This post is part of a series on installing solar panels for your home. Check out the rest of the series.


The idea of renewable energy has been around for decades. Only now are we starting to realize the power and potential of harnessing this energy and putting it to great use, especially in the home, to save money and start to save the planet.

 

Pros and Cons of Home Solar Panel Installation

For the home, solar power is the most accessible and sustainable renewable energy source available and much less noisy than a wind turbine. Of course, there are pros and cons of installing a solar power system in your home, some of which are further explained below.

The credit crunch is still hitting hard and, with times being tight, households are looking for ways to save money. One of the main and most important pros has to be, unlike conventional heating and electricity systems generated by fossil fuels, that once the system is installed, it runs for free. Additionally, little maintenance is required and solar panels rarely need to be changed. Even if you live in an area that is not necessarily a sun trap, the photovoltaic system does not require direct sunlight to produce energy. Unlike fossil duels, the Sun is also an inexhaustible energy source and will continue to shine well past our lifetime. For the conscientious reader this means you don’t need to worry about increasing prices as supplies diminish.

As with every decision you make, you need to look at both sides of the story and there are a few cons. The first of those is that initially, the installation can be costly – the savings come in the long term and the length of time it takes to recoup the cost will vary depending on where in the world you live. A solar power system can only generate electricity during daylight hours so you would need alternative power at night. Keep an eye on this though, as research and development is underway to find a reliable way to store the power generated throughout the day for use at night. Weather such as wind, rain and mist will affect the efficiency of the solar cells, so it’s worth considering your local climate.

The pros and cons are clear to see but let’s go into a little more depth to highlight all areas to think about before installing the system in your home.

 

Getting Financial Assistance

As mentioned, the main downside is the cost of setting up and installing a solar power system, so the first step is to look into Federal and State-level grants and incentives. It is worth checking with your local government body for specific benefits that will apply to you. Renewable energy consumers can apply for this money in the form of rebates, loans, grants and tax rebates from local utilities. DSIRE maintains a database of the majority of incentives by state.

The cost of installation has reduced in price over the past few years and will continue to drop as the technology becomes more established. Panel prices are just one financial aspect of a whole rooftop system; other components like wiring, converters and racking may contribute to up to half of the total costs so be sure to account for these in your budget.

Another factor to bear in mind is the type of roof you have as this can have a major impact on overall costs and panel prices. If the solar panels need additional support structures, this will increase their cost. The type and size of the photovoltaic system can also affect the panel prices. As with everything these days, the more you buy the cheaper the unit cost.

 

Choosing the Right Cells for You

There are two main types of solar panels to choose from, Monocrystalline and polycrystalline. Panels made from polycrystalline cells are the cheapest option whilst Monocrystalline is rapidly becoming the standard. The difference between the two is fairly simple; Monocrystalline solar cells are made from a single crystal of silicon whilst polycrystalline solar cells are made up of multiple crystals.

Monocrystalline has a lifespan of roughly 25 years although it is possible to get even more years of use out of it. It is, however, very fragile and as such needs to be encased in a rigid frame and set on a fixed mounting. Baring physical impacts, it shouldn’t suffer physical damaged once safely installed.

Polycrystalline panels are less efficient than Monocrystalline. As Monocrystalline solar cells are self-sufficient, they can continue to operate at their maximum output even if other cells around them aren’t receiving light. Efficiency in polycrystalline cells drops dramatically when even a relatively small percentage of them are in shade.

Both Polycrystalline and Monocrystalline solar cells suffer a reduction in efficiency when their temperature increases. Usually when the panel’s temperature reaches the 50° C (115° F) you will start to notice an efficiency drop-off. With Monocrystalline panels this will be by around 15% whilst Polycrystalline panels may suffer a reduction in efficiency exceeding 20% of nominal output.

Whilst Polycrystalline panels are cheaper than Monocrystalline the actual difference in cost per Watt of power output is negligible. This gives Monocrystalline panels a slight edge in terms of cost as with their smaller footprint and greater reliability you are likely to get more for your money in the longterm.

 

How Much Solar Power Is Available in Your Area?

The average US household can expect an average of 4-5 kWh per meter squared per day although sunnier regions have been known to achieve up to 8. Generally speaking, the further South West you are located in the US, the more solar radiation is available. Data on solar radiation in your area is available through the National Renewable Energy Laboratory. Find out the amount of space you have available and the average solar radiation in your area and you can work out approximately how much electricity you can potentially produce.

If you don’t fancy doing the math yourself, you can find solar calculators online which will factor in not only the average solar radiation in your Zipcode and available area but also factors such as the type of roof and which direction it faces.

If your installed solar system generates more solar power than needed, the extra power can be automatically sent to the utility. If it generates less, electricity will be drawn from the grid as usual. The rates paid out by utilities for power fed back to the grid in this way will vary by state, but it will contribute to the overall affordability and value of your solar power installation.

 

Average Savings

The exact savings are difficult to state and will vary on a case by case basis depending on the space available, the amount of solar radiation available in your area, your personal consumption levels and the cost of electricity in your state. According to the U.S. Energy Information Administration, the average price of electricity to residential users last year was 11.8 cents per kWh. Assuming an average of 5kWh per square meter per day of sunlight and a conversion efficiency of around 15% for a Monocrystalline cell, then a typical array of 10 2m2 panels will generate about 2740kWh of electricity a year, saving about $320 annually on electricity costs.

Ultimately, the cost of electricity in your region may be the biggest factor in deciding whether to invest in solar power or not. For example, all other factors being equal, if you live in Connecticut based on the above calculations you could save up to $500 per year whereas in Louisiana you might only save about $230.

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