Using Solar Energy

Our most reliable power source. by rlz
Our most reliable power source. by rlz

Have you ever considered making use of solar energy? Unsure how to get started? Let this architect show you the way.

The world is today facing a daunting energy challenge. Though a full third of the globe’s population still lacks electricity, energy use among the remaining two-thirds of humankind is soaring. Within just the next few years, global energy consumption is expected to increase by as much as 50% — provided such prodigious quantities of energy can be provided when and where needed. And, while the bulk of energy consumption has historically occurred in developed nations (with the U.S., for example accounting for 1/4th of all global energy use), the developing nations of the world are scrambling to catch up. What will happen as the citizens of China and India clamor for per capita energy consumption on a par with that of the average American citizen? How will they be accommodated?

The generation of power also has its costs. In addition to the traditional economic considerations of supply, demand, cost and availability, there are those of speculation, power plant construction, power grid maintenance, foreign control of fuels, and the tremendous (and ever-growing) carbon footprint of many fuel uses. Clearly, alternative energy sources must be sought. And one of the most obvious alternative sources to the fossil fuels, hydroelectric power and nuclear generation on which we now predominately rely is solar power.

Solar power systems convert the sun’s light energy into direct current electrical voltage. Photovoltaic (or PV) cells allow electrons to be excited by solar energy, creating an electron flow that becomes electrical current. And the sun is a prodigious power plant; it churns out more power in a single second than our greatest current power plants can produce in a year. All that remains is for us to capture an ever-increasing slice of that solar power. Solar power is estimated to peak at around 40 watts per square foot of sunlit surface. As an energy provider, an effective square yard of well-placed PV cells can thus replace roughly one barrel of oil per year.

Solar power offers many immediately obvious benefits over other energy sources. Destined to shine on for millions upon millions of years, it is the ultimate renewable resource, depleting none of our earth-bound resources. It is also one of the cleanest energy sources, having virtually no carbon footprint, and contributing nothing to air pollution, smog or acid rain. Another of the great advantages of solar power is that, except for minimal system and infrastructure maintenance, the costs of power generation never rise as they inevitably do with other power generation systems. Solar power systems also pay for themselves more readily than almost any other energy system. Payback for even stand-alone residential solar power systems has been estimated at as low as 15 years. Because of these advantages (as well as that state’s growth in energy demand), California has put in place legislation that encourages the building of solar residential roofs and mandates standards of performance. The United States has seen recent growth in the installation of PV systems of roughly 20% per year.

What comprises a PV installation? First come the PV cells themselves, fabricated and assembled into a module, generally several square feet in area or more, embodied as a weatherproof panel. Groupings of modules are arrayed, typically across a steeply sloped roof surface, and are wired together in series. Their collective direct current is routed through an inverter, which converts the power to the alternating current existent on our electrical grids and used throughout our homes. Other equipment — wiring, conduit, junction boxes, switches, disconnects, meters, etc. — complete the overall PV system. PV Installations are quite often ‘on-grid’ systems, meaning they are connected to the existing power grid, so that excess power generated by the PV system flows onto the grid for use elsewhere, and also so that the grid can supplement the PV system at night and through extended cloudy periods.

PV cells may be assembled in varying ways using a range of materials, each offering different cost-efficiency combinations. Thin film cells employing amorphous silicon generally operate at the lowest efficiency, with multicrystalline and monocrystalline cells offering escalating performance. However, the technology of the composition and fabrication of PV cells (and thus their resultant cost-efficiency combinations) keeps advancing rapidly.

How does one determine whether to use solar power? First, one should obviously be where the sun is. The highest possible amounts of daily solar radiation are received by America’s Southwest — generally the states of California, Nevada, New Mexico, Arizona, Texas, Colorado, Utah, Oklahoma, and Kansas — and most of South Florida. Diminished amounts are received by areas radiating northward and eastward from those states. The least amounts of solar radiation or received by the Upper Midwest states and New England. Despite this variability in available solar radiation, however, just about any location in the continental U.S. can viably support a solar power installation (though the overall payback period will likely be extended).

Orientation of PV cells is the next consideration. Sloped roof applications are ideal, as the slope of the roof may position panels more closely to perpendicular to the angle of the sun’s descending rays. PV systems should also ideally orient solar panels to due south or just west of south, to receive the Sun’s most directly overhead radiation. Solar panel systems designers and fabricators often use year-round solar angle data and calculations to determine the most ideal orientation and angle for PV modules. Finally, one should beware of shading or obstruction of the PV cells. Shading, whether by clouds, trees, or adjacent structures, will significantly reduce power generation.

