Frequently Asked Questions
Will Solar Work for You?
We are glad
you’ve taken the time to review this list of frequently asked
questions. The most common question we are asked is, “I’m
interested in solar power for my home (or business), but I’m not
sure if it really works here or what it costs.” We’ll answer these
and many other commonly asked questions. After reviewing this
information you’ll be much better informed about solar power and
when you call us we can discuss your personal situation you’ll be
able to communicate with us at a much higher level.
Before we get
started here is a quick guide to some terminology. An individual
solar panel can be referred to as a “solar panel” or solar “module.”
A number of modules wired together to generate electricity is
referred to as a “solar array.” Solar panels that make electricity
are referred to as PV modules, short for “photo-voltaic.”
First things
first, yes, solar power works just very well in our area of
Washington State. Here on the north Olympic and Kitsap Peninsulas
we average approximately 3.5
hours of
full sun per day. That is about 70% of the sun resources of
southern California. However, unlike southern California most of
our sunshine arrives between March and September when our
electricity needs are low, especially for homes designed to not
require air conditioning. If your system is tied to the grid, you
can sell that electricity back to the Californians during their peak
energy usage.
For another
comparison, western Washington on average receives more yearly
sunshine than does Germany
on average. This is significant because Germany leads the world in
the number of installed solar modules with about 50% of the world’s
deployed solar modules. If Germany can effectively utilize solar
power so can western Washington. And if we can do it, so can the
rest of the United States since most of the U.S. receives even more
annual sunshine than we do.
The bottom line
is solar power is the most practical way to make renewable energy
for a home or business. The following questions and answers will
help explain why this is true.
All utilities
in Washington State are required to allow their customers to install
solar photo voltaic
(or PV
for short) renewable energy systems and provide “net
metering”
to their customers. Net metering allows you to use the solar
electricity your system is generating and to sell any surplus to the
electrical utility at the same retail rate they charge you for their
electricity.
Net metering
regulations have dramatically improved the average person’s ability
to create and use their own solar power. Here in the northwest our
peak energy usage is typically during the wintertime when the days
are shortest, while our peak sunny days are in the summertime. With
net metering, it doesn’t matter. Net metering allows us to earn
credits in the summertime with our grid tied solar PV system and
sell those credits back to the utility in the fall as the days get
shorter and our energy needs start rising again. During the winter
when your solar PV array isn’t producing as much power as your home
or business requires the grid acts as your virtual “battery”
providing steady, reliable power. With net metering you also save
the expense and maintenance headaches that go along with batteries.
Batteries add approximately $10k - $20k to the cost of the system
and must be replaced every few years. We generally discourage the
use of batteries.
We can formally determine the potential of your home or
business for solar power through a
site evaluation
of your home or business (see #20 below). But we’ll give you some
basic facts now so that you can get a feel for your site’s solar
potential.
First, sunshine is
your fuel
so you need a sunny roof
for a
roof mounted PV system
or a
sunny area
on your property
for a ground mounted array.
Solar panels don’t work in the shade. So what do we mean by
“sunny?” During a solar site evaluation we will accurately measure
your site’s annual solar resource with the click of a button on our
solar SunEye. Sites with year round sunshine from about 9 am – 3 pm are
generally good solar candidates. A little morning, evening, or
wintertime shading can be tolerated and you can still have good
overall PV performance.
A south facing
roof is the best
orientation for a roof mounted system and the best
roof pitch
for year round PV performance 5:12 to 12:12. However, if
your roof is steeper or shallower or if you have an east or west
facing roof – DON’T PANIC! Sunny, south facing roofs with a roof
pitch shallower than 5:12 or steeper than 12:12 are still excellent
solar platforms. The difference in production on a 3:12 roof
compared to a 5:12 roof is only about 3.5%.
Chris and Carolyn
Eagan’s home has an excellent sunny, south facing roof with a
relatively low pitch (3:12) now outfitted with a 7.2 kW PV system.
East or west facing roofs, if relatively unshaded, also
serve as excellent solar platforms. A roof can be oriented up to 30
degrees east or west of due south and lose only about 5% of the
potential solar gain. If you have an east or west facing sunny
roof, the shallower the roof pitch, the better for overall solar
gain. In determining the location and design of a solar array, our
goal is to locate your solar array where it will generate the most
power over the course of the year while looking attractive and
intentional on your property.
