Solar Power -- Think Hot, not Watt.

[skids]

Lots of interest in energy it seems on this Silent Fitzmas Eve.

So, high time I reformatted this for DU.

Let's turn the "get off the grid" discussion upside-down, shall we?

It's nice to see people actually looking at improving power in their house... most people focus on vehicles, which is understandable since gas prices are something we have to face up to on a weekly basis or worse. Our home energy bills, though, only hit us once a month and often someone else in the household handles them. We don't get the jolt as often.

In addition a lot of folks focus on electricity. While your electricity bill may be higher, here are some very good reasons why your attention needs to be on hot water, winter heating, and air conditioning instead. You shouldn't try to get off the grid... yet.

Let's take a look at where our energy goes in the residential sector:



...most of it to HVAC and water heating.

Even when we look at just electricity use, ignoring oil and natural gas:



...still a good portion of what we do with electricity is turn it into heat or cold.

I know, yawn, right? Don't give up on this post yet. These may just be graphs to you but these numbers have huge consequences both to your own wallet and to the and to the environment and economy.

Here's why:

1. No technical "fix" is needed for renewables here. The technology to utilize both sun and ground heat is, well, at least as old as glass and rubber (in fact even older.) Yes, there are technical innovations that help -- high admittance glass, vacuum heat tubes, freeze-proof rubber tubes, better heat pumps -- but people have literally been doing these things for ages. Heck, even cavemen knew how to use caves to keep warm/cool, (not to offend the cavemen.)
   
2. There is a fast payback on these systems. You can take out a home equity loan and the savings from the system will most often pay its own interest for the life of the loan, as well as add equity value to your house (you just have to get an evaluation by someone qualified to estimate the system.)
   
3. The basic engineering is so simple that your random backwoods "Cooter" type regularly builds their own from scrap. The Internet has plenty of pages describing home-built systems, and that's just the guys who own a computer.
   

So what are these technologies? Well, I would be remiss if I didn't mention that before you bother with installing a special system for HVAC, you can get more return on your dollar by general efficiency improvements -- better insulation, large south facing "Heat Mirror" windows with a tree or awning, ceiling fans, economy shower heads, and if possible a duct from the top ceiling to the bottom floorboard to blow risen hot air down for reuse before it floats out the attic. Don't neglect these things.

But anyway, the two major technologies to be looking at for a quick payback these days are solar hot water and geothermal heat banking/heat pumps.



Solar hot water is the cheaper option of the two. Maybe you are tempted to scoff that this will not make a signifigant dent -- untrue. Look back up at the chart. Water heating represents 16% of our average energy use. Economy shower heads looking a bit less silly to you now?

Solar hot water works best when combined with an upgrade to an old water heater -- just the upgrade itself (to either tankless/minitank or to point of use tankless) can be well worth doing. But since you have the plumbing torn out anyway, and in some cases you have a spare old water tank from your old system available for free, it is a good time to think solar.

Unlike PV electric panels, solar heat panels collect a lot more useful energy (when "useful" means heat.) That's because it is fantastically easy to convert sunlight to heat -- all you need is a black surface and a glazing that traps heat radiation. They also have less issues with reduced output on cloudy days than PV panels. Many solar hot water installations even have to have built-in measures to prevent overheating.

If you don't try to cover all your water heat needs, a solar water system can be installed for a few thousand dollars.

http://www.solarroofs.com/ (just one of many links, no endorsement implied.)

DIY is not recommended for your average suburbian/exurbian home, though, if you do not have time to learn about these systems thoroughly... practically becoming a pro yourself... there is a lot that can go wrong.

http://www.fsec.ucf.edu/Solar/apps/sdhw/trouble.htm



The second technology helps with indoor heating and air conditioning and is known variously as a "ground source" system, a "geothermal banking" system, a "geoexchange" system, or a "heat pump" system (though not all "heat pumps" are "geothermal".) A brand name "slinky coil" is also helpful when researching them.

But wait, wasn't the subject of this post "solar power"? Yep, I only did that so you'd look.

These systems range from $10K to $30K depending on many factors about your house, your lot of land, where you are, and your current heating system. They are pretty much turnkey systems and would be very difficult to DIY properly, so consult a well recommended professional.

Essentially these systems bring the age-old cave up to you, so you don't have to live down in it.

