Physical efficiency for example is the measure of what portion of the light energy is being transformed to useful electric energy. That currently runs for different types of photovoltaic cell technologies between 8 and 30 and by some reports 38%. We will spare a separate article on the different technologies and their respective efficiency readings.

Economic efficiency or investment efficiency is the dollar cost per nominal generating watt power or simply dollar per watt peak ($/Wp). The investment efficiency can be calculated at the different stage of completeness of a solar photovoltaic system or component – cells, panels, installed systems, power stations. We want to dedicate special studies to the importance of these measures of efficiency. Be prepared to hear our opinion that economic, or investment efficiency is much more important to the useful implementation of this technology than physical efficiency is.

Land area use efficiency is the measure of how much land area is needed for certain capacity of nominal (peak) power of a solar photovoltaic power station (or smaller system). The units of measure used are usually:

acres per megawatt or acres per MW – the land area needed in acres per MW of generation; the way to calculate that is to divide the area used in a project in acres by the peak power of the project in MW;

kilowatt per acre or kW per acre – this is the amount of installed peak power in kW (1 MW = 1,000 kW) divided by the land area needed in acres.

The equivalent units of measure used more often overseas (incl. Europe) are using the derivatives of the metric system for land area – hectares (10,000 sq.meters) and decares (1,000 sq.meters) – hectares per MW, decares per MW and kW or MW per hectare or decare.

We wanted to find out what is the approximate land area efficiency of existing completed and planed projects or ones in progress. We looked first at some of the biggest solar photovoltaic projects around the world, tried to find out quoted figures for their peak capacity and land are used and calculate the land are use efficiency for them.

We also looked at publications discussing proposed project especially for technologies that are just emerging.

This is what we found out.

Some of the largest completed solar photovoltaic power plants, also called solar parks or fields, have area efficiency of about 4.5 to 8 acres per MW. This is when crystalline (mono-crystalline or poly-crystalline) technology cells, modules are used. With thin-film technologies the efficiency is about 10 to 13.5 acres per MW.

For comparison we also looked at data for some solar thermal project and we estimated land area use efficiency of about 5 to 11 acres per MW. The lower values were for projects involving Sterling engines as opposed to the more traditional technology of parabolic mirror throws heating oil in a tube.

Here is a table of our calculations with numbers in the other units of measure and also a list of the resources used.

Resources used:

http://en.wikipedia.org/wiki/Moura_photovoltaic_power_station

http://www.solarpay.com.au/mega-watts-to-nega-watts.html

http://www.jccm.es/fondosestructurales/fileadmin/user_upload/_temp_/00-NOTICIAS/2008_MARZO/07-03-08_LA_TRIBUNA-Renovalia_invierte_en_parque_solar_Puertollano.pdf

http://www.bizjournals.com/sanjose/stories/2009/02/09/daily59.html?ana=from_rss

http://www.gizmag.com/go/4422/

http://www.renewableenergyworld.com/rea/news/article/2007/07/pg-e-signs-agreement-with-solel-for-553-mw-of-solar-power-49448

http://www.pv-tech.org/news/_a/first_solar_finishes_10_mw_pv_power_plant_for_sempra_pge_to_buy_electricity/

http://www.abengoasolar.es/sites/solar/en/technologies/photovoltaic/concentration/index.html

http://www.energy.ca.gov/reti/steering/2008-06-18_meeting/SOLAR_FS-Utility-Scale_Photovoltai

http://i-r-squared.blogspot.com/2008/08/massive-solar-pv-deal.html

http://ieeexplore.ieee.org/Xplore/login.jsp?url=/iel3/60/654/00017907.pdf?arnumber=17907

Related Articles:

Lowest Solar Panel Prices Per Watt 2009-02-24

Can Solar Energy Completely Replace Fossil Fuel and Other Sources?

A Short Science Lesson for Journalists – Watts, Kilowatts, Megawatts, Kilowatt Hours.

Related Articles on the Web:

30 MW photovoltaic solar plant planned for Texas

Gemini Solar Selected to Build 30MW Power Plant for Austin Energy

First Solar Agrees to Acquire Multi Gigawatt Utility Scale

Solar Stock Review: Cost vs Efficiency

Global Solar Technology – FPL breaks ground on 25MW photovoltaic …

SolarByTheWatt.com

Begin by establishing exactly how much of your home’s total energy usage you want to be run on solar power. Do you want solar power merely to heat the water and the water-heating system? Do you want to go completely off-grid and power the whole house by solar power? Either way, you’ll need to know how much energy your home is consuming per month on average.

