(jump directly to calculation tables)

We want to look at a very simple model of economic efficiency where are we interested in the annual return on investment. A project involving a solar photovoltaic installation requires certain amount of capital to be built and will expect certain amount of annual revenue. The simple indicator of efficiency that we want to study is this annual return on invested capital.

There are more complex models that also include the cost of capital. In a model that studies the cost of the electricity produced for example the cost of capital and factored in return for the investor could be very important factors. Cost of capital on its own can be a complex concept too. Whether the capital is borrowed and the cost will be defined by the interest rate of the loan or is cash participation from the investor and the cost will be defined by other opportunities the investor has to invest in (including risk free investments) or the combination of the two, cost of capital is very significant factor in such models.

We simplify our model to the level of looking at potential return from invested amount of capital. Further investment efficiency study and study on the cost of production of electricity should involve cost of capital.

We will also try to come to tables of calculated efficiency depending on different factors but not the size of the installation. The size of the installation definitely impacts the efficiency of a project. This is the traditional concept of economy if scales. A larger project will be expected to be more efficient over all because of the spread fixed expenses that the project has. But we will be building our model around the idea of dollar per watt, dollar per watt peak, so that it is applicable to different. The efficiency that comes from scale can be reflected in the factors going in to our model – specifically cost to build.

Another factor not included in our model is the maintenance cost of the solar installation. We are hoping that the reader can find resources which will indicate dollar per watt peak what the expected cost to maintain the station are.

The factors that expect to influence our model are: cost to build the power installation, insolation at the geographic location, electricity market price.

The cost to build the power installation includes:

• the price of the core photovoltaic components employed: modules, panels, arrays (what exactly list of such components we deal with depends on the design and configuration of the installation),
• the price of the mounting equipment (trackers and, or positioning frames) and wiring;
• price of inverters and grid connection equipment
• service and labor cost to assemble
• management and administration costs and costs of permits

The insolation at the geographic location. The insolation is the amount of solar light energy falling on the surface of the earth at a given geographic location per certain amount of area in the span of certain unit of time. More specifically the unit of measure used is watt per square meter (W/m²) or also kilowatt hour per square meter per day (kWh/m²/day). Insolation in Europe, just for reference purposes, approximately, ranges between 1,000 to 2,000 kWh per year per installed kWp, in the continental US – between 800 to 2,100 kWh per year per installed kWp for different regions. Exact numbers can be found in different reference tables and insolation maps on the internet and elsewhere.

In the photovoltaic industry a measure of insolation is employed which helps us more directly figure out how much electricity in kilowatt hours (kWh) we can produced annually from an installed nominal watt (Wp) – that is kilowatt hours annually per installed kWp (kWh/kWp/y).

The market price of the electricity produced. Since we are trying to figure out economic efficiency – annual return on investment we need to involve in the model:

• the price of the electricity we produce and sell to the grid

or conversely

• the price of the amount of electricity we offset that we were otherwise going to pay for at such market price.

In many places in the world – by country or by specific territory (state, other subdivision) there are financial incentives for investors in photovoltaic power stations in the way of a special feed-in-tariff. These usually are higher price the grid pays to energy producers who utilize photovoltaic power stations. If we have to give some examples these countries have the following feed-in-tariffs (unit of measure is Euros per kWh since classically many of the notable incentives started in Europe and that is the currency used there): Austria 0.57 – 0.59, Germany 0.52 – 0.57, Italy, 0.36 – 0.49, France 0.30 – 0.55, Spain 0.19 – 0.44, Switzerland 0.10 – 0.50, Israel 0.14 – 0.16, Bulgaria 0.40.

The formula.

The annual return on investment in a solar power station will be the annual income from sold (or offset electricity) divided by the amount of the investment.

Annual return on investment = annual income ($) / investment amount ($).

The annual income is the market price of the electricity in dollar ($) per kilowatt hour (kWh) times the amount of energy produced in an year in kilowatt hours (kWh).

Annual income ($) = production per year (kWh) x market price ($/kWh)

The production per year is the solar insolation in kilowatt hours per year per kilowatt peak installed times the installed capacity/power in kilowatt peak (kWp).

