Petroleum replacement solutions will be less convenient and less fun than the world we are used to, the low cost oil world we enjoy today, and so must have a lower total cost than petroleum solutions to be more than technical curiosities. In other words, petroleum will have to get much more expensive before you start seeing roofs covered with solar cells as the rule.
As far as the Prius goes, that car (I have studied it some) has many interesting features. The low internal resistance NiMH main battery charges and discharges at an amazing breakthrough rate. Nippon Electric must have spent a billion or two developing the technology. If the Japanese had to make back their costs on the Prius, like GM or Ford would have to, the machines could not be sold for the price required. Just a little car with a technocult "Modernismus" transmission.
As far as high fuel efficiency cars, BMW produced a car that averaged, city and highway, 50 miles per gallon in the 1950's. My old Rabbit Diesel got over 50 miles per gallon tank after tank. VW has put multi-thousand car test fleets out that average better than 70 miles per gallon. What the Prius is doing is not all that interesting except in HOW it is doing it, not in WHAT it is doing.
A big research operation here in the US showed American type cars could be made that averaged 70 to 80 miles per gallon. My own calculations indicate that much higher fuel economies are possible, though over a hundred miles per gallon current vehicle air conditioning technique consumes more horsepower than does driving the vehicle.
Housing energy use is easily curbed. Energy costs rising enough to pinch and then hurt will have salutary effects. The people will complain bitterly and want war waged against the villains responsible, unless, of course, the war is inconvenient for themselves, personally.
People aren't going to change wanting whatever it is that their cute little heart's desire, and until petroleum becomes more dear are not going to change their energy consumption habits.
Yes, I know this is not anything new. If I remember correctly the original electric distribution system Edison promoted is built upon similar principp, that the energy user and energy provider are in close vicinity to each other. If Westinghouse´s idea had not become the one we use, of long distances between users and large scale power productions in plants, this system could have developed long time ago.
But the beuty of it is that it will be able to incorporate every awailable power source in our environment, nuclear, coal, oil, gas, wind, solar, tides and other that will hopefully come when the market will find solutions, by pushing for innovations, similarly as higher gasoline prices are pushing for the development of better technology to find new oil and better ways to extract it.
The oil is not going to be over anytime soon, but it is all a question of supply and demand. And each time the gasoline prices go up, it is economically sound to extract it from new and new places, from where it was not cost effective before, and each time it is cost effective to harness energy from new and new means, wich were not cost effective before.
And with the cost of solar panels coming down, and other solutions allways surfacing, it will become economically sound for more and more people to use it. But now we need to make our electrical grid able to incorporate all these different means of energy production wich I beliewe will become economically sound for more and more energy companies each day that is passing. They will make their buyers to be able to produce electricity into the grid themselves and get paid from it by f.e. downgrading their energy bills.
Most of such means of producing electricity will not be even, so during time of energy abundance for such households, like the high noon when the sun is shining or when there is enough wind the peak power will go into the grid, but the household will then most likely buy power again from the grid during the night when the sun does not shine or when the wind does not blow. There are still some technological hurdles, wich the companys are overcoming but I guess there are still some regulary hurldles in the beurocratie wich has to be overcome.
But the best about this system is it will not make the fossil fuels and the revenables enemies like some are allways putting it, but mutually compatible, as each will compensate for the pros and cons of the other. It is obvious that demand for energy is going to rise in the next decade, but I am pretty sure that technology, both of finding more fossil fuels and producing rewenable means will be enough to compensate, just if the market will be allowed to run its course freely. I am optimistic, but of course things can get ugly if stand in way of progress.