Solar Power Systems

[xbusymom]

Solar Powered Water Heating Systems (http://www.builditsolar.com/Projects/WaterHeating/water_heating.htm)

lots of free PDF plans to make systems from Solar Power

[yiolas]

Wow Xbusymom,
I checked out the site . It is chock full of ideas. Being the handy person I can't wait to get started on some of the projects.
Thanks !

[xbusymom]

I found this great dual-energy cooker...
Hybred solar/electric cooker (http://www.amazon.com/Hybrid-Solar-Cooker-Portable-Corporation/dp/B002AUGU34/ref=sr_1_6?ie=UTF8&s=home-garden&qid=1272733692&sr=8-6)

and this page for a solar dehydrator (with links for pdf plans and other projects)
http://ecohearth.com/eco-zine/food-and-garden/650-building-a-solar-powered-food-dehydrator-.html

[MargueriteBee]

http://solarcooking.org/plans/

This is a site for plans for making solar ovens.

[Anchor]

This research is interesting...

http://news.stanford.edu/news/2010/august/new-solar-method-080210.html

http://www.nature.com/nmat/journal/vaop/ncurrent/abs/nmat2814.html

Indicates 50-60% conversion efficiency for PV may be possible.

[Come As You Are]

Does anyone have any knowledge and experience in converting from Grid connect/ Solar systems to straight solar? I have a new 1.68kw solar pv system which is rigged to feed back excess to the grid. It's great because my usage is minimal, so I don't get bills anymore, but I would prefer to go completely grid free. I understand it will require batteries or something for storage. Any ideas appreciated.
Thanks

[Anchor]

Does anyone have any knowledge and experience in converting from Grid connect/ Solar systems to straight solar? I have a new 1.68kw solar pv system which is rigged to feed back excess to the grid. It's great because my usage is minimal, so I don't get bills anymore, but I would prefer to go completely grid free. I understand it will require batteries or something for storage. Any ideas appreciated.
Thanks

Yes. Its expensive, but it can be done. The batteries alone may cost you far more than you expect.

The main problem you will face is that the panels you have now will likely be wired to present a high voltage to the grid feed inverter. You will need to know what that voltage is to get more useful answers (the exact model of the inverter would help me) . If it is around the 600vdc level then you will probably need to have the wiring reconfigured so that the voltage is lower. In some case this may mean replacing the wiring as it may need to be beefed up for higher currents.

Solar panels rated for grid-feed often have different voltage ratings - which limits the degrees of freedom in selecting an appropriate solar controller. You are pretty much forced down the path of going with an MPPT device - which are fabulous, but at the higher end of the cost spectrum.

The reason for this is that in order to charge batteries you need a device that can accept the voltage from the panels, convert it to the required voltage to charge the battery array.

Most of these kinds of solar controller do not have as wide a range of input voltages as do gridfeed inverters - hence the need for something that can work with a wide range of voltages (which MPPT do, but not usually up to 600vdc).

In order to use the energy stored in batteries you need an inverter. You also need a charger that can charge the batteries when the sun does not shine.

These days the inverters and chargers are part of the same unit - this saves a lot of money and wiring complexity.

Hope this helps - doing it in detail needs a book.

John..

[joelmags]

We have a 1.1kw (12 85w units) sharp pv array & 2 small 48volt airx wind turbines both hooked up to 12 batteries completing a 48 volt DC charging and storing system.

This is connected to a 3.5kw sine wave inverter which puts out 220v AC.

This configuration is not ideal. When it is overcast, charging is weak. If my batteries are below 48-49 volts before sunset, i press a magnetic switch and we are charging from the grid mains.

Hope this helps (;-))

[Come As You Are]

Thanks John

It's a Sunny Boy - SB 1700

While we're on it, any good ideas for what could be done with two old Ajax pumps, one that was in use and very efficient until recently, which I replaced when a pipeline came on line, and the other that is possibly just a shell (although looks in reasonably good order)? I have been told by a bonafide tinker that Ajax were/ are the best!

Thanks

[Anchor]

Thanks John

It's a Sunny Boy - SB 1700

While we're on it, any good ideas for what could be done with two old Ajax pumps, one that was in use and very efficient until recently, which I replaced when a pipeline came on line, and the other that is possibly just a shell (although looks in reasonably good order)? I have been told by a bonafide tinker that Ajax were/ are the best!

Thanks

http://www.energymatters.com.au/sma-sunny-boy-1700watt-grid-connect-inverter-p-402.html - the specs suggest that the MPPT range is PV-voltage range, MPPT 139V - 400V.

That range is outside most of the MPPT tracking charge controllers I know about, and also with voltage that high you need a qualified installer (I just saw you were Australian).

In short, you can use your panels, they may need rewiring, and you would be in for around $900-$1200 for an MPPT charge controller, but it is do-able. If you go down this path, your Sunny Boy would need to be sold or scrapped - its a one way trip.