Production per year (kWh) = insolation (kWh/y/kWp) x installed capacity (kWp) .

So that we can work on dollar per watt basis we will express the investment amount by the investment cost per watt.

Investment amount ($) = total cost per watt ($/Wp) x installed capacity (kWp) x 1,000

– the 1,000 factor  is to adjust the dollar per watt unit to the kWp in which we are measuring the installed power.

So the complete formula for the annual return on investment will be:

Annual return on investment = annual income ($) / investment amount ($)

If we use the formula for the annual income we get:

= production per year (kWh) x market price ($/kWh) / (total cost per watt ($/Wp) x installed capacity (kWp) x 1,000)

If we use the formula for the production per year we come to:

= insolation (kWh/y/kWp) x installed capacity (kW) x market price ($/kWh) / (total cost per watt ($/Wp) x installed capacity (kWp) x 1,000)

Here we can get rid of the installed capacity (kWp) in the numerator and denominator and get to:

Annual return on investment
= insolation (kWh/y/kWp)   x   market price ($/kWh)
/  ( total cost per watt ($/Wp)   x   1,000 )

Let’s use the formula in an example where $7 per watt were spend in the building of the station, the insolation is 1,200 kWh per installed kWp and there is a $0.52 feed-in-tariff for the electricity produced.

Annual return on investment = 1,200 x 0.52 / (7 x 1,000) = 624 / 7,000 = 8.92%.

This calculated rate now can be compared to cost of capital and maintenance cost can be factored in to look for some more complete number of real economic return.

In addition to this formula the following tables can be used to get to approximate numbers:

The first table is given for insolation of 1,000 (this can be easily factored if we know the specific insolation, i.e. for 1,500 we just have to multiply by 1.5, for 2,200 we simply multiply by 2.2, etc.)

The investment cost per watt is given in a very wide range of $3 to $10 per watt but it is not implied that these are possible, practical or easy to obtain prices in reality. Our research shows that large industrial project can reach down to $6 per watt of such cost and smaller commercial and residential projects can go up to $10 and even $15 per watt peak installed.

The price for kWh of electricity is given in a range of $0.05 to $0.60 to reflect different market prices for electric energy and all possible feed in tariffs.

Annual Return on Investment At Insolation of 1,000 kWh/kWp:

Annual Return on Investment At Insolation of  1,500 kWh/kWp:

Annual Return on Investment At Insolation of 2,000 kWh/kWp:

To factor in the cost of capital  in the numbers from these tables one needs to subtract the cost of capital as a percentage. For example if the cost of capital is 4%  that has to be subtracted from the numbers in the tables above. Similar adjustment can be made for to factor in the maintenance costs.

Configuration efficiency, (performance ratio). We do not know whether this term is discussed in other research in length but we want to mention it for this reason: projects with equal labeled peak power – watt peak (Wp), nominal power, if taken directly from the labeled peak power of the modules involved can have different overall output electricity production – kilowatt hour (kWh) per year at the same geographic location. This could be because of how different modules perform when positioned with trackers or mounted stationary, or how well they perform in different cloud conditions etc. etc. So, realistically the nominal installed power (Wp) that can be used with insolation numbers to figure out annual production can be different for different installations mainly because of the type of modules used a the specific conditions (insolation, cloudiness, positioning etc.) For the different projects this factor has to be specifically researched based on data from similar configuration used in existing projects. By information we can get to such factor can vary between 0.75 and 1.4 – i.e. the electricity produced in a year from the installation in kWh may vary from the above calculation for known insolation from –25% to +40% from the indicated.

Related Articles:

Solar Energy Land Area Efficiency or How Many Acres per MW, kWp per Acre

Can Solar Energy Completely Replace Fossil Fuel and Other Sources?

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

Lowest Solar Panel Prices Per Watt 2009-02-24

Resources:

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

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

http://en.wikipedia.org/wiki/Feed-in_Tariff

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

First lets look at what we are using currently to meet our energy needs, coal and nuclear energy, and how ecologically damaging they are.

