Whew, lots of posts overnight! Thanks for the contrats all
Tyral the Kithless wrote:
Okay, here's one I'm actually interested in: how far away are we from actually having common, widespread use of renewable energy sources? Specifically for homes and businesses, not for cars and such.
Renewable electricity is not so far off.
Hydroelectric power is clean, cheap, renewable and dispatchable (can be ramped up or down nearly instantaneously, unlike coal/nuclear plants). The downside, of course, is that we've already tapped most of our viable hydro sources, unless we want to do Three Gorges Dam-scale hydro projects, which have
huge environmental and social justice downsides. About 20% of US electricity generation currently comes from hydro, though, so many people already use a significant portion of renewable power.
Wind is taking off. I had the pleasure of meeting a former CTO of GE a few months ago -- the guy who took GE wind from nothing in 2002 to a $7 billion business last year. Not exactly a lightweight... he's moved on to working as a venture capitalist (investing heavily in plug-in hybrid electric vehicle companies, incidentally). He said (and I verified) that under the current federal and state incentives, wind is cost-competitive with coal -- and in the current economic climate of skittish investors, its low capital cost makes it the clear choice for constructing new power plants... in regions where the wind blows, anyway. There are some problems with wind, of course:
1) It's variable. Better wind forecasting algorithms, better large-capacity storage techniques (compressed air storage, supercapacitors, better batteries [the ex-CTO is also investing heavily in battery companies like A123], superconducting electromagnetic storage, flywheels, etc. are options), peak backup plants (natural gas isn't going anywhere), and dynamic metering/pricing of electricity (residential "smart grids") are all needed.
2) Like hydro, there are a limited number of economically viable wind sites. 20% penetration is about as far as wind will go.
3) US wind subsidies are erratic. This makes it difficult for investors to assess the payback time of wind projects. We need a consistent, long term wind policy to facilitate widespread investment in new wind farms.
4) Wind turbines aren't manufactured domestically. Bear this in mind when you hear talk about "green jobs." The US has great manufacturing capacity, but it's not being leveraged to build wind turbines, yet. Instead, they're shipped overseas from Europe, adding to their cost and embodied energy.
5) On-shore wind is where the people ain't. The densest wind resources are in North Dakota -- smack in the middle of the country, and far from load centers in CA and the Northeast corridor that desperately need more power. Significant upgrades to the grid, in the form of new high-voltage DC lines that cross many state boundaries (a political friggin' nightmare to get through), need to be made.
Solar gets a lot of press, but is currently a factor of 5 away from being cost-competitive with wind/natural gas/coal, and that's
with federal/state subsidies. It's 10x more expensive than coal without subsidies. Like Tarot and others have said, there are new PV technologies in the pipeline that could bring the price point down. Economies of scale will also take effect once the solar industry grows and gains momentum. The Secretary of Energy (Nobel physicist Steven Chu, for those of you who didn't know!) has said a few times that there is a Nobel-level discovery waiting to be made in photovoltaics. We'll see -- science has a way of changing the game. But for now, PV plays a negligible role in the electricity picture. Concentrating solar power (focusing sunlight with big ass mirrors to boil water and run turbines) is actually cheaper on the utility scale, and there are some 100+ MW plants in the Arizona desert making money off of this tech today. Solar, of course, carries the same variability problems that wind does, and requires the same technological solutions.
Biomass is a source that gets less press, but is more viable than solar. And I'm not talking about corn ethanol here, or any other liquid fuels. That's another beast entirely. I'm talking about burning wood in rural areas, or burning municipal solid waste in urban areas (shit and garbage). There are significant unanswered questions about whether feedstock forests for wood-burning power plants can be harvested sustainably, and what the actual carbon balance of such a plant is (advocates claim it is carbon-neutral, without real proof; the scientific jury is out on this one). Municipal solid waste, however, is a win. Greenhouse gases from trash are by and large vented to the atmosphere, except in situations where landfills are capped. Might as well emit the same level of GHG through combustion, and get energy in the process. How much energy? NYC could get 30% of its electric power from the waste it produces. A city of 10+ million people generates a
lot of trash.
Nuclear, while not renewable, is at least clean (in the carbon sense). It's stalled in the US, though -- no new nuclear plants have been built in this country since 1973. The nuclear waste storage problem needs to be solved before anyone's willing to invest in new nuke plants... and the Obama administration is essentially killing the Yucca Mountain project by halving its funds every few months. On top of that, nuclear plants take 5-7 years and $3-5 billion to construct (compared to 1-2 years and a few hundred million for a wind farm). Nuclear will play a role in our energy future (France is 70% powered by nuke plants; Japan almost half), but there are significant barriers to uptake in the US. Nonetheless, 20% of US electricity is currently generated by nuclear reactors, so again much of our electricity is carbon-free.
SO! To answer your question, we're at least a decade away from significant penetration of renewable electricity resources. The DOE goal is 20% wind by 2020, and this is honestly feasible -- not due to national altruism, but simply because it's cheap and easy. This assumes we continue to have Obama-esque support of clean energy projects (here's hoping).
In the mean time, new coal plants with no form of carbon capture tech are being built every week (multiple per week in China). The climate change problem isn't going anywhere, I'm afraid.