(Oh, and a preemptive please, no comments to the tune of "that's not geothermal" -- the term is regularly used for both heat banking and deep drilling by people in the industry. Times change, and so do words.)

http://www.waterfurnace.com/ (again, no endorsement implied.)

Now some bad news. The market is full of gougers. You'll find various companies charging a wide variety of prices, and some of them are unconscionable rip-offs.

In fact, there is a technology I skipped here and the only reason I skipped it is that it is impossible to buy it at a reasonable price: Solar air heat. As a DIY project solar air heat can be very inexpensive and with a good amount of scavanging for salvage, I would not be surprised if one could not manage payback periods of less than a year.



I've written about this before, and you may want to check out this link where a small-volume local operation is actually bothering to fabricate solar air units at a decent price:

http://www.democraticunderground.com/discuss/duboard.php?az=show_mesg&forum=115&topic_id=31258&mesg_id=31258

...but look at what some of the other people are charging:

http://www.solarunlimited.net/prices.html
http://shop.altenergystore.com/items~Cname~Solarsheat+Recirculating+Air+Heating+Sys~Cc~SOLARSHEATG~iTpStatus~0~Tp~~Bc~.htm
http://shop.altenergystore.com/items~Cname~Cansolair+Recirculating+Solar+Air+Heater~Cc~CANSOLAIR~iTpStatus~0~Tp~~Bc~.htm

...shameful. That last one is even made out of soda cans -- recycling is nice and all but not at over a grand!

Granted the above systems are nice and large and have all the needed gizmos included, but a message to people in this business -- it isn't supposed to be about charging the customer a large percentage of what they would save (or in republi-speak "what the market will bear") but making enough profit to sustain the business and scale up production. The mere presence of products so grossly overpriced is bad for the renewables business, scaring off potential customers.

As an aside, another "no duh" technology that sounds simple but is not even available anymore, AFAIK, nevermind cheap, is a refrigerator that uses outdoor air when it is cold. Go figure.

http://www.sunfrost.com/passive_refrig.html

Or how about holding bathwater for a short time after use in a drainage tank so it heats the house. Or preheats clean water.

If we were smart about heat, we wouldn't use a lot of the power we consume today. The question is definitely not "do we have the technology"? The questions are "do we have the will?" and "do we have the clout?" to get this done on a massive scale.

Further reading:

http://www.eere.energy.gov/consumer/
http://www.pathnet.org/sp.asp?id=13076

Finally to address electricity, the following is extremely graphics heavy, but gives you a quick look at energy savings including the "watt":

http://www.democraticunderground.com/discuss/duboard.php?az=view_all&address=115x28899

[dave502d]

1. Thank you for the good links.n/t

[hootinholler]

2. WWII had Victory Farms,

Why not Power Panels? Free us from oil. Carbon neutral too.

-Hoot

[skids]

7. As far as farms go...

...I'm more a fan of decentralized production, but as far as centralized stations, the bang for the buck is currently in solar thermoelectric, not PV panels.

http://www.democraticunderground.com/discuss/duboard.php?az=show_mesg&forum=115&topic_id=29660&mesg_id=29660

http://www.democraticunderground.com/discuss/duboard.php?az=view_all&address=115x33644

[hootinholler]

12. I guess it was really Victory Gardens,

Not farms, I seem to have had a brain fart, but they were certainly decentralized. Small plots in backyards across America there were.

-Hoot

[SnoopDog]

3. Thank you for your efforts on this post...

We all need to fight for energy common sense. Otherwise these pricks will keep on building nuke and coal plants....

[MelissaB]

4. Somebody suggested a DU meet-up at this place

http://www.thefarm.org/general/visit.html

Click around on the site. It's pretty amazing.

[CottonBear]

5. Thank you for this informative post.

I'd like to add that planting deciduous shade trees on the proper side of an existing house and to shade an existing HVAC system can make a huge difference in energy use. Any local landscape architect or urban forester or local Ag outreach office can advise the homeowner.

Google Reference: CityGreen urban forest benefit computer analysis

New construction is another issue. A qualified LA or Urban Forester can assist the homeowner with site design and orientation. Proper orientation, tree preservation and planting plan for one's particular area can make a huge difference in energy savings. Of course, consult with an architect or local building official to determine maximum building efficienct design.

Always refer to vernacular architectural and landscape architectural models.

