Solar Power From Home Curtains

kaliann writes "With the push for more sustainable energy, easy DIY kits for alternative energy sources are likely to become quite popular in the coming years. We may see some big improvements in our ability to 'green up' if these photovoltaic curtains become widely available."

Comments

I have only one question...

[GigaHurtsMyRobot]

Does the carpet match the drapes?

I doubt it...

[Darkness404]

With the push for more sustainable energy, easy DIY kits for alternative energy sources are likely to become quite popular in the coming years.

Two words. Doubt it. There are all kinds of ways to save money, but most people don't do them. To put it into a computer perspective, how many people do you know upgrade RAM? Out of that many how many do them themselves? How many people upgrade a CPU? How many people salvage CD-ROM drives from old computers? How many save old cases and build computers in them? Very few I would think. Same thing with these, they are a way to save money, but for most people they will just complain about high oil prices, try to get a raise, petition for an increase in minimum wage, repeat. These will be about as popular as running BSD on your toaster. You can do it, it might be cool, but most people don't see the need.

Re:I doubt it...

[CodeBuster]

One other thing -- how come I've never seen, anywhere, the idea of putting a hydroelectric turbine in a sewer line?

I once worked in a office full of civil engineers so perhaps I can answer that question, here goes...

There is one point that should be understand right off the bat and that is that any time a generator is introduced into a system where current, water, sewage, or energy flows freely a load is induced upon the system and the total energy outflow is reduced (i.e. the velocity of the outflow is slowed by the generator as the generator converts that energy into electricity or perhaps a water wheel is turned in which case some of the energy of the outflow is being converted directly into mechanical work). I realize that this is a very rough description of the physics, but would the thermodynamics geeks please cut me some slack? Thanks.

Now, the typical sewer lateral (the pipe from your home or building to the main in the street) has an average fall of 1/2 percent over the distance that it travels to the main or just enough to ensure that the raw sewage makes it all the way to the main without backing up in your lateral. It might be possible to introduce some sort of turbine in there but there several problems:

1) Raw sewage tends to be sludgy with lots of trash, hair, and other assorted junk that is just perfect for chocking or clogging your turbine (this might be less of a problem if you are only talking about the outflow from your home, but it is still an issue).

2) As previously mentioned there is barely enough fall to ensure that the sewage makes it all the way to the main without obstructions (and the turbine is an obstruction) so any back pressure will back up your sewage.

3) Digging a ditch for your lateral with greater average fall is possible but the main sewer line is only so much deeper than the street surface so practically speaking how much extra slope could you fit into the distance between your home and the street? Probably not enough to increase velocity substantially and thus not enough extra energy to convert to electricity with a turbine.

4) Greater slopes mean higher velocities and ultimately higher pressures and higher pressure pipes and turbines are always more expensive (just ask the guys who run oil and natural gas pipelines). In fact, they used to hydraulically mine gold in California using pressurized jets of water at lethal force from slopping troughs over long distances into ever narrower pipes fed from upstream rivers and streams.

To sum up: There is not enough useful energy to extract from your out flowing sewage over the distance from your home or building to the sewer line in the street to make the generator worth a crap (pun intended), it would probably just back up your sewage lateral and even if you had a very large property there probably isn't enough difference in slope between your toilet and the street to build up enough energy to make it worthwhile unless you have a very large property and your house is built on top of a hill our mountain. There is also the problem that toilet flushes are very sporadic in most residential situations so even more energy will be lost to spinning up the turbine on each flush as opposed to keeping a spinning turbine going. Basically, in most cases it just wouldn't be worth it.

Two ways to look at this...

[credd144az]

Summer months in the Desert: Closing drapes helps keep heat out, solar technology helps to power the Air Conditioner.

Non-summer months everywhere else: Close the curtains to power the lights that you need because the curtains are closed.

I don't buy that we have a land shortage.

[CrazyJim1]

I know we're at a point where solar is looking like a good investment. Still... Isn't it easier for a solar contractor to just make large solar power plants to supplement the grid than worrying about the specifics of installing home to home?

I'm all for the day when I can offset my electricity bills a small amount because I have my house decked out in solar material... I'd rather just have cheaper electricity though especially in the near future. Plugin, hybrid cars are going to start sucking on the power grid. If we don't add more solar or nuclear plants to the grid, we could see an electric shortage in the form of higher prices for one.

Oh and I'm still bummed about the study the government is doing to make sure solar is environmentally friendly. I mean, isn't the waste output from coal plants harmful to the environment? If we had the option to cut that waste back, aren't we helping the environment?

Anyway, the future looks bright to me. The US economy is holding even though it has taken some hits. If we can just get to a new era in surplus solar energy, we can get into some really interesting solutions to getting off oil. Some people think it will be hydrogen. Some people think it will be electric cars. I'm not sure which is going to take off in the long run. I think it is going to be hybrids that make the most initial impact because they don't have the limitations of the electric car's maximum range. For electric cars to have a long range, gas stations will have to be refitted with a tool to swap out battery arrays. Hydrogen faces a similar challenge in that it'd need special fill up stations too. Plug in hybrids work off traditional gas stations.

I like Nanosolar's approach because it is so high tech and also economically feasable. Still low tech solar options such as parabolic mirrors to focus sunlight and run steam turbines could be good at first. I think we have a lot of unused land on Earth, and the faster we can cover it, the faster we can have surplus energy. Surplus energy makes transportation costs go down so you can travel all that you want even if you're poor. And even more interesting is that surplus energy lowers the cost of transporting food, so impoverished people can be supplied better. Oh yeah, and surplus energy also means that everything is cheaper so people have more disposable income which incidentally, also helps poor people.

Re:But they only produce power--

[peragrin]

Exactly.

Combine this with either solar hot water heater on our roof, or even more photovoltaic cells, possibly a 2 kw wind turbine and suddenly 50% of you average home power is being used by green energy.

The coming energy crisis isn't going to be solved by any one thing, but dozens of small sub systems that work together. they don't have to be massive farms or fields either. just 30-50% of your home electricity is enough to offset the demand.

Re:Serious flaw

[niiler]

This is a non-issue. When I was in Spain over a couple of summers, most houses had black-out shades, and many of them were dark in color. Few Spanish houses had AC, so everyone just draws their shades during the day while they are at work, but also during siesta (think nap time). You'd be amazed how much cooler it was with the shades down than with the shades up.

That said, I realize that in the US we don't have siesta, but we do have a ton of work-aholics who don't spend much time at home during the day. I would be more concerned with the reflection from the glass diminishing the efficiency of the curtains. Perhaps putting them on the roof *would* be a good idea.

Re:Cooling the Roof.

[xalorous]

Study some heat transfer principles. Depending on their reflectivity, these curtains may cause the roof to absorb MORE heat than the roofing does.

Ideally, solar installations for home use will not transfer heat directly into the house. A curtain laying directly on the roofing surface will absorb some light and create some electricity. However, light and heat that is not reflected will absorb and the greater part will transfer through to the house a large amount of heat. A smaller portion will radiate from the house.

Solar panels are typicaly elevated above the house. The air gap allows the panels to be cooled by airflow.

The actual news here is that they can create solar fabric. I'm sure they can design a roofing system that will use the material to generate electricity while the system maintains an air and water seal and reflectivity of the largest part of the sun's energy.