So don't run at full power. Our current power usage is horribly inefficient, there's a lot of improvement to be made in that area.

It also depends on how much power you've collected during the day. Current solar photocells haven't begun to approach the theoretical limits of efficiency, who knows what forty more years of development will bring?

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"If this were play'd upon a stage now, I could condemn it as an improbable fiction."
Shakespeare, Twelfth Night
"The Mayan symbol for "book" looks a lot like a triple hamburger, but I've never seen them claiming it as proof the Mayans had Big Macs." - KaiYeves
"Distance doesn’t matter much in space, where if you just start a thing off with the right kind of shove, sooner or later it will get where you want it to go." -Frederik Pohl, Mining the Oort

Bingo. Antimatter is a battery (energy storage device), at best, and an incredibly poor one at that. It would be far more efficient to pump seawater 500 miles from from LA to Lake Meade and use that head of water as energy storage for later energy production through water turbines.

Nuclear fission is good for several hundred years, if not thousands, and is the only long-term source of baseline power. Waiting for pie-in-the-sky to come along is very irresponsible.

There is a very slight possibility that a practical fusion method will be announced soon and it will supply 1% of Earth's energy needs by 2019. If so, does 2020 meet your requirements for "after fusion"? That is about the soonest the space elevator could give us cheap access to space. Ten years after the space elevator, SSP = space solar power could supply 1% of Earth's energy needs. I agree most of the others mentioned are unlikely to reach 1% before 2030, perhaps never.
Geothermal and oil from algae in transparent pipes = a form of solar have perhaps the highest probability of reaching 1%. Hydro is already almost 1% and could grow another 1% by extracting the rather dilute energy from ocean tides, waves, current and thermal gradient = OTEC. While large scale thermal solar plants store perhaps an hour of energy by their nature, and one hour is a big improvement over the micro second that PV stores energy, Near term more than an hour is best made up by natural gas powered turbines.
HVDC = high voltage direct current is used to transmit electricity up to 1000 miles, and can theoretically add 1% to USA long distance power line capacity in the coming 5 years. Less copper is an important advantage as adding 1% to the world's long distance power lines will likely drive up the world price of copper, especially if we also do smart grid.
Agingjb made a valid point on Oct 23d. Very large scale up of energy demand will produce a heat disposal problem for Earth which may be hotter than it is now. This is especially true for those of us who live in buildings of ten cubic miles or more = intolerably hot near the mass center. Asteroid habitats at the center of asteroids will eventually over heat even with one megawatt of of waste heat. Far below the surface of Earth (and other planet) habitats also have a difficult waste heat problem. See the dense population thread. Neil

I see you guys are talking about baseload power from Renewables (Wind and Solar, etc), well although they cannot provide baseload at the moment, there are some potential solutions. A while ago I was at an interesting lecture in Ireland about how we could use wind power (something we have lots of potential for) to provide baseload power.

The problem with wind is of-course that it doesn't always blow, and when it does it's not at a fixed rate, it changes rather erratically. But for an efficient power grid you need to meet spikes in demand at certain times, but you can't necessarily rely on the wind to be blowing at that time. The idea is to set up thousands of windmills and use the power they generate to pump sea water into artificially flooded valleys near the coast, and then use Hydro plants at the mouth of the valley to steadily release the water and generate a constant and manageable power flow.

The idea is from a rather eccentric Ukrainian scientist who has now set up a campaign to get the Irish government to adopt the scheme. This is the Website http://www.spiritofireland.org/. I think it is essentially a form of Pumped-storage (http://en.wikipedia.org/wiki/Pumped-...droelectricity). Apparently the potential energy of the water stored in these valleys would be enough to power the entire country for a week or two, thus solving the problem of the wind not blowing at all for a long period.

The idea is pretty new to me, but I don't see any reason why it wouldn't work (though I think his estimate that the project could be done in 5 years is hopelessly optimistic). I guess the same sort of concept could be used to get baseload power from Solar plants as well.

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The Sky is no longer the Limit

I had wondered if enough water could be pumped high as an energy storage scheme . Clearly, peak demand energy has a premium price.
Coastal sites would seem to have an advantage.

Best regards,
Dan

Pumped storage is the most cost effective method of storing large amounts of energy from the grid. But it's still not cheap, even though it is worthwile in many locations. Many salt water dams for pumped storage could well be built, although they will rely on suitable natural locations. Also there is no particular need to use salt water. Fresh water will do, and in a dedicated pumped storage facility the same water will be used over and over so there will be little loss. There are also ideas for using underground caverns or mines for pumped storage.

But in Australia, power companies are planning to use current base load coal plants to supply peak power once a carbon trading scheme is introduced. As the price on carbon is increased coal plants will be adapted to become load following instead of base load and they will also start to use biomass instead of coal. As the coal plants are already built they are sunk costs, so this should be the cheapest way of providing peak power.

U-channels topped with glass panel segments are a lot cheaper, and the glass can always be acid-washed.

We have this in Alabama:
http://en.wikipedia.org/wiki/Compres...energy_storage
http://web.archive.org/web/200706050.../mcintosh.html

Pressure-feds might also be useful for space launch--and not just Sea Dragon http://hypacc.com/
http://www.spacedaily.com/news/future-00q.html

Too much atmo in Venus, bury it for power. Release as sunlight erodes the upper atmo' away to replenish.