Bury the powerlines???
What would the squirrels do? What about the birds?
Did you even think about the squirrels and birds before you suggested burying the powerlines?
My gut reaction to your original question is that talking about going off the grid, as the norm, is not likely until/unless solar or wind become more efficient and cheaper on the small scale.
As I understand it there are economies of scale that come into play when one is dealing with power generation. It’s much cheaper, on a kw*hr basis, to have large generation facilities, and then deal with the losses associated with transmitting that power, than to actually have power generation distributed throughout the community. Looking at the Honda generator mentioned above there are a lot of parasitic processes that go on while the generator is operating that reduce efficiency. AIUI all method of generating power from combustion fuels are Carnot Heat Engines, which sets an absolute limit to the efficiency of the cycle, even before real effects are put in.
Most of the common ways to boost Carnot engine efficiency either artificially reduce the temperature that the engine is using as a heat sink, or to raise the combustion temperature. Both those strategies usually work by playing games with pressure-temperature relationships. The moment one starts talking about having your processes occuring at other than atmospheric temperatures the engineering costs for the reaction vessels starts to go up. It’s a lot cheaper to build only a few large pressure vessels for large scale power generation plants than lots of smaller ones for the distributed model.
Then there’s the real costs of getting fuel to the distributed generation facilities. This is not insurmountable - many emergency home generators are powered off the same household gas lines that power stoves and hot water heaters. But it is another factor.
I can’t give you any hard and fast numbers, but if Una Persson comes in, that would be a source with some better ideas than I have. The numbers I recall, however, are that large power plants operate in the high nineties for efficiency (That is amount of energy in fuel converted to useful energy, compared to a Carnot Engine, which is a different thing than Carnot efficiency.) while smaller household sized plants do well to hit the low to mid eighties. Again, I may be wrong, but that’s my impression.
This doesn’t mean that it’s impossible for a distributed model to become economic. As BubbaDog’s posts allude to - there are real losses involved in the power distribution network, as well. But I think that’s where the increases in small power plant efficiency are going to look to make inroads on the current model for power generation: If the losses inherent to the smaller power plants ever gets less than the average losses involved in sending power over the high voltage lines, then the Honda model starts to make sense. But I think that’s still a ways off. It’s also a marginal sort of competition: it’s not trying to fight the larger power generation plant’s greater efficiency, just trying to pick up some of the losses involved in power transmission.
I think you are making some huge leaps and assumptions. The first is why you are so sure that everyone will go “off the grid” completely. People may very well generate some of their own energy through solar of other means but each home would have to generate 100% of their own power all the time to disconnect from the power companies. Even then, it is questionable why it would be a good idea to disconnect in the event of inevitable problems in the household power. Furthermore, houses that generate more power than they need can stay connected and sell the excess power to the utilities. There are people that do this today.
You also can’t disconnect, say 30% of the house on a straight street and expect to see a corresponding decrease in the main powerlines on the street. The entire street would need to be disconnected for that to happen. Home power generation like solar aren’t the only green power alternatives. Hydroelectric ans wind power are considered green but you still need powerlines to send the energy somewhere.
I can’t see this happening in my lifetime.
The one thing that might make us all go off grid is solar power.
The world needs a huge amount of power. A lot of the so-called green energy sources just don’t provide enough power. What you really need are a bunch of big honkin coal plants or nuke plants. Coal causes greenhouse problems. Nukes make nuclear waste. Cecil seems to have a lot of faith in nukes, and as much as I hate to disagree with the big man, I personally think nukes and coal both suck. But there really isn’t any alternative, yet. A lot of folks talk about hydrogen like it’s an accepted fact that we’ll all be switching to hydrogen in the next few decades. Then you ask them exactly how we are going to generate all of that hydrogen and they start mumbling and waving their hands a lot.
Solar power, though, has hope. A couple of decades ago, solar power was so hideously expensive that no one could afford to generate electricity for a house from it. Now it’s gotten down to the point where the rich and famous can power their homes completely from solar. In 50 years, it might be possible for solar to compete with coal and nukes.
Solar would fundamentally change the way we generate electricity. Instead of centralized plants, each home would generate its own electricity and store it in local batteries. Right now, if you generate more electricity than you use, the power company is required to buy your surplus (unfortunately, not at the same price they sell it to you). If a lot of folks start switching to solar, though, the rules may have to be changed. The power company may be forced to charge you just for having a line connected or else they’ll end up losing money. If that happens, a lot of folks might be forced off grid simply because they don’t want to pay for their own local solar plus the power company’s connection.
It’s interesting to think about, but not guaranteed to happen.
Yeah, but with buried power lines you can have fun with worms. A friend of mine works for a power company, and one of the techniques they have for finding a fault in a buried line is called “thumping”. Basically, they whack the faulted line with a short burst of power, while everyone stands along the route where the buried line goes and they literally listen for the thump. They also look for worms, which come to the surface near the fault.
Squirrels are fun and all, but you can’t do your Dune style “WORM SIGN!” shout without buried lines.
You may be confusing combustion efficiency (percent of fuel burned, which is often 98-99.5%) with boiler efficiency (percent of heat released by the burned fuel which heats water or produces steam, which is typically 83-89%) with Net Plant Heat Rate (overall conversion rate of fuel energy to electricity delivered at the busbar at the plant) - which, converted to efficiency in %, is anywhere from 20% for an old coal plant to 40% for a new coal plant to 50-55% for a top of the line gas turbine plant.
Very likely. Thanks for giving us some good numbers, vice my flawed memory or understanding.
Seem to be 2 questions here:
- will everybody eventually go ‘off the grid’, and generate all their own electricity?
and - will the grid eventually go entirely underground, with no visible power lines.
To deal only with the second question.
Low-power lines (like those going to individual homes) are usually put underground now, as new houses are built. Older homes are occasionally changed to underground supplies, but there is little economic advantage for either the homeowner or the power company, so it happens only occasionally.
Medium-power lines (like those serving a whole neighborhood) are often put underground in new developments. But existing ones generally stay as they are. There is seldom a compelling reason for the power company to tear down working power lines and move them underground. And most of them run in alleys or the back of houses, and people are used to seeing them there, so there isn’t much demand to bury them for aesthetic reasons.
High-power lines (which carry the big current to supply whole towns or more) are almost never underground, and are likely to stay that way. There are technical reasons why underground burying of high-voltage lines is not very feasable. For example, air is an insulator, dirt is not. Underground lines would need much more insulation, would have to worry about water leakage, and would generally be much more expensive than running the lines overhead. Even in big cities, the major, high-voltage lines run overhead. It’s only the minor, feeder lines that go underground.