That's good news, but no matter how cheap it is, solar only works when the sun shines. The real impediment to a solar/wind economy is energy storage, which is still very expensive and hard to scale.
We can definitely use solar for about 20% of our energy, with fossil or nuclear plants backing it up. But until we fix the storage problem, the only route to a post-carbon economy is nuclear.
That post was written by someone with a vary superficial understanding of these issues. For example Hydro power already provides a lot of 'grid storage' and is totally missing from his analysis. Also, photovoltaics are far less impacted by clouds than you might assume with partially cloudy days offering similar power levels to sunny days. And even on days where it rains constantly you get some power and often see an increase in wind power output.
Smart grids enable many applications like large scale cooling to shift of demand without building new storage infrastructure on the supply side. Not to mention simply shifting maintenance cycles can shift a lot of 'supply' to different parts of the year without building any infrastructure at all.
Add it all up and Wind + Solar meet total energy demands and have near ideal capacity factors with ~2-4 new hours of total grid energy storage. VS. the 6 days which he assumes.
There's a limit to how far you can expand hydro. There aren't that many more places to build dams. You can expand a little more by putting reservoirs at higher elevations specifically for storage, but that's expensive.
Even at 4 hours of storage, the scale we need is a bit mind-boggling.
Your link is really interesting though. That's the kind of analysis we need. I see too many articles that just talk about rated capacity with no consideration of actual output or reliability.
My second link does similar analysis for Australia, and there it doesn't work out so well. The wind drops low over wide areas for days at a time.
In any case I have nothing against renewables, as long as they don't use up too much land...offshore wind is perfect. But I think we should be building GenIII and better nuclear reactors, too.
Hydro is already used for peaking power, at most we would retrofit things it increase peak power output where it's reasonable to do so.
Building 4 hours of storage is a rather extreme step that's also extremely unlikely. California already has a 40c/kwh cost differential between peak summer demand and the middle of winter, but nobody is building massive grid energy storage to smooth that out. Even over the course of a single day you could make 10c/kwh just from grid storage but nobody is building it. Rather we add peaking power plants because base load power + storage costs more than peaking power plants and that's likely to continue to be the case even in a world dominated by solar + wind power plants.
Rivers don't have constant flows so it's more natural to have variable output than constant output. And dam's never have zero output, it's more a question of 30-80% and back down.
You mean just like the natural pattern of storms and snow melt that the areas you build hydro in already have?
Hydro here have carefully regulated flows to reduce the natural variation in the river so that for example an optimal flow is created for the various salmon runs.
2-4 hours of the worlds entire energy consumption is staggering large amount of energy. You also need the currently non-existent capability to move massive amount of power around the globe.
I just came across some free software for designing energy systems incorporating renewables:
http://homerenergy.com/
"The HOMER energy modeling software is a powerful tool for designing and analyzing hybrid power systems, which contain a mix of conventional generators, cogeneration, wind turbines, solar photovoltaics, hydropower, batteries, fuel cells, hydropower, biomass and other inputs."
Edit: looks like it's for small-scale installations.
excuse my ignorance with these questions, but this is something I've been wondering every time I see an article like this (specifically the batteries needed for solar).
1) shouldn't we be concentrating our efforts on reducing the requirements from the grid to near zero for new housing builds?
Newer builds will (hopefully) also incorporate the latest in conservation technologies (better performing insulation, etc) resulting in a lower energy requirement regardless of the source. One would also imagine that new home builders implementing solar solutions would see cost benefits from scale.
2) wouldn't the efforts of concentrating on new home builds have a two pronged benefit on everyone else?
Not only would technology advances become available for retrofit projects, but the reduced strain on the grid could potentially reduce the costs grid wide?
3) what would be the benefit of having a centralized solar installation?
Any solution that centers around having a mile square cube (from the linked article) seems a bit silly to me, wouldn't houses having their own battery solution make much more sense? Having individual batteries would allow for a market for these solutions and, one would hope, from the competition within this market, new and better solutions would emerge.
Pretty sure he's not advocating actually making a mile square cube of battery. He's just illustrating the scale of the problem. It's the same amount of battery no matter how you divide it up.
Efficiency is definitely some low-hanging fruit. It only gets us so far, though. Rooftops are probably the most effective place to deploy solar, but housing is only one piece of the puzzle.
Just heard about this the other week, but if the SMU study [1] from a week or so ago is true, I don't see why geothermal couldn't provide the base load. I've seen related articles claim that no new tech is required and there's an enhanced geothermal facility that just opened in Australia. Strikes me as...simple.
20%? Over 60% of our electricity is consumed when the sun shines. Currently we get less then 1% of our power from solar. Storage will not matter for a very long time.
I remember seeing some research into using nanotech to create multi-surface structures that can capture lots of hydrogen. Hopefully we'll get some break through in that area.
A good post that runs the numbers and conveys the scale of the problem is here: http://physics.ucsd.edu/do-the-math/2011/08/nation-sized-bat...
And another that takes a close look at wind is here: http://bravenewclimate.com/2011/10/29/gws-sg-es/
We can definitely use solar for about 20% of our energy, with fossil or nuclear plants backing it up. But until we fix the storage problem, the only route to a post-carbon economy is nuclear.