Photovoltaic Systems

Sam Deane answers:

Photo voltaic cells are an ecological disaster, costing (read using lots of resources to manufacture) a lot, and they have a limited life. They are uneconomic which is why solar farms use mirrors reflecting light to a central tower or to water pipes, where the high temperatures generated heat water to drive a turbine.
In a hostile environment like the sahara, photovoltaic cells or mirrors would be sand blasted into oblivion.

Sam Deane answers:

Depends on the model about £50

Sam Deane answers:

It depends on the size of the system. $3/watt is a typical installation price in most parts of the country, after rebates are considered. In wealthier areas, or where rebates are higher, it may be more. That’s only for the labor, not the materials. With materials included, it will be more like $8/watt.

If you want to see a breakdown of how much our system costed, it’s at http://www.angelfire.com/ca2/roderick/solar/photovoltaic.html . But we self-installed, so it’s not truly a fair comparison.

Sam Deane answers:

WPA is a tough place especially in the winter with lack of light and snow plus energy storage for overnight is a problem. The last I looked it was about $8K in raw materials. From what I co

Sam Deane answers:

But the BNP can promise what they want, secure in the knowledge that they will never have to deliver. The British people will not elect a single BNP MP, as they know that the BNP are a bunch of racist thugs.

Here’s one promise that Nick Griffin would try to keep, however (no apology for repeating it)

“Without the White race nothing matters [other right-wing parties] believe that the answer to the race question is integration and a futile attempt to create “Black Britons”, while we affirm that non-Whites have no place here at all and will not rest until every last one has left our land.”

EDIT REDMONK: Sceptic hasn’t said “Livingstone will probably get in again”. I know I shouldn’t quarrel when you finally admit I’m probably right, but you’re making that one up.

Sam Deane answers:

Hey Zeus, I have to assume you are talking about the solar electric, or photovoltiac type of panel, they are the most common and are used to make electricity directly from the sun. They are made up of basically 3 things, pure silicone, sliced in thin slices from solid ingots, acrylic for the glass covering, and aluminum for the frames. The thin silicone slices, or “wafers,” are doped in two different chemicals, boron and phosphorous. When the two different wafers are glued together with a conductive epoxy, and put in the sun, the incoming photons from the sun strike the wafers and force electrons from one wafer onto the other. This is referred to as the, “photovoltiac effect,” and it creates 1/2 of a volt between the two wafers. By connecting a suitable number of these pairs of wafers together, we can generate any voltage we need by simply putting the panel in the sun. Take care Zeus, Rudydoo

Sam Deane answers:

A solar panel out of a calculator

Sam Deane answers:

It’s amazing what you can find by utilizing the power of a search engine.
Http://en.wikipedia.org/wiki/Solar_cell

Sam Deane answers:

They’re made of wafers of crystalline silicon, and attached wires.
They make pollution free electricity.
Dis- not so good under cloudy skies, expensive.

Sam Deane answers:

 
How to make a solar generator from scratch is less expensive but more labour intensive. You will need raw copper sheeting and it is available at hardware stores and then a heat source. The copper must be heated for at least a half hour for a chemical reaction that produces copper oxide.  When the copper sheeting is cold you combine it with another non-oxidized copper sheet of the same size. You then add a salt-water solution and then all the components is enclosed in a durable glass panel. You have a low voltage panel now. It depends on how much power you want on the number of panels you will have to make.

Sam Deane answers:

Go up to the attic and see if there are wires or pipes coming from the panels. Could be you have a solar water heater. They are more common. Your hot water system will have a circulating pump controlled by a thermostat.

Electric solar panels will generate DC which will not be usable in a standard house unless it is converted. Solars usually are used in conjunction with batteries.

Sam Deane answers:

This may help. I dont want to tell you where to go so I have provided you with enough info to make the decision on your own.
Types of technologies
Many technologies have been developed to make use of solar radiation. Some of these technologies make direct use of the solar energy (e.g. To provide light, heat, etc.), while others produce electricity.

Solar design in architecture
Main article: Passive solar building design
Solar design in architecture involves the use of appropriate solar technologies to maintain a building’s environment at a comfortable temperature through the sun’s daily and annual cycles. It may do this by storing solar energy as heat in the walls of a building, which then acts to heat the building at night. Another approach is to keep the interior cool during a hot day by designing in natural convection through the building’s interior.