Jeff and Shelly
Randall’s home in Port Townsend utilizes their west facing roof to
generate electricity from the sun with a 2 kW PV system.
If you have a flat roof it is possible to orient the panels
south through the use of a fixed tilt racking system. This is
typically the only situation where we will tilt or “rack-up” a solar
array. Normally a solar array is “flush mounted” parallel to match
the pitch of the roof.
This Bremerton
duplex utilizes its flat roof with full sun exposure to generate
electricity for its occupants.
As a general rule of thumb, it takes approximately
75 -
90 sq. feet of roof area to
accommodate 1 kW of PV array.
Solar panels
are roughly 3 feet wide by 5 feet high and each module generates
approximately 200 watts (note: exact dimensions and power outputs
vary by manufacturer).
6 kw system
on garage/ADU in the Sequim Bay area. The garage was located and
designed to maximize solar production on the roof. The roof has an
8:12 pitch and faces due south. The solar modules are Sanyo 200
watt panels. 30 modules x 200 watts = 6000 watts or 6 kW.
We attach our
solar arrays to the structure of the roof using equipment
specifically designed for the purpose. Heavy duty lag bolts attach
the array to the roof framing. The roof penetration is sealed and
flashed with the appropriate type of materials depending upon the
type of roof we are working on. All roofs are designed to be safely
penetrated and sealed against water penetration. If you look at
your own roof you will see roof vents, plumbing vents, skylights,
etc. all safely installed and sealed.
The equipment
that lies between your solar modules and your roof is made of
stainless steel, aluminum, or galvanized steel to prevent rust and
all components are engineered by the manufacturers to withstand wind
speeds in excess of 100 mph.
Aluminum
rail, standoffs, and heavy duty stainless steel lag bolts hold the
solar array to the roof. Flashing and sealant used at each point of
roof penetration ensure no leaks on composition asphalt shingle
roofs.
On metal
roofs Deck-tite style flashings are used over the standard metal
standoffs to prevent any roof leaks and ensure a strong attachment
can be made to the roof structure. These flashings are warranted
for 25 years.
On a flat
roof, the standoffs are attached to the roof structure and sealed
before the rails are attached.
Power Trip
Energy has successfully installed solar PV arrays on many types of
roofing including metal, asphalt composition shingle, cedar shingle,
concrete tile, aluminum shingles, fiberglass, rolled asphalt (flat),
and corrugated metal. We have the experience gained from over 180
installed systems and we are confident we can work safely on any
roof surface that is a good location for a PV array.
Yes, if a roof is has too much shade or is otherwise not
appropriate for a solar array, a
ground mounted
system is often a
good solution. We have had customers who take this as an
opportunity to build that tool shed they always wanted but with a
roof designed specifically for a PV array.
3 kW on tool shed
roof in Sequim Bay area built specifically as a platform for the
solar array. The power from this system is transferred to the
nearby home’s service panel. We have trenched power in this manner
up to 300 ft.
Alternatively Power Trip Energy can install your PV array on
a pole or multi-strutted ground mount structure. Ground-mounted PV
is more expensive as compared with a roof mounted array because of
the need for structure, trenching, and in some cases, additional
fencing.
Pole mounted
PV array in Sequim. Poles work best when a small PV footprint is
desired. Trackers can be utilized on this type of array but
increase the cost and complexity of the system.
This ground
mounted array on Bainbridge Island uses 2” heavy duty galvanized
pipe. This type of structure works well for large ground mounted
systems and is adaptable to uneven terrain.
Ok, so you’ve
got a sunny spot picked out.
How much electricity
over the course
of an average year can you expect to generate with your solar PV
system? Are you ready for some math? Each 1 kw of installed solar
panels generate approximately 1,000 to 1,200 kilowatt hours (kwh) of
electricity over the course of an average year on the north Olympic
and Kitsap Peninsulas (1 kw installed = 1,000 to 1,200 kwh/yr).
Sites with full sun where the solar panels are oriented due south
should expect to be at the upper end of this range. Calculate your
roof area (75 – 90 sq. ft. of roof area required per kW of PV array)
and multiply it by this figure and you’ll have an idea of the annual
electricity a PV system on your roof could generate. Shading will
decrease this output based on the percentage of shade a location
receives through the year.
