rate to buy us a little extra cushion, but I am not at all confident that we could produce with renewables only anything close to the almost 100 quads that the US presently consumes, or even half that. I am not at all sure that a major ramp up of nuclear beyond just maintaining present capacity net of decommissionings is even desirable, let alone feasible.
To my way of thinking, then, 25 quads - or about 1/4 of what we presently consume - should be the long term target. We need to be thinking seriously about how we can get our energy consumption down to that level over the next few decades.
When you look at energy usage on a per-capita basis globally, it is hard to argue that we truly NEED to consume more energy than this. A lot of the excess is just waste, or discretionary frivolity that we could just as well do without. However, honesty requires admitting that to cut back by that much means that some of the cutting will really hurt.
How do we get there? Obviously, a big part of it is going to have to be in transportation; it accounts for about 39% of the total energy going into end uses. (Note: I work off of figures from Lawrence Livermore Laboratory.) We've discussed a lot of that here already, and most of us could recite a pretty good list of a dozen or more major initiatives that need to be undertaken in order to substantially reduce the amount of energy that goes into transportation. We need to get to work on all of these. Unfortunately, one of the biggest savings is going to have to just be staying where we are and not traveling around so much. In a 25 quad economy, we're going to have to learn to content ourselves with not leaving home nearly as much as we have been accustomed to. We simply can't cut back our total energy use by 75% without cutting our transportation energy use by at least 75%, and probably a bit more than that.
The industrial sector accounts for another 33% of energy end use, so we'll need to achieve a lot of savings there, though if we can achieve more than a 75% reduction in transportation energy savings then that can "buy" us a slightly smaller cutback in the industrial sector. A big part of it is going to have to be stopping the production of useless and non-necessary stuff. The industrial sector has already achieved a lot of efficiency gains, because it is profitable to save energy. There is a little more that can be achieved through efficiency, but a lot of the saving is going to have to come through simple downscaling of the material basis of our economy.
Everyone thinks about the residential sector when it comes to energy efficiency, and there is plenty of room for improvement there. However, at only 16% of our total energy end use, the potential of the residential sector to contribute to the magnitude of energy consumption reductions required is going to be considerably less than some might realize. Also, while sealing and insulating the building envelope and installing energy-efficient lighting and appliances will help, a lot of the savings are going to have to come from just being hotter in the summer and colder in the winter, and being more crowded and enjoying less personal privacy as more people concentrate in fewer and smaller homes.
The commercial sector accounts for only 12% of energy end use, so the potential for savings there are limited. Nevertheless, I suspect that a disproportionate amount of energy savings will come from the commercial sector. The US is absurdly overbuilt when it comes to retail space. Given that "recreational shopping" is unlikely to continue to be an affordable activity for most people, we can expect to see massive store closures, vacancies, CRE foreclosures, and demolitions or repurposing. Such will also be the fate, to only a minor extent less, for office space as well. There may also be big cutbacks and downsizings and failures in governmental, educational, and other institutional facilities as well. The commercial sector probably will be declining by more than 3/4 over the next half century or so.
IMHO, I simply refuse to be impressed or take seriously any national energy "plan" that doesn't come at least somewhat close to this rather draconian scenario that I have just outlined.
[new] WNC Observer on June 1, 2010 - 11:57am
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WNC Observer on February 22, 2010 - 1:08pm Permalink | Subthread | Parent | Parent subthread | Comments top
As I said in another response in this thread, I agree that the potential for hydropower expansion is pretty limited. However, we presently only import a net 0.11 quads, almost all from Canada, and there is certainly considerable potential to increase that - at least a half quad I would think, maybe as much as 1.5 quads?
Wind is presently a half a quad, but that is ramping up pretty quick. Are four doublings out of the question before we level off at our 25 quad target, over a course of maybe 50-75 years? That doesn't sound too extreme to me, yet that would bring us up to 8 quads from wind. Challenging, but possible IMHO.
Solar is a mere 0.09, and I would not assume that PVs will ever be more than a niche product and contribute a very big deal to the total. Solar thermal is another matter altogether. There is considerable potential for deployment of solar thermal (for both water and space heating) on both residences and commercial buildings. Solar thermal is not super high-tech, and is not all that hugely expensive, so I suspect that if any renewable energy technology is deployed on a widespread grass roots basis, that will be it. We've got about 8 quads of natural gas that right now is going to residential and commercial buildings, mostly for space and water heating. Is it unreasonable to think that solar thermal might enable that figure to be cut in half? Not IMHO, which suggests that it should be within the realm of possibility to ramp solar up to 4 quads.
Geothermal presently supplies a tiny 0.35 quads, most of it for electrical generation at a few locations. Geothermal heat pumps are an up and coming technology, but they are very expensive, and will probably be cost-prohibitive for most households. On the other hand, if we started shifting to district heating systems, considerable economies of scale in geothermal heat pump technologies could be achieved. It may take us 50-75 years to get there, but I don't see 2 quads as being out of the realm of possibility for geothermal.
Biomass presently supplies 3.88 quads, much from wood waste, some from ethanol and biodiesel, and some from biogas (methane - the forgotten biofuel). Given our massive landmass, it should be well within the realm of possibility to at least double biomass energy production, and that would bring us up to 8 quads.
Add in 1 quad for new oceanic technologies (tidal, wave, thermal gradient) that may come on line within the next half century or so, and there you are with a full 25 quads.
I don't know if this is what we WILL do, but I continue to insist that we COULD do this.
(All figures from Lawrence Livermore 2008 US energy use flowchart) |
