Solar Power for Houses: Your Residential Solar Power System

There are now many types of portable solar equipment available.  They range from the truly gimmicky to the sensible. From hats with a solar panel and fan for cooling your head to  solar powered calculators and portable solar charging systems.  Keeping track of what’s out there can be a challenge.

Portable Solar Devices:

Some of the solar powered items for sale on the Internet include halogen lanterns, hats with fans, Christmas lights, radios, portable refrigerator/freezers, battery chargers, bags, outdoor lighting of almost every description, rodent repellers, children’s toys and others.  Examples of such things for sale can be found at solarhut.com, as well as many other places on the internet.  Many solar objects are new designs or are being made by companies without a long reputation in the field.  This means that while there is a wonderful selection, the quality is rather variable.

Portable Solar Charging Systems

Portable solar charging systems are much more practical than they used to be.  Many of them make use of technologies like thin film photovoltaics so that they can be folded up and packed away when not in use.  For people like backpackers, this means that you can stick your solar panel in your backpack and have power wherever you go.  There are also battery chargers that are part of bags or backpacks.  A review of such an item can be found on treehugger.com. On a somewhat larger scale, solar panels are also used on boats and RVs to power appliances and charge batteries.

Solar thermal and solar photovoltaic power are similar in that both use the sun as an energy source, and both are renewable. However, there are quite a few differences between them, including price, type of energy output, and the things that energy can be used for in your home.  The table below should give you a good idea of the pros and cons of both types of solar power.

Prices are global average for July 2009 and are US denomination. They exclude rebates your government may give. They assume the system is grid-tied.

http://www.solarbuzz.com/solarindices.htm

Solar pool heaters are the most common use of solar thermal technology in North America.   This is because they are extremely cost effective: a solar pool heater will typically pay for itself in 2 to 3 years (Can. Solar Industries). Even without considering the savings in greenhouse gas emissions, solar pool heaters make a lot of sense.   The total price of solar heating a pool is usually $3,000-$4,000 US including installation, but can range from $2,500 to $7,000 US (Costhelper.com).

Solar hot water panels used in pools are flat plate collectors. They are usually made of rubber or black plastic and are a very simple use of solar thermal technology compared to solar water heating systems for drinking water.

The solar hot water panels are usually about 50% of the pool’s service area.  If a pool is indoors or is not in direct sunlight, a larger area of solar heating panels must be used to reach the same temperature.   A pool cover should be used at night to reduce heat loss.  If you don’t use a pool cover, you’ll need to install twice the area of solar hot water panel.

While solar pool heaters make excellent sense for swimming pools, they don’t work as well for hot tubs.  The water temperature can be raised high enough using metal collectors used for heating domestic water, but if the jets in the hot tub are used, the water will swiftly cool down again.

Sources:

Canadian solar industries association.  Solar pool heating overview.  Retrieved June 20, 2009

Costhelper.com

Residential solar pool heating systems: a buyer’s guide 2001 retrieved June 20, 2009

In climates where there are freezing temperatures, the water in solar hot water panels is in danger of freezing.  No hot water is produced when this happens, and it’s possible that the panels or piping could be damaged when the water expands as it freezes.   However, it’s perfectly possible to get solar  hot water in a cold climate – even during the winter.

The most common way to prevent the solar hot water panels freezing is to use glycol-based solutions in the panels. This requires a closed loop system where the heat is transferred from the glycol solution into the water you use in your house via a heat exchanger.   These systems are more expensive than simpler systems, but they are much more resistant to freezing and can continue to produce heat through the middle of a cold winter.   You will probably want a tankless hot water heater as backup because they may not produce enough for your needs when there are long spells of cloudy weather, but they will still produce hot water.  Both active and passive heaters can be outfitted with glycol so long as there’s a closed loop system.

