Question: What happens to  a solar power system when the power goes out?

Answer: It helps to think of a solar power system as one giant funnel.The panels are the funnel and the bottom of the funnel is where the inverter lives.

The sunshine (direct current) pours through the top of the funnel, filling it up with sun rays.

When it’s time for the sun rays to pour out of the bottom of the funnel, the inverter steps in. The inverter converts the sunshine into electricity (alternating current) for your home. The more the inverter converts sunshine through the bottom of the funnel, the more new sunshine can come in.

So far so good so? Let’s pause right there.

Now we begin to diverge based upon whether a system is grid tied or off-the-grid.

GRID TIED

When the system is tied to the utility company (the grid) and the power goes out, the inverter shuts off. When the inverter shuts off the sunshine (direct current) will just continue to sit in the funnel because the bottom is now “plugged up” do to the inverter not working. So, when the power goes out your system doesn’t produce any electricity for use in your home (alternating current).

OFF-THE GRID

When the system is off-the-grid and the power goes out, the inverter can still remain on. The inverter, in an off-the-grid system is powered by two possible sources- a battery or a generator. When the sunshine goes down the funnel and gets converted into direct current, and isn’t consumed by the household, it needs a place to be stored- that’s what the batteries do. When all the direct current electricity is used up in the batteries, a back up generator will take care of electricity needs.

Check out the article below in which Edward Whitaker, Second Generation Energy's Director of Business and Development, was quoted.

 Solar Panel Installers Like the Weather Here

published: Oct 14, 2011, Boston Business Journal by James M. Connolloy, reporter

Despite the dings that solar energy manufacturing has taken, Massachusetts is a pretty sunny
place if you are among the folks who install solar panels for a living.
Not only are local solar installers busy, the Bay State is attracting big national and regional
players who want a piece of the business where incentives make solar the right choice for
many home owners and businesses.

“We have seen an increase in the activity here in Massachusetts based on the number of solar
installers that have started here or have come in from other states,” said Mark Sylvia,
commissioner of the Massachusetts Department of Energy Resources.
Sylvia noted that the number of installers doing business under the Massachusetts Clean
Energy Center’s Commonwealth Solar program has grown to 301 today from 134 in 2008. He
said that low global prices for solar panels, incentives — some of them driven by stimulus
funds — and Gov. Deval Patrick’s goal of generating 250 megawatts of solar power by 2017
are making Massachusetts one of the more attractive states for installers. That total capacity is
59 megawatts today. A megawatt is enough to power about 100 homes.

Edward Whitaker, executive director of business development at Second Generation Energyin Hopedale, said business is booming for installers, in part due to the state’s Solar Renewable Energy Credits (SREC) program, but that it may not stay that way. He noted that the SREC program offers a strong incentive, but that it could have a limited shelf life. “Massachusetts has turned into a cutthroat business in residential. That’s not what we are. I think there is still some shakeout coming. Some people are selling leases at a loss, and we’re not sure they are going to be around in five years.”

One out-of-state company that was drawn to Massachusetts is Independence Solar of NewJersey, and now with an office in Boston. “Business is doing well. Massachusetts is a new market for us. The state recently enacted an SREC program, so that laid out a path for continued growth in Massachusetts,” said vice president James Schwartz. He said New Jersey’s SREC program is already over subscribed.

Schwartz added that while Massachusetts is particularly high on solar, there is growing interestin solar across the country, due in part to Europe’s woes. “There has been renewed interest in the U.S. Europe had been the leader in solar, but with the economic problems there they arereining in some of the subsidy programs. So manufacturers are looking for new markets, and they are turning to the U.S.,” said Schwartz.

Another new entrant in Massachusetts is Maryland-based Astrum Solar, which opened an office
in Hopkinton.“Massachusetts has always been on our radar screen,” said Michelle Waldgeir, Astrum’s vice
president for marketing. The market has been very responsive from a solar standpoint, and
the incentives in place in your market are making it so folks at all levels can go solar.”
Waldgeir reports that nature of solar installation companies is changing as the market grows.
“When we started, the competition was the local electrical contractor. Over time, what has
happened is that it started to be regional companies. Now what happens is the regional
companies are affiliated with a national company,” said Waldgeir.

Instead of going off the grid you can modify many of your behaviors and strike a fine balance. Think using less, buying less, slowing things down, etc and of course installing a solar PV system to offset some to most of your electricity needs.

The first time I ever heard the concept of being off the grid, was last summer when a fellow co-worker spoke about how she did just that for a few years when she was a child. Initially it sounded frightening. The beginning of a bad horror movie- out in the middle of nowhere without any means of connecting with the rest of the world, no electricity- all ripe opportunities for a man with mask a chain saw.

