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Solar Power – Like Vitamin
D for Your House
How to Run Your
House Solely on Solar Power
BY CHERISE THREEWITT
The real question might be, why wouldn't anyone want to
convert the family homestead to function off the sun's rays? Sounds like quite
the formula for happiness, right?
The truth is, deciding to go
solar has some pretty big benefits -- but they're somewhat offset by potential
drawbacks.
Solar power is free,
after the initial investment of setting up the system.
Solar power is also efficient
(although its actual level of efficiency is debated by some experts) and free
of pollution.
But once you decide to go
fully solar -- off the grid -- you've got to cope with foul weather that might
put a damper on your plans.
If you stay on the grid (the
traditional electric system), you can still use traditional utility-provided
power in situations where you can't make enough power or don't have any power
stored.
The goal is often to
eliminate the need for fossil fuels entirely, but this option might be enough
to convert some skeptics who are hesitant to make the leap.
The terminology might also be
off-putting, since "going off the grid" is sometimes associated with
tax dodgers and serial killers.
Rest assured, a wholehearted
solar home is entirely wholesome.
Planning to run your house
completely on solar power requires considerable financial, mental and emotional
investments.
The infrastructure is a
little more complicated, the calculations must be more precise, and a mistake
can leave you without enough juice to get by.
At least there's already a
light to guide you along the way.
Concentrating the Rays
The
first practical instance of controlling the sun's energy might have been when
someone noticed that a magnifying glass, held at the right angle, could set
fires and burn ants.
And from there, it was
practically eons before humans discovered a way to use the sun's rays truly
constructively.
The
first silicon photovoltaic cell (what we know of as "solar panels")
was produced in the United States in 1954.
Our current solar panels are
a direct descendant of this technology -- they've just been made more efficient
over the years.
Over
the years, from the 1950s through now, various residential and commercial
buildings were developed with different solar priorities.
One office building gained
recognition for solar water heating.
Residential milestones went
from sunrooms to hybrid solar/grid systems to standalone fully solar homes (one
of the first of which was completed in 1983).
In 2000, a Colorado family
completed a solar installation that nearly completely powered their home for
their eight-member family.
There
are other useful innovations besides roof-mounted solar panels, such as a
modified version of a radiant heating system.
By carefully routing the
home's plumbing, water can be heated by the sun and, as it's pumped through the
house, that heat can be dissipated to help control the house's temperature.
This type of heat won't add
to the home's electric consumption.
In a nationwide solar home
design competition in 2007, a group of students from Santa Clara University in
California even figured out how to use a solar radiant heat system to help cool
the house, as well as heat it.
As appealing as this idea is,
it may be particularly difficult to execute; a Tennessee couple who designed a
home with a similar system had trouble finding a contractor up to the challenge
[source: Lewis].
The Tennessee house, though
not part of a competition, evokes the same sense of spirit. It's notable for
its use of SketchUp, an architecture and design program from Google.
The home's other features
include energy-efficient LED lighting and insulation derived from corn.
Some
designs give more responsibility and flexibility to the home's occupants.
In the 2007 competition, a
team from Virginia Tech added weather monitors to the house, which, among other
features, would help the residents decide when to open and close insulated
window shutters to maintain the desired interior temperatures as efficiently as
possible.
In 2010, there was a similar
competition in Europe. A group of students in England focused on designing a
prefabricated house that could be ordered and assembled anywhere -- and they
made sure it complied with the country's most restrictive building codes.
They hoped to demonstrate
that prefab solar houses were an approachable and desirable alternative to
custom construction or an inefficient conversion of an existing home.
As a bonus, the assembly-line
simplicity of prefabrication might negate concerns about wasting energy with
new custom construction projects.
Cost,
of course, can make or break any initiative. The price of solar technology has
held fairly steady from decade to decade, but there were a few notable
improvements.
Solar cell prices were
reduced by about 80 percent in the 1970s, which drastically improved their
potential.
And in February of 2009,
First Solar, a manufacturer of solar panels, announced that the cost to make
its wares had dropped to a dollar per watt -- an eagerly-anticipated milestone.
Experts say that "grid
parity" is the necessary milestone to making solar power really work.
Grid parity is achieved when
solar power costs the same as conventional power -- without the help of the
grants, subsidies and rebates that make it possible for many customers.
At that point, the supply
probably won't be able to keep up with demand, since some of the solar panels'
raw materials are hard to obtain in large quantities [source: Hutchinson].