Why focus on
the amount of electricity per year as opposed to per day? Here in
the northwest we receive very different amounts of sun in the summer
vs. winter months. So rather than try and estimate per month
production we focus instead on a yearly average. With net metering
and Washington State’s production incentive program (discussed
further below) the total power generated over the course of the year
is what matters.
You should review your
electric bill
to get an idea of how much electricity you are currently consuming
over the course of the year. Your utility bill will express your
energy consumption in kilowatt hours (kWh) per day, month, or year
(typically referred to as average daily consumption). You may be
surprised to see how much energy you use and how big a solar PV
system you would need to satisfy 100% of your energy needs. However
the economics of Washington State’s financial incentives allow you
to cover your annual electricity costs with a smaller system.
See the Power Trip financial incentives page
for more information.
As you consider generating your own renewable energy, you
should also consider reducing your overall power demand through
conservation.
On average, it is 3 – 5 times cheaper to save a watt
of energy through conservation than it is to generate that same watt
of energy through solar power. Conservation techniques include
designing your home to take advantage of
passive solar
for both heating and natural light,
energy efficient appliances
such as Energy
Star certified, super
insulation
and high efficiency
windows and
exterior doors,
and compact
fluorescent light bulbs
which are 4 – 5 times more efficient than incandescent bulbs or
LED bulbs
(now becoming available) at 90% more efficient than incandescent.
An incandescent bulb is actually a heater that happens to produce a
little light – 90% of its energy consumption is lost to heat, only
10% is used for light. Compact fluorescents are also cheaper than
they’ve ever been and are now designed with a warmer, more natural
appearing light. Other conservation techniques include utilizing a
solar dryer (a
fancy name for a clothesline) and the elimination of
phantom loads
(appliances that
use power even when not in use) by installing power strips or kill
switches.
Typical costs
range from $7,000 - $10,000 per
installed kilowatt (kW)
before the federal income tax
credit.
Because each system has common components, the larger the system,
the lower the cost per kilowatt. These components include
solar panels
which generate the power (about 60% - 70% of system cost), an
inverter or microinverters
which convert the DC power produced by the solar panels to AC power
that can be used by your home and the utility grid, a
production meter
that measures
your
gross electricity production, one or more
safety shut off switches
which isolate your solar panels if they require maintenance,
wiring, racking
for the solar
panels, and finally the cost of
installation.
The larger the system, the greater percentage of the budget goes to
your solar panels and the lower price per kilowatt you can achieve.
From left to right:
SMA 7000 watt grid tied synchronous inverter with integrated DC
disconnect, system production meter above the AC disconnect
(middle), and the utility revenue meter (pre-existing) which has
been retrofitted by the utility to be a net meter capable of
metering both incoming and outgoing electricity. Not pictured is
the home’s electrical panel (inside) behind the utility net meter
where the PV system interconnects with the grid via a two pole
breaker.
9. What financial incentives are available for solar PV systems?
Washington
State and the federal government currently offer excellent financial
incentives for solar PV systems. At the time of purchase customers
in Washington pay no sales tax (currently exempt through June
2013) and receive a 30% federal income tax credit on the
total cost of the system, including installation (authorized through
December 2016). Some utilities also
offer rebates on PV systems at the time of purchase (Clallam
PUD offers $500 per installed kW).
Several
financial incentives also exist which boost the value of the
electricity that is generated by the grid tied PV system. The first
is called net metering. Washington State law requires all
utilities to allow their customers to interconnect their renewable
energy system to the grid (subject to connection rules) and receive
credit for electricity generated at the same retail rate they charge
their customers. In addition, once a year a production incentive
payment is paid to customers of participating facilities of 15 cents
or 54 cents per kWh for all electricity generated. To receive
the higher rate of 54 cents per kWh both the inverter and modules
must be manufactured in Washington State. In our area Puget Sound
Energy, Clallam County PUD, Seattle City Light, Tacoma Power, and
Mason County PUD #1 and #3 all participate in this voluntary program
with the State of Washington. These utilities receive tax credits
from the state equal to payments made to their customers for the
production incentives. In addition, grid tied PV customers can sell
their green tags or carbon offsets from their PV
systems to a non-profit. A payment once a year is made to the
customer for the green tags for all the electricity they produced
that year because that electricity was made without burning carbon
dioxide.
