Solar Energy » photovoltaic solar energy

Is solar Photovoltaic energy is good investment ROI?

admin — Wed, 14 Sep 2011 07:53:13 +0000

ROI is all over the place … what is that actually mean ?

It’s like a low yield bond, you’ll make a return but if you had just continued living on the grid for another couple of years and then invested, you would’ve had a much higher return. Current efficiencies of commercial systems are about 15%, the current record in the lab is 42.8% and 65% efficient photovoltaic’s are on the drawing board. Is it worth it to barely have a return over the next 15 to twenty years when the return could be double that over that time period if you just waited another two years?

ROI is return on investment. If you invested in 10 year US Treasury bonds now, you would be getting about a 2% return on investment so it doesn’t make sense to invest on anything unless you get at least a 2% or better return. 20 years at 2% per annum gives you a 48.6% overall return that is $100 invested would give you $148.59 over twenty years, at 4% per annum it would give you 119.11% return over the twenty years in that $100 invested would return $219.11. If you had to wait two years to get the 4% per annum return and then only get 4% for 18 years, you would still get 102.58% return so does it make sense to invest for 20 years at 2% per annum to get a return of 48.6% or to just wait two years to get the 4% per annum return and have a return of 102.58% over the same time frame?

how can we store electrical energy generated by solar photovoltaic system?

admin — Wed, 24 Aug 2011 09:52:18 +0000

there isn’t a good way at home. on a very large scale, there was a double reservoir that generated electricity as water flowed from the upper to the lower sections, and when there was excess capacity, it pumped water from … Continue reading →

Capturing Wind Energy versus Solar Energy — Economics Questions — SEE QUESTIONS BELOW?

admin — Fri, 10 Jun 2011 16:16:38 +0000

1) Suppose that you want to erect a 3 Kilowatt [peak energy output in a strong wind] wind turbine.

Assume that the site is located in an area rated in top 20% for annualized wind energy potential [in an inhabited location in the 48 states of the U.S].

1a) Approximately how much will it cost for an off-the-shelf, name-brand wind turbine and suitable tower?
[I am only looking for a range here, I know that the exact cost will depend on vendors, location, other variables, etc.]

1b) How much additional $ for the installation and hookup? Assume that the unit will be hooked up to the grid and unused electrical power will be sold to a local utility company.
[Again, I'm only looking for a range here, I know exact cost will depend on many variables.]

1c) If you amortize the cost over the lifetime of the unit, and include related costs such as maintenance and insurance, and also factor in about half of the power being sold to the grid, what will be the average cost per kilowatt of the electrical power used on-site?
[again, I'm only looking for a range here, I know exact cost will depend on many variables.]

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2) Similar questions, only this time for a bank of photovoltaic panels — sufficent to produce about 3 kilowatts maximum in full sunlight. Assume that the site is to be located in an area rated in top 20% for annualized solar energy potential [any inhabitable location in the 48 states of the U.S].

2a) Cost for solar photovoltaic panels, for a 3 KW max capacity? [range]
[Assume they will be installed on a pre-existing rooftop.]

2b) Cost for installation hardware, installation, and hookup? [range]

2c) Amortized net cost per kilowatt? [range]

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Solargreenearthenergy.com

What can be used to harvest energy from solar power?

admin — Mon, 30 May 2011 18:34:54 +0000

Solar plates? Solar collector? Photovoltaic cells?

You have 3 good answers right in your question.
Through tools such as those, solar power is harvested, and to take it a step further, storage by batteries would be a way to keep that harvested energy. There are many different machines/tools that could be used directly from the cells, and depending on these machine’s requirements, an inverter or converter would be installed just after the plate/collector/cell to feed the electrical device used.

Which of the following would be a feature included in a home being built using passive solar energy features?

admin — Sat, 28 May 2011 12:49:04 +0000

Which of the following would be a feature included in a home being built using passive solar energy features?

a. tile floors
b. photovoltaic cells
c. solar panels
d. natural gas furnace

a. tile floors to absorb day time sun/heat

I am doing an essay about solar energy (mainly talking about photovoltaic cells)?

admin — Tue, 26 Apr 2011 01:14:48 +0000

I’m writing this essay and i need to make a table so i can make a graph but does anybody know what i can compare? i had a table of the comparison of solar panels to wind turbines but my lecturer said it was not related and to do somthing else.

Thanks dave

Compare current (amps) output with the brightness of the sun (irradiance). As the sun gets weaker during the afternoon, the output of the panel goes down.

