HURRICANE SANDY CARNAGE IN NEW JERSEY The effects of Hurricane Sandy on the New York/New Jersey metropolitan area are devastating. Not only has the New Jersey shore been completely redefined physically, but tens of thousands are still without power a full two weeks after the storm as utility companies struggle to remove large quantities of downed trees that lay across crippled electrical distribution lines. Without power many are left without heat and water in their homes, and bottled water, firewood, chainsaws and generators are in scarce supply at the stores that are even open. A sense of desperation and helplessness has taken over the affected population like many have never experienced in their lifetime.Whether or not you believe that climate change is the cause of the increase in severity and frequency of our planet's natural disasters, certain facts remain, particularly that we depend on century-old utility grid infrastructure for our power supply- and the utility workers to repair the system quickly after an outage. In short- we are not only vulnerable, we are unprepared for subsistence without grid electricity. Any of us could lose power for a day or more from a single downed tree- a thousand downed trees and we have the current situation in New Jersey, Brooklyn, Queens, and upstate New York.Some home and business owners have standby generators that supply backup power to their electrical distribution panels. This is a great precautionary step to take to increase your level of preparedness for extended power outages. However, generators are subject to a couple of main problems. Most commonly, generator owners simply run out of fuel and have a hard time resupplying while roads are impassable and businesses are closed. One person informed me that they had been living off of their generator for a couple days already when it broke down and failed to restart.Perhaps the greatest solution is a grid-tied solar PV (photovoltaic) system with battery backup. Many people own or have heard of a grid-tied PV system where the solar energy produced is used directly by the loads of the house, and excess energy is stored on the grid through a net-meter allowing the homeowner to use that energy at night when the system is producing zero solar energy. However, as a safety precaution for linemen and other utility workers, when a grid outage occurs the PV system shuts down so as not to push electricity back on a line that is otherwise considered to be de-energized. As a result grid-tied PV system owners are subject to the same power outages as their neighbors.So how, in a power outage, can these system owners benefit from all that potential solar energy that exists every day on their roof? By integrating into their system a bank of deep-cycle batteries and a battery-based inverter. The owner of a "Grid-tied Battery Backup PV System "selects their critical loads such as their well pump, furnace, refrigerator, freezer, lights, etc. and puts them on a sub-panel commonly referred to as a "critical load panel". When the inverter senses a power outage it automatically supplies backup power to the critical load panel within a millisecond- the lights won't even flicker. What the inverter is doing is drawing off of the capacity of a direct current (DC) battery bank and converting that energy to household alternating current (AC) energy for running the critical loads. The beauty of this system is that as the loads draw the battery capacity down, the solar energy produced by the PV panels on the roof simultaneously recharges the batteries. In effect the home is now energized the exact same way an 'off grid' house is. And unlike generators that are bound to run out of fuel at some point, the battery-based PV system is powered off of a completely clean and renewable resource- THE SUN!The grid provides us with an incredibly convenient power supply on a largely consistent basis, but we don't have to depend on it. We have the abundant, renewable resource of the sun- and the technology to harness its energy to power our lives, both in times of grid stability and tragic natural disasters.