To start, most existing coal plants release many different toxins directly into the air we breathe, from sulfur to lead and mercury. Even the newer plants coming on line, which reduce toxins dramatically, still produce massive quantities of CO2, a greenhouse gas and a direct cause of global warming. Natural gas is far more benign but still produces large quantities of CO2 when used to produce electricity. How much CO2 is released – a 5-kilowatt solar system will prevent the release of nearly 10,400 pounds of CO2 every year for the life of the system. The average home uses 8,000-kilowatt hours per year. A coal power plant producing that much electricity emits about 18,000 pounds of CO2 per year.

When coal is burned, carbon dioxide, sulfur dioxide, nitrogen oxides, and mercury compounds are released. For that reason, coal-fired boilers are required to have control devices to reduce the amount of emissions that are released. Mining, cleaning, and transporting coal to the power plant generate additional emissions. For example, methane, a potent greenhouse gas that is trapped in the coal, is often vented during these processes to increase safety.

Secondly, large quantities of water are needed to remove impurities from coal at the mine. These large quantities of water are used for producing steam and for cooling systems. When coal-fired power plants remove water from a lake or river, the fish and other aquatic life can be affected, as well as animals and people who depend on these aquatic resources. At the same time, pollutants build up in the water used by the power plant boiler and cooling system. If the water used in the power plant is discharged to a lake or river, the pollutants in the water can harm fish and plants.

Last, the burning of coal creates solid waste, called ash, which is composed primarily of metal oxides and alkali. On average, the ash content of coal is 10 percent. Solid waste is also created at coal mines when coal is cleaned and at power plants when air pollutants are removed from the stack gas. Much of this waste is deposited in landfills and abandoned mines, although some amounts are now being recycled into useful products, such as cement and building materials.

So, you may say, what about nuclear power? While nuclear power plants do not emit carbon dioxide, sulfur dioxide, or nitrogen oxides – fossil fuel emissions are associated with the uranium mining and uranium enrichment process as well as the transport of the uranium fuel to the nuclear plant. Nuclear power plants also use large quantities of water for steam production and for cooling. When nuclear power plants remove water from a lake or river, fish and other aquatic life can be affected. Water pollutants, such as heavy metals and salts build up in the water used in the nuclear power plant systems. These water pollutants, as well as the higher temperature of the water discharged from the power plant, can negatively affect water quality and aquatic life.

Waste generated from uranium mining operations and rainwater runoff can contaminate groundwater and surface water resources with heavy metals and traces of radioactive uranium. Every 18 to 24 months, nuclear power plants must shut down to remove and replace the “spent” uranium fuel. This spent fuel has released most of its energy as a result of the fission process and has become radioactive waste.

All of the nuclear power plants in the United States together produce about 2,000 metric tons per year of radioactive waste. Currently, the radioactive waste is stored at the nuclear plants at which it is generated, either in steel-lined, concrete vaults filled with water or in above-ground steel or steel-reinforced concrete containers with steel inner canisters. This waste will remain radioactive for many thousands of years.

As you can see, the more solar power is used, the more it helps our environment. By investing in solar today you are investing in your future and your children’s future and you do this by combating global warming and reduce our nation’s dependence of foreign energy sources. And, you are helping in the reduction of CO2 emissions and protecting clean water sources. It’s amazing how such a small change in one’s life can do so much. ARI Green Energy is a manufacturer of wind generator technologies. Visit them today for a full line of wind turbines and solar technology solutions. Think green.

Article Source: http://www.articlealley.com/article_830778_45.html

About the Author:  Author: Robert Bell

We want to look at the needs of energy of the United States and the world and compare with the practical size installations of solar power stations needed to replace that.

The question of completely replacing all fossil fuel or all other sources of electricity and other energy is much more complex than just looking at the numbers. Probably replacing the other sources in just electricity production is simpler but still in addition to simply adding capacity, changes of large scale are needed in the national grid configuration.

Replacing resources used to produce other energy, other than electricity, is even more complex. That will mean changing how energy is being transported and used. While electricity is a type of energy easy to transport what may  need to be changed is the way it is utilized at the end consumer – industrial, residential or transportation. That will involve changes and costs again more than the ones related to replacing the source with solar power stations.

