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United States Science

Green Housing Takes Root in Oregon 388

baldinux writes "I was reading an article in the Portland Tribune which showcased the City of Portland's noteworthy 'Rose House' (1.8mb PDF) project, part of the Office of Sustainable Development and Oregon Department of Energy's plan to encourage sustainable, energy-producing, environmentally-friendly housing for the future, a plan which is gaining national and international attention. The Rose House, at only 800 square feet (approx. 244 sq. meters), is equipped with solar panels and incorporates technologies that recapture lost heat and energy during normal appliance operation, such as ventilation. During peak hours -- when power is at highest demand -- the Rose House could produce surplus energy, feeding kilowatt hours back to the power grid, and `rolling back' the meter -- the power authority's way of purchasing the surplus energy and lessening the burden on comparatively 'dirty' power plants. The article suggests that homes like this could see net power bills as low as $0 per year. The environmental benefits of a lessened burden on centralized, often fossil fuel or nuclear, power generation plants would be considerable."
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Green Housing Takes Root in Oregon

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  • by Eunuchswear ( 210685 ) on Monday September 20, 2004 @04:14AM (#10295617) Journal
    Oh dear. Isn't it sad that it's impossible to correct a post without making an equaly silly looking error.

    You mean 800 sq ft = 74 m2.

    P.S. Google? Just use units(1).
  • Re:Initial Cost (Score:4, Informative)

    by Veridium ( 752431 ) on Monday September 20, 2004 @04:22AM (#10295630) Homepage
    You know what the real shocker is? The installation cost. It costs as much as the hardware in my area. We're going to do it, but we have to refinance our house in order to afford it. Fricking ouch.
  • by bhima ( 46039 ) <> on Monday September 20, 2004 @04:24AM (#10295640) Journal
    I am wondering how it is you went from units of area to units of volume?
  • by mx.2000 ( 788662 ) <> on Monday September 20, 2004 @04:35AM (#10295669)
    What's new about this stuff?

    I've seen "passive" houses being built for years (in Europe).

    Maybe 6 years ago this would have been kind of innovative. But in the year 2004? C'mon!
  • by Gopal.V ( 532678 ) on Monday September 20, 2004 @04:47AM (#10295717) Homepage Journal
    > Portland relies on hydro power rather than dirty power

    Hydro power is sometimes more disruptive than nuclear power - you never hear nuclear power causing an earthquake [] do you ? .

    > Why don't the regions of the US that rely heavily on coal or nucler power have the same impitus for cleaner alternatives ?.

    Solar panels, Wind power and tidal power plants need a few natural resources which aren't easily transportable. (or think about solar panels in a hailstorm ?).

    The best use of solar panels I've ever seen was for AirConditioning ... if the sun's not out, the air's cool anyway and if it is solar power kicks in . Don't know if it'll work for a bigger scale , unless we have spray on solar panels for those BIG tinted windows.

  • by dustmote ( 572761 ) <fleck55&hotmail,com> on Monday September 20, 2004 @04:55AM (#10295740) Homepage Journal
    I don't know about the energy programs in Oregon, but alternative architecture is alive and well [] there.
  • by hazem ( 472289 ) on Monday September 20, 2004 @05:09AM (#10295766) Journal
    Right, but even if you're a net-$0 customer, that power they buy from you is power they are selling to someone else (or not having to pay to produce). As long as they're able to sell it to others for more than they pay you (plus costs), then you're still profitable.

    The economics change, of course, if a majority of the people employ systems like this. At that point, though the energy you sell back is worth less because so many more people are producing it as well.

    I realize this article is about Portland, but its state, Oregon, offers tax incentives for certain energy efficiency improvements:
    Oregon Residential Energy Tax Credit Program []

    Tax credits are available for the following categories:
    fuel cells
    Water Heaters

    "The maximum amount of tax credits a resident may receive per year is $1,000 for appliances including heating, ventilation, and air conditioning (HVAC) equipment. The maximum amount of tax credits a resident may receive per year is $1,500 for renewable energy equipment such as solar and wind systems. "

    If you're smart, you can probably plan part of yoru purchases in December of one year and the rest in Jan of the next. Or possibly spread your project over a few years to maximize the tax break.

    Plus, these improvements amount to capital investments in your property which should reduce any taxes incurred from selling a house (though, I think the capital gains tax was eliminated for the owner's residence).

