Battery Power - September/October 2012 - (Page 18)

FEATURE Why Your Next Renewable System Should be Built Around Energy Storage Mark Cerasuolo, Senior Marketing Manager OutBack Power In the renewable energy industry, there has been much discussion about how to convert variable resources such as wind and solar into consistent and continuous energy similar to the electricity consumers are accustomed to enjoying from the utility. Meanwhile, more frequent instances of extreme weather such as tsunamis, heat waves, hurricanes and ice storms are causing sustained blackouts and giving residents and businesses pause: what if the grid isn’t as reliable as we once assumed? Or consider another possibility: systems designed around installation and production incentives such as net metering (running the meter backwards and selling back to the utility) can have their entire economic rationale altered if those incentives change, and policies invariably do change. Finally, consider the fact that a grid-tied PV system is always offline at night, but if surplus energy generated during the daytime can be stored, it can be used at night when electricity costs may be at their peak. These independent but related concerns, grid stability, renewable system economic viability and consistency, create opportunity for renewable energy systems that can thrive when paired with an energy storage system to provide electricity during power interruptions and peak use times. Originally, many solar installations were off-grid entirely, with users getting all their energy from solar panels, perhaps with a diesel generator and battery system for backup power. These consumers stayed completely off the grid, often because they were located in remote areas where it’s too expensive for a utility to build energy infrastructure. This off-grid technology wasn’t feasible for all geographies or appropriate for all needs, which is why grid-tied systems came into the mainstream. Today, most commercial and residential solar system users in the developed world use technology that’s grid-tied where the utility acts as energy storage, supplying power as needed when the installation isn’t producing enough electricity due to a week of cloudy days or other disruptions in maximum solar exposure. Developments in technology now offer a system choice beyond black and white, either tied to the grid or completely independent of it. Hybrids called grid-interactive photovoltaic (PV) systems offer more of the best of both worlds: grid-tied economics when the grid’s available or cost-effective, and off-grid independence when it’s not. Grid-interactive systems are based on grid-tied technology, and once they are combined with proven energy storage technology, the comparable payback expectations and greater capabilities will drive higher adoption levels in the industry. While grid-interactive PV systems offer users increased flexibility and reliability in installations, they are not so different from the grid-tied systems integrators most frequently recommend. Grid-Tied and Grid-Interactive Systems The Similarities For an analysis of the differences between grid-tied and gridinteractive systems, one must first examine what both have in common. Both types of systems deliver several similar benefits. • Lower Bills: Grid-tied and grid-interactive systems save users money on utility bills in several ways. First, they simply use less grid-produced electricity. Second, during times of strong sunlight and relatively light load demand, surplus energy can be sold back to the utility in many states and localities. Net metering means that an owner can run the meter backwards and potentially save a home or small business up to thousands of dollars during the life of the system. Some states have a cap, but between geographical amounts of sunlight, incentives and electricity costs, solar users stand to shave a big chunk off their bills. • Better Resell Value: According to recent statistics, solar energy system owners can see a potential return of 97 percent of their investment when it’s time to put their homes on the market. This is higher than any other home improvements or amenities, and it’s important to keep in mind this is on top of the money owners save by reducing their energy bills and taking advantage of net metering. Additionally, a US Department of Energy study showed that homes equipped with solar energy systems are on the market for half the Photo courtesy of SolTerra time, even when you factor in challenging housing markets. If homeowners want the flexibility to move to the next property, grid-tied and grid-interactive systems are both attractive investments. • Decreased Carbon Footprint: After installing weather sealing or efficient lighting, solar power can be the lowesthanging fruit toward attaining a greener lifestyle. Unlike wind turbines and micro-hydro installations, solar does not have prerequisites such as regular breezes or a running stream on the owner’s property. Sunlight is accessible to everyone. Solar power also has zero impact on the environment as a solid-state, low-impact energy source with no moving parts compared to the other methods, it requires no transmission paths past the roof and it is used at the point of generation. • Incentives: Both grid-interactive and grid-tied systems make their owners money by qualifying them for production credits. Depending on the state, incentives pay owners per 18 Battery Power • September/October 2012

Table of Contents for the Digital Edition of Battery Power - September/October 2012

PRBA Battery Proposals Adopted By UN Transport Sub-Committee
The Use of Lithium-Ion Batteries in Uninterruptible Power Supplies
Monitor Your Battery Cells for Superior Reliability
Juicing Up the Battery: Cutting Edge Research Delivers Battery Enhancements
PEM Fuel Cell Systems – Reliable Backup Power Source for Remote or Extended Run Power Outages
Why Your Next Renewable System Should be Built Around Energy Storage
ICs & Semiconductors
Charging, Testing & Monitoring
Power Supplies
Industry News
Calendar of Events

Battery Power - September/October 2012