Archive for Technology

Heating a building with heat from a road

The December 6 Technology Quarterly from The
Economist
magazine profiles
a Dutch office building which is both heated and cooled using heat (or cold) from the asphalt of the road outside the building
, as opposed to the more conventional use of solar thermal panels on the building’s roof.  The article optimistically ends,

The result is cheap heating in winter and cheap cooling in summer. And there is a bonus. Summer heating softens asphalt, making it easier for heavy traffic to damage the road surface. Dr de Bondt’s system not only saves electricity, but also saves the road. Expect to see more examples of it, in other countries, soon.

While this is a very elegant solution, the author fails to grasp that,
because the road is essentially an unglazed thermalOoms collector, and only gets
warm in the summer or cool in the winter, requiring that seasonal heat be stored.   Summer heat from the asphalt is used to heat the building in winter, while the chill of the inter road cools the building in summer. 

In this particular case, seasonal storage is accomplished with heat exchangers placed in not one, but two separate natural aquifers near the building.  The fortunate proximity of two such aquifers is extremely rare.  While this is a very elegant way to heat and cool a building, the lack natural aquifers in which to store seasonal heat will likely prevent widespread adoption of this
technology, no matter what the author believes.

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Transport Fuels and Solar Technologies: Bird’s Eye View

For my last couple AltEnergyStocks Columns, I’ve been taking a step back and looking at how we can get an understanding of the broad trends of energy technologies. Last week, I added to the Visual comparison of Electricity Generation Technologies I did last spring with a new Visual Comparison of Transport Fuels.

Following up, today I published a look at the varius solar technologies through the lens of their applications.

Before we go back to looking at trees, I hope you enjoy this look at the forest.

(and don’t miss the National Tour of Solar Homes next Saturday)

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Visual Comparison of Electricity Generation Technologies

I just put together a couple graphs for a talk I’m giving on Monday to give people a visual feel of the various technologies for generating electricity.  These come with a gigantic caveat: the numbers are far from precise.

With changing technologies, it’s impossible to represent any of this with a single number anyway.  I’m trying to show how the technologies compare to each other, and I used four parameters:

  • Cost ($/MWh),
  • Availability (better the closer the profile of the technology matches a normal demand curve (wind is bad, baseload is okay, dispatchable is best, solar),
  • Emissions (and I count waste storage when it comes to nuclear),
  • Bubble sizes represent the size and durability of the resource (I’ve tried to combine in one number how much power we can get from the resource, but also how long supplies of fuel will last.) 

In both charts, the “best” technologies are in the upper left (low cost, low emissions, and available when we need them.)

I know that I’m going to upset a lot of people because I was too harsh with their favorite technology, so feel free and comment on the numbers I’m using, but also please provide references for where you get your numbers.  Most of these are off the top of my head, so their accuracy is admittedly questionable.   Here are the numbers I used to make the graphs.

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Holistic Approaches to Energy Problems

H. L. Mencken said, “For every human problem, there is a neat, simple solution; and it is always wrong.”  When it comes to solving the problems of peak oil and global warming, I also think that the loudest barking is up the wrong tree.  We look for the quick fix, trying to find a substitute energy source that allows us to change the way we do things little as possible, when the real problem is actually what we’re doing, not how we’re doing it.   We need holistic solutions, not quick fixes.

Too abstract?  Here are some concrete examples:

 Problem: Peak Oil

Quick fixes: Ethanol and slight increases in vehicle efficiency standards.

Holistic solutions: Change our driving culture and infrastructure, by changing the way car use is priced from fixed charges to a per mile basis (“Pay as you drive”).   Removing subsidies to use cars when other forms of transport are available, and redesigning our cities to make them easier to get around on foot, bike, and public transport.  Like other holistic solution, all these steps increase safety and reduce congestion, reduce obesity and associated health problems, as well as reducing the use of gasoline.

Problem: Wind and Solar are intermittent resources, but coal produces too much CO2 and natural gas prices are rising rapidly.

Quick Fixes: Nuclear power and “Clean” Coal.

Holistic Solutions: Shift our demand for electricity to times when it is available, by using time of use pricing, energy storage and demand alignment, and distributed energy storage such as plug in hybrid vehicles.