    And, such investments done on rental properties will count as costs and will, while reducing your profit, will also reduce the tax on your profit, which could be as high as 40%.
  • by hazem ( 472289 ) on Monday September 20, 2004 @05:13AM (#10295775) Journal
    This link from the DOE shows various incentives in different states:

    Database of State Incentives for Renewable Energy []

    That includes Federal Incentives []
  • Hello America (Score:4, Informative)

    by Noizemonger ( 665926 ) on Monday September 20, 2004 @05:13AM (#10295776)
    Tis is ridiculous. We had that kind of houses for YEARS in europe, at least in germany. And its not a niche-market around here but mainstream. Due to the fact that energy and heating costs are very high in germany a lot of people consider a "low-energy-house" or even a "zero-energy-House". But im happy to see that america finally found out about some enviromentally sound ideas from last century. Whats next cleaner air? Less fuel? Kyoto?
  • by alwayslurking ( 555708 ) <> on Monday September 20, 2004 @05:19AM (#10295790)

    You install solar panels in Long Island and LIPA will buy power off you.

    random link from google []

    Suggests those technical problems aren't insurmountable

  • Re:The future... (Score:5, Informative)

    by hazem ( 472289 ) on Monday September 20, 2004 @05:20AM (#10295793) Journal
    The best solution is to educate the world. Educated people tend to have more options and fewer babies.

    The last I heard, Italy has negative native population growth and its overall population growth is only positive when immigration is taken into account. And while the US has positive native population growth, a great deal of the overall growh is also from immigration.

    It probably has to do with more guys getting educated and becoming computer geeks. Their chance of reproducing then drops precipitously because they spend all their time on slashdot.
  • by Zog The Undeniable ( 632031 ) on Monday September 20, 2004 @05:28AM (#10295809)
    One of the big problems with mains electric power is that it can't easily be stored. This means that wind/wave/solar power all need backup fossil or nuclear capacity for when it's not windy or sunny. Batteries are bulky (look in the basement of your data center), contain nasty chemicals, are expensive and have a short life. Maybe the answer is a few more schemes like Dinorwig []? This was originally conceived as a means of responding instantly to spikes in demand, but fundamentally it's a clever way of storing excess power from the grid and releasing it later. How much would it cost to hollow out a few of the Rocky Mountains?
  • by RKBA ( 622932 ) * on Monday September 20, 2004 @05:30AM (#10295816)
    "I really don't see the government, at least not with current policy/spending/etc., creating any sort of incentive here."

    The State of California will reimburse homeowners who install wind or photovoltaic power approximately 45% of the cost of the system.

    In my case, the City of Glendale, California, paid 50% ($21,000) of the total $42,000 cost of having a 4 KW photovoltaic array installed on my roof. What I heard is that they were required to do so by the California Public Utilities Commission. My photovoltaic system is a so-called "net-metered" system that feeds power back into the grid whenever the sun is shining and the system is producing more power than I'm consuming. It provides for almost half of my power usage. During most days my electric meter actually does run backwards.

    Since then, I've had "blow-in" insulation installed in the exterior walls of my home (it's an old house and didn't have any insulation in the walls at all!). The odd thing is that although the insulation only cost $1,200 to install, it cut my power bills (most of which are for electric air conditioning during the summer) almost in half - about the same as the photovoltaic system did! I estimate that my electric bills for next year will only be about 25% of what I used to pay.

  • by Chagrin ( 128939 ) on Monday September 20, 2004 @05:45AM (#10295854) Homepage
    This is not at all infeasible and is done quite frequently. It's not very economical though as the power company will only pay back at wholesale rates.

    Yes, the power man would be in for a shock if the loads weren't properly handled. The power company will require that a cut-off switch (to cut output when the power goes out) be installed for any grid-tie setups.
  • Re:Initial Cost (Score:5, Informative)

    by AaronGTurner ( 731883 ) on Monday September 20, 2004 @05:52AM (#10295870)
    An alternative to solar panels is solar heating, in which water is pumped into solar heated areas. It is less efficient but lower tech (essentially plumbing) and can be cheaper, depending on how much plumbers charge in your area. Essentially you use the solar heating to provide hot water for your house (people like hot water even in summer!) and thus reduce utility costs to heat it. In theory the hot water can be used for other tasks as well, but again at the cost of efficiency, but then the cost of the total solution tends to go back up to the cost of solar panels again. One of the nice things about solar heating is that there isn't a requirement for heavy metals and the like, although if the demand for copper pipes increased dramatically that might be a problem in itself!

