• Solar Photovoltaic

    A residential solar photovoltaic system is a reliable, proven technology that permits the homeowner to self-generate most or all of his/her electric needs. Perhaps the greatest benefit of a PV system is that it fixes the cost per Kwh that a consumer will pay for electricity over the 25+ year life span of the system. In Connecticut that is a significant benefit. The state of Connecticut has the second highest residential electric utility rate per Kwh in the United States, second only to Hawaii. Also, electric rates have consistently been growing at nearly 10% per year over the past 20 years. Since Connecticut’s electric power is generated by fossil fuel plants; as fossil fuel prices continue to increase, so must future electric rates. Beyond the dollars and cents benefits of a solar P.V. system, it also provides clean, sustainable power.

    Solar photovoltaic systems have been around for a long time and have undergone significant improvements in efficiency over the past 30 years. A typical system consisting of an array of single crystalline solar panels and a quality power inverter is highly reliable and very low maintenance since there are no moving parts. Newer thin film technology allows silicon material to be deposited on various surfaces that can be configured to look like roof shingles and other building components – making them less visually intrusive than crystalline flat panels. Thin film applications tend to be more expensive and only produce about half the output of crystalline panels – so you pay a lot for the appeal. Some types of building integrated photovoltaic products are also available with crystalline wafers.

    Solar P.V. systems can be configured as either an off-grid system that relies on batteries to store surplus power or a grid-tied system that interconnects with the local utility and feeds surplus power to the utility grid. Through net metering the grid-tied system gets full credit for the surplus power by selling it to the local utility at residential electric power prices. In effect, your electric meter runs backward. You can then use the equivalent amount of electricity later, without additional cost. In Connecticut, the grid-tied system is almost exclusively the system of choice given its greater simplicity and lower cost.

    Grid-tied P.V. systems are fairly simple. The heart of the system is the flat panel crystalline or flat film silicon array that is either roof or ground mounted. Most residential installations are fix-mounted, to avoid the added complexity, maintenance and cost of tracking mounts. The array is connected to a power inverter that converts the DC power generated by the panels into AC household power. Some systems require a separate DC disconnect that is a safety device that can separate the power generating panels from the grid. Software is available to monitor the power production and status of the system on a home computer.

    The typical American home consumes 20-to-30 kilo-watt-hours daily or approximately 9,000 Kwh per year. In Connecticut, a typical residential 5 Kw P.V system would generate approximately 7,000 Kwh per year, meeting approximately 75% of the home’s electrical needs. Most residential P.V. installations are designed to meet 60%-to-80% of the total electric load demand. The actual generation capacity of any P.V. system is determined by site-specific conditions. Although costly, P.V. systems qualify for various Federal and State tax credits and rebates that significantly reduce the initial installation costs.