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Basically there are two kinds of solar panels. Solar collectors which heat the water and then there are photovoltaic solar panels which converts solar radiation directly to electricity. Both systems use completely different technology and they are related only because they’re using sun as a source of energy.
Solar collectors (or solar thermal panels) as mention above are used to heat water. Basically it’s a area where water flows on the flat plate or in tubes and solar radiation is used to heat up the water. There is a layer of insulation and often a black absorber plate to make sure that the most of radiation is used. When the water is heated then it’s stored in boiler for further use.
Solar collectors could supply you very large amount of your annual heating needs for a very interesting price.
Photovoltaic panels on the other hand converts solar radiation directly to electricity. The technology is more advanced and materials are more expensive.
A single crystalline silicon PV cell typically produces a voltage of about 0.5V at a current of up to around 3A which is a peak power of about 1.5 W. So to cover your electricity needs you would need a lot of cells.
Photovoltaic is a very interesting topic to which we will return many times in the future.
In the following days and weeks, many of us will take out the Christmas lights from the last year and you might notice that the bulbs are broken and there are no spare bulbs to replace with. So, you decide to buy new ones. But before you do that, let’s spend a little time on thinking.
There are several options you have.
Option 1 - buying new lights with standard bulbs
Option 2 - buying LED lights
Option 3 - not buying new lights at all
As you can see there is no option with no cons, but some have more cons than others
PS: We’ve chosen an option 2 because we want light, no heat (95% of energy in standard bulb is emitted as heat) and we don’t want to buy new lights every second year.
Many people are afraid that wind turbines kill a huge number of birds. Opponents of wind power often use this argument to stop development of wind farms but is it really the true?
It is estimated that each year in the USA
In comparison each wind turbine kills 0 - 2 birds per year at worst.
Global Wind Energy Council (GWEC) figures show that total installed wind energy capacity in 2006 was 74,223 MW
Let’s say that every wind turbine has a capacity of 100kW (usually they have more - even over 1500kW), it gives us around 742,230 wind turbines worldwide.
Let’s count with the worst scenario - 2 killed birds per turbine per year
Wind turbines kill 1,484,460 birds worldwide annually
Let’s have a look at the list above again and bear in mind that those numbers are only from the USA.
Alright, you’d like to buy a photovoltaic panel or even several of them to reduce your electricity bill and to lower pressure on the environment but where to start?
First, you should decide how powerful panel you need. Let’s say that you need to power 100W appliance. If you buy a 100W panel will it really deliver 100W? Actually, it’s a bit more complicated. Solar radiation varies from place to place, fluctuate under different weather conditions, etc.
It was necessary to create a standard how to label photovoltaic panels and it was agreed that their output will be measured under these conditions:
How can you find out how much solar radiation your area receive? There are maps which will show the average annual solar radiation. Below is a map of Europe.
From the map you can easily find out the 100W panel will produce around 200W in the South of Spain but only around 60W in the Iceland if the panel is facing South and is under the right angle.
Also check how efficient the solar panels are because some panels are more efficient than others. They could vary from around 10% to 20% so you would need twice as big surface of 10%-efficient panels than you would need with 20%-efficient panels. It means that the cheaper 10%-efficient panels could cost more in comparison with delivered power.
Many people still use standard incandescent light bulbs. A product which was introduced 120 years ago, converts only 5% of energy to light and lasts only 1000 hours.
Tip: Change all your light bulbs to energy saving ones.
No matter if you use CFLs or try LEDs, both will consume much less energy than incandescent light bulbs. Also note that incandescent light bulbs will be probably banned soon (at least in EU and Australia).
We also don’t want to hear excuses that you cannot afford buy them because they are expensive. Detailed calculation on our eco forum tells completely something different, just have a look.
Some might complain that CFLs contain mercury which is also harmful to the environment, that is true and you’ll need to recycle old CFLs properly. But mercury emitted from power plants during generating electricity to feed your incandescent light bulbs could be even higher as you can see from the diagram below.
There are various shapes of CFL light bulbs including candle light shapes so nobody can complain that there isn’t their type available. Also various light colours can be purchased. So just choose which colour you like the most.