    At the moment, though, solar heating or panels are expensive for home owners. You can reduce energy use from the grid more cost effectively with other techniques (insulation, shading windows, more efficient boilers, or even just servicing your boiler) at the moment until volume sales reduces solar panel costs.

    Some governments (e.g. Germany) have provided tax incentives to install solar solutions, or required that new government buildings include solar solutions where possible. The latter makes a lot of sense as the cost of solar panels on a new office block is a comparatively small proportion of the total cost, but stimulates the demand for solar panels, hopefully then bringing new production onstream.

    Another area that people sometimes neglect when working out how much energy they use is watering their garden. Using tap water means using water that has been purified to human drinking standards, with quite a lot of energy input. Collecting rainwater run off from your house and storing it to water your garden directly saves energy. Given the downpours in the UK in August stopping run off going into your garden and flooding it (we had to bail our sunken patio out!) is helpful too! Mind you, since we had 6 inches of rain in 24 hours (I'd left a glass out in the garden) you'd need a huge water butt to cope!

  • Re:Solar Electricity (Score:5, Informative)

    by AaronGTurner ( 731883 ) on Monday September 20, 2004 @05:54AM (#10295875)
    " I think I've read somewhere that solar panels cost more in energy to create than they ever produce. Is this correct? " No. Current solar panels generally recover the initial investment in 3 to 5 years (depends on how much sun they get, obviously) and last for about 20. They do degrade a bit in performance towards the end of their lives, but will typically provide 3 to 4 times the initial energy investment during their lifetime.
  • Re:Size matters! (Score:2, Informative)

    by AaronGTurner ( 731883 ) on Monday September 20, 2004 @06:01AM (#10295890)
    You can have a large but efficient house, over and above the things that are common to all house construction, large and small (insulation, etc).

    For example, open plan houses require more energy input as to be comfortable you have to heat or cool a large area. Separate rooms means that you can have a cold kitchen in winter if you are only going to be spending 5 minutes in their putting milk on your cornflakes. Also you can subdivide large living areas with temporary partitions and open them up when you have large gatherings, and so on.

    Also the surface area of the house is important. A small bungalow can end up being less energy efficient than a larger 2 storey house.

  • by Technician ( 215283 ) on Monday September 20, 2004 @06:02AM (#10295891)
    The best use of solar panels I've ever seen was for AirConditioning ... if the sun's not out, the air's cool anyway and if it is solar power kicks in . Don't know if it'll work for a bigger scale , unless we have spray on solar panels for those BIG tinted windows.

    For the simple answer to cost of instal is check the power requirement for a simple AC unit. Remember they don't like power sags. Now price a solar system big enough to run the AC. Also price the storage battery or co-gen setup to keep it running when a puffy cloud passes by.

    For most people, the required expense to run a high power draw device is beyond a home solar instalation. Most solar instalations are for hot water, and enough electric to run a few small energy effecient appliances. Don't expect to run a regular all electric home of just solar. Expect to use an alternate power source for things like the hot water, heating, cooling and clothes dryer. They won't be solar electric.

    Another place to check is your monthly electric bill. Our home of 6 in the summer runs about 35 KWH/day. This is about an order of magnetude above a typical home photo-voltaic instalation. Very deep cuts in electric use are in order to even consider moving off grid. I simply don't have enough money or roof space to supply my current electric demand. Things like the dishwasher, electric dryer, AC, electric heat, and un-effecient refrigeration (fridge and freezer) would have to be replaced.

    A high effeciency fridge is a serious chunk of change. I've looked into them.
  • I don't get this. (Score:2, Informative)

    by BJH ( 11355 ) on Monday September 20, 2004 @06:03AM (#10295895)
    I've been looking into building a home here in Japan, and the only thing that turned up in the article that isn't offered by most construction companies/builders here is the staggered studs. The rest of it (roof insulation, foundation insulation, well-insulated windows, single heating/cooling system for the whole house, 3.3KW solar panel) is pretty much standard, or if it's not standard, it's available as a unexceptional option.