Investing opportunities:On thing that’s striking about these examples is it’s much easier to find investment opportunities in the quick fixes than in the holitistic solutions.  To invest in ethanol, you can just buy ADM or one of the multitude of ethanol stocks that have been going public recently, but I have yet to come up with a satisfactory way to invest in better urban planning (except buy a house in a walkable community, which is something I’m planning on doing this summer.   Stapleton is the community.  I currently live there, but I’ve been renting and waiting for the end of the housing bubble.  I actually don’t think that housing is going to go up again any time soon, but I’m tired of waiting.) 

The investment landscape is a little better when it comes to energy management.  Itron and Siemens both have divisions that help utilities manage their grids better, and there are many battery and other energy storage companies to choose from.  Still, it’s a lot harder to pick through battery companies than to just buy a nuclear powered utility or uranium miner.

Holistic solutions, by their nature, have weak boundaries… the benefits tend to be diffuse, and spread over society as a whole, so it is difficult to charge fairly for them.  This, I think, is why there are so few companies pursuing them when they can pursue a quick fix that they can charge for up front.  

Companies have an obligation to their shareholders to make money.  It’s our job, as human beings, to work towards regulations that make it easier for companies to make money with holistic solutions that actually solve the problem than it is to make money with quick fixes that just cover the problem up.

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Vision of a sustainable energy future

I’ve been meaning to write an article outlining a vision of a sustainable energy future, where biomass is converted into fuel and electricity through pyrolysis and the waste product, carbon is used as a fertilizer a-la terra preta to produce more biomass.  The good news is I don’t have to.  The Engineer Poet did, and it’s just part of a much broader vision you’ll find here.   He also goes into a great discussion of transportation technologies and efficiency which would never have made it into the article I’d write.  I like it when other people crunch numbers, so I don’t have to.

Give yourself a half hour to read the whole article.  It’s worth it.

( Terra Preta: I got a comment from Erich J Knight on terra preta here that went into a lot of depth, but I deleted it by mistake.  Forturnately, he says pretty much the same thing in his blog.  I first heard about terra preta from Ron Larson, chair of the American Solar Energy Society, who is very active in the local (Denver) renewable energy scene.  If you haven’t heard about terra preta, and are concerned about globabl warming or soil fertility without fertilizers from fossil fuels, it’s worth looking into.)

Read the rest of this entry »

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Large Scale Electricity Storage.

One of the biggest barriers to the adoption of wind and solar electricity generation is the lack of storage technology with the capacity to handle the hundreds or megawatt hours necessary.    

Large scale electricity storage technology also allows utilities to flatten their demand, and defer construction of expensive new generation. 

Here’s a quick rundown of some of the technologies vying to meet this need.  Most of this is information is drawn from the Electricity Storage Association website.

Technology

Description

Comments

$/kWh; efficiency

Investment opportunities?

Pumped Hydro: Reservoir to Reservoir

Energy is stored by pumping water from a low reservoir to a higher one, and recovered by running the water back out through a turbine.  This system can be easily retrofitted into existing reservoirs, but has limitations due to water regulations.  First used in 1890.

The cheapest and most developed technology, pumped hydro is nevertheless limited by the availability of suitable sites.

$3-$50 per kWh;

70% to 85%

The major supplier in the business is private.  Could look for opportunities in utilities that have good potential projects.

Compressed Air Storage (CAES)

Energy stored by compressing air into large underground caverns.  Air combined with natural gas on exit and burned in turbine.  The gas compensates for the cooling as air decompresses. 

Gas used is about 40% of the amount used in comparable peaking turbine.  First built in 1978.

70% to 80% efficient; $30-$100 per kWh

 

Underground Pumped Hydro

As above, but water is pumped between an aquifer and an above ground reservoir.

More sites available, developing application.  Might have some water quality issues.

Costs Low

75% to 85% expected efficiency.

Small turbine/pump makers.

Polysulfide Bromide battery

A regenerative fuel cell based battery technology (aka “Flow Battery.)  Seems have run into difficulties due to the toxicity of the chemicals involved.  

15 MW demonstration project in 2003; more recent projects canceled.

75%, unknown cost;

Regenysis, the owner of this technology, was a subsidiary of
Germany’s RWE.  No recent activity; the program may have been wound down.

Molten Sodium-Sulfur (NaS) Battery

Molten battery technology.  “Safety concerns addressed in

30 sites in
Japan, mostly for peak shaving.  Largest is 6 MW for
Tokyo electric

Cost “High” compares to BrS and hydro/ CAES.

NGK, Japanese power equipment supplier focused.  Can be bought by US investors on the Pink Sheets NGKIF.PK

Regenerative Fuel Cell (Hydrogen)

Fuel cells can be run in reverse for electrolysis, with the hydrogen stored in large tanks.