Cheers. CB

[skids]

9. We've got a well placed tree.

...unfortunately it's very old, and hence very large compared to when it was placed there back when this house was a farm. For some reason (cough, cough, climate change) the leaves haven't fallen yet this year. It's starting to get on my nerves -- I can't test my air heaters in the south windows until then.

Often an awning or porch can do the same job, if you've got a small
back yard.

[GreenPartyVoter]

6. Great post!

[papau]

8. Excellent info - but in GD it will be lost - could a Energy Forum post be

done by you - just a duplicate of the above?

thanks,

I just hate to not see the info preserved - and I keep losing my "bookmarks" of posts that I want to refer to in the future.

:toast:

:-)

[skids]

10. It's linked in various comments in E/E.

But I'd use the dkos link at the top if you want a bookmark.

[papau]

17. Thanks :-)

:-)

[Telly Savalas]

19. It shouldn't be lost if it keeps getting kicked.

This is exactly the sort of thing that should be in GD. All the people who wanna obsess on Bush's latest poll numbers, bitch about undocumented workers, and propagate bullshit conspiracy theories about the Illuminati forcing people to get flu injections, can have their own little forums where their threads can disappear.

Threads like this are what makes GD worth reading.

Kick Kick Kick

(I don't mean to sound like I'm jumping on you with this, since it seems like you agree. :toast: )

[PurityOfEssence]

11. HVAC means "heating, ventilation and air conditioning"

In case you were wondering. I sure as hell was, so I used my trusty old source.

www.acronymfinder.com

[Jose Diablo]

13. That first link, the one with

This Plugs in:

http:////www.dailykos.com/storyonly/2005/10/13/182220/73

You need to redo the link. instruction to take out the 2 slashes.

But that dailykos article is pretty good.

The idea of using solar to supply heat for the stuff like water heaters is good. Thermal heat energy has higher entropy than electricity, so trying to take that thermal energy to make electricity and then back to thermal energy is inherently wasteful, inefficient.

The best I figure that could be accomplished converting thermal energy to electricity would be in the 20% range, meaning the potential to do work versus how much we get out would be in the 20% range. So, why not just keep that energy thermal rather than attempting to convert it to electricity first.

As for HVAC, the one that makes most sense to me is the geothermal heat pump, using a closed loop heat exchanger with the ground. These things can be installed practically anyplace. Even in subdivisions if there is enough yard for a vertical loop. Their cost though is pretty high, with the loop cost being around $1000-$3000 per ton capacity of HVAC. Therefore for a 3 ton system, you can expect a $4-11,000 premium over a regular air heat pump. But, the loop lasts the life of the home, so eventually it pays for itself. Energy wise, a geothermal heat pump uses on the average 30-60% of the energy than a fuel HVAC. Big savings there as this figure is based on old prices for energy too. All this is detailed at:



If you can afford the premium for the loop, the geothermal system is the way to go IMHO.

Most people don't live in an area for wind power, however if you do, then for my money to supply electricity, wind turbines are the way to go.

There needs to be improvements in pricing for photovoltiac. True, they have a long life, but a $5.50 a watt just for the collector, thats pretty steep, especially considering at northern lat there just isn't many sun hours in the day to make it have a reasonable payback, unless of course there is no fuel whatsoever, then it becomes cost effective because there is no other way.

I'd be interested in seeing if that price per watt can be brought down dramatically for photovoltiacs to be competitive with wind.

We better start thinking about this stuff soon, because we are gonna run out of fuel eventually.

[skids]

15. Thanks.

Too late to edit the link. Worked for me but I guess other browsers might not tolerate the slashes. So for convenience here it is again:

http://www.dailykos.com/storyonly/2005/10/13/182220/73

I think what most people miss with the geothermal is that they should do the math on financing it with a HELOC, (and check with the local assessors to ensure they will factor it into the fair market price of the property on resale) before they let the sticker shock turn them away.

Photovoltaics will get better for areas that don't have cloud cover first -- the first wave of price cuts will be for concentrator systems, which require direct sunlight, not omnidirectional. There are a few products that will probably be available next year in that respect, and bring down the cost to $3/peak watt or maybe lower -- however they will be targeted towards the office building market first.

As far as using electricity for heat, I totally agree. Except I do wonder in areas that have high ground gusts, since those tend to cause drafts, whether a simple ground-level savonius discharging through a space heater wouldn't be workable economically -- no batteries, regulators, or fancy electronics needed in that case, just a straight load couple with maybe an external diode load shunt to prevent overheating in the event of the most extreme squall. I suppose people would be just too tempted to harness it for other purposes :-)

[Jose Diablo]

16. You know something else about photovoltiacs

An off grid system needs storage, batteries. This is the second most expensive thing in the photovoltiac system. Plus, they don't last forever.