Once you add up
all these financial we commonly see that the first year’s financial
returns amount to 4% to 9% of the net cost of the project. If these
financial incentives sound complicated, don’t worry, as part of your
contract with Power Trip Energy we will prepare and mail in all
these forms for you. More information on the current state of the
financial incentives is located on the Power Trip Energy
Financial Incentives
Page
These solar
modules manufactured by Silicon Energy of Arlington, WA when
combined with an inverter also made in Washington State (also
available from Silicon Energy) qualify for an annual production
incentive payment of 54 cents per kWh.
The
solar modules
we use carry 20 – 25 year
warranties
(depending upon the manufacturer). Most modules are warranted to
perform at 80% of their original manufactured power at the end of
the warranty period. What is their overall life expectancy? It is
hard to know. Solar panels constructed by Bell Labs in the 1950s
are still working today, after over 50 years.
Inverters
carry
10 – 15 year warranties
(varying per
manufacturer) and the entire system contains no moving parts.
We sell high quality components so that we (and you too!) can sleep
well at night. If you have a problem with your system, we’ll
be there to take care of it.
.
How long does it take for a solar
panel to generate the same amount of energy (output energy) that
went into its manufacture (input energy)?
A recent
study by the National Renewable Energy Laboratory conclusively
demonstrates that energy payback for photovoltaic systems, in the
worst case scenario, is less than 4 years. Evergreen Solar has
studied their manufacturing process and is claiming 24 month energy
payback. Given that PV module lifetimes are generally in excess of
20 years, a PV system will produce far more energy than went into
its manufacture over its lifetime. Technological progress in the
years since the issuance of this report has tended to bring down the
energy input of PV manufacturing yet further, as solar cell
manufacturing processes become more efficient. For more information
about this and other “myths” of solar energy, please see: http://www.seia.org/cs/about_solar_energy/myths_and_facts
Solar grid-tied
PV systems have no moving parts and are nearly maintenance free.
The tempered glass surface of the panels naturally shed water (and
any accumulated dust) and are about as tough as a car’s windshield.
Manufacturer’s rate solar panels to withstand 1” hail at 50 mph
(hopefully we’ll never see hail that big here!). We mount the
modules about 4 – 8 inches above the surface of your roof so that
stray branches or leaves will not be trapped under them and to allow
natural air circulation under the panels keep them as cool as
possible thereby boosting electrical output. In a particularly
dirty or dusty location, it can’t hurt to clean the modules during a
period of dry weather when there is no rain to take care of this
chore. Most of our clients do not bother with this task. With grid
tied PV there isn’t much to do except read your meter and inverter
and watch your kilowatt hours of renewable energy add up.
In the case of
a power interruption, the inverter is designed to immediately shut
down. This is a safety measure built in to ensure that during a
blackout your solar array will not back-feed the grid and
potentially injure utility service personnel. If you are interested
in having a back-up power source in times of extended power outage,
we recommend you consider a small, efficient generator. A solar
array is independent of and will not interfere with a back-up
generator.
There are
several reasons we do not recommend batteries for back-up power.
The most economical batteries available today are flooded lead acid,
deep cycle batteries (think heavy duty car batteries each one about
the size of a five gallon gas can). First, on a residential scale,
they and the additional equipment needed, are quite expensive.
Second, they require power management and regular maintenance
(checking and refilling water levels, unless you spend an extra
premium on gel or AGM batteries, and don’t even ask about NiCAD or
Lithium batteries). Third, they must be replaced periodically even
with the most diligent maintenance and care. Fourth, you will need
a large physical area to house 8 or 16 of these gas can-sized
batteries, which by the way are toxic and potentially dangerous.
Fifth, in time of a power outage, even with a massive battery bank,
you will be limited to the amount of power stored in your batteries
and the limited power your solar panels can put back into them.
Because power outages most often occur in the winter, when days are
short and skies are cloudy, this may not be very much power. So to
back up the batteries you may still need a generator. Have we
talked you out of batteries yet?
If you are
still interested in back up batteries or an off-grid system, we will
be happy to work with you. Designing a successful off-grid home and
adapting to an off-grid lifestyle is a serious undertaking. If an
off-grid home is the best solution for your situation, we will be
glad to help.
