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Dr. Hess
Dr. Hess SuperDork
1/25/12 8:05 p.m.

OK, alfa, Mr. EPA, destroyer of our economy. Here's my contribution to society, forever forgotten in bum-berkeley web sites. I've mentioned it here before. It's production, not storage. I already mentioned the solution to storage.

The Organic Rankin Cycle (ORC). Google it up. You set up a hot water collector on the roof. 1KW/M^2 of energy falls on every roof of the planet. On average. Run the hot water to a heat exchanger to the freon driving the ORC engine. The ORC engine needs to be an all in one unit with only connections: Freon in, freon out, electricity from the generator connected to the freon turbine. I figure the turbo-generator will cost a few hundred to make in the 5KW range, enough to power a house. Just needs a small team of the right engineers and a couple million to design and prototype. Have your president outsource the manufacturing to China with the rest of our industry and they can probably make them for $300. Put one on every roof and we are instantly energy independent. Oops, how we gonna charge people for sunlight falling on their roofs? There's the problem. Maybe if we charge them for breathing instead, it will all work out. Oh, that's right YOU (or your organization) declared CO2, the molecule around which life is based, as A POLLUTANT. Now, just tax breathing.

alfadriver
alfadriver SuperDork
1/25/12 8:15 p.m.

In reply to Dr. Hess:

If you read this before I deleted it, sorry. I typed before I thought.

Taiden
Taiden SuperDork
1/25/12 8:20 p.m.

I remember reading about a guy who dug a giant hole next to his house and lined it with concrete, a-la basement foundation. In the winter, he would shovel all of his snow into it. During summer, it would still be frozen, and he would use ducts to pipe the cool air into the house.

redrabbit
redrabbit Reader
1/25/12 8:38 p.m.

I read about an earth sheltered home in the '80s. Front of house was glass. (Full length glass enclosure/ porch) Inside glass enclosure were plexiglass tubes (upright, 4' to 6' tall) holding water. Solar storage.

ProDarwin
ProDarwin SuperDork
1/25/12 8:56 p.m.
Keith wrote: As for energy storage from solar/wind - one interesting proposal I've heard is to use the excess energy to pump water into a reservoir. When demand outstrips supply, use the stored water for hydroelectric power generation. The cool thing about this is the fact that the stored potential in the water doesn't decay and it's quick to ramp up in response to demand. It's also using mature technology - we know how to pump water Of course, it would work better in Colorado than Nebraska.

I've heard this is in-use now. IIRC some power-plants run beyond their needed output off hours dumping excess to reservoir, and below needed output during peak using the reservoir as a supplement. It does require planning though.

FlightService
FlightService Dork
1/25/12 9:03 p.m.

The advantage of geothermal is they use the earth as a steady state heat sink. It isn't a thermos, it will disapate energy. That is why you use it.

You heat pump/AC needs cool air to exchange hot air to make cold air. You use air from the ground for a steady state temp (useually 62-68 year round depending on depth and location)

Now your heat pump/heater has to heat air, this is where you loose some of the advantage overall but in the case of the ground source vs standard heat pump, GS wins because it tries to remove heat from a 62-68 source as opposed to the really cold stuff outside. A traditional heater unit just heats internal air so but it has to compete with the phase change energy of the GS HP system.

Also GS HP can have integrated hot water.

To summarize Earth not thermos for hot stuff Earth good constant source for 62-68 stuff Earth great Sun energy avoid-er/reflector

Lots and lots of possibility for solar. Focused mirrors is a great one for a steam cycle.

Taiden
Taiden SuperDork
1/25/12 9:04 p.m.

I honestly believe that if all households were fitted with a passive solar system similar to DrBoost's but larger, we would cut energy consumption across the nation by a huge percentage.

DrBoost
DrBoost SuperDork
1/25/12 9:11 p.m.
Taiden wrote: I honestly believe that if all households were fitted with a passive solar system similar to DrBoost's but larger, we would cut energy consumption across the nation by a huge percentage.