A year later I can see the appeal to living off the grid. Not only would it vastly reduce your carbon footprint, but can also bring an element of appreciation for filling one's needs in a simplistic way. I don't know when or if I'll ever get a chance to live off the grid but for now I'll live vicariously through Craig Lasher's installments in the NYT's Green blog about how he and his family doing just that for the next year in Maine.

Interestingly enough many homeowners think that if they install a solar PV system for their house they too can be off the grid. Not quite. Most homeowners will always be tied to the grid for a few primary reasons.

The first is that a home would need a large solar power system to accommodate all the household's electricity needs. Unless the house has a very large roof that would probably mean there would need to be a ground mount system.

Secondly, it would take very large batteries to store all the electricity generated by the solar panels. When a house's solar power system is tied to the grid the electricity generated from the solar panels feeds back into the system and gets stored there to use. Whatever electricity isn't used will be utilized by other utility customers.
A third consideration is, if you're relying entirely on a solar pv system, what will happen when there are several cloudy days solar electricity is not generated? There would have to be a back up generator. The size of the generator will depend upon how many "modern comforts" you feel comfortable living without.

So that's the deal.

If going off the grid is still calling your name check out how others have been successful doing so on the site Living Off The Grid. It is totally possible especially when a homeowner understands the costs and possible energy sacrifices that must be made, as there are some wonderful benefits. For instance if you're off the grid and utility power goes out, you're still in business and of course the amazing environmental savings.

Instead of going off the grid you can modify many of your behaviors and strike a fine balance. Think using less, buying less, slowing things down, etc and of course installing a solar PV system to offset some to most of your electricity needs.

Never before have I realized the true significance of what it means to have a “steep learning curve.”  The amount of knowledge one can acquire in a summer is quite spectacular—prior to this May, all I knew about solar energy was the little I had learned from general overviews in my environmental science and policy classes.  The everyday bustles and excitement that fuel this small but rapidly growing Mom-and-Pop-run company have allowed me to fully immerse myself in experiencing what it means to be a part of a green business in an increasingly competitive market.

My internship at Second Generation Energy has certainly given me hope for the energy crisis we are all facing, not just because they install clean energy projects, but because of the various little sustainable practices that add up within the business.  For instance, every site visit is planned strategically in order to minimize carbon dioxide emissions from transportation, not to mention that the company car is a hybrid Prius.  They print as little as they can on recycled paper.  Additionally, although they service throughout Massachusetts, Second Generation tries to stay as local as possible.

One huge advantage of working at such a small company with about ten other colleagues is that I was able to help out in every department.  Whether it was operations, sales, marketing, or customer care, the variety of projects I have worked on this summer were all successful in furthering my understanding of Massachusetts’ solar policy. In particular, my knowledge about the intricacies involved with SRECs, federal, and state incentives has grown tremendously.  A few mini-projects involved putting together pictures required by the MassCEC in order finalize rebate paperwork.  For one interesting project, I used Google Earth to identify buildings in local industrial parks with potentially good roofs for commercial solar installations.  Yet another assignment involved assessing our clients’ PV energy production through the online monitoring system and comparing it to the estimated generation.

Summing up my experience into just a few words has proven difficult, as expressing the impact it has made in developing my career goals and life path seems to be inexplicable in terms of describing the evolution of myself as a person.  What I can say, however, is that before this summer, I never knew it was actually possible to look forward to going to work 9-to-5 in the “real-not-college-world.”  My internship has taught me the importance of prioritizing and juggling a plethora of tasks, from completing Annual Performance Reports required for commercial jobs that receive funding from the 1603 Treasury Grant to making Home Depot runs.  The experiences I have gained in the solar industry have been enlightening (no pun intended…) and positive in every aspect, and have made me optimistic that individuals and communities will collectively realize the power that we have to end our addiction to fossil fuels.

This may sound like a foolish question but a trend is emerging here in Massachusetts with the ‘no site visit required’ sales pitch for solar power systems.  ‘We have all the technology to analyze your roof from California’ the story goes.  There are a number of variations on this theme but the underlying motive is the same.  Do what you need to do to get the deal!  This is where prudence, Integrity, and Honesty get thrown out the window to make room for good old ‘market share’.  So here come these companies with millions of investors dollars charged with the responsibility of growing the company and gaining market share-at any cost.  This is a disturbing trend.  Of course reading the fine print in the agreements of these companies reveals a whole host of exclusions and conditions designed to protect guess who?

So yes Solar Panels do need sunlight, as well as a decent roof, a structure to support it, and a knowledgeable, competent, responsible, and trustworthy installer.  So do your homework and get your facts straight and ask lots of questions.  And listen to what your gut tells you. 
If something doesn’t make sense and sounds too good to be true, guess what?