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What you need to know about solar energy


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Right now, you can install relatively cheap technology on your own roof and power your house, gadgets and even your car. For free! Sorcery? Not so much. The Earth receives more energy from our sun in about one hour than humans consume in an entire year. That's why solar power was the second leading source of new energy last year, and why companies like Google and IKEA are now in the solar panel business. However, many argue that the drawbacks -- cost, environmental pollution, etc. -- outweigh the benefits (free energy!). Getting onboard is also tricky with things like tax credits, the grid and the complexity of solar panel installation to consider. But that's why we're here, right?


Like other new tech that's helping us break our debilitating fossil fuel habit, solar is utterly imperfect. But it has immediate benefits to society and to you personally -- even if you don't paper your walls with money.

Our sun, Sol, is powered by nuclear fusion. It produces energy when hydrogen fuses into helium, according to Albert Einstein's famous E=MC2 equation. We can't safely perform fusion on Earth yet, but we can harvest the energy produced by Sol's fusion from pumps, collectors or photovoltaic (PV) solar panels. Such installations are referred to as "active solar." On the flipside, "passive solar" means improving your home's energy efficiency with new windows, better insulation, etc. In so many words: If your home is very inefficient, address that first.

So, how do solar/PV panels work? They use something called the "photoelectric effect," described by -- you guessed it -- Einstein. (Fun fact: He received the 1921 Nobel prize in physics for that discovery, and not his arguably more important work in relativity.) In brief, PV panels are made from semiconductor materials that give off electrons -- energy -- when excited by light. How many electrons you get depends on the efficiency of the panel. Most commercial and domestic solar panels convert about 20 percent of light energy into electricity, while pricey solar panels used by NASA for satellites can be up to 40 percent efficient.


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Few technologies exist that can do more for you personally than solar power. If you play your cards right (and live in a region that gets enough sun), a solar installation can be literally free over the long term, and can actually pay you in the end. Having said that, the pitfalls (e.g., your money falling into a pit) are everywhere, meaning it also requires some research to avoid becoming a catastrophe rather than a benefit.

With companies like Google jumping into the fray by leasing solar panels to US homeowners, things may get a bit easier for you and me. But these initiatives are just kicking off, and if you're worried about targeted ads in your electricity (or something), you're on your own. Luckily, the government really, really wants you to install this technology. For starters, you'll get a 30 percent federal tax rebate on the price of a solar panel installation without any dollar limits. Most states offer similar rebates making it possible to recoup up to 80 percent of the price of solar panel setup.

Considering that the average price of a solar installation fell dramatically last year to $4.72 per watt, a median 5KW installation will cost about $23,600 (that varies wildly between states and regions). Rebates included, you could whittle that down to $7,000 - $15,000, a reasonable sum for many homeowners. That's before we factor in energy savings.

According to industry figures, solar power users saved about $84 per month or $20,160 over 20 years. Most panel installations are grid-connected too, meaning your clean energy flows back to other users so that they, too, avoid using polluting sources like fossil fuels. If you produce more electricity than you consume, your power company may actually cut you a check.


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The United Nations is 95 percent sure that human activities like burning fossil fuels are causing the planet to heat up. Climate scientists are similarly in agreement. The White House recently issued a report saying that the consequences of climate change are being felt right now, not in some far-flung, dystopian future. The future isn't looking great either: With scientists proclaiming that Antarctic glacier melt has now passed the point of no return, to name just one recent example.

The resulting changes in our climate will reportedly result in higher sea levels and more extreme weather, as we've already seen with disastrous hurricanes in the US (shown above) and other regions of late. Other consequences include the destruction of coral reefs by over-acidified oceans, less sea oxygen for marine life and drastic changes in the food supply for both humans and animals.

On a less dramatic note, energy is expensive. Depending on your state or country, a large chunk of your household income goes toward heating your home and running its myriad devices. If you can come out ahead of the game, why not do it? Sure, it's subsidized by the government, but officials are looking at the longer-term picture -- and so should you, because owning a set of solar panels for 20 years can end up being virtually free.


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Despite sounding like a pretty good deal, not everyone's high on solar panels. There are serious and valid arguments, for instance, that tax dollars should be invested elsewhere if we really want to reduce atmospheric carbon. Some say we should be pursuing wind or nuclear power instead, both of which are currently far more cost-effective than solar power -- and produce energy at night.

Despite the plunging cost of solar, it's still more expensive per megawatt-hour of energy than most others, including coal and gas. As the argument goes, if the government took the billions of dollars it otherwise would've reaped without solar tax rebates, it could've spent that money on cleaner systems that produced far more energy. As a result, critics say we're propping up an inferior system, which is counterproductive to the main goal: reducing greenhouse gases. That means that on top of not reducing pollution enough, taxpayers who can't afford solar panels are actually paying more, not less for electricity. Finally, many think that solar panel production is not carbon neutral and doesn't produce lasting jobs in the way that, say, a nuclear power plant installation does.

But solar proponents say to chill out and think longer term. For one thing, a solar installation can produce virtually free power for a hundred years following the initial installation costs. And though critics argue that solar tax credits could be better spent, government investment is pushing the state of the art, reducing costs across the board. It's also creating a steady increase in solar efficiency, with technology like thin-film panels from US outfit First Solar and ultra-efficient modules from Sharp (see the chart above). If the current decline in prices continues, the solar industry believes the unsubsidized cost of photovoltaic panels could hit parity with coal in some regions as early as 2016. The economics will also improve when battery tech ramps up, so that solar energy can be stored for use at night.


Thinking about getting solar panels? As we mentioned before, you'll want to hit up the US government's site for information about the Residential Renewable Energy Tax Credit program. The next stop should likely be the Fed's DSIRE site to see if your state or regional bodies will also kick anything in. (In you're in the UK, Canada or elsewhere, you should check your federal government's websites for more information.) Finally, you can find information about choosing an installation company from the US Energy Department and industry-sponsored American Solar Energy Society, though the all-important final decision is obviously all yours.

The debate about solar energy is complex, so you'd better be informed. Though UK-oriented, this Economist-sponsored debate nicely lays out both the pros and cons of sun power and applies very well to the US. If you're interested in following the progress of solar technology, scads of information are flung far around the web. Luckily, Clean Technica has laid out the current state of photovoltaic panel art in a recent article, discussing the efficiencies of both prototype solar modules and commercial panels.

[Image credits: NASA, NREL, AP, Getty Images]

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