I agree. I'm planning a larger one this summer so I can actually reduce my bills next winter. It's really not terribly hard or expensive.
Oh, and talking about Geothermal. Once you are 6' below grade, the ground is the same temp as your annual mean temp. Just an FYI.
My friend went geothermal when he re-built his house after a fire. The cost to heat AND cool his house (Michigan) is about $400 a year. The electricity is at a discounted rate because it's a "green" technology.

alfadriver
alfadriver SuperDork
1/25/12 9:15 p.m.

In reply to FlightService:

That's exactly why it's used as a constant temp source for a heat pump. They are pretty amazing.

alfadriver
alfadriver SuperDork
1/25/12 9:16 p.m.

In reply to DrBoost:

I actually regret not thinking more about the heat pump when I installed my garage/patio. I could have dug for it then, and after it I installed an a/c system into a new heater. Coulda, woulda, shoulda.

They are reported to be super quiet, too.

curtis73
curtis73 GRM+ Memberand SuperDork
1/25/12 9:21 p.m.

Agreed on the 6' underground thing. I often thought about things like this when I visit caves. Use the thermal stability of the sub-ground to keep your temp stable in the house.

T.J.
T.J. SuperDork
1/25/12 10:30 p.m.

Biological fuel cell is what I want. I want to have some friendly microbes eat my sewage effluent and turn it into electricity. Septic tank = fuel source.

I'd also like to have a passive solar home that relies on geothermal heating and cooling.

FlightService
FlightService Dork
1/26/12 5:28 a.m.
alfadriver wrote: In reply to FlightService: That's exactly why it's used as a constant temp source for a heat pump. They are pretty amazing.

Yeah but someone said it was a thermos, more like a heat sink

alfadriver
alfadriver SuperDork
1/26/12 6:47 a.m.
Dr. Hess wrote: The Organic Rankin Cycle (ORC). Google it up. You set up a hot water collector on the roof. 1KW/M^2 of energy falls on every roof of the planet. On average. Run the hot water to a heat exchanger to the freon driving the ORC engine. The ORC engine needs to be an all in one unit with only connections: Freon in, freon out, electricity from the generator connected to the freon turbine. I figure the turbo-generator will cost a few hundred to make in the 5KW range, enough to power a house. Just needs a small team of the right engineers and a couple million to design and prototype.

Deleting the inflamatory stuff....

The web pages are calling Organic Rankine Cycle, for some reason. The idea is very good, and probably for home use could use a turbo charger sized device for the power recovery.

Would be perfect insource industry that could be help started internally with our tax research dollars.

DILYSI Dave
DILYSI Dave SuperDork
1/26/12 7:31 a.m.

While I think fuel cells are a marginal at best answer to cars, I think they are brilliant for homes. Use wasted energy to convert water to hydrogen, and store the hydrogen. When you need energy, use the fuel cell to convert the hydrogen back to water. Hydrogen becomes the medium in which you are storing potential energy. This seems far better than batteries.

Dr. Hess
Dr. Hess SuperDork
1/26/12 7:59 a.m.
alfadriver wrote: In reply to Dr. Hess: If you read this before I deleted it, sorry. I typed before I thought.

That's OK. You work for the government. I understand. Oh, and spelling was never my strong point.

alfadriver
alfadriver SuperDork
1/26/12 8:18 a.m.
Dr. Hess wrote:
alfadriver wrote: In reply to Dr. Hess: If you read this before I deleted it, sorry. I typed before I thought.
That's OK. You work for the government. I understand. Oh, and spelling was never my strong point.

No, I don't.

Curmudgeon
Curmudgeon SuperDork
1/26/12 8:34 a.m.

Retrofitting existing houses could be easier if, instead of running everything off of batteries and inverters, the various systems were separated. Average home's power consumption split by type of device:

Woops, this guy got torqued about hotlinking his pie chart. Click this link http://michaelbluejay.com/electricity/howmuch.html and you will see the one I am referencing.

First, lighting does not need 240/110v. 12v LEDs are coming into their own, even lower voltages can put out really bright light and they are available in 'warm' light output which is very similar to the light from an incandescant bulb, which most people like. So put a solar panel on the roof, add a bank of storage batteries and wire the LEDs completely separate from the 240/110v. With properly installed skylights, the house could be completely grid independent as far as lighting is concerned. There's roughly 11% of your power usage, according to the above chart.