Four-Season Solar Thermal Systems

Glycol-based solutions are typically used in active solar thermal systems, but they are also used in some Thermosyphon systems.  In order to use glycol in a Thermosyphon system, it must be a closed-loop system in which the solution in the solar thermal panels does not mix with your household water supply.  The glycol acts as antifreeze, preventing the pipes from freezing.  These solutions are typically 50/50 glycol and water.  Active glycol systems tend to be expensive, but they are considered the best choice for very cold climates.

There is one type of water-based system that can be used in frost-prone areas.  This is the drainback system, which does not easily freeze so long as the piping is sufficiently inclined so that drainback can occur quickly.  However, I suspect that this system is less tolerant of extremely cold temperatures for long periods of time than a system that uses a glycol fluid.

Three Season Solar Hot Water Systems

It is also possible to use a very simple system such as the batch heater during the summer and drain it during the winter.  You will get no hot water from it in the winter, but it should still be usable the next summer.

As you can see, there are several choices of thermal hot water systems for homes in a cold climate. Whether active or thermosyphon glycol, drainback or summer-only batch, there is probably something available that will fit your needs and pocketbook.

Sources:

US Department of Energy. Energy Efficiency and Renewable Energy. Energy Savers: Solar Water Heaters. Retrieved June 19 2009

Homepower.com. Retrieved June 19 2009

Build it Solar: solar water heating. Retrieved June 19, 2009

To create hot water using solar thermal energy, the sun’s heat is used to heat water directly without converting it into electricity.   The most common use of solar hot water in North America is heating swimming pools, but solar thermal’s potential goes far beyond this.

Solar thermal is commonly used for water heating and for heating houses.  The cost of heating by a solar thermal system is usually lower than the cost of an equivalent amount of electricity supplied by photovoltaics because solar thermal is on average 3x more efficient at converting the sun’s heat into energy, although the savings depend on the type of solar thermal technology used.  Solar thermal systems are also low maintenance.

Types of Solar Water Heater

1) Collector (solar hot water panel) Types

There are three main collector types: flat plate, batch, and evacuated tube.  Evacuated tube technology is generally more expensive than flat plate and batch because it is mechanically more complicated.

2) System Type: Passive or Active

Active systems include a pump; passive systems do not.  Passive systems are less expensive and may be more reliable but are less efficient (Energy Savers: Solar Water Heaters).

Passive Solar Water Heating

Batch Heater

A batch heater is the simplest type of solar water heater available.  They are also sometimes known as breadbox heaters, since the tank of water on the roof is often about the size of a breadbox.  If you wish to build your own solar hot water system, a batch heater is probably your best bet.   Being water-based, they are not suitable for winter use in climates where freezing weather can be expected.  They also have the disadvantage that hot water cools overnight and usually isn’t hot early in the morning.   The Florida Solar Energy Center has a free set of plans and instructions for building one, which can be found here.  They give the materials cost as being US $70.00.

Thermosyphon

This design tends to be more expensive than batch heaters.  However, because there is an insulated storage tank hot water is available at all times of the day or night, unlike the batch filter.  This design is actually the world’s most popular solar water heater (Homepower.com).  It may be closed loop or open loop.  If it is a closed loop system, glycol can be used.  This modified design is suitable for using in climates with freezing temperatures.

Active Solar Water Heating

Drainback Heater

This type of heater is more complex, being a closed loop system where the water in the collector does not mix with the house’s water.  A heat exchanger is used to move the heat from the liquid in the collector to the house’s water.  Like most active systems, it is more expensive than a batch heater.  On the other hand, this system can be used in the winter in climates with freezing temperatures if the pipes are adequately sloped to ensure drainback occurs quickly.

Glycol-based Solar Thermal Systems

Systems containing glycol are primarily used in areas which have freezing temperatures during winter.  This is because they continue to work and provide hot water during such weather, unlike most systems that use water.  Water-based systems may also suffer damage when the collectors freeze that will then need to be repaired.  Glycol-based systems are more expensive than systems that use water, but in a cold climate this disadvantage is outweighed by their resistance to freezing (Homepower.com).