Solar heating systems
Main articles: Solar hot water and Solar combisystem
Solar hot water systems use sunlight to heat water. They may be used to heat domestic hot water, for space heating or to heat swimming pools. These systems are composed of solar thermal collectors, a storage tank and a circulation loop.[8] The three basic classifications of solar water heaters are:

Batch systems which consist of a tank that is directly heated by sunlight. These are the oldest and simplest solar water heater designs, however; the exposed tank can be vulnerable to cooldown.[9]
Active systems which use pumps to circulate water or a heat transfer fluid.
Passive systems which circulate water or a heat transfer fluid by natural circulation. These are also called thermosiphon systems.

A Trombe wall is a passive solar heating and ventilation system consisting of an air channel sandwiched between a window and a sun-facing wall. Sunlight heats the air space during the day causing natural circulation through vents at the top and bottom of the wall and storing heat in the thermal mass. During the evening the Trombe wall radiates stored heat.[10]

A transpired collector is an active solar heating and ventilation system consisting of a perforated sun-facing wall which acts as a solar thermal collector. The collector pre-heats air as it is drawn into the building’s ventilation system through the perforations. These systems are inexpensive and commercial models have achieved efficiencies above 70%. Most systems pay for themselves within 4-8 years.[11]

Solar lighting
Main articles: Daylighting and Light tube
Solar lighting or daylighting is the use of natural light to provide illumination. Daylighting directly offsets energy use in electric lighting systems and indirectly offsets energy use through a reduction in cooling load.[14] Although difficult to quantify, the use of natural light also offers physiological and psychological benefits.

Daylighting features include building orientation, window orientation, exterior shading, sawtooth roofs, clerestory windows, light shelves, skylights and light tubes.[15] These features may be incorporated in existing structures but are most effective when integrated in a solar design package which accounts for factors such as glare, heat gain, heat loss and time-of-use. Architectural trends increasingly recognize daylighting as a cornerstone of sustainable design.

Daylight saving time (DST) can be seen as a method of utilising solar energy by matching available sunlight to the hours of the day in which it is most useful. DST energy savings have been estimated to reduce total electricity use in California by 0.5% (3400 MWh) and peak electricity use by 3% (1000 MW).[16] However, there is some question whether these estimates are valid. In 2000 when parts of Australia began DST in late winter, overall electricity consumption did not decrease, but the peak load increased.[17]

Solar pond
A solar pond is simply a pool of water which collects and stores solar energy. It contains layers of salt solutions with increasing concentration (and therefore density) to a certain depth, below which the solution has a uniform high salt concentration. It is a relatively low-tech, low-cost approach to harvesting solar energy. The principle is to fill a pond with 3 layers of water:

A top layer with a low salt content.
An intermediate insulating layer with a salt gradient, which sets up a density gradient that prevents heat exchange by natural convection in the water.
A bottom layer with a high salt content which reaches a temperature approaching 90 degrees Celsius.
The layers have different densities due to their different salt content, and this prevents the development of convection currents which would otherwise transfer the heat to the surface and then to the air above. The heat trapped in the salty bottom layer can be used for heating of buildings, industrial processes, generating electricity or other purposes. One such system is in use at Bhuj, Gujarat, India[26] and another at the University of Texas El Paso.[27]

Solar chemical
Solar chemical is any process that harnesses solar energy by absorbing sunlight in a chemical reaction in a way similar to photosynthesis in plants but without using living organisms. No large-scale systems have as yet been constructed.

Another chemical (but not photochemical) approach has been to use conventional solar thermal collectors to drive chemical dissociation reactions. Ammonia can be separated into nitrogen and hydrogen at high temperature and with the aid of a catalyst, stored indefinitely, then recombined later to release the heat stored. A prototype system was constructed at the Australian National University[28].

A promising approach is to use focused sunlight to provide the energy needed to split water into its constituent hydrogen and oxygen in the presence of a metallic catalyst such as zinc.[29]

While metals, such as zinc, have been shown to drive photoelectrolysis of water, more research has focused on semiconductors. Further research has examined transition metal compounds, in particular titanium, niobium and tantalum oxides.[30]

Unfortunately, these materials exhibit very low efficiencies, because they require ultraviolet light to drive the photoelectrolysis of water. Current materials also require an electrical voltage bias for the hydrogen and oxygen gas to evolve from the surface, another disadvantage. Current research is focusing on the development of materials capable of the same water splitting reaction using lower energy visible light.

It is also possible to use solar energy to drive industrial chemical processes without a requirement for fossil fuel.