If TVs etc continue on the LED path, it's conceiveable that in a few years they too could run off of this type system. Right now the average LED/LCD TV uses areound 110 watts. http://reviews.cnet.com/green-tech/tv-power-efficiency/ That might account for another 8-9% or so, again according to the above chart.

So there is 20% of the power consumption moved off the grid to a lower voltage self sustaining system.

Next is heating/cooling. With current technology, it's not feasible to run refrigerant pumps etc off of lower voltage (although that ORC cycle engine could possibly generate enough power). So that would probably have to remain on the grid but using the Earth's mass as a 'flywheel' to cut power bills has been proven to work all across the country. If heating/cooling are 43% of the power consumption and that is cut by 30% via geothermal, between the 12v lighting and cutting HVAC power usage there went 33% of your power bill. If a desuperheater is added to a geo system, this can help heat the household water thus cutting even more of the power bill.

Adding a solar mass storage system to the HVAC for winter use would help also. It's difficult to calculate the full benefit because it varies so much from area to area and even from day to day, but it would have a measureable impact.

Refrigeration can be a problem. During the summer, the refrigerator and freezer add to the cooling system's heat load, meaning the A/C has to work harder. This is reversed during the winter, it would actually be a benefit (however small) in helping to keep the house warm. So there's the challenge: develop a refrigeration system which can be used to best efficiency in both seasons. I sort of thought a simple duct system to draw outside air through a underground tube (like a geo system) could be run to the cooling coils of a fridge or freezer for summertime use, then the ducting could be 'flipped' to put that waste heat back into the inside environment during the heating season.

Same with a clothes dryer: its heat adds to cooling load in the summer and if just ducted to the outside is wasted during the winter. I would think a heat recovery system which did NOT vent the damp air to the indoors could be a benefit during the heating season.

It's not just one thing, it's a multitude of them which when used together could really cut the average house's electrical consumption without greatly inconveniencing the inhabitants.

Curmudgeon
Curmudgeon SuperDork
1/26/12 8:44 a.m.
ProDarwin wrote:
Keith wrote: As for energy storage from solar/wind - one interesting proposal I've heard is to use the excess energy to pump water into a reservoir. When demand outstrips supply, use the stored water for hydroelectric power generation. The cool thing about this is the fact that the stored potential in the water doesn't decay and it's quick to ramp up in response to demand. It's also using mature technology - we know how to pump water Of course, it would work better in Colorado than Nebraska.
I've heard this is in-use now. IIRC some power-plants run beyond their needed output off hours dumping excess to reservoir, and below needed output during peak using the reservoir as a supplement. It does require planning though.

Duke Power has a 'on demand' reservoir system which works exactly like this. http://en.wikipedia.org/wiki/Bad_Creek_Hydroelectric_Station During peak hours (generally 4AM-8AM) the turbines are used to generate electricity. Duriing off peak times they are reversed and they refill the reservoir. Part of the reservoir is underground.

alfadriver
alfadriver SuperDork
1/26/12 8:47 a.m.

In reply to Curmudgeon:

Too bad your picture source doesn't like to be hot-linked- it doesn't come through...

12/24V subsystems- a pretty easy question to answer- how much energy is needed over a long enough period of time to average out power generation? If it's similar power to what a hybrid battery can deliver over that same average- that's a pretty easy solution. If not, Dave's idea of using chemical storage by means of using the excess energy to make H2 to use later is good (assuming you can get all of the efficinecies high enough to work). Storing H2 in the home isn't all that hard, since it's stationary, and solid storage would work.

Heat mass/storage. I have read some about salts that change phase right around room temperpature- and material phase change always stores more energy than temperature alone. The big issue is it's still a huge mass of stuff to be anywhere close to natural gas. It seems a lot easier to store cool, since ground temp is so nice and stable. In the end, the geoexchange heat pumps seem to be the best option.

