Saturday, July 24, 2010

Solar Power Guide

1. I keep hearing about renewable energy. What is it?Renewable Energy is energy created from resources that cannot be depleted e.g. solar power.Fossil fuels are non-renewable energy since coal or oil will at some point run out.Renewable energy does not produce as many greenhouse gases and other pollutants as fossil fuels.


Renewable energy accounts for about 14% of the world's energy consumption, but the technical potential is large enough to cover many times current and several times projected energy consumption in 2100. Technologies such as solar power are substantially more expensive, although future costs may decline to a fraction of current levels.Source: wikipedia 2. I've heard there are many types of solar power available. What are they?Solar energy can be applied in many ways, including:Generate electricity using photovoltaic solar cells.Generate electricity by heating trapped air which rotates turbines in a Solar updraft tower.Heat buildings, directly, through passive solar design.Heat foodstuffs, through solar ovens.Heat water or air for domestic hot water and space heating needs using solar-thermal panels.Heat and cool air through use of solar chimneys.Source: wikipedia 3. I live in a very cloudy country with a poor amount of sunlight (the UK!). Surely solar power doesn't work?Once again this depends upon the type of solar that is being utilised.If you use sunlight to heat pipes on your roof for hot water for your house, then this process is less dependent on the actual amount of direct sunshine but more on the ambient temperature of the environment.If you are using solar energy to create electricity, then a lack of actual sunlight will affect the amount of energy produced. A cloudy day will definitely produce less electricity than a sunny day.Also, the position or latitude of the part of the UK you live in will make a difference.We all know that Glasgow is colder than Cornwall. This is because of the position of those places on the earth with regard to the sun (see the MET Office website).


In summary the UK receives between 600 and 800 hours of sunshine during the summer months and 100 to 250 during the winter months. Probably more than you would think.If we take the assumption that we get about 1300 hours per year!Based on that very rough estimate, you could say that a standard 65 Watt solar panel would generate 1300 x 65 = 84500 Watts and that's just the sunny days!Electricity generating solar panels will generate electricity based on light and not just sunshine.There are a number of different solar panels manufactured with different tolerances and light wavelength conversion. SunnyTronic recommends Suntech solar panels for best light to electricity conversion in the UK. 4. I want to reduce my electricity bill or "carbon footprint". Does solar power help?Well this is a difficult one.If you use electricity to power your home, then the chances are it is fuelled by coal or oil from the power station. If you have hot water in your house, then you will more than likely use gas to heat the water.Oil, gas and coal are not renewable energy sources and cause carbon dioxide gas (the un-burnt dark smoke) to be put into the atmosphere when they are used to fuel our lives.Solar power, along with other renewable energy sources all help to reduce the amount of carbon released into the air.Of course there are issues with solar power because we must manufacture the solar cells in the first place, which requires energy. That is why we must measure the benefits of solar power for the life of the solar cells (the square blue bits on the solar panels). This solar cell life is usually long enough for the solar cell to produce more renewable energy than the non-renewable energy it took to produce the solar cell in first place. This means you will have helped reduce the carbon output.


As for reducing your electricity bill. It depends upon:- How much electricity you use.- How many daylight hours you get where you live.- How much power your solar panels can output.


Your electricity bill is measured in UNITS. One UNIT is one kWh (kilowatt-hour).One kWh = one Watt of electricity used over one hour.The term watt (symbol: W) is the SI derived unit of power, equal to one joule per second. (source wikipedia).


To calculate any useful savings you need to know how many UNITs you use in one year.In the UK we have an average of 4 hours sunshine every day. We will use this as the basis of our calculations since it is not as much as it would be so we don't give you too much optimism but you should expect a higher output than this.Basically, one 65 Watt solar panel if it worked at optimum performance for 365 days of the year would produce 65 x (365 x 4 (hours sunshine)) = 94900 Watt-hours per year.Therefore 94900 Wh / 1000 = 94.9 kWh or 94.9 UNITs.Based on my current electricity bill average, I pay 8 pence per UNIT. Thus I would save 94.9 x 0.08 = 7.50. This is a very very under estimated value to ensure we don't give you the wrong impression! 5. How do I calculate my electricity usage?Your electricity bill is measured in UNITs.1 UNIT = 1 kilowatt-hour of electricity (kWh).I normally pay about 8p per UNIT on my electricity bill.If I use 800 kWh (or UNITs) it will cost 800 x 0.08 = 64.00I run my computer which uses 100 Watts of electricity (it says so on the bottom of the power supply).If I run my computer for 24 hours a day every day of the year I would pay:


100 Watts x 24 hours x 365 days = 876000 Watt-hours or 876 kWh (876000 / 1000) or 876 UNITs.Thus 876 UNITs x 0.08 = 70.08 ex VAT.


Now you need to do this for real for all your appliances based on the real Wattages and the amount of hours you use them each day and use the real amount you pay per UNIT on your bill. 6. Now I know how much electricity I use, how can I calculate the size or power of the solar panel or device I need?This is your personal preference.How much energy would you like to save? or how much can you afford to spend up-front?Investing in solar power is exactly that. Investing.The only returns you get straight away is that less CO2 is being released because you are using solar.Gradually over time, you will have reduced your energy bill and as the years go by you will at some point have saved more than the cost of the solar panels.Your electricity bill gives you all the information you need to see how much electricity you use over one year. Don't forget that 1 UNIT = 1 kWh of electricity.


If I use 2000 UNITS of electricity in one year, I am using 2000 kWh.So I need to generate 2000 kWh via solar panels if I don't want an electricity bill.This would mean I need 21 x 65 Watt solar panels (see answer to question 4). That's a lot of roof space and about 5,000 to pay for the panels.


As you can see, the amount you need is down to you but it's nice to know you are doing something. 7. But solar power seems so expensive, surely it's a scam?This is because solar panels are expensive to produce.The techniques used require a very specific manufacturing process to ensure that the crystals within the panels are of the best quality.Until this cost is reduced, they will remain expensive.Various companies are experimenting in trying to use new materials or combinations of materials that will produce a more efficient conversion of sun light to electricity.At the moment the most efficient ever produced has been in a science lab. They managed 40% efficiency. This is more than double that of today's existing methods.The more efficient the panels, the smaller the area required and the less material. This will then hopefully make them cheaper to produce. 8. OK so I like the idea of "free" power, what's next?There are various different ways that you can have your solar power.From small devices like our Solar Charger that can provide power for electronic gadgets, to gadgets that actually incorporate their own solar panels.Even something like a solar security light can be saving 100Watts of power.For your home you can have a grid-connected system that feeds any extra electricity you don't use back onto the electricity grid. The electricity company will then give you credits that will reduce your own bill.You could set-up an off-grid system that is connected to an array of large batteries.This will store the electricity which can be used in the evening (when the sun is not shining).Both of these types of systems require careful planning to ensure that you are going to meet your expectations for the system that you want.


Contact us for further information: info @ sunnytronic.co.uk

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