Using your monthly utility bills, calculate your home’s average energy usage. Note any peak times when you use radically more energy. The Christmas period can cause surprisingly heavy energy demands. In essence, you need to design your solar power system to cope with your home’s maximum energy demand.

Once you have these figures, I recommend multiplying the amount by at least 1.5. This will give you a working leeway for any extra appliances you might add to your home over time. Now you know how much solar energy you need to pull in from the sun, you also have an idea of the amount of solar panels you will need to buy.

I would advise you to buy solar panels online. Go to Ebay and input the words “solar panel pallet”. You’ll probably get an amazing bargain there. Prices have dropped dramatically recently. For an average family house, you can probably buy enough panels to power your home for less than $15,000.

Get good quality skilled and experienced tradesmen to do the job. Again, look online or check your local phone book. Always get at least three quotations. Cost is central, but it is very important that they have previous experience in installing solar power for homes.

Once you have someone you can trust at a good price, discuss with them which inverter to get and how much that will cost. Solar panels harness the power from the sun and turn it into direct current (aka DC power). The inverter converts this DC current into alternating current, (aka AC power). Everyone who installs solar power for homes needs to buy an inverter. Just about everything in your home runs off AC so your inverter is essential.

A good inverter will cost about $2,000. Add another $500 or thereabouts for installation. Inverters have a lifespan of about 10 years, while solar panels, if looked after, will last 25-30 years. So you’ll probably need to replace your inverter over time.

If you want to go completely off-grid, you’ll need to store your excess energy in good quality batteries to store excess solar power harnessed on sunny days. That way, you’ll have a reserve of power to run your household appliances on darker days and at night-time. They cost about $50 – $100 each for the deep-cycle types. You’ll need about 10 of them. New batteries generally need replacing every 3-5 years.

Typically, your installation costs shouldn’t be much more than $10,000. However, installation costs depend on a variety of factors. How is your roof constructed? Steep roofs or Spanish tiles cost more to install as the panels need to be properly secured. Yet further cost goes into ensuring leak-proof seals in these roofing systems.

Installing solar power normally doesn’t need much electrical work to set up. Older houses may require additional rewiring, though this is rarely extensive. Nevertheless, have a qualified, experienced electrician check all the wiring.

Don’t forget to look for government support. Most local governments around the world are offering major tax credits. Your utility company might also have incentives to offer. These can all add up to as much as 50% of the total cost.

Final point – if you are investing in solar power for homes, it makes sense to protect your new asset. Ask your insurance advisor to add this to your homes and contents policy. Adding your new solar power system to your homeowner insurance policy won’t cost you more than $100 per annum. This will protect the investment you’ve made on your house. An additional $100 per year to cover your $40,000 solar system against any disaster really is an absolute bargain!

Look on your solar power system as a long-term investment. Each step of the installation process should be taken carefully. To remind yourself of the value of your investment, ask yourself, “What is the payback time?” Of course, after it’s all paid off, you have free electricity for years to come.

Consider if you were to take a loan to finance your solar power for homes system. Although it may seem like a hefty initial outlay, the monthly payments will probably be less than your current utility bill. So all ways up you’re saving money.

Of course saving money is not the only reason it makes good sense to install solar power for homes. It’s good to know that you are reducing your carbon footprint. Thereby your children and their children can inherit a planet worth living in. That’s the very least you can do for them, don’t you agree?

——

As a travel magazine editor and publisher, a life coach and trainer, Sam Deane has seen the world. Nowadays, he dedicates most of his free time to maintaining the well-being of this precious, miraculous planet on which we live. Sam runs an important and lively blog about solar power. http://www.gosolarpowerforhomes.com

Article Source: http://www.articlealley.com/article_766371_27.html

Author: samdeane author www.articlealley.com

We list the lowest prices per watt that we can find on the internet and through direct research. We do not claim at all that these are research and results of an absolute character. That is, we realize that there might be products, vendors, pricing structures for certain types of projects and quantities that we are not able to identify through our effort.

That is why nobody should get offended that their product brand or vendor company is missed in our research or they are not ranked correctly because we have not found out about their lowest, low or otherwise competitive prices.