BTW, I'm also of the opinion that much of what is proposed for a home can be included in large buildings.

(as another alternative, if you can find alternative ways to process bauxite into aluminum that's not so electrical intensive, or more efficient ways to process any metal for that matter- billion$ will find your doorstep).

Curmudgeon
Curmudgeon SuperDork
1/26/12 9:04 a.m.

Yeah, he got peeved about hotlinking.

My thought was by splitting off the subsystems which do not require big A/C current they can be run easily off of batteries. I'm actually working on this on a small scale; my brother's Beneteau sailboat has a completely 12V lighting system which will run all day on a single charge, using small incandescent bulbs. We are currently looking at how to retrofit this for LED which would just about double (or even triple) the time the lights will work without the batteries being recharged.

The interior lights are easy, the problem we are having is the nav lights; currently no one is making an easily installed LED that's truly bright enough. There are LED nav light bulbs out there but if you look real close they do NOT meet the minimum visible distance rules! So if someone runs into you at night and it turns out they couldn't see you because your nav lights weren't bright enough, uh oh. We will for the time being use a hybrid system of interior LEDs and exterior incandescents. There's also the need for red interior lights so night vision doesn't get screwed up, again that's pretty easy. I just need to get him off his wallet.

I dunno about bauxite processing. I'm thinking LEDs won't get hot enough.

Curmudgeon
Curmudgeon SuperDork
1/26/12 9:12 a.m.

Stupid question for someone a lot smarter than me: is it possible to use an ORC as a solar powered compressor for an HVAC system, with a normal AC powered compressor as a backup? Or am I just plain asking too much of thermodynamics?

alfadriver
alfadriver SuperDork
1/26/12 9:37 a.m.

In reply to Curmudgeon:

One of the areas that I seem to want to take technology FROM is sailboats. They have the micro-wind turbines to keep things changed- I'd love to put one on my garage. They have 12V lighting systems that can be run withing that power system- that would be cool.

Just thinking- alternate power systems are not unheard of in homes- we have under cabinet lighting where each light uses it's own power system... hmm.

Curmudgeon
Curmudgeon SuperDork
1/26/12 10:11 a.m.

Sailboats have to be pretty much self sustaining so there's a lot to be learned from studying their systems. For instance, the micro wind turbines are used because they take up less space than a solar panel. They can easily be put at the top of the mast etc and are not as susceptible to damage as a solar panel. They work well but part of that is because due to the uneven solar heating there's usually a pretty constant wind over the water.

Houses can't be moved easily to take advantage of the prevailing winds. Duh. That's why I lean more toward solar panels to recharge the batteries. LEDs for 110v use commonly draw ~1/10 the power of a comparable incandescent bulb for the same light output. So a 75w incandescent can be replaced by a 7.5w LED array. That power consumption includes the rectifier used to step the 110v down to whatever the LEDs are using, on the current 110v versions the rectifier has to have cooling fins. Dumping that in favor of a straight 12v source would eliminate that extra power draw.

The drawback is all this really needs to be considered in the original house design. Retrofit is certainly possible but it's much easier to do this while the house is being built or remodeled.

Dr. Hess
Dr. Hess SuperDork
1/26/12 10:13 a.m.

Once you're capturing heat and the ORC turbine is spinning, gear it down and run a HVAC compressor with it. Why not? It would be more thermodynamically efficient than converting the thermal energy to mechanical energy, to electricity and then electricity to mechanical energy. But, I see my design ORC gizmo as being modularized. Want 10 KW? Plug 2 together and 1 becomes master of the system, syncing the AC output power. 10KW would (theoretically) take 10 square meters of roof. Or 33 ft by 3.3 ft. Half a roof? Of course, there's efficiency, blah, blah, but cover an entire south facing roof with inexpensive liquid heat collectors and I bet you could pull 10 KW from it on a typical day. Daisy chain a couple of 5KW units together, run the house.

Why it won't work: The government can't figure out how to tax sunshine. Multinationals can't figure out how to sell you sunshine. Why, do you realize you could plug an electric car into your house, powered by the sun, and then drive to work FOR FREE? We just can't have that.

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