Sam Deane answers:

1. Solar panels are extremely inefficient, on the order of only 1-2% efficient.

2. The cost is so high, it is not worth it. The panels cost far more than any “free” electricity.

3. The cable from space would be too heavy, and air resistance would bring the solar panels down.

Instead, use mirrors to concentrate the sunlight, and use it to drive a steam turbine. The efficiency can easily be over 90% if done properly, yielding about 1,000 watts per square meter at high noon at the equator. A mere 20 square kilometers would provide about 360 megawatts. And 2/3 of the energy can be stored for evenings and cloudy days.

Sam Deane answers:

You are wasteful in your power usage. To use 980 kWh per month in such a small home is just unbelivable. Chage your lights to CFL (a 28 watt cfl is = to a 100 watt bulb) and use space heating and window A/C units. Unplug that tv set when not in use and same for other items. I found that our tv set alone uses amost 12 watts when turned off. You may say that is not much.. Well add in 4 tv sets and a couple of stereos and other items and do it for a years time. Lots of waste. Our home is twice the size of yours and we only use on a heavy month about 500 kWh. With 1860 watts in solar power my last months electric bill was 19 dollars and most of that was meter fees.

18K is really about right and not bad. You will get back 2000 dollars if installed before the end of 2008 but it looks like we may be Bushed and they may not extend the tax credits.
Just have to wait for John McCain to get in office and hope he will do something about it. But McCain is running for a 3rd bush term. Hillary is not going to make it in to office an every time Obama gets under pressure he gets so scared he starts stuttering. So he will just get walked on by big oil and big money. So better do it now while you can get something back.

Just to clear something up about the cost.. If you rent power you have nothing in 30 years but if you buy a system you have a system in 30 years.

As far as new lower priced solar modules.. BS!!! Big time
BS!!!

If they can make a 3000 watt solar module for 1 cent they can sell it for the current market price. So it would take a FOOL to drop the prices. So don’t waste your time setting on your thumb waiting for this great lower price.

Ask Evergreen Solar if they lowered prices when the used OUR TAX DOLLARS to find a new way to make their panels. Well they found a cheaper way and did it and charge the same as anyone else. But that don’t stop them from braging. If they can get your money and don’t take it they woudl be fools.. Would you drop your price if people would pay the higher price? Plus someone would by them out and bring the prices back up anyway..

Sam Deane answers:

Solar panel is made up of a collection of special cells known as photovoltaic cells. These cells are joined together with copper wire and each of them can to generate 5 volts of electricity. You can install as many cells as per your requirement. These solar panel generate AC power which is converted in DC by using an inverter.

Normal installation cost of a solar panel at home is around $5000 but it is true that if you have zeal to learn you can build a solar panel of your own within $200. Making a solar panel is not much difficult but you need to follow a good DIY guide to do that.

For more information visit: http://www.howtobuildasolarpanel.info

Sam Deane answers:

Solar panels absorb energy from the sun and then converts it to energy that you can use. Its obviously a renewable source, so its very good for the enviorment! Unfortunately theyre expensive and there arent many of them.

Sam Deane answers:

This would be called a low end, non-skilled job. People who do this work for solar panel dealers, and are typically trained on the job. It’s not much above minimum wage, and the only decent career path is in someday owning your own business.

For that, a business degree would suit you better than any tech degree.

An AS in electronics would prepare you for the job you described.

Did I mention that it’s a low end, low paid job, with not much future?

Sam Deane answers:

You need to talk with people who are already knowledgable in the field, and in the business of designing systems for a specific set of location, conditions, applications, and goals. Government incentives make a big difference in evaluating choices. Those vary widely by country and even state within country.

Sam Deane answers:

I really disagree with the above poster. It’s always productive to search and try new methods to solving our problems. It’s how science works. We may invest a great deal of time and effort into a single promising approach only to have it fail in the end. But then we’d know more and can better prepare a new one.

My only complaint is that Obama seems determined for our renewable energy sources to be developed here. There are actually two very promising energy plans being done in the UK and Canada atm. One involves tides and the other man made tornadoes. It made not be made in America but good ideas are good ideas regardless of where they come from.

Fuels for cars do need to be reliable and rather set as they require massive amounts of infrastructure. But what the above poster fails at realizing is that what is needed is a better way to produce electricity. If we can do that in a cleaner fashion it’s much easier to make use of cars that can use existing and proven technology.

Sam Deane answers:

Normally it is not connected directly because the voltage and current output from the panel is fluctuating as it is entirely dependent on the sun’s rays.
So the solar panel is therefore connected via a “Charge Controller” to a 12V lead acid battery to charge it.
The battery is then connected to the inverter.