Like Vitamin D for Your House
To
envision how solar power can provide enough juice for a whole house, it's
necessary to cover a bit of the basics.
We've probably all seen
traditional solar panels by now -- flat, glare-inducing, unwieldy-looking
things that jut from rooftops.
They certainly aren't streamlined
in any way, which makes them seem cumbersome.
As we discussed, their
ongoing refinement has gained some critical respect in the industry, but they
still work about the same way.
As solar panels protrude from
the precipice at various angles, they capture whatever sunlight is available,
and convert it to DC power.
An inverter converts the DC
power to AC power (which is what we use to power electronic devices).
And for people who want to
completely power an entire home with the sun's rays, there are systems
available to convert and store extra power in the form of battery energy.
This way, the house still can
have a source of power at night or in poor weather (but -- and this will be
important later -- it can't cover the shortfall of a poorly-designed or
inadequate system).
Solar shingles are a recently
available option, a subtle, streamlined alternative to those telltale glaring
flaps.
They are solar panels, made
from the same materials as traditional solar panels, that also happen to be
shingles, and they look pretty much like a regular roof...perhaps just a bit
shinier.
Solar shingles, contrary to
popular belief, can work even in weak or scattered sunshine conditions (which
implies, but doesn't confirm, that shingles outperform panels in such
circumstances).
So, why does converting to
solar take a bit of persuasion?
Generally, houses in the
United States can get heat either from gas or from electricity.
For the sake of argument and
purposes of this article, let's assume that someone gung-ho ongoing solar wants
off the grid entirely -- and that means no gas or electricity.
So, solar power needs to
accommodate for heating, air conditioning (which, by far, is one of the biggest
drains of power in a house), other parts of the house's infrastructure like
lighting and vent fans, all major appliances (refrigerator, stove, washer and
dryer), and other electronics like the microwave, stereo, television and
computer.
This list, of course, is by
no means comprehensive (how many members of your family need to constantly
charge their smartphones or tablets?), and there are a lot of variables.
If your house is huge or
you're a power hog who leaves the electronics on all day, you'll need a more
intense solar setup.
It would be nice to assume
that anyone serious about performing this conversion is already pretty
conscious of consumption and makes an effort to reduce power usage, like using
insulated window shades instead of cranking the a/c, or foregoing a dishwasher
that heats up and churns for hours.
Right now, that's probably a
fair generalization, but as solar goes more mainstream, the eco-conscious early
adopters might not be the majority.
The point is, you have to
calculate all the electricity your house uses, and for the amount of time per
day, and assemble a solar panel setup that can meet that demand.
If it seems like too much,
try cutting back on your consumption for a while and see if the numbers become
more realistic.
Though it's certainly
complicated and definitely not cheap, people with the resources to design and
build a solar-power home from scratch have some advantages when it comes
to flexibility.
A lot of subtleties come into
play when planning a residential solar system for a specific existing house.
The actual design of the
house is one such factor. How big is the roof's surface (which affects its
potential solar surface area)?
What direction does the roof
face, and what's the degree of its pitch? Are there obstructions that cause
partial shade?
You can see most of these
obstacles are impossible to change, but you might still be able to work with
them. Location is also a factor.
A house in Scandinavia, with
its notoriously short days, won't fare as well as a house near the equator.
The average number of sunny
days matters too; if it's raining until nightfall, it doesn't particularly matter
if nightfall comes late.
When you're trying to figure
out how much power you can produce and how much you'll need, it's helpful to
look at meteorological data for your area.
It'll show you how much
sunlight you can expect in any given month, based on past averages.
You should have copies of
your utility bills nearby, which will let you know how much power you use, and
you can use this information to figure out if the system you want will make
enough electricity.
General guidelines recommend
a setup that generates 1 kilowatt per 1,000 square feet of house.
Don't let your optimism take
over -- you need to ensure you can produce enough power to get you through the
worst times, not the best. You'll want to literally prepare for the proverbial
rainy day.
Paying for What's Free
The
sun's rays are available to anyone for the taking, but it takes a lot of
expensive equipment to turn them into power.
Solar panels are the
least-expensive form of renewable energy, but they still cost three to four
times as much as traditional energy.
If you're serious about
making the switch, don't let that discourage you -- there might be ways to make
it happen.
"Grid
parity" is a term that's thrown around to describe one of the ultimate
goals toward solar power sustainability -- when alternative sources of
renewable power (which, in theory, includes other sources besides solar) will
cost the same as traditional power.