Overall, solar thermal hot water is a technology that is economical to install and run by renewable energy standards and can be used almost anywhere.  It has excellent potential for home use and should be perhaps the first alternative energy technology considered by a homeowner wanting to reduce dependence on the electricity grid.

Sources:

Build Your Own Solar Batch Water Heater. Florida Solar Energy Center Retrieved June 12, 2009.

http://www.builditsolar.com/Projects/WaterHeating/FSECFS36Batch11349.pdf

US Department of Energy. Energy Efficiency and Renewable Energy. Energy Savers:Solar Water Heaters. Retrieved June 12 2009

http://www.energysavers.gov/your_home/water_heating/index.cfm/mytopic=12850

Homepower.com

http://www.homepower.com/basics/hotwater/

Increasing energy conservation and energy efficiency are the most cost effective ways to reduce the amount of money you pay for energy.  Before you invest in alternative energy sources, you should check that your house uses as little energy as possible while still allowing you the lifestyle you want.   Of the two approaches, the simpler is energy conservation.

Energy conservation involves using less energy by doing things like turning off the lights when we’re not in the room.  There is no upfront cost to such actions, although they do typically require behavior changes.

Ways to reduce your power use through energy conservation

• Turn all lights out when you leave the room
• Set your computer to fall into hibernation mode when it is not in use
• Unplug appliances when not in use, or get a power bar and turn the power bar off at night
• Buy a timer for your home’s thermostat so that your home will be warm when you’re home and moving about and cooler at night and when you’re at work
• Turn your home’s thermostat down a couple of degrees Celsius and wear a sweater – presuming your home is not leaky enough that you’re wearing a sweater anyway and freezing cold besides
• Turn the TV off if you’re not watching it

Basically, if you aren’t using it, it shouldn’t be on.

Energy efficiency involves using appliances that can do the same amount of work with less energy.  It does not involve you changing your daily behaviour.  The classic example is replacing incandescent lighting with compact fluorescent, but it goes far beyond this.  The largest use of electricity in many homes is heating.  By insulating the house, the amount of energy required to heat the house is reduced.

Cheap ways to reduce your power use through energy efficiency

• Replace incandescent bulbs with compact fluorescents
• Insulate your hot water heater
• Insulate your hot water pipes
• put plastic film over windows during winter

More expensive, but very useful

• Buy an energy-efficient refrigerator if your current fridge is more than 10 years old
• Insulate your ceilings, walls and floors
• Replace single-glazed windows with double or triple glazed windows

Of course, if you really want to increase energy efficiency there are a variety of methods for passive solar heating, but that is beyond the scope of this article.

When you install that new appliance…

I once lived in an apartment where the landlord had replaced all the windows with new windows that were supposed to be much better insulated and lose less heat.   However, he had installed them badly and there were gaps between the windows and the frame.  One of the gaps was so large you could see right through it to the outside.   Because of this, the house would not stay warm despite the new windows and the landlord complained about his energy bills to us.  Meanwhile, we complained that we were always cold.

This shows the importance of installing new energy efficient objects correctly.  If installed incorrectly, the object may well work badly if it works at all, and you may have done a lot of work and spent a lot of money for no energy savings.  So do it right the first time!

Pros

The most obvious advantage to solar energy is no operational carbon emissions.  Other advantages include reduced dependence or even complete independence from fluctuating energy markets and efficient power generation in areas that do not have access to a power grid.  In areas that do not have access to the power grid, it is frequently cheaper to buy a photovoltaic system than it is to pay to extend the grid, or to buy and run a diesel generator.

While energy prices have gone down recently with the global recession, it is unlikely that they will stay down.  When the economy improves oil prices will likely go back up, and energy prices in general will probably follow.  Once your solar panels are set up, the vast majority of your costs have already been paid, and rising electricity prices will be something that happens to other people.

In certain areas of the USA, there are programs that will let you lease solar Grid-tied Systems. This eliminates the high start-up cost problem if you are lucky enough to live in one of those areas.