    Is the US really that far behind in construction techniques?
  • by sciuro ( 97151 ) on Monday September 20, 2004 @06:47AM (#10296001) Homepage

    in case any non-americans are wondering why the size of the apartments is "only 244 square meters", 800 square feet is in fact about 75 square meters.

    converting areas is different from converting lengths... tsk tsk.


  • Re:The future... (Score:5, Informative)

    by mcrbids ( 148650 ) on Monday September 20, 2004 @06:49AM (#10296006) Journal
    We can't stop people from having kids. We can try and conserve natural resources, but eventually the number of people will be more than the planet can support.

    Over-population is not quite the problem you think it is. In the United States, pop growth has slowed to a crawl, and most of our growth is due to immigration.

    Developed countries the world over have slow (and declining) birthrates. Heck, Italy is trying to encourage their population to reproduce - they are suffering from net population decrease!

    World population, based on current trends, is due to stabilize [] around 2075 at around 9 million people. []

    There are a number of reasons for this. Affluent people tend to have fewer kids, merely because they are a hassle. In the more impoverished nations, existing infrastructure is failing to provide for current needs, let alone future growth. For example, one of the largest mass poisonings ever in human history is taking place in Asia [] because of arsenic-laced drinking water.


    What truly amazes me is the sheer number of people who don't google whatever they're talking about before they say it. The volume of uninformed, stupid comments on the Internet that can be corrected with 10 minutes of googling and quick research is mind-boggling.

    People with access to this kind of information should not be making the stupid comments they are. That they do, anyway, and don't get flogged on the streets is a mere testament to the fact that humanity does not yet value intelligence and critical thinking over stupidity.

    I daresay we are entering a new era of humanity - the era of the informed but ignorant idiot. The information is there - cheap, easily available. Tools that our ancestors would have killed for - and we use it to pass along mundane drivel because "we feel" or "we think" rather than actually use that tool to anywhere near its true potential.

    Sad. TV is used for network television and advertising, instead of mass education and information. News shows on TV are remarkably shallow and uninformative. The best bet are the "nature" shows, which are nice but curiously designed towards complacency.

    We are in the middle of a mass extinction event [] brought about, no doubt, by people who chcose not to be informed, and make decisions based on ego and inadequate information.

    We need to pay attention, people!

  • by sasenfus ( 710540 ) on Monday September 20, 2004 @07:18AM (#10296065)
    It shouldn't be said any longer. This was true in the early days of photovoltaics (PV), but the technology has been steadily improving. It is no longer true (a little like saying "integrated circuits will never become commercially viable for home users"). These days, PV recovers its costs in 3-5 years, in most residential applications, and then keeps working well for another 15 at least. And getting better all the time.
  • by the_twisted_pair ( 741815 ) on Monday September 20, 2004 @07:30AM (#10296091)
    Simply not true. Autarkic housing can be achieved simply, and the result need not look like a pudding. Their usual issue is actually overheating in spring and autmn seasons (low-angle sunlight comes in through windows, during seasons of near-minimum heating requirement).

    Even 'regular' houses have no excuse not to be more efficient. Heat reclaimation units deal with pre-heating incoming air with the outgoing (hey, Wickes in the UK sell a packaged unit suitable for retrofit to an average UK house for less than 160quid last I checked; payback is 15-18months ). That also deals with odour, air moisture content etc. It's quite easy to get a 3-bed UK semi (say 100sq.m.) down below 1.2Kw design heatloss for a 19degC interior / -1degC exterior temp difference.

    At which point, you might note, overheating can actually become an issue with typ. family (2 adults at 135W each @average activity, two kids at 100w each, modicum of household gizmos). Your only real losses are top-up heating overnight and domestic hotwater.

    (yes I am an architect)
  • by Jesrad ( 716567 ) on Monday September 20, 2004 @07:37AM (#10296112) Journal
    The thing I can't help but wonder, is why if these are so effecient, is why there isn't one under the hood?

    That's because of low power-to-weight ratio, because they take time to start up, and because they run at a constant, low RPM.

    They are used a lot as power generators, on boats for example.