If you want to be able to do both grid feed and off-grid - you still need to scrap the Sunnyboy and get a high end multi-function inverter (or combination of components) that supports Grid Feed, (Mains import/export), Solar charging, Mains/generator charging and inverter - not cheap - but still do-able.

[panopticon]

G'day All,

A query in regards to battery banks.
The Vanadium Redox battery system is supposed to be exceptional.
Website for developers of system (University of NSW):
http://www.vrb.unsw.edu.au/
Website for authorised UNSW distributors (recently ceased trading :confused: ):
http://www.vfuel.com.au/

Does anybody here have any hands on experience with these systems?
I've read about them for years, just been waiting for the present bank to need expanding...

Regards,
Panopticon

[Lazlo]

Thanks John

It's a Sunny Boy - SB 1700

While we're on it, any good ideas for what could be done with two old Ajax pumps, one that was in use and very efficient until recently, which I replaced when a pipeline came on line, and the other that is possibly just a shell (although looks in reasonably good order)? I have been told by a bonafide tinker that Ajax were/ are the best!

Thanks

http://www.energymatters.com.au/sma-sunny-boy-1700watt-grid-connect-inverter-p-402.html - the specs suggest that the MPPT range is PV-voltage range, MPPT 139V - 400V.

That range is outside most of the MPPT tracking charge controllers I know about, and also with voltage that high you need a qualified installer (I just saw you were Australian).

In short, you can use your panels, they may need rewiring, and you would be in for around $900-$1200 for an MPPT charge controller, but it is do-able. If you go down this path, your Sunny Boy would need to be sold or scrapped - its a one way trip.

If you want to be able to do both grid feed and off-grid - you still need to scrap the Sunnyboy and get a high end multi-function inverter (or combination of components) that supports Grid Feed, (Mains import/export), Solar charging, Mains/generator charging and inverter - not cheap - but still do-able.

SMA now has a "SUNNY ISLAND" that is a grid interactive inverter with a battery back up that swiches loads to your battery bank when the grid drops out. You might be able to get some trade in on your sunny boy. But like John said, it's going to cost you.

I used to be entirely off the grid, but I ended up running a generator sometimes. Oil from Saudi Arabia instead of local coal so to speak.

[CorLian]

Is there anyone who can direct me to a website, or who knows about instaling solar panels in Wisconsin USA. Its not for a while, a year at least but I would like a decent place to start. The pamphlet at Menards just had a color coded map and some non-spesific directions on panels facing south. I looked some stuff up on the web but they were all trying to sell panels and other things. Thanks much.

[Positive Vibe Merchant]

From Zeitnews.....

New solar product captures up to 95 percent of light energy

Efficiency is a problem with today's solar panels; they only collect about 20 percent of available light. Now, a University of Missouri engineer has developed a flexible solar sheet that captures more than 90 percent of available light, and he plans to make prototypes available to consumers within the next five years.

Patrick Pinhero, an associate professor in the MU Chemical Engineering Department, says energy generated using traditional photovoltaic (PV) methods of solar collection is inefficient and neglects much of the available solar electromagnetic (sunlight) spectrum. The device his team has developed – essentially a thin, moldable sheet of small antennas called nantenna – can harvest the heat from industrial processes and convert it into usable electricity. Their ambition is to extend this concept to a direct solar facing nantenna device capable of collecting solar irradiation in the near infrared and optical regions of the solar spectrum.

Working with his former team at the Idaho National Laboratory and Garrett Moddel, an electrical engineering professor at the University of Colorado, Pinhero and his team have now developed a way to extract electricity from the collected heat and sunlight using special high-speed electrical circuitry. This team also partners with Dennis Slafer of MicroContinuum, Inc., of Cambridge, Mass., to immediately port laboratory bench-scale technologies into manufacturable devices that can be inexpensively mass-produced.

"Our overall goal is to collect and utilize as much solar energy as is theoretically possible and bring it to the commercial market in an inexpensive package that is accessible to everyone," Pinhero said. "If successful, this product will put us orders of magnitudes ahead of the current solar energy technologies we have available to us today."

As part of a rollout plan, the team is securing funding from the U.S. Department of Energy and private investors. The second phase features an energy-harvesting device for existing industrial infrastructure, including heat-process factories and solar farms.

Within five years, the research team believes they will have a product that complements conventional PV solar panels. Because it's a flexible film, Pinhero believes it could be incorporated into roof shingle products, or be custom-made to power vehicles.

Once the funding is secure, Pinhero envisions several commercial product spin-offs, including infrared (IR) detection. These include improved contraband-identifying products for airports and the military, optical computing, and infrared line-of-sight telecommunications.

http://www.zeitnews.org/energy/

PVM