Solar roof systems are most often constrained by the available roof area (or the available roof area that is of the proper orientation and/or tilt). There are, however, other mounting arrangements, in which PV panels are applied to walls, atop poles, or are ground-mounted. More and more designers are also experimenting with photovoltaic systems that are more seamlessly integrated into other building components (so-called BIPV, or building-integrated PV systems).

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Comments 13 comments

Singular Investor profile image

Singular Investor 6 years ago from Oxford

Excellent hub - but why do people put solar panels on their roofs ? Why not just put them in the garden (assuming they've got one of course) it seems like a lot less hassle and if anything goes wrong with them they're easy to get access to. What is this infatuation with roofs all about ? I don't think the extra 20 feet closer to the sun is going to make any difference.

And P.S. Why don't they put solar panels on wind turbines ? Wind turbines stand out in the sun all day long, surely they could stick sone solar panels on the bit that doesn't move and get two sources of energy for the price of one? Seems nuts to me to build a whopping great tower and totally underuse its possibilities. But WTF do I know ?

rickzimmerman profile image

rickzimmerman 6 years ago from Northeast Ohio Author

Singular investor: Perceptive comment: some of the largest solar panel arrays ARE just placed on the ground (as if in a garden). The advantage of roofs is that they are sloped anyway, and throughout all of North America the sun is always shining down at an angle, never perpendicular to the ground. In fact, the sun angle in winter is very low to the horizon, so a steep sloped roof is better than level ground. Also, roof panels are out of the way, won't very likely get damaged, and can be washed off regularly by rain, which might not happen if they're on the ground. As for poles, there have recently been developments in creating wraparound flexible solar collectors that can wrap a highway pole and thereby power its light. (Once again, you're just about right on the mark.)

Singular Investor profile image

Singular Investor 6 years ago from Oxford

Cool thanks for the info. Rick, I had never heard about the wraparound solar collectors, but self-powering street lights sounds like a good idea that should be expanded to include lots of other things.

rickzimmerman profile image

rickzimmerman 6 years ago from Northeast Ohio Author

In cities throughout the country, many streetlights and traffic signals are either coming off the power grid or depending on it less, as municipalities implement solar powered lighting.

Chef Jeff profile image

Chef Jeff 6 years ago from Universe, Milky Way, Outer Arm, Sol, Earth, Western Hemisphere, North America, Illinois, Chicago.

In our area of Illinois wind turbines have been popping up like weeds! I also have started using solar power in my home - nothing major, just some lighting that seems to be better to use with "free" electricity. Did all the Christmas lights that way this year.

Great hub!


Chef Jeff

rickzimmerman profile image

rickzimmerman 6 years ago from Northeast Ohio Author

Chef Jeff: Another great way to add solar energy is with solar/LED lawn & yard lighting. Maybe the best part is not having to run power lines. Also, don't feel bad about indulging in microwave popcorn or burritos. Turns out microwave cooking is the most energy-efficient of all. — Rick

stars439 profile image

stars439 6 years ago from Louisiana, The Magnolia and Pelican State.

Most definitely the best way to save money on an electric bill,and reduce polution. Great hub. God Bless

adair_francesca 5 years ago

fantastic hub! Using solar energy is really helpful especially at this time everybody want to save in every single way that they can. What's great about solar energy, it is free so once you have panels installed you do not need to worry about running out of electricity because the sun always shine.

rickzimmerman profile image

rickzimmerman 5 years ago from Northeast Ohio Author

Thans, a_f! The more of us that go solar, the more we help the planet and future generations.

riachu 5 years ago

I live in Northern West Virginia along Ohio river. I have a son room and garage that have souyhern oriented roofs. Would like to put up solar panels to supplement electricity. All the inverters I see have AC outlets on the ends of them. Are there inverters that have wires to hook into the main electric box to supplement directly into the home's electrical grid?

rickzimmerman profile image

rickzimmerman 5 years ago from Northeast Ohio Author

You might contact your local electrical supplier to see whether it's feasible to directly connect to your home's incoming electrical service panel, and how. (There may even be some local utility service regulations that govern such a connection.) Or investigate a battery storage device that will allow your panel to charge batteries that are then drawn on by household appliances, night lights, landscape lighting, back-up emergency power, etc. There are also direct-connect solar-panel-to-hot-water-heater systems you might try.

pinto2011 profile image

pinto2011 4 years ago from New Delhi, India

Quite enriching and knowledge imparting hub. Things will surely bent on the solar side as it is the only unlimited and pollution free energy that is coming at free of cost, we only need some more research and equipment to trap it.

rickzimmerman profile image

rickzimmerman 4 years ago from Northeast Ohio Author

Thanks for viewing, Pinto!

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