Cons

There are also disadvantages to solar photovoltaic power.  Solar energy requires sunlight.  Photovoltaics do not produce power at night, and the amount of power they produce on cloudy days is much reduced from what they produce in sunlight.  They also produce more electricity during the summer than in the winter.  This is an advantage if your air-conditioning bills are higher than your heating bills, but in colder climates this is a disadvantage to solar power.  In climates with many cloudy days, power output is reduced from its full potential, which means that your initial investment takes longer to pay back than you might expect from tests in Spain or California. 

Purchasing and installing a solar system involves a substantial outlay of capital.  Prices for solar photovoltaic sytems are falling, but the cost is still prohibitive for many people.

Sources:

Home Power Magazine http://www.homepower.com/home/

Solar Photovoltaic Cost and Price Trends Retrieved May 16, 2009 http://www.solarbuzz.com/StatsCosts.htm

The exact pros and cons of photovoltaic solar power depend partly on whether you have a grid-tied system or an off-grid system.  So, what exactly are those pros and cons?

Off-grid Solar

Off-grid solar systems require substantial maintenance because of the battery banks necessary for storing electricity.  These batteries require occasional replacement and can be a fairly expensive investment on top of the solar panels.  However, if you live far from the power grid it can be far cheaper to have a solar system than to pay for connection to the grid.  Also, if the grid goes down your power source will not be affected.

Grid-tied Solar

Grid-tied systems without battery backup are the cheapest to set up for most people.  They do not offer any protection if the power grid they are tied into goes down, but they do offer the possibility of selling excess power to the local power company provided that the power company is set up to accept that.  This should be checked before you set up a Grid-tied solar Power System.

Grid-tied Solar with Battery Backup

It is also possible to set up a system that is Grid-tied but has a backup battery bank.  This is considerably more expensive than the standard batteryless Grid-tied System, but it means that if the grid goes down you will not have a power outage due to that failure.

In the end, which system is best depends on your needs and how you plan to use your photovoltaic array.  Photovoltaic power is not a one size fits all technology, and while the array of options in systems can be confusing, at least it gives you a good chance of obtaining a system that suits your needs.  More information on solar power and photovoltaic systems can be found at http://www.homepower.com/basics/solar/, as well as many other places on the web.

It is hardly surprising that with the growing interest in renewable energy sources, there is a corresponding growth of interest in people wanting to enter the solar jobs space. The area of solar energy is one that is proving to be particularly attractive, and is one that has expressed a growing demand for qualified and capable personnel to enter its workforce.

All of these developments have naturally given rise to the question of what training and certification requirements are needed for those who are looking to build a career in the solar energy industry. The obvious place to start is the training courses offered by both traditional learning institutions and technical and vocation organizations. These venues in particular have subsequently experienced a huge increase in the number of people interested in taking solar education courses.

This is a fairly logical turn of events since the gap between environmental and economic concerns is ever narrowing in the face of the need to develop alternative energy sources such as solar energy. The fact of the matter is that the rise of environmental technologies will result in the development of environmental jobs and �green� jobs, and students are becoming cognizant of this fact.

In fact, the high demand for solar courses has resulted in certain learning institutions being forced to place applicants on a waiting list. While this is a need that definitely has to be addressed in order to supply the personnel demands of the solar energy industry, it is a positive indicator in that it points to the fact that more and more people are interested in entering the field.

For those who are not able to get into any of the solar courses, further training options can be found in local community colleges, many of which have begun to offer courses directly related to renewable energy. Many of these courses offer the advantage of being taught by professionals that actually work in the areas of solar energy. Furthermore, community colleges also typically offer courses in electrical theory and construction, which provide just as much valuable training as specific solar courses�such as photovoltaic training for example�for someone who is looking to get a start in the solar energy industry.

It is interesting to note that while many professionals that currently work in the field of solar energy have earned their qualifications from traditional learning institutions�that is through regular degree programs and professional training programs in science, engineering or related disciplines�many of them have picked up the actual skills required by the job through direct, hands-on experience. In fact, there is a considerable number of professionals in the renewable energy industry that have developed the bulk of their skills and qualifications by way of solar training programs provided by their employers, even those that have previously worked at similar jobs in related fields.