While we maintain that prices as dollar per Watt ($/Wp, dollar per Watt peak) is the number that will take the solar power industry to the stage of playing a major role of resolving the gigantic issues the US and the world have with securing clean, safe and abundant source of energy, we also realize that with many products groups prices reflect many other things than just willingness of the manufactures and the marketers to provide an affordable product.

Namely, different prices may reflect different quality and quality preference of the market – i.e. higher quality products would maintain relatively higher prices given all other factors being equal.

Different prices may reflect different costs to manufacture products of certain type of technology. We are well aware that this is especially true with solar panels. We will try, as effort grows to provide a way for our readers to be able to separate prices listed and researched for different underlying technologies of products.

In any case if any one buyer or seller of solar products thinks that our best research effort has not presented certain vendors, brand or price – please, feel free to contact us and forward to us details of the the product and price we should list. We will add additional level to research that such price is being offered on regular basis and will try to reflect this in our report.

Here is or current ranking:

($/Wp, $ per module, Wp of the module, nominal voltage, technology, Brand, Model, Vendor, URL to the vendor’s page)

$2.84 / Wp, $567.60, 200W, 18.1V, Poly-crystalline, Sun-A-200, SUN, KULLY Solar, http://kullysolar.com

$3.54 / Wp, $637, 180W, 24V, Poly-crystalline, CSI ECOSENSE CS6P-180, Canadian Solar, Affordable Solar Group LLC, http://www.affordable-solar.com

$3.56 / Wp, $142.49, 40W, 17.3V, Poly-crystalline, BP Solar, Discount Sales Electronics, http://discountsales.com

$3.83 / Wp, $230, 60W, 67V, Thin-film, Kaneka, GSA-60, Living Off The Grid, http://livingoffthegrid.ecrater.com

$3.94 / Wp, $630, 160W, 24.9V, Poly-crystalline, ES-160-A, Evergreen Solar, KULLY Solar, http://kullysolar.com

$4.62 / Wp, $1,016, 220W, 28.7V, Poly-crystalline, SCM220, REC Solar, Affordable Solar Group LLC, http://www.affordable-solar.com

$5.16 / Wp, $1,032, 200W, 55.8V, Mono-crystalline, HIP-200BA19, Sanyo, Affordable Solar Group LLC, http://www.affordable-solar.com

$5.48 / Wp, $328.88, 60W, 12V, Poly-crystalline, CD Tech Solar, RV Fun Products, http://www.rvfunproducts.com

$5.52 / Wp, $552, 100W, 18V, Mono-crystalline, SW100C, Sunwize, atlE Store, http://store.altenergystore.com

Please, be patient, we are adding more to this list. We are hoping the prices at the top of the list will reduce as we add more vendors.  Feel free to send suggestions through comments on our articles or the Contact Us page.

Related articles on the web:

Utility Scale Solar aims to bring solar costs level with coal, natural gas

Renewable Energy in China: Solar Energy, Wind Energy and other green energy

2009 Solar Energy Overview

6N Says Lower Silicon Purity Means Lower Solar Prices

Europe Solar Price Falls to Record Low, Global Prices Begin Drop

SolarByTheWatt.com

Grid parity, or the potential for electricity generated from solar power stations, to compete in terms of price with other energy sources on the national electric grids, is a phenomena expected to critically turn the table so that solar ultimately becomes a major player in the efforts to find a clean, reliable, on mass scale, source of energy.

When we say price per watt we refer to the watts in Wp or watt-peak – the nominal or peak power output of a device (solar module, etc.)

SolarByTheWatt.com will collect data from solar products vendors and will publish price reviews and comparisons specifically focusing on the price per watt.

In addition SolarByTheWatt.com (Solar By The Watt dot Com) will publish news and commentary on the developments in the industry that leads to lower price of the solar cells and solar modules (panels).

Related articles on the web:

earth2tech.com: Can First Solar Shake the Earnings Blues?

VentureBeat.com: Utility Scale Solar aims to bring solar costs level with coal, natural gas

earth2tech.com: Solar Prices Drop, Deeper Discounts Expected

HuffingtonPost.com: Solar Prices Poised to Fall Dramatically

SustainableBusiness.com: Non-Module Costs Responsible for Decreasing Solar Prices – Report

SolarByTheWatt.com