It's estimated that one of
the milestones toward achieving grid parity is when the manufacturing costs for
solar power infrastructure drop to about 65 cents per watt [source: Hutchinson].
Then, it can be sold at a
profit for the companies, but it'll still be easier for homeowners to make the
leap.
Before
the housing bust, banks were known to lend a little extra to customers who
planned to invest in efficient energy improvements and green technology, but
it's a bit more difficult now to make such a case convincing.
A "green mortgage"
might still be an option for homebuyers who have good credit, and reliable
numbers that demonstrate good research and commitment should help.
A solid argument will show
the bank how much the investment will save, and the time period necessary to
recoup the costs.
Energy-related
incentives and rebates vary so much, and change so frequently, that anyone
considering a solar home conversion should take a close look at state-specific
benefits.
The right combination of
grants, tax credits and per-watt rebates might make the initial investment more
affordable than many homeowners think.
As of 2012, the Energy Policy
Act of 2005 still provides owners with a tax credit of 30 percent, or up to
$2,000, in the year the system is installed.
Beyond the short-term
benefits, experts estimate that for every thousand dollars of annual energy
savings, the value of your home will rise by $20,000 [source: Solar Energy World].
If
and when you sell your solar-powered home, the investment should pay off
big-time.
Energy costs also vary by
location, so living in a less-than-sunny state might still provide considerable
benefits (where electricity costs so much that the savings are worth the
investment, even if the house doesn't generate as much power as it would
somewhere else).
As
utility costs rise and your neighbors pay more for power, you might actually be
entitled to a refund from your utility company.
If your solar panels make
more power than your house uses, you can sell your extra power back to the
grid.
Companies that install
residential solar power tout this benefit as an easy way to recoup your
investment, but of course, the results can vary widely (and the laws about this
also vary depending on where you live). That's good motivation to pare down
your family's energy consumption.
Some
locales have made an effort to bring solar power to the masses.
Berkely, Calif. and Boulder,
Colo., have municipal solar programs, in which the city makes the
infrastructure investment and recoups the cost through taxes.
Other locales offer special
loans that are paid back through additional property taxes.
And at least one company has
come up with a leasing program (kind of like leasing your cable box or
satellite dish from your cable company), focusing on states that have
particularly high energy costs to appeal to as many consumers as possible.
There
is a dark side to solar power -- in some places, it truly isn't feasible.
Germany has provided more
than $130 billion in solar power subsidies, only to decide in 2012 that those
benefits would be phased out.
The infrastructure, they say,
is too expensive and inefficient to use on a large scale, even if the sun's
rays are free.
The country's landscape and
orientation might just be unsuitable to make the investment sustainable;
experts figure that Germany's seemingly impressive solar initiative will have
no effect on reducing global warming.
But
if you don't live in Germany, the Netherlands, or any other country with
notoriously short daylight hours, go outside and celebrate.
If you want to convert your
house to full solar power, it's probably possible.
Author's Note
I
read a lot for this article (more than usual) because I got distracted by the
chasm between practical solar homes and showpiece solar homes.
In both cases, most
solar-related technology innovations were pretty much what I expected.
The extreme homes --
million-dollar mansions and such -- are fascinating and beautiful, and of
course I'd want to live in one, if I could.
The problem is, such design
studies (and that's really what they are) don't serve much real-world purpose.
They're aspirational, but the
average person can't afford one.
And if the average person
can't afford a mansion that was designed to show off solar-powered capabilities,
the end message is that the average person probably can't afford a
solar-powered home.
That's
unfortunate, because, after all, shouldn't the residents of a solar-powered
house be interested in living more efficiently, in general?
By which I mean, perhaps each
resident does not need their own several thousand square feet.
Even if a huge roof covering
a huge house generates enough solar power to run off the grid, there are other
resources being used inefficiently.
Not
to judge the owners of solar mansions too harshly -- after all, such projects
certainly generate positive publicity for the technology.
But my interests found their
way to the other end of the market, toward the homeowners or homebuyers who
want solar power, but are forced to consider the investment, carefully weighing
the benefits against the drawbacks.
I was
surprised to discover that, aside from the initial investment as compared to
traditional power, there really aren't any drawbacks.
A solar system can be
designed for almost any house and can run so smoothly that the owners will
barely notice there's anything different.
That's when solar power will
truly be a success -- when it's the norm rather than the exception. It's hard
to say how long it will take before we get to that point.
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