Now on a grid tie system, there is no need for batteries. I'm thinking that with these two-way systems when the homeowner has the photovoltiac, say on the roof and when its putting out more than needed for the homeowner, the power company then buys that electricity from the homeowner. Most states have this available.

But here is the deal, what if the power company could take that excess electricity then store it like they do at Niagara. In Niagara they pump water from the river into storage ponds then release the water during peak usage to feed the energy to the grid.

I am thinking say the cities have each south facing house roof with cost effective photovoltiac collectors (about $2.5/watt). When its sunny, all these collectors feed the grid which then pumps water uphill. Then the during the night or sunless days the water then flows downhill and drives generators to feed that energy back to the homes.

Sort of like socializing the cost of the energy storage.

Spelling

[skids]

18. If we had dealt with storage back in the 80s

...we wouldn't be in such a jam.

Here's how it works -- most power companies didn't want to buy into energy storage, even really at a research level, for the same reason renewables suffered -- at 80s gas prices the investments took too long to make money. So the plants that cannot be simply shut down at night because they take too long to "warm up" (nukes, fossil) had to produce extra energy to deal with increasing daytime use, and then just throw away energy at night.

They invested in rerouting technology, but not much in storage. Storage would have been a welcome addition to the grid, because once renewables start contributing an excess, it could be used to funnel power back to nighttime and reduce the need for base load generation.

As far as tiny home power "off grid" operations go, keep an eye on high-speed maglev flywheels and on vanadium redox batteries -- two technologies which hold promise for greatly reducing this component of the cost.

More info here:

http://www.electricitystorage.org/technologies.htm

[Jose Diablo]

20. Yeah, I've been watching those flywheel storage systems already

I think its out in LA, there is/was a company trying to put together a flywheel using carbon fiber and super high rotation. Most people don't realize its not so much mass but velocity that determines inertia thats stored. Well, actually it's mass*velocity but with carbon being a hundred times stonger than steel, then the lighter carbon is far more able to store inertia energy. Lighter and stronger makes sense to me. They taked about a off-grid application that would store 250KWH. That works for me. There was no price listed as it wasn't developed at that time.

Anyway that place in LA was trying to put something together for NASA, I imagine Bu$h has screwed that deal up also.

Clarity, or is it mass*velocity^2, I think it's squared, that is why velocity is more important. Anyway, converting between energy forms is very efficient in a Gravity or Inertial system. Chemical storage, is the dog in storage systems from an efficiency standpoint and lifespan too. Thus for storage, Gravity/Inertial is the way to go.

[skids]

21. We have one here in MA -- Beacon Power.

They already have a product being tested by a power company and ISO folks.

http://beaconpower.com/

Been tracking them in these threads here:

http://www.democraticunderground.com/discuss/duboard.php?az=view_all&address=115x29575
http://www.democraticunderground.com/discuss/duboard.php?az=view_all&address=115x32953

[Jose Diablo]

24. Hmmm, Enviroment/Energy forum

Never knew it was there, thanks. Actually, the politics in GD gets kinda hard to take sometimes. I'll look forward to being in the other forum more.

It's like working on something useful rather than just bitching all the time. Know what I mean?

That link to Beacon, they mention the device has 6kwh storage, would that be enough? It would work for a UPS system, but storage for a city for 3 days? We are talking some serious money here. Gravity, especially if 2 location with a difference in altitude of a couple humdred feet would be far cheaper than a flywheel system, more reliable too. Plus there is no loss, it's totally frictionless other than the harvesting from friction in the pipes. But evaporation may take some of the potential energy away.

I don't know, wouldn't a inertial/kinetic system have friction even with floating bearings and taking the container to a vacuum, whats the loss, 1%/hour?

[skids]

25. See the "Smart Array" product.

The 25Kwh units are designed to be linked into massive arrays.

Evaporation is a big problem with pumped hydro storage -- geography permitting a large elevation might allow for a smaller covered tank, but generally at the scale needed they use natural features. It is one of the better storage options nevertheless.

The Beacon Power units don't lose much power at all in standby. There's no friction at all, AFAIK -- just a small bit of magnetic flux leakage I would imagine.