A considerable number of the workers in solar energy field are experienced construction workers who have undergone apprenticeship programs. These solar education programs are either offered by trade associations or by vocational schools and community colleges, and they may last anywhere from a few weeks to a year. Applicants that manage to successfully complete these solar education apprenticeship programs are given a certificate of completion. These courses typically offer instruction in solar electrical system installation, system maintenance, and solar panel retro-fitting, and may even be applied for by high school level applicants that want to learn how to install or repair solar systems as a means of breaking into the solar energy industry.

While the people who work in the solar energy industry will likely continue to benefit from actual on the job experience for the foreseeable future, an increasing number of the future workforce will enter the field already possessing knowledge and qualifications that are specific to the field of solar energy. These individuals will be particularly suited to positions in the solar energy industry wherein relevant qualifications are more essential.

Those who are looking to become solar electrical system installers will greatly benefit their careers by obtaining certification through a program that is overseen by North American Board of Certified Energy Practitioners or NABCEP. While relatively few industry practitioners have earned their certifications through this program since it was established in 2003, the number will likely increase in the future as the program is implemented as an industry standard.

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Solar Training, Solar Energy, Renewable Energy
Education-Boots on the Roof.

For additional information on solar training courses, please visit Solar Training Boot Camps at
Boots on the Roof.

Article Source: Populate.net

Solar power and “green” building has become a focus in the construction market for several reasons. With the steady climb of energy prices, along with a decline in the price of solar installations, solar living has become a topic of interest for more than those that live in rural areas, or those looking to save the environment. Solar energy has become a viable alternative energy source, and the rates of both commercial and home installations are rising dramatically.

Who can use PV (Photovoltaic) training or solar courses?
People from all walks of life could benefit from solar training. Anyone interested in renewable, sustainable energy sources are good examples. Due to the expected rise of needed manpower in the solar industry, however, reasons other than the environment should compel others.

Already, the solar industry has discovered a skills gap in solar training. Those that know how to install photovoltaic arrays, develop other ways of harnessing solar energy, maintain the necessary equipment and several other areas are retiring � without the younger generation replacing them in knowledge and training.

Another area where the skills gap is showing is in “greener” building. Environmentalists, and others who just happened to notice solar energy is ultimately cheaper, are demanding energy efficient appliances, solar panels, rain catchers and any number of newer, more environmentally safe changes to their homes. As a builder without solar training, one may find themselves losing business due to lack of knowledge. With a little bit of time and effort, a general builder can turn into a “green” builder, with all the training and certifications necessary.

So how do you get involved?
As a “green” builder or solar installation provider, the first place to gather information would be your local homebuilder’s association. They’ll have information on solar product supplies, rules and regulations, and what’s need for PV certification. This is especially important, as each locality has its own regulations. They may not vary much from one to the other, but they do vary.

Training and certification is necessary. As a homebuilder using solar design, you’ll want to make sure that the finished home is certified as an energy efficient, solar domicile. For that to happen, you’ll need solar training and certification.

Likewise for solar installers. Each individual PV installation will be different, having its own requirements and sets of issues to overcome. This means that adding a PV system is not “plug and play”. Requirements and needs will have to be assessed, problems will have to be circumvented, and a custom solar installation will have to be designed. This is why PV training and certification is a must.

PV training and certification programs are readily available at our Boot Camps. Our programs are all NABCEP (North American Board of Certified Energy Practitioners) Approved. There are three types of certification; an Entry Level certificate, a Solar Thermal Installer Certification (solar heat), and the PV Installer Certification. To hold these certifications, you would be trained to design and install all types of custom solar solutions.

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Solar Training, Solar Energy, Renewable Energy
Education-Boots on the Roof.

For additional information on solar training courses, please visit Solar Training Boot Camps at
Boots on the Roof.

Article Source: Populate.net