This is a question we get a lot, “Should I act now or wait for the
big breakthrough in solar that I hear is coming?” Keep in mind that
solar PV is now a mature technology. Solar panels were first
developed in the 1950s and their price per watt has dropped from
$1,400 per watt in the 1950s to around $3.75 - $5.75 per watt today. Solar
PV manufacturers include companies recognizable in the electronics
industry such as Sanyo and Sharp. While solar PV manufacturers
today continue to make improvements in efficiency and strive to cut
costs, these improvements tend to be incremental.
Here at Power Trip Energy, we
receive press releases nearly every day about new developments in
solar technology, usually focused on improved efficiency or
decreased cost. We have been seeing reports like these since our
business was first established in 2003 and they are increasing in
frequency as solar gains momentum. Most of these reports originate
from commercial laboratories or academic institutions and are likely
designed to generate more research and development funding. Keep in
mind that any product currently being developed on a laboratory
table is years away from being deployed commercially, and in fact
may never prove commercially viable.
The Sanyo and
SunPower PV modules we use are
about 20% efficient, which is the highest efficiency available on
the market. The PV modules on the Hubble space telescope are 40%
efficient (using exotic materials) so we know higher efficiencies
are technologically possible, just not able to be mass produced at
competitive prices right now. Many of the new developments we hear
about currently involve thin film (amorphous) PV technologies
that claim a decrease in the cost per watt. The challenge with thin
film modules is they are much less efficient in terms of watts per
square foot (about 8% - 10%) than conventional framed modules (like
the Sanyo modules). The thin film route is being pursued by giants
like Sharp and Honda, and startups like NanoSolar and FirstSolar.
On a commercial or utility-scale, thin film may be a better option
if the price per watt is lower and roof space or land area is not a
limiting factor. However, on the typical residential roof our goal
is to generate as much power as possible in a finite space. Framed
mono or polycrystalline PV modules such as made by Sanyo are usually
just the ticket.
1.3 kW thin film PV array (dark
area on barn) at Wildberry Farm owned by the Cochrane family. If we
had used framed modules we could have fit 3 kW in this same area.
So to wait or not to wait, that is
the question. There are several reasons why we do not recommend
waiting for the “big breakthrough.” If you are building a new home
or business, it is best to capitalize the solar aspect concurrent
with the rest of the project, as there are excellent financial
incentives available right now. A second reason is that acting
means changing the status quo. We are contacted by more than a few
folks interested in solar but reluctant to act, expressing the
desire to wait and see what comes. Our experience has been that
these folks don't ever seem to find what they are waiting for.
Changing the status quo does not come easy. We think that
American’s tendency to wait for something better to come along and
continuing the status quo has gotten our society to its present
energy situation, which to us is unacceptable. We want to change
the way America makes its electricity. Our sights are set high.
If you have the ability to move
ahead with your PV system now we urge you to do so! We hope to see
continued increases in efficiency and decreases in PV pricing. But
we also think that 5 or 10 years from now if you hear about such
developments, you will not feel disappointed that you acted too
soon, rather you will take pride in the fact that you have helped
bring about this progress.
15.
What are the environmental benefits of PV?
Solar electricity generated at
your home or business is a lot friendlier to the environment
than the electricity from the grid, which relies primarily on fossil
fuels, nuclear, and massive hydro projects. Fossil fuels contribute
significantly to many of the environmental problems we face today –
greenhouse gases, air pollution, and water and soil contamination –
while renewable energy sources contribute very little or no
pollution.
The use of fossil fuels has significantly increased
greenhouse gas emissions creating an enhanced greenhouse effect
known as global warming. Renewable energy technologies, however, can
produce heat and electricity with a very low or no amount of carbon
dioxide emissions. Specifically, each installed kilowatt of PV
prevents 15 tons of CO2 over a 30 year period compared to that same
electricity generated from coal.
People
often think of the electricity we use in Washington State as being
“green” because it is generated by hydropower. In actuality, only a
portion of our electricity comes from hydropower. By 2007, over 56%
of PSE’s power supply profile was coming from fossil fuels and 42%
from hydropower. See the fuel mix from PSE’s web site @
www.pse.com/energyEnvironment/energysupply/Pages/EnergySupply-Electricity-PowerSupplyProfile.aspx
below:
.
* Other equals biomass,
landfill gas, petroleum waste, wind and solar.
In 2007, PSE sold
renewable energy credits (RECs) associated with the power output of
its two wind-power facilities, so this power is not included in the
fuel-mix report.
