So You Think You Want to Go Solar?

So You Think You Want to Go Solar?

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You’ve got your solar-powered battery charger to keep e-waste in check, and your hybrid solar LED lantern to make sure you’re never left in the dark. You even have a solar swimming pool cover, which delivers heat from the sun to your Caribbean-blue pool. Not to mention that über-eco solar-powered attic fan which uses the energy from sunlight to pull hot air up and out of your home, allowing your air conditioner or passive cooling system to work better.

In fact, you’ve completed a total immersion in coolth, defined as being not only eco-friendly but very, very hip to renewable technologies. So what’s the next step?

Since you already have more than a nodding acquaintance with solar energy, you could take that to the nth power and purchase a whole-house solar photovoltaic (PV) panel electricity system, which will give you a roof loaded with solar panels. It may also give you all the electricity you need at a cost of about $20,000 (DIY), or from about $30,000 to $50,000 installed, with all the bells and whistles (34 300-watt panels, rack mounting, inverters, engineering drawings and permits). Good grief, Charlie Brown! But don’t forget to hire a building inspector to make certain your roof is up to the task of shouldering that additional weight.

A 10-kilowatt (kW) roof-mounted solar energy system – which supplies 1000 kilowatt hours (kWh) per month – will occupy 90 square meters (about 970 square feet). At about 3 pounds per square foot of solar panel and rack, this is 2900 extra pounds on one side of your roof. Add the weight of snow, which also obscures the panels’ surfaces and eliminates any energy gain, and you have a very expensive “roof press.” Then factor in the real problem, uplift (wind getting under the panels and lifting both them and your roof off), and you have ample reason to be cautious.

Bear in mind that only one side of a peaked roof is “good” for solar; that is, the side facing south. Assuming your house is 48 feet wide and 60 feet long, you have enough room (1440 square feet on one side) for a solar energy system. If your house is smaller, say 24 by 40 feet, you won’t be able to install the full 10 kW system. Of course, a smaller house generally means less electricity consumed. Factoring in the constant (and almost exponential) rate of improvement on panels, this will mean that soon you will have the opportunity to buy a single-panel 5 kW system. And yes, I’m aware of the (Shockley-Queisser, or theoretical maximum efficiency) limit for single-junction solar cells.

Also, don’t assume that because your personal handyman is familiar with electricity – is perhaps even a journeyman electrician – that he/she knows how to install a solar system. There are almost a dozen pages in the electrical code test book, and – like your high school immersion in calculus – may have been (conveniently) forgotten if never used. Trust only an electrician who routinely installs solar, or a state-licensed solar installer.

That eventuality brings up an interesting dilemma. Why go whole-house solar power now, when rapid improvements in solar technology and wireless connectivity predict better, safer and cheaper solar energy systems just around the corner?

The answer is simple. The current crop of solar panels not only delivers surprising levels of energy, but provides it coupled with equally improved inverters and mounting systems. In fact, given the current cost/benefit ratio, waiting another 5 years won’t make a system cheaper because all new technology has to go through a period when development and commercialization costs must be recouped. Today’s solar technology has already done this and is now creating such a glut of panels (in China, for example) that commercial solar costs have virtually reached grid parity. Grid parity is the point at which renewable energy technologies can successfully compete with coal, oil, gas and nuclear in the marketplace.

Thus, while current solar system costs are probably as low as renewable energy is likely to get, percentage-wise, and energy costs are increasing by leaps and bounds (or at about the same rate as incentives are being erased by regions, states and even the federal government meeting renewable portfolio standards, or RPS’s), early adopters are finding solar energy costs being cut to the bone instead of their bank accounts.

A word to the wise; don’t count on that happening again within the decade. And if solar energy just isn’t your thing, check back for our coverage on other up and coming renewable energy technologies.

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