    But that could change some day. There is this company [] that tries to manufacture and market an aviation Stirling engine. And I'm working on a very low weight, variable-RPM Stirling engine based on this concept [] of an improved rotating internal combustion engine.
  • by ajs318 ( 655362 ) <sd_resp2@earthsho[ ] ['d.c' in gap]> on Monday September 20, 2004 @07:53AM (#10296156)
    The reason why conventional air conditioning units {and refrigerators -- a fridge is just a cupboard with its own air-con venting into the kitchen} are sensitive to voltage drops, is the kind of motor they use to drive the compressor; a capacitively-started induction motor. The idea is that once the motor has started, a time delay relay disconnects the starter winding. This time delay relay typically uses a simple bimetallic strip and heater coil arrangement; in pre-semiconductor times, this was about the only way to do it, and it just kind of stuck. At first, the strip is touching a contact which sends current through the capacitor and starter winding; as it heats up, it bends away from the contact and cuts the power to the starter winding, so only the main winding is powered. If you don't use the starter winding then the motor will sit still (unless you spin the armature by some external means).

    The problem is that at low voltages, the heater doesn't get hot enough to open the bi-metallic switch. The starter winding stays connected all the time and the motor draws about double the power it should ..... and gets hotter than it should. Now, if the delay relay were mounted in good thermal contact with the motor, then it would be helped to operate by the excess heat building up in there; but that huge hefty chunk of a motor would slow down the resetting action. This means next time the refrigerator's thermostat is calling for cooling, the motor won't start because the delay relay is now in the "run" position. So the motor just gets hotter and hotter. And he fridge certainly isn't getting any cooler, so the thermostat won't open in a hurry. It has actually been known for fridges to fail castastrophically under low-voltage conditions!

    (As an aside, I know that an electronic delay relay could be built that would do the same job, but using a simple R-C delay circuit coupled to a conventional electromagnetic relay, for about 50p in bulk. Maybe modern fridges do actually use this kind of thing instead.)

    If you wanted to build an air conditioner that was really immune to supply fluctuations, the obvious choice would be a DC brushless motor. You could run it from mains via a switch mode supply -- they're cheap as chips nowadays -- or straight from DC. Brushless motors are quite tolerant of voltage variations anyway, as long as you can get enough whack to shift the spindle and not so much as to damage the transistors in the drive circuit. And it would also be an idea to give a refrigerator a chimney of its own, so as to dispose of the hot air it produces directly rather than relying on your home's aircon to shift it. If you added a nice big air relief opening, the draught thus created should help to cool the kitchen. In winter, you could divert the fridge flue into an upstairs room (you don't want to get it back anywhere near the fridge). With an aircon, you probably could do something sensible with the meltwater from the ice that builds up on the evaporator, too.
  • by Umrick ( 151871 ) on Monday September 20, 2004 @08:04AM (#10296201) Homepage
    It's very real (buyback/rollback) and required by law in most states, although they don't necessarily have to give you cash if you exceed, and most cap credits.

    It's not so simple as plugging into a socket though. You need a unit that takes your power (usually DC from the source) and matches the phase to the supply source.

    A grid-tied system is generally much cheaper than an off-grid solution, as there's no need for batteries. Of course, you lose power when the grid does unless you install batteries and a service disconnect...

    Plenty of sources out there on this very thing.
  • Re:Size matters! (Score:3, Informative)

    by Paulrothrock ( 685079 ) on Monday September 20, 2004 @09:28AM (#10296727) Homepage Journal
    My dad works with a federal agency building low-cost housing in rural areas. A similar government official came to visit one year and balked at the fact that we make roofs that only last 20 years! He said people in England wouldn't buy a house without at least a 50 year-guaranteed slate roof.
  • by Jaiden ( 64072 ) <jaiden0@hotmail.FREEBSDcom minus bsd> on Monday September 20, 2004 @10:10AM (#10297074)
    In MA at least, you can choose who makes your power.

    For a few cents extra per kwh, you can have clean power without an initial investment. If you truly care about the environment, you should be buying clean power. You have a choice of wind, solar, hydro or various mixes (at varying cost.)
  • Heat Pumps (Score:2, Informative)

    by justanyone ( 308934 ) on Monday September 20, 2004 @10:46AM (#10297410) Homepage Journal


    Heat pumps are electrically powered. They combine air conditioning (AC) (cooling) with heating. The heating is NOT electrical resistance heating; they run AC in reverse, cooling the outside air and moving that heat to the inside.

    The efficiency (IMHO IIRC) is based both on the mechanical efficiency of the unit and the outside weather. Very frigid temps mean the unit works very hard and is not very efficient, and sometimes must be supplemented with electrical resistance or other heating methods.