Source of data:
as reported by PSE to, and published by, the State of Washington
Office of Community, Trade and Economic Development, Energy Policy
Section, 2007.
Also, here in the NW, we are especially aware of the
damage done by hydro-power producing dams, as they are the major
factor in the devastation of one of our most valuable resources, the
native salmon runs. The loss of salmon has decimated the NW fishing
industry and has had significant negative impacts to local Native
American cultures.
16. What is
distributed energy?
Solar PV
grid tied systems are examples of distributed energy systems.
Instead of the electricity being generated at a far away power plant
and transmitted by high voltage power lines, the power is generated
at the point of use on the roof of the home or business. Grid tied
systems first supply energy to the home or business where they are
located and excess electricity is fed back to the grid for use by
other consumers. Typically no improvements need to be made to the
utility lines to accept the back-fed power from grid tied systems.
Grid tied solar PV systems can
turn every sunny roof into an electrical generation plant. No one
has to deal with pollution from smokestacks or the nightmare of
nuclear accidents or storage of radioactive waste. Because PV
arrays only make electricity during the daytime, grid tied solar
power must be complemented by other power sources that can be
brought on line as needed. With our country’s increasing need for
energy, we feel that grid tied solar PV will be an important part of
the solution and once widely deployed will offset the need for new
coal fired or nuclear power plants.
17. How does renewable energy help our local economy?
In Washington, we rely
heavily on energy produced from natural gas and coal, both imported
from out of state, to provide our electricity. The cost of these
fossil fuels can add up to billions of dollars. And every dollar
spent on imported energy is a dollar lost from our local economy.
Renewable energy resources are developed locally, literally
converting our local sunshine into electricity and dollars. The
dollars spent on energy stays in our local economy, creating more
jobs and fostering economic growth.
Solar power made in WA
state: Silicon Energy solar modules made in Arlington, WA.
It is now possible to generate local renewable energy from locally
made solar modules.
Renewable
energy technologies are labor intensive. Jobs result from the
manufacture, design, installation, servicing, and marketing of
renewable energy products. Jobs even arise indirectly from
businesses that supply renewable energy companies with raw
materials, transportation, equipment, and professional services,
such as accounting and clerical services. In turn, the wages and
salaries generated from these jobs provide additional income in the
local economy. Renewable energy companies also contribute more tax
revenue locally than conventional energy sources.
18.
How about solar thermal? Can I use the sun to make hot
water
for domestic use
or for space heating?
Solar
thermal systems heat water using the sun’s heat. There are many
solar thermal technologies in use around the world. Here in the
northwest where we can get freezing weather in the winter and cold
temperatures regularly at night, most systems utilize flat plate or
evacuated tube collectors, internal insulated storage tanks, and
closed loop circulation systems that glycol antifreeze.
Two evacuated tube collectors
being installed on the roof of a Port Angeles area home.
The completed system.
The evacuated tube collectors are on the upper part of the roof and
two rows of Sanyo PV modules are located below. The two solar
systems work independently.
Solar thermal systems use a collector (flat plate or evacuated tube)
to collect the sun’s energy and heat water that is pumped to the
collector using electric pumps. A tank is needed to store the hot
water generated by the system, insulated plumbing transmits the
water to and from the collectors and a pump and control equipment
manage the movement of the heated water. These systems can be used
to preheat water before it enters the home’s water heating system
(back up water heating is needed for winter time, nights, and cloudy
weather) or can be expanded to help with space heating needs.
A nearly complete integration of a
solar thermal system. A 120 gallon storage tank is on the left.
Note the plumbing entering the tank. This tank contains three heat
exchange loops, one for the solar thermal (bottom) one for the back
up heat source (middle) and one to the radiant floors (top). An
on-demand propane boiler provides back up heat. Other equipment
includes the floor radiant heat controls.
The most
practical use of a solar thermal system is to preheat domestic hot
water. Most homes use a fairly consistent amount of hot water
throughout the year for bathing, drinking, clothes washing, etc. A
solar thermal system can be designed to meet roughly 100% of a homes
typical hot water needs in the summer and much less during other
parts of the year (again, the need for the back up water heating
source). The energy savings comes in the form of electricity or
propane saved by heating the water with the sun.
