Tag Archive | "solar panels"

How Does Temperature Effect Solar Panels

One common question that many people have when buying a solar system is how temperature effects PV solar panels.  I used to think that when the weather was really hot, it was great for the solar panels, and should mean more electricity is being produced.  But that is not so much the case.  For each solar panel there is a specific temperature which is ideal for making electricity.  And it turns out that solar panels will be “more efficient” when the outside temperature is colder than 100 degrees, and closer to 50 degrees or even less.

The next logical question that most people should have is, How much does temperature effect efficiency? The answer is NOT VERY MUCH.  Infact, the effect that temperature has on the production of PV solar panels is so small that it is rarely talked about and pretty much forgotten as something to be concerned with.For the average homeowner who is buying a solar system, temperature will not be on the list of things to review.  For a large corporation that is deciding between which warehouse to place their multi million dollar PV system, they may consider the roof temperatures of various locations they are considering.

The major factors to consider with regards to having maximum output of your solar panels is shading, angle towards the sun, and making sure the solar panels strings are sized properly with the inverter you are using.  If you really want to optimize the output and efficiency of your solar system, take some time and ask your solar professional some questions about panel temperature, and what types of ideas he/she has to minimize the negative affects that temp can have.  One common practice it to have an airspace between the underside of the panels and the roof, this allows for venitllation of air and tends to keep things cooler during hot summer days.

Good Luck with your solar panels!

Here is another link about shade and solar panels

Posted in Solar EquipmentComments (0)

Solar is a longterm plan right?

Is Solar the Right Thing to Do, quick answer is yes.

But, this is a rather loaded question.

After being involved in the residential solar energy field for quite some time now, I thought it would be beneficial for me to put together some information for the typical homeowner who is considering going solar.

There are many different things to think about before getting a solar professional involved ( they are sometimes referred to as “installers”).

Here is the first question everyone should ask themselves: why am I looking into solar right now, what are my reasons for wanting solar power?

Once you have asked yourself that, and come up with some answers that are true answers, you can begin to find out if solar is a good idea for you.

Let us get right to the point,
in the hundreds of interested homeowners I have talked to over the year, everyone wants to know what the investment in solar looks like. Before breaking into other points about solar, let us address the costs and returns you can expect from a solar system.

Please realize that if you are the type of person who is currently having a hard time paying your electric bills, car payments, mortgage etc… solar is probably not going to be possible until you have some more disposable cash. Systems usually run between $20,000-$40,000 prior to any incentives. After incentives, the systems can cost quite a bit less, but you are still going to need to find many a thousand of dollars.

If you are still with us here, let me tell you some of the bright points of solar. It lasts a very very long time, systems should be on your roof working well for over 25 years. That is one of the most important things to realize, they will be with you longer than most of your neighbors!

What Size Solar System is right for you? It depends on what percentage of your electric bill you want to have covered by solar.
Also, it depends on how much available space you have, you may want to cover all your electricity with solar, but if you only have enough space to cover half, then there you are… For the purpose of getting you on your way to understanding a solar system’s size, I will assume that you have good access to the southern skies, and no shading from trees or other buildings.
Here is the math:
take the total number of kilo watt hours you purchased from the utility company the past twelve months. That number will be your kwh annual total. Next take that number and divide it by 12 to get your monthly average.

Next, take that number and divide it by 30 to get your daily average.
So this number is the number of kwh’s that the solar system would need to produce on average per day per year to meet your 100% needs.
At this point to figure out exactly the size system you need, we would need to know your location on the planet, as that will dictate how many sunlight hours you receive on average per day per year. This number is between 3.5 to 7 depending on where you are in the country. These hours are hours that the solar panels can operate at optimal efficiency, you may think you have 15 hours of sunlight some days of the year, and you do, but all sunlight hours are not created equal. For example, when the sun is coming up in the morning, it does not operate the panels at 100% efficiency. Take weather changes, clouds, and seasonal differences, and you will be between 3.5-7.

Back to the math,
to get the system size you need, take your daily total kwh use and divide by average daily sunlight hours. That will end up being the output the Solar System will need to have per hour in AC (Alternating Current) per hour to meet your 100% electric needs. Since Solar Systems are in DC (Direct Current) you should multiply the number you just got by 1.2 to bring your system size to a DC number. This is the system size you would need to meet your electric needs. What would something like that cost? Well, right now, the national average for residential Solar System installations (grid tied PV systems) is just about $7.00 per watt prior to incentives. That would mean that if you came up with a number of 6 from the math above, that would equal 6000 watts, and when multiplied by $7/watt you are at about $42,000 for that size system after shipping and installation.

Because the initial investment in Solar Power Systems can be expensive, it is feasible to think about the ways in which the costs can be reduced. If a person is technically oriented or very good at home improvement, it is possible that they might consider building their own solar system. The amount of electricity or heat that can be generated is directly influenced by the wattage of the solar panels, as well as by the intensity of the sun light that touches their surface. First, of course, it would be important to learn how solar panels work, what materials are required, the cost of the raw materials and the availability of them, and finally the difficulty involved in assembling and installing them. In the long run, will your effort be rewarded with a solar system that will serve you for a reasonable period of time?

Posted in Saving MoneyComments (3)