First pilot project 2004

“much less” than 80%

Fuel cell manufactures: Ballard, FCEL, and others.

All these technologies except hydrogen are dealt with very well on the Electricity Storage Association site.  They have some great technology comparison graphs which deal with a lot more variables than I have here in their technology comparison section.

Cost Comparisions

Click to enlargeClick to enlarge

Efficiency/Quality Comparisons:

Click to enlargeClick to enlarge

Of these technologies, Pumped Hydro and CAES are the only ones ready for near term, large scale deployment (with NaS and Flow Batteries applicable in some markets highly constrained markets.)

The major downside for pumped hydro is siting, part of which problem can be solved with the smaller scale reservoir to aquifer option.   For CAES, the downside is the need to use gas to run the turbine, albeit a very efficient one.  One option might be to substitute for the natural gas used in CAES with hydrogen from electrolysis, allowing the system to work at locations remote from natural gas supply, and, for wind energy storage systems, be 100% renewable.

 10/20/06- Article about a flow battery from VRB power systems for an Irish wind farm.

8/5/07: Here’s an article I just wrote about two potential investments in utility scale electricity storage.

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That “Free” set-top box isn’t free

Here’s an article from Reuters about the hidden costs of set top boxes… up to $76 a year in electricity bills for a cable set-top box.

This is one of those opportunities for energy conservation that I really like to push: you not only can save energy, but money as well, and it does not require sacrificing quality of life.  CFLs and Passive Solar architecture also come to mind… there are so many energy saving opportunities that pay for themselves, it breaks my heart.

Most consumers don’t see the money or electricity they’re wasting here, and so they don’t know that they need to be more discriminating.  These hidden cost provide a great opportunity for useful government regulation.  Requiring that A/V equipment have a sleep mode that uses 1 watt instead of 30 watts would only add marginally to the cost of most equipment (See this great Economist in-depth article on the subject from this spring)  Oops- it’s only available to subscribers.   Some highlights:

 STRANGE though it seems, a typical microwave oven consumes more electricity powering its digital clock than it does heating food. For while heatictq237.gifng food requires more than 100 times as much power as running the clock, most microwave ovens stand idle—in “standby” mode—more than 99% of the time. And they are not alone: many other devices, such as televisions, DVD players, stereos and computers also spend much of their lives in standby mode, collectively consuming a huge amount of energy. Moves are being made around the world to reduce this unnecessary power consumption, called “standby power”.

In 1998 … standby power accounted for approximately 5% of total residential electricity consumption in America, “adding up to more than $3 billion in annual energy costs”…. results, published in 2000, revealed that standby power accounted for as much as 10% of household power-consumption in some cases.

…In 1999 the International Energy Agency, based in Paris, adopted Dr Meier’s proposed “one-watt” standard as a target for standby consumption. In 2000 Australia became the only country to adopt this standard nationally, in the form of a voluntary scheme that began in 2002. The aim is for most new products to meet the one-watt standard by 2012.

In addition to these various voluntary schemes, there have been some mandatory measures. Perhaps surprisingly, one of them was introduced by President George Bush, as a result of the California energy crisis of 2001. That year, Mr Bush issued Executive Order 13221, which states that every government agency, “when it purchases commercially available, off-the-shelf products that use external standby power devices, or that contain an internal standby power function, shall purchase products that use no more than one watt in their standby power consuming mode.” Given that Mr Bush is not renowned for his environmental credentials, this came as quite a surprise to those in the industry.

That law does not apply to consumers, and there are a ton of energy hog products out there.

What can you do?  Buy Energy Star  rated products.   I also have a tester called a Kill-a-Watt from P3, to see which of the gadgets I already have are energy hogs.  Some nonprofits have these available for loan, and if you live in Denver, I’ll loan you mine.  The Center for Resource Conservation in Boulder has a nice little calculator you can use with it, too.

If you find you already have products that use a lot of power on standby (and you probably will,) consider plugging them into a power strip, and turning them off that way.  That’s not always an option, though.  I found that my VCR/DVD combo uses 30 watts all the time, and it would lose it’s programming if I turned it off with a power strip.   I’m thinking about replacement.

I also think this is a great argument for laptops over desktop computers… laptops are designed to conserve power, because they have to make the battery last… most desktops are not.  If you want a big screen and a keyboard, you can always use a docking station. 

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