Compare voltage output with temperature. As temp goes down, voltage goes up (which is why the output of a panel is higher in the winter than the summer, it’s just sunny longer in the summer, so the total output for the day is higher.)

You should be able to find some of this on datasheets. http://www.altestore.com/mmsolar/others/SANYO-HIT-220A-solar-module.pdf

For example, the Sanyo module temperature coefficient is -0.145 V/ °C, which means for every degree Celsius it goes up, the voltage output goes down 0.145 volts. Conversely, for every degree it goes down, the voltage goes up. The rated voltage is 52.3 V at 25°C. So, if it is freezing out, 0C, that is 25 degrees colder than what it was rated at. 0.145 x 25 = 3.6V. 52.3V – 3.6V = 48.6V. This is important, because if the current stays pretty much the same, the watts out goes up when it is colder and down when it is hotter (V x A = W)

What do you think of photovoltaic and solar energy field as a field to study?

admin — Sat, 23 Apr 2011 23:24:38 +0000

I m considering this field for master’s degree
I mean i find that it will be a recommended field more and more in the future but i m afraid that it might be narrow
To be specific,i m want to know ur opinions career wise

I think that energy technology will be one of the really good engineering fields for the next few decades.

Concerning the narrowness of it, all areas where you get a master’s degree narrow focus but increase depth of knowledge. It gets even narrower if one gets a PhD, but the depth is much greater.

Solar energy question, which i am having trouble with..?

admin — Tue, 22 Mar 2011 23:54:17 +0000

. The amount of sunshine on a horizontal surface at the equator is 5kWh/m2/day. Suppose this house is to run entirely off grid on solar electricity alone using a high performance silicon photovoltaic module with specifications shown below:

Maximum power = 210 W
Module power conversion efficiency = 16.4%
Open circuit voltage = 50.9 V
Short circuit current = 5.57 A
Width = 812 mm Length = 1580 mm
Note: The surface of this photovoltaic module is entirely covered by solar cells (figure 1).

a.Work out how many such photovoltaic modules would be needed and show your reasoning.
b.What is the total area of the modules used?
c.What other energy device must be included in the solar photovoltaic system for this household?
what i am confused, is whether to use the filling factor(max power/ (open circuit volt x short circuit current)). in addition, what does the module power conversion efficiency represents?
i forgotten to add in the details that the house uses 82Kwh in 6days.

The first thing to note is the solar panel is rated at 210w at peak efficiency.
That means it will produce 210w at a given temperature range.
The %efficiency has no bearing on the panel. If it was 10% efficient the panel would be bigger and if it was 40% efficient the panel would be smaller.
The radiation is 5kwh/m2/day.
So assuming that the temperatures are perfect the panel produces 210w per hour for the sunlight hours available. eg.10 hours sunlight by 210w = 2100wh per day or 2.1kwh
The radiation is normally given as a yearly figure not a daily figure.
Assuming we get 10 hours sunlight the panel can produce 2.10kwh.
Now the efficiency of the connections from the panel to the batteries will be less than 100% so assuming a loss from the panel to the batteries or electrical appliance is 25% then the total power generated is 2.1kwh *0.75 =1.575kwh of usable energy.
If the sunlight is 7hours then adjust the figures accordingly.
Finally the total usage of power in a given day is governed by the habits and needs of the family occupying the house.
To get a fix on that read the electricity bill and divide the kwh used by the days covered in the bill.
If the daily use was say 15kwh per day then you would need 15kwh/1.575kwh of usable generated power which equals about 10 panels

photovoltaic solar panels cheap?

admin — Sun, 19 Dec 2010 17:20:49 +0000

I need some help. I am looking for cheap ways to get solar energy, possibly built it yourself solar panels, or cheap commercial options…

This site is amazing

How is energy from the sun used?

admin — Wed, 15 Dec 2010 16:30:52 +0000

Apart from photovoltaic (solar) cells how do we use solar energy?

The sun makes the wind blow (warm air rises and the wind is air filling the gap left) so sun power drives windmills, wind turbines and sailing ships.

The sun makes the rain (seawater evaporates and is carried inland by the wind) so water wheels and hydro-electric stations are sun powered.

The wind makes the waves on the sea, so wave powered generators are sun powered.

But tides are driven by the moon so tidal barrage generators are moon powered.

Cheers, Alan.

PS just got back fromTibet where every body uses Solar cookers, a parabolic mirror of aluminium about 1.5 metres across with a little stand to put a kettle or saucepan, looks like a little radio telescope or radar dish.

Alan