Making Your Home Outage-Proof by Adding Batteries to Your Solar Installation
Have you been thinking about installing solar panels on your roof or in a nice sunny patch of your yard? If so, you’re certainly not alone. In just the last two years, solar panels and the infrastructure needed to make use of them has become surprisingly affordable, accessible, and even encouraged by the big players in residential power like the government and power companies. In fact, many homeowners and businesses are considering installing solar panels not just to be green, but for the opportunity to claim a large Federal tax credit and benefit from the utility savings provided by net metering programs.
Most solar systems installed today are purely grid-tied, without batteries. But new technology has made having batteries and therefore a resilient power system more affordable than ever.
Grid-Tied Solar and Net Metering
So what exactly does ‘grid-tied’ mean? When you install grid-tied solar panels on your home or business, you are directly supplementing the pre-existing utility grid connection between the building and the municipal power supply. The power that flows through the walls and into your light fixtures and outlets may still come from the city and you may still have a utility bill. Only now, the excess energy being generated by your solar panels is being pushed onto the grid, and when you need more power than you’re making, you’re pulling power from of the grid.
This leads to a deal offered by power companies known as ‘net metering’. The idea is that your power meter ‘goes up’ when you pull power off the grid and ‘goes down’ by the same amount per kilowatt-hour (kWh) when you contribute power to the grid from your solar panels. Since your power becomes accessible to everyone else on the grid, reducing the amount of power your local energy company needs to generate, they credit your power bill. If you manage to generate as much power as your house uses up, you have reached ‘net zero’ and depending on your energy company, may have also zeroed-out your bill. In mtvSolar’s service area, all states have implemented 1-to-1 net metering, which means you get back just as much as you put in.
In some cases, energy companies will even pay you for your power if you provide more than you use (at the wholesale rate), but this is not a guarantee and depends a lot on both the state you live in and the power company you contract with.
But What About When There’s a Utility Outage?
Installing grid-tied solar is almost always as much of a financial decision as it is about sustainability. The problem is that when the grid breaks during a storm and power stops flowing through the lines into your house, you lose 100% of the functionality from your solar panels as well. Sure, those panels are still soaking up sunlight and producing energy, but during a power outage, there’s no grid for them to feed into. The grid is required for the system to operate as it functions like a virtual battery.
Thunderstorms, ice storms, fallen tree branches, broken lines, and neighborhood power line maintenance can all completely cut you off from power to your home, just like everyone else on the block who may or may not have solar panels. However, with one addition, you can turn those exact same solar panels into an opportunity to be the only house on the block with lights, television, refrigeration, running water and sump pump. All you need are batteries and some specialized equipment to form your own micro-grid. While a generator can also perform this task, without batteries your solar panels still have to be off; as if they force power back into the generator it will be destroyed. In addition, generators use costly fuel and are noisy if all you want is refrigeration and some lights.
How Off-Grid Solar Works
While the latest generation grid-tied solar and net metering are appropriate for most consumer solar installations, the traditional application for solar is still incredibly useful. Those seeking to be prepared, environmentalists, and people who live in incredibly rural locations have been powering their homes with a combination of solar panels and batteries for decades.
The way this is done is to create what has been coined a ‘micro-grid’. Just like the enormous municipal grid sends electricity from a power plant to the city and surrounding area, a micro-grid is a small local power system that draws energy from the solar panels and sends the power directly into your home. After the power has been used as needed in your home, anything left over is poured into your batteries. Then, when the sun goes down or on rainy days, your little private power grid pulls electricity from the batteries to power your home until the panels are soaking up sunbeams again. In some cases, an auxiliary fossil-fuel generator can also kick in to provide power when the panels can’t, such as during a blizzard.
In the many real-world applications of this method, the term ‘micro-grid’ is actually a little bit misleading because they can be almost any size. Some people start by experimenting with a single solar-powered shed while some neighborhoods build a shared community micro-grid in which all of them benefit from each other’s panels, batteries, and infrastructure. In fact, this is becoming more common in new sustainable developments around the world.
On and Off the Grid
But what does this mean for your own home? Most homeowners getting into solar power don’t want to separate completely from the municipal grid, often because running the average American home off-grid is prohibitively expensive. This is a perfectly reasonable concern and a good argument for grid-tied solar. With batteries added in you won’t be stuck in the dark during an outage.
Modern micro-grids installed by certified professionals can actually allow you to have two modes, on the grid and off the grid. This way, you can set up your solar panels to first fill up your batteries for emergencies, then send power to the grid for net metering purposes when power is flowing normally.
However, when a storm blows through and the power goes out across the neighborhood, your important electrical devices continue to be powered. While the weather is bad, you can run on the fully charged batteries and if the power hasn’t come back by sunrise, the solar panels will start powering the house and charging the batteries all over again. If you’re interested in a hybrid solar energy system that is both grid-tied and capable of keeping the lights on during an outage, ensure you choose a contractor with NABCEP certified employees and proper licenses.
In the Maryland, Virginia, West Virginia and Pennsylvania 4-state area, mtvSolar is your local contractor.
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