Friday, November 29, 2013

Energy futures

The challenge of "green" is aggregating small amounts of energy – ultimately days of sunlight per surface[1] – into amounts useable in quantity and continuity. Plants convert some of that energy continuously in daylight hours, but aggregating is the challenge. Currently we rely almost entirely upon a fossil fuel process that takes eons and is not sustainable – even if the amounts of recoverable fuels remains large, the environmental side effects are rising, not falling. Global economic growth has almost immeasurable benefits – hundreds of millions of Chinese no longer face hunger daily. Only recently has the government sufficiently overcome the fear of famine to eliminate the mandate that farmers grow grain. In China point- and regional-source pollution is now sufficiently bad to generate local political action, as it was first in California and then in the US as a whole in the 1960s. But no local government, and most national governments, are uninterested in denying access to electricity (air conditioning, refrigeration, lighting) or mobility (cars). Desirable or not, I don't think it's realistic to expect that governments will do much to repress energy demand. Supply-side developments are thus crucial. That means improving the feasibility of solar, wind, hydro and biomass.

One challenge is operational size. To what extent are economies of scale so intrinsic in the physics (and their engineering implementation) that only large facilities are feasible? Let me speculate on alternatives for wind power to frame this question.

Currently the trend is towards very large turbines. Winds blow stronger above ground; if you're building a tall tower, you then want to generate a lot of power per tower to cover costs. That may work, with better engineering of blades and generators and mechanical connections. Scale on the manufacturing side can help, as standardized designs lead to economies in production, from poles to turbine blades.

What would a small system look like, something found in every backyard? First, the turbines would have to be short and spin on a vertical rather than a horizontal axis; they couldn't look like windmills, but rather spinning windpoles that would face different wind sheer and so might be cheaper structurally – the pole would be the turbine access, with lower stresses cheap bearings or even bushings would do. Now close to the ground they'd "enjoy" far less wind, so would have to be really cheap. Windpoles might be relative to windmills on a watt-hour basis.

Then there's the aggregation issue. Such windpoles probably couldn't each turn a generator, that would be too high in cost per unit of energy. They might however be able to turn a small scroll compressor that would feed through standard lines to a centrally located turbine. Scroll compressors are pretty well understood, there are lots of refrigerators and air conditioners out there. Storing compressed air is also a mature technology, providing a means to enhance continuity. Small air tools – small turbines – have also been around a long time. So the pieces could be assembled quite readily.

I'm not enough of an engineer to cost any of this out. There may be simply too little wind energy at ground level. But versions of this – systems whose cheapness and small size make up for conversion efficiency – seem worth exploring. Perhaps they already have been, and have been found wanting. But in some parts of the world small rooftop solar water panels are pervasive – highly inefficient in the amount of energy they convert but so cheap as to make sense.

...[we'll see] a multiplicity of energy systems … [as in] vehicle drivetrains

In any case, any attempt to move away from fossil fuels is likely to lead to a multiplicity of energy systems – just as we are currently seeing a growing variety of vehicle drivetrains, depending on local fuel options and driving patterns.

mike smitka

Note 1. Nuclear – including geothermal – and tidal sources are exceptions. While in principle fusion is possible only uranium-based fission is commercially available, but that suffers from both political and economic pressures that make it a small slice of currently harnessed energy. Geothermal and tidal energy are at present unimportant.

Thursday, November 7, 2013

Here are assorted data for your perusal – unfortunately due to the government shutdown data releases are delayed or (for certain data) a month will be skipped. For example, the "Employment Situation" was scheduled for November 1st; instead it will come out November 8th. Click on charts to expand to full size.

First, the first three charts on employment show a slow gain relative to age-adjusted population growth, but only slow. We still are far below normal levels of employment, and there's no particular reason to think that the fundamental structure of the labor markets and participation decisions changed over the course of a few months back in 2008-9 – no big shift in the ability to claim disability, no basic change in unemployment benefits, no change in wages [indeed, this recession reinforces the claim that wages are rigid downward, absent inflation], and I've already corrected the data for boomer retirement. That's clear if you look at the fourth chart of age-specific participation rates. Older workers – those of historic retirement age – are working more than ever [the chart gives data only from 2000, before then employment structures were relatively stable]. But in 2009 the share of people working in prime age brackets dropped, and that of younger people plummeted. Basically, while the economy is growing, it's not growing enough to eliminate the excess capacity of the Great Recession.

The fifth chart is investment. Again, we're out of the trough of 2009, but the level is still below that of some previous recessions. So more of the same: the economy is growing, but not recovering quickly.

That's not true for all sectors. As per the sixth chart, car sales have boomed; suppliers are at capacity, makers are having a hard time launching new vehicles at target levels of output. Still, we remain below the hyped level of the 2000s, and my sense is that sales are leveling out. There's still an overhang of vehicles from the go-go years, though depreciation operates far more rapidly in housing market. At the micro level I'm an example: since I'm stuck with an unsold house, we waited to replace our aging (240K miles 15 years) Volvo until the last minute – it wouldn't restart in the dealership parking lot so they gave me a tradein value lower than the local junkyard. We did buy a new car, as I judged the price differential relative to used cars too slim. However, too many people are underwater on their mortgages, median income [the point at which half the population has higher, half lower income] is falling. So my judgement is that the upside isn't going to move up very fast, despite our rising population. And while I only include the last couple years in the seventh chart, market shares have been relatively stable – with Toyota and Honda at a lower level. The eighth and final chart is of market groups. The top 4 firms have in the aggregate lost share, but over 2012-13 the Big Three and the Detroit Three have been stable.

Finally, interest rates have dropped back to the new normal under the Fed's antirecessionary monetary policy. With the fears of default eased, short rates are essentially zero. Now from day to day rates jump around, but remain extraordinarily low by historic standards, all the way out to 30 years. The yield curve is flat at maturities under 5 years, but there's now a moderately steep differential at longer maturities. With rates low, this isn't reflecting expected inflation but rather that eventually the economy will recover and with it short-term interest rates will rise. The market, however, is pricing that as years away – like 3-5 years. That is unfortunately consistent with my straight-line projection of labor market growth – at the current pace the gap won't be erased until the start of 2019. While I would not be surprised to see things accelerate as the housing stock normalizes ... well, the housing stock doesn't normalize quickly: according to the IRS, which is generous in such things, depreciation takes 30 years, and with median incomes stagnant, half the population isn't in a position to upgrade their "digs".

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