# An Introduction To Solar Power



## RamboMoe (Dec 16, 2011)

Hey guys, new to the forums so I thought I'd start with a bang. I've had the opportunity to do some research on solar power, and hopefully this post can serve as a solid introduction on the topic.

*INTRODUCTION*
In a solar power system (also known as a photovoltaic or PV system), power is produced for your home using a 3-part system. Solar panels, usually placed on your roof and facing south in the northern hemisphere, absorb sunlight and convert it into direct current. Mounting systems adjust the angle of your solar panels, to optimize energy absorption. Then an inverter converts the power from direct current to alternating current, making it useable for household appliances.

There are 4 kinds of solar panels available commercially.

Single crystal modules have been around the longest and are the most effective. They are the most efficient (10-17%) but also the most expensive. They are the dotted or octagon shaped panels you would often see on satellites.

Poly/Multicrystalline modules are second in line. They are cheaper than single crystal, but run at 9-14% efficiency. They are the blue colored panels you sometimes see.

String ribbon modules are fairly cheap and are 7-8% efficient.

Thin Film (Amorphous) modules are a thin layer of silicon deposited on top of steel or glass. They are cheap to make, but their efficiency is very low (5-7%). This is what they use in solar powered calculators.

Solar modules are rated by wattage output, more accurately peak watts (STC). These are based on laboratory conditions, and real life results will tend to fall short of these. Plan for an 80-90% output of the STC.
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ON-GRID AND OFF-GRID SYSTEMS*
There are two options for the surplus energy produced- a grid connect system and a standalone system.

A grid connect system works like this- during the day, solar panels produce electricity, supplying all of your energy needs. All surplus energy is fed back into the grid, for which your energy provider pays you. This is commonly known as a Feed in Tariff. During the evening, the grid supplies your household's energy needs. In this manner households can greatly reduce their energy bills, sometimes even turning a profit when the energy they feed to the grid exceeds the energy they take from it.

A standalone system is designed to be independent of the gird. The surplus electricity generated during the day is fed into storage batteries. The system should be designed so that enough energy is collected during the day to supply the energy needed for the evening. A backup generator is an extremely good idea for such a system, to supply power in periods of very high demand or extended cloudy weather/winter months. Where overall performance is the focus of a grid connect system, in a standalone system daily energy generation to meet your needs is critical.

*THE COST OF SOLAR PANELS*
A PV system tends to cost a lot up front, and pay for itself over the years. Costs are always changing, and there are a ton of factors involved- how much direct sunlight you receive, the cost of the system, the efficiency of the system, how much energy your household uses, installation costs, etc. It would be silly to give any specific figures, but as a general range systems tend to cost in the $7500-$25,000+ range depending on various factors. An average household would probably be looking at just over $10,000 for having a system installed, as of the time of this writing.

Off-grid systems tend to cost significantly more, because they're required to produce more power, and have battery systems/back up generators that must be included as well.

There are various incentive programs to make solar energy cheaper. In the US there is a federal tax credit that will rebate 30% of your overall system and installation costs. There are also various programs at the state level (check out this site to see what your state offers: DSIRE: DSIRE Home).

All in all, in most cases it will take 10-20 years for the solar panels to pay for themselves. But considering some are guaranteed for 30+ years, it's not a bad investment at all.

*SOLAR WATER HEATERS*

A good first step into the world of solar power would be solar water heating. The systems cost less over all, and will pay for themselves quicker. They're the low hanging fruit of energy independence, especially if you live in warmer, sunnier climates.

A solar water heater will generally cost $2000-8000 US, and can produce 50-90% of your daily hot water energy needs, depending on the efficiency of the model. This usually leads to a 10-20% reduction in your overall energy bill, and the solar water heater will usually pay for itself in 5-10 years. Again, a very solid investment when many models are guaranteed for 30+ years.

Solar water heaters are also subject to the Federal tax rebate plan (30%) but only up to $2000.

For the more industrious of you, I've got a DIY solar water heater primer on my site to get you started (DIY: HOW TO BUILD A SOLAR WATER HEATER FOR YOUR HOME | Prepared For That)

Anyway, I hope this is helpful to some of you.

Glad to be a part of the forums!

Cheers,

RamboMoe


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## cantinawest (Nov 9, 2011)

*Basic, entry level cost of using Solar*

Greetings,

If I may, could I suggest that Solar Cooking is also a great way of taking advantage of the sun's energy. In fact, I would suggest that it is the most economical form/method of taking advantage of solar power when you compare the cost of a home made solar cooker or even a manufactured solar cooker to most of the solar powered equipment available to the public.

I have nothing against solar photo voltaic panels, solar water heaters, generators and such, and most people would love to have those items, but many are not financially able to do so.

Solar cooking though is so easy to do and is very effective with the proper tools.
If, I could share some basic solar cooking information, on our website, I think it would give a great starting point for those who are looking for a great alternative to traditional cooking methods. With Solar Cooking it's all About Great Food, Naturally!


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## RamboMoe (Dec 16, 2011)

Cool, to be honest I have never even heard of solar cooking before. I'm reading the article you posted and am going to do some research on it. Thanks!


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## The_Blob (Dec 24, 2008)

This is the type I make out of discarded water heaters, so that I'm sure to not run out of hot water.


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## RamboMoe (Dec 16, 2011)

@The Blob:
That's batch collector style, which uses a simpler ICS system (basically the water tanks and collectors aren't separate, but are the same). 

Curious, do use a pumping system to move the water, or is natural convection enough? I've heard mixed things on whether the force of convection is powerful enough to keep the water moving in most passive systems.


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