Using solar
thermal for space heating is more complex than domestic hot water
use alone because the solar thermal systems must be bigger and more
powerful. In the northwest we typically need to heat our homes from
late fall through early spring, corresponding to exactly when we
have the least solar resource to work with. A different problem
arises in the summertime when a solar thermal space heating system
can generate more heat than the home uses and the tanks can safely
store. This excess energy will need to be dumped into an outdoor
concrete slab or blown into the air using a fan and exterior
radiator. Does this sound like a lot of money spent on equipment
that doesn’t work efficiently much of the time? We feel that this
money could be better spent in generating electricity with solar PV
that could then be used by electrical heating equipment (a heat pump
or electric on demand boiler).
When
compared to solar PV, solar thermal has some disadvantages. The
first is there is no net metering. If you make more hot water than
you use the utility will not pay you for it. To save money you must
use the solar hot water when it is available thereby reducing the
amount of energy you would have used to heat the hot water. Your
time of use must correspond to when the solar heated water is
available. The second disadvantage is that solar thermal systems
require regular maintenance for proper operation. There are
moving parts (pumps, etc) that must be periodically maintained or
replaced, antifreeze coolant annually checked and replaced if
needed, and extreme hot or cold weather requiring management of the
system to deal with excess heat or freezing temperatures. These
systems will fail if not properly maintained. If you own a solar
thermal system you must be an active participant in its successful
operation.
Currently
Power Trip Energy is not installing solar thermal systems, though we
have installed or participated in the installation of 15 of these
systems. If you are interested in solar thermal in addition to PV,
we will evaluate your home for both during our site evaluation
process (see below) but we cannot install these systems for you at
this time.
Solar
thermal systems qualify for a $2,000 federal income tax credit if
the system will offset at least 50% of a home’s domestic hot water
or space heating needs and also qualify for the existing Washington
State sales tax exemption (expires June 2009). There are no other
financial incentives typically available for solar thermal systems.
We have
often heard people say they’ve heard that the “payback” is faster
with solar thermal systems. This is no longer true (if it ever
was). The efficiency and decreased costs of PV make it more
attractive in both the near term and the long haul.
What steps will you go through to
evaluate my home or business?
When you call
our office we’ll answer your remaining questions about grid-tied
solar PV. If you are interested in having your home or business
evaluated for a solar PV system, we can schedule a
site evaluation.
During a site
evaluation, we will come to your home or business (or vacant lot if
your planning to build) and we will evaluate the solar potential of
your site. We’ll climb on the roof of your house and take the
measurements necessary to design your system. We’ll use a
solar SunEye and/or pathfinder
to accurately assess the orientation and solar potential of your
roof or ground mount site. We’ll look at your home’s electrical
system to determine how we will connect your solar array to your
service panel and the utility grid. We will look at your energy
bills to determine how much electricity you are currently consuming
and how much of this load various sized PV systems would cover over
the course of an average year. Finally, we’ll sit down with you so
you can share your goals regarding generating your own green power.
We’ll answer all your questions about costs, financial incentives,
location options, various system sizes, maintenance (there really is
none), and whatever else you can throw at us. Within a few days of
the site evaluation we’ll send you a written bid for one or more PV
systems and an installation contract. The
cost for a site evaluation
on the north Olympic Peninsula within 50 miles of Port Townsend is
$150 and for the Kitsap Peninsula $175. We charge a little more
beyond these areas to cover our time and travel cost. If you
purchase a PV system through us, we’ll credit this amount towards
the purchase of your PV system.
How does the process work?
Great! When
you are ready to commit to buying a system, we’ll ask you to initial
the system bid you are accepting, sign the installation contract,
and send us a deposit that equals one-half the cost of the materials
and the shipping. We will then order the solar modules, inverter,
and other equipment. When the materials arrive (2 – 6 weeks
depending upon availability) we’ll schedule their installation with
you. When we deliver the materials to the site you’ll pay us the
other one-half of the material and shipping costs and we’ll begin to
install the system. System installation typically takes 2 – 5
working days depending upon system size and complexity. Once the
system is installed and passes the electrical inspection you’ll make
the final payment to us which covers the installation labor. The
cost of the electrical permit is included in the bid and we’ll take
care of the permit, utility contracts, and the various rebate and
sales tax exemption forms. We’ll make it easy for you to invest in
solar power and to help change the status quo.
