Frenquently Asked Questions
General solar FAQ
Q) Do we have enough sun in our area for solar to make sense?
A) We do. In fact we have more solar energy available here than they do in Germany. Germany produces more solar energy per capita than any other country
Q) What is the difference between solar thermal and PV?
A) Solar thermal systems use the heat of the sun to heat an antifreeze solution which is pumped from the collector outside back into a heat exchanger to heat water. A PV (photo voltaic) system. Uses the radiation from the sun to generate DC electrical current in the panels which is either stored in batteries or immediately converted to AC power with an inverter.
Q) what are the different types of PV systems?
A)There are 3 basic types of PV systems.
The first type is grid tied. This type of system does not have batteries. It consists of solar panels and a grid tie inverter. The goal of this system type is simply to reduce or eliminate you electric bill. A grid tie PV system typically does not provide backup power during power outages. Some systems can provide limited backup power during sunlight hours.
The second type is a hybrid system. These systems also connect to the grid , but they have a battery bank as well. They are capable of supporting some or all of your loads during a power outage.
The third type is an off grid system. These systems are not connected to the power grid at all. They rely on solar power with
batteries, and a backup generator that acts as a battery charger for days when the demand is greater than the supply of sunshine.
Q) What is the difference between the types of panels?
A) There are 3 main types. Mono crystalline, poly crystalline, and thin film. The mono crystalline panels are generally the most efficient and most expensive. Poly crystalline are a close second in efficiency and price. The Cells in these two types of panels are cut from a solid bar of silicon. Thin film panels are less efficient, but somewhat cheaper. Thin film panels are more effective at collecting energy from diffused light and on cloudy days. They are also more tolerant of extreme high temperatures that are encountered on rooftops in the summer.
Q) What is net metering?
A) Net metering is the practice of taking the difference between your power produced and power consumed at the end of the month either charging you for power used or putting a credit on your account for excess power produced. In Indiana they will not actually pay you for excess power, but they will let you use the credit next time you don't generate enough. A good example of this is when you generate more than you need for several months through the summer then use the credit in the winter when solar output is lower.
Solar thermal FAQ
Q) How much money will I save?
A) Hot water accounts for about 1/3 of the typical household electric bill. You will be able to make up to 80% of your hot water from the sun. This is a year round average. During the summer a properly sized system will make all the hot water you need and often it will have enough excess capacity to ride through rainy days without running out.
Q) How well does it work on cloudy days?
A) As long as the clouds are not very dark such as rain clouds, the system will still make a lot of hot water. A lot of radiation penetrates the clouds. Evacuated tube collectors are very effective at capturing every available bit of light.
Q) What happens when we have several rainy day in a row? Will I run out of hot water?
A) Every solar water heater is designed with a backup system. In most cases it will be an electric heating element in your storage tank. It will come on as needed to make sure you don't run out of hot water. You can also use a tank-less water heater (also called inline, or on demand) as a backup as well as a separate tank type gas water heater.