by David Verner

Let’s face it; energy is something we cannot live without. It powers our homes, businesses and devices. For most of us, that energy is derived from nonrenewable resources taken from hundreds, if not thousands of miles away. But things are changing. The growth of renewable energy interests is skyrocketing. Both the Federal and State governments are supporting this change.

Many types of renewable energy technologies are viable in our region but most have limitations, except solar. We all have access to the sun. You may have a neighbor’s garage or a tree in the way, but in general most of us can utilize the sun for clean, free renewable power. Unless you live in a big open cornfield or on top of a mountain, capturing wind is probably not an option for you. For those who have a river running through their property then hydropower is the perfect option. But there probably aren’t too many of you who have such a luxury. Geothermal and biomass are options but the systems are very expensive and complicated.

That leads us to solar. Every minute enough of the Sun's energy that reaches the Earth's surface meets the world's energy demands for a whole year. That’s a lot of energy and we can capture some of it with technology. There are several types of solar technology that can be used by the average business or home owner.

One type of solar technology is solar thermal energy, and is used to heat hot water. The technology is very simple. A solar collector is filled with either water or a heat-transfer fluid; these fluids are heated directly by the sun’s rays. Once hot, the fluid is pumped to either a storage tank for direct use or to a heat exchanger where it transfers its heat to a conventional water system. Once the heat-transfer fluid passes off its heat it is then pumped back to the solar collector where it starts the process all over again. Solar thermal collectors in our region cannot support all of the hot water needs for the average family, though. Backup systems are still needed for winter months.

Another type of solar technology is one where electricity is generated from photovoltaic cells (PV). PV systems are sized to meet all of your electricity usage, or a percentage of usage, and are designed using the terminology Kilowatt (kW).  An average residential-sized system would use as low as a 4kW system to over a 10kW system. A commercial application can go up several hundred kWs.

A PV system is a little more complicated than a solar thermal system. A PV system has several components that each play a specific role in generating power. The first and most familiar are the PV panels, or “modules.” These are the thin box-like units that either sit on a roof, are attached to a pole embedded in the ground or are mounted to a ground structure. Many people think that the sun’s heat is what creates the electricity but it is actually light rays that interact with the solar cells that create the electricity. Once the light is converted into electricity it is then sent to the next component, which is called an inverter. The inverter turns the electricity from its DC (direct current) state into the AC (alternating current) state. The AC type of electricity is what most appliances like to use for energy. From the inverter, the electricity can either be stored in batteries for systems with battery backup or used to turn your lights on at that moment.

One example that we’ll look at is Bill and Jennifer’s home in Malta. They live in a 2,100 square foot home and have 2 young children. They use on average 450 kWh per month, and would like to install PVs for their home. In the next edition, we’ll discuss how a family like Bill and Jennifer can determine what type of solar system is best for their home, how large of a system they would need to meet their needs and the costs involved.

David Verner is CEO of Adirondack Solar (ADKsolar.com), a solar installation company specializing in all aspects of solar technology including grid-tied battery backup systems and off-grid applications. He can be reached at 1.877.407.3356, This e-mail address is being protected from spambots. You need JavaScript enabled to view it