The current electricity generation capacity in the US is about 1TW (1,000,000 MW). About 395 GW (1GW = 1,000 MW) is from natural gas, 315 GW from coal, 100 GW from nuclear, 100 GW from hydroelectric 56GW from oil products, 30 GW from renewables  other than hydro, and other small components.

We will look at these numbers separately to see what it will take to replace the more urgent ones of them – coal, oil etc.

The US total energy consumption, not just electricity is 3.5 TW. Most of the difference between just electricity and this number is made up of energy produced from oil so we are not going to try to break this down. We will look at this as one of our theoretical targets.

The world total energy consumption is at around 16 TW of which 4.5TW is electricity.

So, lets build a scale of the different stages that theoretically can be achieved in solar replacing other energy sources.

For our calculations we will assume installation / construction cost for one 1MW of $5m. This is a number ($5/Wp) we think smaller than the recent historic numbers for cost to install solar capacity. But we want to factor for future falling prices of solar modules and other components and overall improving efficiency in the industry. Anyone is free to factor the $ numbers we have if they believe $7/Wp or $10Wp is a better number.

For surface area needs we will assume 200 kW per acre. With different design and technology 800kW per acre is possible but we will go with the low number on this to be on the safe side. Since 1 sq mile is 640 acres, with our assumption we will have 128 MW per sq mile.

We tried to display this comparison between energy currently produced by different sources and capacity needed in solar in gigawatts (GW), cost of  installation in billion dollars ($bn), land area needed in sq. miles, marks of different countries GDP, and land areas of different geographic locations (certain US states in this case).

Click here or on the graph below to see it in full scale.

On the above diagram, since it uses a linear scale for the capacity, cost and land and the large values (world energy needs) are much larger than the smaller ones (oil and coal for electricity in the US), the small values are not given a good presentation. So here we put the same numbers on a logarithmic scale for the solar capacity, cost and land requirements. We have much better clarity on the comparisons now for the smaller values.

Click here or on the graph below to see it in full scale.

We think in general our study is much more important in reference to the smaller values. They deal with some levels of scale of capacity that are practically easier to achieve in terms of replacing with solar. We are talking about the unquestionably very polluting coal and oil burning for electricity. Again – look at the numbers to replace oil products used for electricity generation in the US we only need $280b and spending that will create jobs, help growth in technology and give all sorts of other economic and social benefits.

The numbers given in our study in reference to the higher levels – world electricity and total energy consumption are simply for getting a better view of the comparative size of all levels.

Related Reading:

Solar Energy Nanotechnology Can Replace Fossil Fuels – SF Chronicle

Argument: Abundant solar energy can replace fossil fuels and slash emissions

Replacing fossil fuels: the scale of the problem

Alternative Sources of Energy Can Help to Save Our Planet

The potential of solar energy for replacing fossil fuels

newnet news – Scalable electric power from solar energy

Can alternative energy effectively replace fossil fuels

Solar Power – Europe Rallies Behind Nanotechnology To Wean World From Fossil Fuels

Resources:

http://www.eia.doe.gov/cneaf/electricity/epa/epa_sum.html

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

http://www.eia.doe.gov/oiaf/ieo/ieoecg.html

http://en.wikipedia.org/wiki/List_of_U.S._states_by_area

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

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

http://en.wikipedia.org/wiki/List_of_countries_by_GDP_(nominal)

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

RV solar panels are a component of an electrical system which converts light from the sun to electricity. This electricity is used to charge the RV batteries and are capable of running all the basics in your RV, including the lighting and appliances. On great advantage of using RV solar panels is that you can travel to a wider variety of locations. No longer will you have to worry about finding a source of power for your vehicles when you travel. As long as the sun is shining, you will be taking your power with you.

Thousands of companies in countries around the world now offer different RV solar panels for your convenience. When you decide to make the purchase, spend time researching which options are available to you so you can buy the best system and the lowest possible price.

Silicon Solar

Silicon Solar have a wide range of RV solar panel kits and can cater with providing anything from a single 15W amorphous solar panel up to the top of the range RVMaxx 330W RV Solar Power Kit.

This can provide enough power to run most of your small appliances.

