Tag Archives: Residential

Understanding Solar Energy

Solar technologies are broadly characterized as either passive solar or active solar depending on the way they capture, convert and distribute solar energy. Active solar techniques include the use of photovoltaic panels and solar thermal collectors to harness the energy. Passive solar technologies are means of using sunlight for useful energy without use of active mechanical systems (as contrasted to active solar). Such technologies convert sunlight into usable heat (water, air, thermal mass), cause air-movement for ventilating, or future use, with little use of other energy sources. Active solar technologies are employed to convert solar energy into usable light, heat, cause air-movement for ventilation or cooling, or store heat for future use. Active solar uses electrical or mechanical equipment, such as pumps and fans, to increase the usable heat in a system. Solar energy collection and utilization systems that do not use external energy, like a solar chimney, are classified as passive solar technologies. Photovoltaics (PV) is a method of generating electrical power by converting solar radiation into direct current electricity using semiconductors that exhibit the photovoltaic effect. Photovoltaic power generation employs solar panels composed of a number of cells containing a photovoltaic material. Due to the growing demand for renewable energy sources, the manufacturing of solar cells and photovoltaic arrays has advanced considerably in recent years. Photovoltaics are best known as a method for generating electric power by using solar cells to convert energy from the sun into electricity. The photovoltaic effect refers to photons of light knocking electrons into a higher state of energy to create electricity. The term photovoltaic denotes the unbiased operating mode of a photodiode in which current through the device is entirely due to the transduced light energy. Virtually all photovoltaic devices are some type of photodiode. Photovoltaic production has been increasing by an average of more than 20 percent each year since 2002, making it the world’s fastest-growing energy technology. Due to the growing demand for renewable energy sources, the manufacture of solar cells and photovoltaic arrays has advanced dramatically in recent years. Photovoltaic power capacity is measured as maximum power output under standardized test conditions (STC) in “Wp” (Watts peak). The actual power output at a particular point in time may be less than or greater than this standardized, or “rated,” value, depending on geographical location, time of day, weather conditions, and other factors. Top 10 Photovoltaic Manufactures Fun Facts about Solar Energy usage: -Solar Energy is measured in kilowatt-hour. 1 kilowatt = 1000 watts. -1 kilowatt-hour (kWh) = the amount of electricity required to burn a 100 watt light bulb for 10 hours. -According to the US Department of Energy, an average American household used approximately 866-kilowatt hours per month in 1999 costing them $70.68. – About 30% of our total energy consumption is used to heat water. -A 1-kilowatt home solar system takes about 1-2 days to install and costs around US$10,000, but can vary greatly and does not take into account any incentives offered by the government. -A 1-kilowatt home solar system consists of about 10-12 solar panels and requires about 100 square feet of installation area. -A 1 kilowatt home solar system will generate approximately 1,600 kilowatt hours per year in a sunny climate (receiving 5.5 hours of sunshine per day) and approximately 750 kilowatt hours per year in a cloudy climate (receiving 2.5 hours of sunshine per day). -A 1-kilowatt home solar system will prevent approximately 170 lbs. of coal from being burned, 300 lbs of CO2 from being released into the atmosphere and 105 gallons of water from being consumed each month! -About 40 solar cells are usually combined into a solar panel and around 10-12 panels mounted in an array facing due North to receive maximum sunlight. Is Solar Power Right for You? How much you’re willing to spend upfront? The cost of solar cells for your home can varie wildly on the size of the Solar System, the location of your home, and the amount of electricity you plan on producing. A $25,000 system is a decent figure to work with (or about $40,000, before tax and federal incentives). If you were thinking more along the lines of $10,000 or under, installing a solar hot water system may be more suitable for your price range. This is especially true if your home uses a good amount of hot water, you have an oil or gas fired hot water heater, and/or the location of your home gets sun light 65%+ a year. Solar hot water can provide most of a home’s hot water needs. Residential systems typically cost about $6,000 or $7,000 to install, are highly reliable, and are eligible for the same federal incentives as solar panels, in most cases. Commercial Systems are usually twice that cost. Overall Solar hot water is a great alternative to true Photovoltaic Systems if cost is a determinant. If your finances allow for less than $10,000 but you still want solar panels, don’t worry. Some states have incentives making panels completely feasible at this price, and in many other states you could simply build your own system using places like SolarCity.com and Fry’s Electronics as your source for solar cells, regulators and converters. San Francisco solar companies offer many solutions and can help any residential project. Find your average electric usage. Take a look at a recent utility bill. How much energy (in kilowatt-hours (kwh)) did you use last month? What about the last 6 months? The last year? The best number to work with is an average. To find your average usage, add up your total usage over a year and divide it by 12. This will give you the average per month. If you’re paying a relatively low amount for your electricity (low= 8 cents per kilowatt hour) it’s likely that a solar photovoltaic system would have an unattractive payback period. Solar panels are a better investment in regions where conventional electricity from the grid is relatively more expensive. This is because electricity generated by solar photovoltaic panels gets credited back on your monthly electric bill. The higher the rate, the more attractive a solar photovoltaic system looks as an investment. So, a solar panel system in California, where residents can pay as high as $0.49/kWh, will have more attraction and a better return on investment than places like South Dakota, where electricity is cheaper than the national average. The more money you pay per month on each kWh of electricity, the better a Solar Photovoltaic System could benefit your home. Review your state’s rebates and incentives before installing solar. After reading through your state’s incentives on the DSIRE database, you should have some idea of the kinds of financial incentives your state provides for solar installations. The most standard incentives are tax credits, sometimes as high as 35 percent of system cost, and rebates. Rebates are usually calculated per watt of system size, and good ones will reimburse you for $1.50-$3.00 per watt you install. (For our average 5-kW system, this equates to $7,500-$15,000 in solar rebates.) Other incentives include electricity buy back or Net Metering, where your local Electric Company will pay you for electricity that your Solar Photovoltaic System puts back into the grid. This usually comes in the form of bill reduction. If you have any questions or want to find out how you can get a PV Solar System on your home. Please fill out the contact form and a representative from your region will contact you.

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