FAQ's: Solar Energy
FAQ's: Solar Energy
Going solar has a wide range of benefits and whether it’s economic, environmental, or personal, all of these benefits are fuelling the South African solar power boom.
Here are our top 10 reasons to go Solar:
1. Reduce your electric bills
Electricity costs can make up a large portion of the overall budget for your home, business or organization. With a solar panel system, you’ll be generating power over your system’s 25-30 year life cycle. Even if you don’t produce all of the energy you consume, your utility bills still will be much smaller. Either way, you’ll be saving a lot of money.
2. Earn a great return on your investment
Solar panels need to be seen not as an expense but as an investment that pays handsome returns often challenging those of more traditional investments such as stocks or bonds. Substantial savings as well as the potential in some areas to generate revenue result in Return on Investment (ROI) of 20% or more, making solar one of the best ways to invest your money.
3. Protect against rising energy costs
Because energy prices can be unpredictable, they make managing your budget very difficult, especially for businesses or homeowners whose cash flow changes from month to month. By making these costs more predictable, solar power systems have the added benefit of improving a home or business owner’s expense management capabilities.
4. Increase your property value
Early studies have found that buildings and homes equipped with clean energy systems have higher property values, selling twice as fast over similar homes in the same area. Appraisers are increasingly taking solar installation into consideration as they value the home at the time of a sale. As appraisers and consumers become more educated, homes or commercial properties equipped with solar panel systems will be more in demand and may even get even a higher premium.
5. Boost South Africa’s energy independence
Solar energy is a pathway to achieving energy independence from coal and a viable solution to our growing energy crisis.
6. Create jobs and help your local economy
Studies predict the clean energy sector will generate over a million ‘green’ jobs over the next 10 – 15 years. Because these jobs tend to be higher paying and sourced locally, they represent a significant contributor to our economy.
7. Protect the environment
Solar is a great way to reduce your carbon footprint. Buildings are responsible for close to 35% of all carbon emissions and going solar can decrease that number significantly. A typical residential solar panel system will eliminate 3-4 tons of carbon emissions each year—roughly the equivalent of planting over 100 trees every year.
8. Build your brand, demonstrate your commitment to sustainability
Sustainability and corporate social responsibility not only tie to an organization’s culture and values, they also produce bottom line results. Increasingly, consumers and communities are recognizing and rewarding businesses that choose to operate responsibly. Businesses are finding that “green” credentials are a powerful driver of consumer purchasing decisions, creating goodwill and improved business results.
9. Increase employee morale
Just like consumers, employees have a demonstrated appreciation for their employers’ commitment to operating responsibility. Employees share in the success and contributions of their organizations. When they feel good about where they work, they are more engaged, have higher levels of morale and lower turn-over rates.
10. Stay competitive
Companies quickly are realizing the social and economic benefits of adopting solar power. As early adopters pull ahead of the competition, many companies are exploring solar power as a way to keep up.
Myths about solar.
Myth #1. Solar power doesn’t generate enough electricity
Solar energy is now mainstream and contributes to electricity grids around the world. Globally, solar installations grew by nearly 30 percent in 2015, and the industry is on an upward trend. Texas, Colorado and other U.S. states have successfully integrated solar and other renewables to the point that at certain times of year more than 50 percent of their electricity can come from renewable sources.
Myth #2. Solar energy is expensive
Not anymore. Solar has become very affordable. Costs of solar technology have fallen dramatically — by 80 percent since 2007 — and are expected to become even cheaper. In sunny places, electricity generated from solar is becoming cheaper than electricity from other sources.
Myth #3. Solar energy only works when the sun shines
Not so. Solar energy can be a reliable energy source even when it is cloudy and in winter, as long as there is some sunlight. And electricity generated in businesses and homes may be sent to power grids in return for energy credits, paid back as the users draw from the grid after the sun goes down. Electricity also may be stored off the grid. Storage technologies are becoming increasingly efficient, with larger storage capacities.
Myth #4. Solar panels are hard to maintain
On the contrary, there are no moving parts to repair, and solar panels are durable and long-lasting. Hailstorms pose no problem. Most companies offer 25- to 30-year warranties because solar panels are so low-maintenance and reliable.
Myth #5. Solar energy isn’t profitable
Solar energy has become cost-competitive with coal and other polluting energy resources. That’s one reason 2015 saw installed solar capacity increase 16 percent over 2014. The Solar Energy Industries Association says solar energy is growing at a record pace in the United States. California dominates the U.S. solar market, but other states are accelerating solar installations, notably Massachusetts, New York and Texas.
Those are the myths. Now a few facts.
- Solar energy is creating lots of new jobs. In the United States alone, more than 200,000 jobs are in the solar industry — three times more than in coal. That figure is set to double by 2020.
- Widespread use of solar energy will dramatically reduce air pollution, providing health and economic benefits. Solar technology can electrify remote and low-income communities without expensive grid infrastructure. That’s why the Chinese, Indian and U.S. governments, and many more, are investing heavily in solar technologies.
- Expanded use of solar and other renewable energy resources is essential to meet climate goals of keeping global temperature rise well below 2 degrees Celsius, as outlined in the Paris agreement.
Impact of Temperature on PV Module Performance
Solar Photovoltaic modules use light energy (photons) from the Sun to generate electricity through the photovoltaic effect, but not using the heat which the Sun generates. The solar Module electrical connections are made in series to achieve a desired output voltage or in parallel to provide a desired current capability (amperes), depending upon the application of choice.
Module performance is generally rated under standard test conditions (STC): irradiance of 1,000 W/m2, solar spectrum of AM 1.5 and module temperature at 25°C. Electrical characteristics include nominal power (PMAX, measured in W), open circuit voltage (VOC), short circuit current (ISC, measured in amperes), maximum power voltage (VMPP), maximum power current (IMPP), peak power, (watt-peak, Wp), and module efficiency (%). The actual performance parameters of the module changes as lighting, temperature and load conditions change.
Impact of temperature on PV module performance
Temperature is the key factor that impacts the output power of solar panels and it needs to be within the specified limits. Behavior of different solar panels changes with its operating ambient temperature resulting in decrease of the output power with every increase in temperature.
Sun’s radiation consists of two components – heat and light. An increase in temperature does not change solar energy reaching the panels, however, it reduces the amount that can be converted into electricity from the solar panel.
Energy that the solar panels produce is a function of power, further power is the product of current and voltage (P= I x V). So, while an increase in temperature slightly increases the current in solar cells, the voltage is decreased by a greater amount which results in reduced power output, and resulting in solar module parameters going away from the desired system specifications.
The Temperature Coefficient
Every PV modules has its different unique temperature coefficient value (Pmax) in the data sheet provided by the manufacturer. This is in the form of negative percentage and it reveals the temperature effect on the PV module.
Solar Panels are rated at 25oC and therefore the temperature coefficient percentage depicts the change in efficiency with each degree up and down in temperature. For instance, if the temperature coefficient of a panel is -0.40%, then for every 1oC rise, the panel’s maximum power will reduce by 0.40%.So, on a hot day, when panel temperatures may reach 45oC, a panel with a temperature coefficient of -0.40% would result in a maximum power output reduction of 8%.
Similarly the temperature coefficients of voltage are also represented in negative, indicating the drop in voltage of the solar modules at elevated temperatures. Considering the voltage temperature coefficient value of -0.3% for each and every degree raise in temperature, for a module installed in field with operating at a temperature of 45oC, the voltage of the module will drop by 6% from the rated value measured at STC conditions on the nameplate.
So, it becomes imperative for solar system installers and owners of the solar system to consider these things while installation and owning a solar system for various applications.