    Efficiency can be improved by using "ground loop" heat pumps. Instead of heating/cooling air, they run a working fluid through a long pipe that can be put either in the ground or into a nearby lake. Thus, instead of grabbing heat from -10 degree F air, they get it from 33 degree or warmer water. A medium sized pond (1/3 acre+ and 10+ ft. deep IIRC) will not freeze to the bottom where the pipe runs given normal home heating loads. The DISADVANTAGE to ground loops is cost; they add significantly to installation costs, but these prices are dropping slowly and steadily as techniques and technology improve.

    Heat pumps have generally good efficiencies in warmer climates, in Kansas and to the south.

    A prominent disadvantage of a heat pump is dependency on the electrical grid. When it's summer, AC is not usually vital to survival (at least in most states; sorry to Houston). BUT, when it's -10 degrees, heat is vital. If the power fails, this is a problem (remember ice storms in Canada 10 yrs. ago?). The competing technology, Natural Gas (90%+ methane, 10% propane etc.) is typically underground and has a very, very reliable distribution system by comparison to electricity.

    So, if you live in the right states, heat pumps are great, and can be even better with a little more capital investment in a ground loop. But, more cold northern climates (last time I checked) are far less well served by this technology. Oh - and most of Oregon doesn't count as "cold northern climate" for this - it's very moderate due to the pacific). Heat pumps in Oregon probably work very well, but in places like Chicago, and especially Duluth or Fairbanks, not so much.

    Just a few bits from my research for my own home.
    -- Kevin
  • Since I lived there for six years, I find it odd for another reason. Portland is cloud covered for most of the year (especially when you need it most, in the winter). Probably not the most econimical location for an expensive solar panels installation.
  • Re:The future... (Score:3, Informative)

    by WOV ( 652967 ) on Monday September 20, 2004 @10:49AM (#10297444)

    Apparently, though, Italy views that population decline as a real problem - Italy and France are both examining re-upping an old WWII policy of giving medals and other recognition to new mothers. = )

  • Re:Heat Pumps (Score:2, Informative)

    by hb253 ( 764272 ) on Monday September 20, 2004 @12:14PM (#10298322)

    Until it died last year, my parent's had an American Standard steam boiler (circa early 1970's) tied to a millivolt thermostat system. It was natural gas fired.

    A small amount of electricity was generated by a thermopile in the pilot flame. That was enough to run the heating system without outside electricity.

  • Re:800 SF? (Score:4, Informative)

    by jdray ( 645332 ) on Monday September 20, 2004 @12:38PM (#10298558) Homepage Journal
    I went through the home this weekend, and yes, it's small; about the size of the first one-bedroom apartment my wife and I had. The (two) bedrooms aren't very large, but they're big enough. The house is constructed on the back of a large lot. The people occupying the house are recent retirees, and either their son or daughter (I forget which) owns the home on the front of the property. They encouraged their parents to build a home on the property and move in BEFORE they were old and debilitated, which seemed to make sense to me.

    Slashdotters will be happy to know that the "spare bedroom" has been converted to a home office, and is well stocked with computer gear. These folks aren't dottering old people, they're very active. No, the house doesn't have a formal dining room, a media room, an acre-sized kitchen or any of the other appointments common in the million-dollar, Street of Dreams homes on your average home tour, but it is comfortably sized for a retired couple who want to live life.

    Home construction prices in Portland seem to run somewhere over $100 per square foot, but when you get down to smaller sizes, the price per square foot goes up, because you still have to have a kitchen and bathroom, no matter how large or numerous your rooms are.
  • Re:I don't get this. (Score:3, Informative)

    by Quikah ( 14419 ) on Monday September 20, 2004 @02:19PM (#10299574)
    No, everything is pretty standard in the US also except the solar panels.

    The general idea is that the house was designed with the goal of 0 net energy use.
  • You store it as heat (Score:1, Informative)

    by Anonymous Coward on Monday September 20, 2004 @03:35PM (#10300544)
    There are CAES systems already in operation which do this. One in Germany and one in the US.

    e.g. rgystora ge_report/node7.html

    This and the system you mentioned builds in storage capacity to the grid. Storing energy overnight from solar and during calm days for wind power is then straightforward.

Truth is free, but information costs.