Alpine Survival

Alpine Survival is one of the top choices for people looking to purchase RV solar panels. The RV solar panels that they sell are durable, lightweight, and easy to transport. One of the benefits of these and other top of the line solar panels is that they continue to generate electricity even if they are in partial shade.

Even the clumsy need not worry about the durability of Alpine Survival RV solar panels. You can pack them up and transport them without worrying about breaking them. They are so durable that it has been reported that dropping them and stepping on them still does not cause them to be ruined (although I would not recommend trying)! These RV solar panels have a unique design with lightweight construction and a nylon fabric covering which allows the entire unit to be folded into the size of a book. This makes them perfect to store and transport.

Mr. Solar

Another brand to consider when purchasing RV solar panels is Mr. Solar. They sell many of the most high efficiency brand names and kits, including such reliable names as Sharp, Sanyo, Photowatt, Mitsubishi, BP, GE, and more. This selection of RV solar panels and kits will ensure that you can find the exact one you want for your RV.

If you love to travel, RV solar panels are the perfect option. Your trips will be more convenient because you will no longer have to base your destination on where you can find a power source. Not only that, but you will save money by reducing your use of a traditional gas generator. With rising fuel prices, RV solar panels make practical sense for any traveler.

By TJ Greene. In this day and age with the ever-increasing cost of everything from gas to groceries, we’re all searching for for ways to cut back on the outflow of money.

One of the areas with the biggest jumps in costs is home energy. Who looks forward to that monthly electric bill? Not me, not you or anyone else because that bill gets bigger every single month. And it’s not going to get any better.

And yes there are ways to conserve some of your money as you help the environment also. And yes it’s the “green method”, which doesn’t bring up thoughts of communal living or mother earth nuts that it used to. More and more people just like you and I are looking for ways to save money and one of those ways is to stop paying for electricity by generating our own.

By constructing your own wind turbine to create all the electrical power you need..renewable wind energy is now the fastest growing source of energy around the globe. And stop what you’re thinking…it’s not that difficult to build your own…and really a lot easier than many wind generator companies would like you to believe!

To put it simply…it’s cheaper to build a electricity-generating wind turbine of your own and get the rewards for doing so YEARS before you’d get the benefits from a over-priced wind generator that you bought from a company.. And the technology is very basic! You can build your own renwable energy source for under $500. That’s something utility companies and most renewable energy companies that “offer” you renewable solutions for thousands of dollars, don’t want you to know.

The materials you need to construct a wind generator: the DC motor, batteries, towers and hub, are very inexpensive – you can build your own wind generator for under $500 and there are programs to sell back the excess energy you create to your power company. A professional installation from a energy generating construction company can run into the thousands of dollars, making it years before your system can pay for itself. Not the case when you’re doing it yourself.

There are also federal government programs that can help you pay for these energy-saving additions for your home or business.

Other governments and smart people in the United States are putting together their own wind-generated turbine systems everyday. And more are constructed daily which means more people are finally realizing what a very smart investment it is, and how it PAYS to do it!

The main problem I’ve seen across the internet to building your wind turbine is that these people who are doing it themselves are making it more difficult than it has to be, and they are spending too much money building their own electricity-generating wind turbine system.

So…don’t you think it’s about the time YOU became more aware of the future of renewable energy and started planning your OWN wind-generating turbine? And what about solar panels laid out on your home or property to collect the energy from the sun, which again takes you off the meter of the power company?

Come on…it’s time all of us begin taking care of our futures by removing ourselves from fossil-burning energy consumption. You only have to take that first step!

About the Author

By TJ Greene.  TJ asks:  How would you like to unplug your house from your electrical company, knowing that you are “100% Powered By Nature” with renewable energy? Take few minutes a look at these tips to “stop paying for electricity”! You’ll be surprised at how easy it is to change over and you’ll breathe a little easier at night knowing you’re doing your part to stop the consumption of fossil fuels!

Related articles on the web:

New BiFeO3 Crystal Can Improve Solar Cells Efficiency & Price

Solar PV Getting a Little Cloudy?

Rise & Shine: February 23, 2009

Long Term Solar Price Decline Trend Seen

Cost of Solar Power Dropping

SolarByTheWatt.com