Solar, Natural, & Renewable Energy | Magnetic field Energy

Archive for March, 2010

The intensity of electromagnetic waves from the sun is 1.4 kW/m^2 just above the earth’s atmosphere. Eighty percent of this reaches the surface at noon on a clear summer day.
Suppose you model your back as a 27cm & 51cm rectangle.
How many joules of solar energy fall on your back as you work on your tan for 0.70h?

80% of 1.4 = 1.12 kW / m²

Area = 0.27 * 0.51 = 0.138 m²

Power = 1.12 * 0.138 = 0.154 kW

Energy = Power * Time
Time = 0.7 * 3600 = 2520 seconds

Energy = 0.154 * 2520 = 389 Joules

I have made a wind generator out of cheap, everyday materials.
Is it possible to make solar panels for generating electricity from everyday materials, perhaps something like a thermocouple with two different metals?

Not unless you can figure out a way to produce a semi-conductor at home. Basically a solar cell (photovoltaic cell) is a couple of layers of silicon P type and N type. Electrons become excited when light quanta penetrates into the P layer. The excited electrons move to the N type and (very oversimplified) create electricity.

I doubt you would have the facilities to create the materials at home.

I am writing a literature review essay..and i have to discuss about the political impact of solar energy..can anyone give me some advices or examples for what i can do about this topic.

One of the issues the US presidential candidates are tackling is oil dependence, terrorist and concerns about global warming. Solar energy will keep the US from depending on foreign oil, which we hope would lessen the the resources of the terrorist. On top of that, solar energy is clean energy. given our environmental problem– the global warming. therefore i many areas and solar wind affects the US presidential candidates campaign.

I just want to make sure I was well informed, thanks for any input. If anyone knows of other options to heat my pool with out solar panels please let me know. I should let you know that I do not have enough space nor want panels on my yard either.

Warranty on roof or pool?
Consult manufacturer or vendor or installer for warranty info

Im stuck on this question for homework and i have looked really hard to try and find it but i still can’t. I need the answer to this question:
What impact does solar energy have on people, animals and the environment? Thankyou for helping

The sun’s energy, when converted through photovoltaic cells, has the positive impact of being a renewable energy source as contrasted to fossil fuels.
The sun’s energy, as a heat source, can be positively used to to warm water via solar hot water heaters or cook food via solar ovens.
The sun’s energy heats the ocean which results in the wind. The temperature of the oceans, impacted by the sun and the location of the earth relative to the sun, also moderate the earth’s temperature making existence on the earth bearable for us humans.
Negative impacts of solar energy could be when there is an excess of sun that leads to sunburns, or excessively hot cars (that you should not leave animals, humans, or ice cream in).
A negative of solar energy may also be in the negative impact the making of photovoltaic cells has on the environment because of the energy they consume use and chemicals they emit during the manufacturing process.

I want to heat a room that is 20" by 16 ". I have a 1500w ceramic heater and a 12v battery. How many solar panels would i need to heat the room?
and what size panels

fred k is right – far too many. and you probably need to buy an inverter too – a 1500w one isn’t cheap, also need to buy more batteries. A much more efficient way to use solar to heat you house is to use solar heat collectors (they are more efficient than PV cells). But then you would need some kind of mass to store the heat in until you needed it.

Hi there!

Can someone tell me what are the current status of solar energy, research and development and initiatives here in the philippines? Or any links about solar energy? Your help will be much appreciated. Thanks.

I have no idea. But you should be able to research this fairly easily. Start with Google. If that doesn’t suffice, try the library (I assume there are some in the Philippines). Check whatever governmental office would over-see this area in your country.

I was wondering how many 700 W solar panels it would take to run a household A/C unit. Also curious how many batteries it would take to keep A/C running in inhospitable environments. Would a 3500 W inverter be enough if it were to run 220 AC?

Here we are doing the math of two facts to multiply or divide, to find the third, and you don’t give enough to make up the equation!

My 2.5 ton unit needs 220 VAC at 5 KW for the heater coils, and 3.5 KW for the cooling and fans, but, in electricity, we are always having to discriminate between inductive loads (transformers, oven coils, heater coils) and other uses, like lncandescent lighting.

To run my HVAC unit, in my 1,000 square foot home, would demand a10KW unit, and the 5200 watt (5500 watt Surge rated)
would not work. A generator simply stalls out under load, possibly smokes the generator electrics, while a solar unit and batteries can reverse potential under severe load, and explode!
The surge rating for my HVAC unit is 3X higher, (the Switching Load), for either heating or cooling. When figuring out the generator load for an emergency generator, for warranty purposes, they demand we install a generator with a ’surge’ power rating triple the start-up load of our equipment, and that is the way to try to load your Solar panel, also!

Now, go to the hardware store, and get a booklet or pamphlet about emergency power generation, and look at the descriptions of the generator start up power capabilities for the ’switching loads’!

What are engineering challenges to develop solar energy for comfort/home uses?

Solar is an old technology now and is fairly developed. Cost is a bit of a barrier but that is coming down quickly. Production scale could also be considered a barrier, as the industry can’t yet make enough solar panels to satisfy demand. The panels themselves are limited in how much energy they can take out of the sun’s rays, but they are getting better at this. Materials are a big thing now, mostly in trying out different materials and structures in the cells to bring down the cost and boost the efficiency.

We are considering buying and installing solar panels on our house… I don’t know how much it’ll cost us. Anyone knows where I could find a free quote? Thanks

Unfortunately without knowing your energy usage it is impossible to give an estimate on total system costs for a solar electric system. You can find out more about sizing your system by reading this article.

http://howto.altestore.com/Articles-on-Renewable-Energy/Solar-Panel-System-or-PV-Systems/How-Many-Solar-Panels-do-you-need-in-your-Solar-Array/a88/

-Dave C.