[Jose Diablo]

28. I would think that, what do they call it,

counter EMF caused by mechanical resistance of material during flux reversal, I can't remember the term though, wouldn't this cause a drain during standbye that amounts to no less than 1% loss of stored energy per hour. And the only way to eliminate this loss is through supercooling the material, but that's an engineering nightmare getting into supercooling and a deep vacuum.

Not to change the subject, but a similar potential technology to a kinetic system would be rather than a rotating mass use a quantum tube to store circulating electrons. I've never heard of this before, but I wonder if a buckey tube of carbon atoms forming a quantum tube, what happens to an electron if its forced into a tube. It seems like to me it's wave function would form into a straight line the length of the tube forming a standing wave of electromagnetic energy. Now this standing wave would experience zero loss because within the buckey tube there can be no interaction with matter. Thus a zero loss electricity storage system. I think I'm going nuts here, but does this make sense to you?

[lastknowngood]

14. almost free heating and cooling check this out for use without

any pumps or heavy use.
http://webk.ask.com/redir?u=http%3A%2F%2Ftm.wc.ask.com%2Fr%3Ft%3Dan%26s%3Da%26sv%3Dza5cb0d70%26uid%3D063C221A61FD63B24%26sid%3D14BF821A61FD63B24%26o%3D10234%26qid%3D28D435FE8325EB499B11DA29948E2406%26io%3D0%26ask%3Dhow%2Bdo%2BI%2Bcalculate%2Bthe%2Bfan%2Bneeded%2Bfor%2Bhvac%2Bfor%2B2000%2Bsquare%2Bfoot%2Bhouse%26uip%3D44326006%26en%3Dte%26eo%3D-100%26pt%3DFree%2520Home%2520Air%2520Conditioning%2520and%2520also%2520Winter%2520Pre-Heating%26ac%3D24%26qs%3D0%26pg%3D2%26ep%3D1%26te_par%3D152%26te_id%3D%26u%3Dhttp%253a%252f%252fwww.mb-soft.com%252fsolar%252fintake.html&bpg=http%3A%2F%2Fweb.ask.com%2Fweb%3Fq%3Dhow%2Bdo%2BI%2Bcalculate%2Bthe%2Bfan%2Bneeded%2Bfor%2Bhvac%2Bfor%2B2000%2Bsquare%2Bfoot%2Bhouse%26o%3D10234%26page%3D2&q=how%20do%20I%20calculate%20the%20fan%20needed%20for%20hvac%20for%202000%20square%20foot%20house&s=a&bu=http%3a%2f%2fwww.mb-soft.com%2fsolar%2fintake.html&qte=0&o=10234&abs=...in%20November%2C%202000%2C%20we%20...%20Any%20local%20engineer%20(HVAC%20...%20designers%20to%20calculate%20...%20is%20over%20500%20square%20feet%20of%20...%20and%20another%200.14%20kW%20for...&tit=Free%20Home%20Air%20Conditioning%20and%20also%20Winter%20Pre-Heating&bin=&cat=wb&purl=http%3A%2F%2Ftm.wc.ask.com%2Fi%2Fb.html%3Ft%3Dan%26s%3Da%26uid%3D063C221A61FD63B24%26sid%3D14BF821A61FD63B24%26qid%3D28D435FE8325EB499B11DA29948E2406%26io%3D%26sv%3Dza5cb0d70%26o%3D10234%26ask%3Dhow%2Bdo%2BI%2Bcalculate%2Bthe%2Bfan%2Bneeded%2Bfor%2Bhvac%2Bfor%2B2000%2Bsquare%2Bfoot%2Bhouse%26uip%3D44326006%26en%3Dbm%26eo%3D-100%26pt%3D%26ac%3D6%26qs%3D0%26pg%3D2%26u%3Dhttp%3A%2F%2Fmyjeeves.ask.com%2Faction%2Fsnip&Complete=1
this link is incredibly long but it show how to use PVC and low power fans to get free air condition and bring 60 deg heat into your house when it is extremely cold outside. Cheep and low tech. almost no moving parts.

[RedEarth]

22. Outstanding posts.....thanks for the information.....

[glitch]

23. happy to kick and recommend this thread!

excellent post, thank you.

[Nihil]

26. Kick for a lot of good stuff in the OP! (n/t)

[Dora]

27. Great Info. Kick for the afternooners. n/t