Grid-Tie Systems

Independent Power has begun to increase the number of grid-tied net metered solar electric systems that we design and install. We have long been a company with extensive off-grid pv expertise and recently David Palumbo has taken all of the necessary steps to receive the best training available for the design and installation of state of the art grid connected pv systems. David traveled to Sacramento, CA during November of 2005 to take the Advanced PV System Design & Installation Course taught by Bill Brooks. David also received his NABCEP certification with the very first class of pv system professionals back in 2003. For information on the significance of being a North American Board Certified Energy Practitioner check out their website www.nabcep.org/about.cfm 

Grid-Tied PV Systems come in two basic types. The first system consists of an array of pv panels and the associated mounting hardware and wiring, and with a sell back power inverter. The inverter takes your solar electric power and feeds it into your power lines. Any power that is additional to that used in your home is fed onto the power grid. When this happens your meter is spun backwards so that amount of power comes directly off of your electric bill. If you happen to generate more power than you use during the month the utility company gives you a credit to use against future power use. 
The second type of grid tied system adds a battery storage system that acts as a back up, with the inverter, in case the utility has a power failure. This type of system has that distinct advantage but it costs more than the straight sell back system and it is not as efficient. 
 
Vermont Now Has Incentive Money Available!
As of September 1, 2007 Vermont's Department of Public Service is now helping fund the installation of grid connected net metered renewable energy systems. The residential and commercial incentive is presently set at $1.75 per rated watt of the installed pv array up to a maximum of $8,750. For multi-unit Low Income Housing the incentive is set at $3.50 per rated watt of installed pv array up to a maximum of $35,000. Solar Domestic Hot Water (SDHW) incentives for residential and commercial properties are currently set at "The Total Rated Output of the SDHW System x 10 x $1.75" up to a maximum of $8,750. For Low Income Housing  the incentives are set at "The Total Rated Output of the SDHW System x 10 x $3.50" up to a maximum of $35,000. Small wind incentives are also available.   In order to be eligible for Vermont incentive funds the system must be installed by a registered Vermont Solar Partner. Independent Power is a registered Vermont Solar Partner. For more information on the incentive program go to
www.rerc-vt.org/incentives/index.htm  



Environmental & Economic Benefits of Solar Electric Power
You can't buy a cheaper source of clean electric power generation than photovoltaic power. Combined with a significant use of energy efficiency measures in your home, you can now offset a high percentage of your electric bill with electricity produced by pv panels installed on your roof, or in your back yard.
With retail electric utility rates expected to double within the next five years, and then double again within another five years, the investment of purchasing your own pv system certainly looks like a wise hedge against escalating price hikes. PV system components typically last from 15 to 25 years. With these rising electric rates the payback time in dollars is continuing to come down every year. However any cost benefit analysis has to take into account the immediate environmental payback that begins to take place as soon as your pv system is in place. Consider the following numbers.
Each kilowatt of installed pv capacity offsets the following pollutants annually in San Diego, CA De-rate these numbers by 33% for Vermont: 
- up to one pound of oxides of nitrogen .
- .o4 pounds of sulfur dioxide.
- and 1,924 pounds of CO2 (carbon dioxide) . Source: www.epa.gov/cleanenergy/egrid. 

The energy payback time of a typical pv module is now only 1.4 yrs for sunbelt installations and is 2.7 years in less sunny areas. Energy payback is the amount of time that it takes the pv module to produce more energy than it took to manufacture the module.
Source: www.nrel.gov/ncpv/energy-payback.html