We know that going solar is a tricky subject and no matter how much research you do there are always more questions. Our customers and users know that they can look to us for the best info.
Are there any state incentives to help with the cost of the solar system?
Go to www.dsireusa.org
to find out what grants or incentives are available in your state.
What will it cost for me to go solar?
Many factors can come into play, such as your energy usage, roof
orientation, and shading. Several states and cities also have rebates that
can dramatically affect the install price.
What are photovoltaic cells?
Photovoltaic cells were developed at Bell Laboratories in the early 1950s
as a spinoff of transistor technology. Very thin layers of pure silicon
are impregnated with tiny amounts of other elements. When exposed to
sunlight, small amounts of electricity are produced. They were mainly a
laboratory curiosity until the advent of spaceflight in the 1950s, when
they were found to be an efficient and long-lived, although staggeringly
expensive, power source for satellites. Also, the utility companies
couldn’t figure out how to get their wires out into space, so PV was
really the only option! Since the early ’60s, PV cells have slowly but
steadily come down from prices of over $40,000 per watt to current retail
prices of around $5 per watt, or in some cases as low as $3 per watt for
distributors or in very large quantities.
How long do PV modules last?
PV modules last a long, long time. How long we honestly don’t yet know,
as the oldest terrestrial modules are barely 45 years old and still going
strong. In decades-long tests, the fully developed technology of
monocrystal
and polycrystal modules has shown to degrade at fairly steady rates of
0.25%-0.5% per year. First-generation amorphous modules degraded faster,
but there are so many new wrinkles and improvements in amorphous
production that we can’t draw any blanket generalizations for this
module type.
The best amorphous products now seem to closely match the degradation of single-crystal products, but there is little long-term data. Most full-size modules carry 25-year warranties, reflecting their manufacturers’ faith in the durability of these products.
PV technology is closely related to transistor technology. Based on our experience with transistors that just fade away after 20 years of constant use, most manufacturers have been confidently predicting 20-year or longer life spans for PV systems. However, keep in mind that PV modules are seeing only six to twelve hours of active use per day, so we may find that life spans of 60-80 years are normal. Cells that were put into the truly nasty environment of space in the late 1960s are still functioning well. The bottom line? We’re going to measure the life expectancy of PV modules in decades - how many, we don’t yet know.
The best amorphous products now seem to closely match the degradation of single-crystal products, but there is little long-term data. Most full-size modules carry 25-year warranties, reflecting their manufacturers’ faith in the durability of these products.
PV technology is closely related to transistor technology. Based on our experience with transistors that just fade away after 20 years of constant use, most manufacturers have been confidently predicting 20-year or longer life spans for PV systems. However, keep in mind that PV modules are seeing only six to twelve hours of active use per day, so we may find that life spans of 60-80 years are normal. Cells that were put into the truly nasty environment of space in the late 1960s are still functioning well. The bottom line? We’re going to measure the life expectancy of PV modules in decades - how many, we don’t yet know.
What is the difference between Solar Thermal and Solar Photovoltaic?
Solar Thermal systems collects and converts Ultraviolet radiation from the
sun into heat. This heat is then used to warm a glycol-water mix that is
then used to heat the domestic water supply, provide heating for your home
or business, generate electricity, or provide air conditioning. Solar Photovoltaic
systems collects and converts visible light into electricity.
I've always heard that solar is more wasteful than efficient since it costs so much to produce the materials. Is that true?
In the early years of the PV industry, there was a nasty rumor circulating
that said PV modules would never produce as much power over their
lifetimes as it took to manufacture them. During the early years of
development, when transistors were a novelty, and handmade PV modules
costing as much as $40,000 per watt were being used exclusively for
spacecraft, this was true. The truth now is that PV modules pay back their
manufacturing energy investment in about 1.5 years’ time (only a
fraction of the typical warranty period), depending on module type,
installation climate, and other conditions. Now, in all honesty, this
information comes to us courtesy of the module manufacturers.
The National Renewable Energy Laboratory has done some impartial studies on payback time. It concludes that modules installed under average U.S. conditions reach energy payback in three to four years, depending on construction type. The aluminum frame all by itself can account for six months to one year of that time. Quicker energy paybacks, down to one to two years, are expected in the future, as more “solar grade” silicon feedstock becomes available, and simpler standardized mounting frames are developed.
The National Renewable Energy Laboratory has done some impartial studies on payback time. It concludes that modules installed under average U.S. conditions reach energy payback in three to four years, depending on construction type. The aluminum frame all by itself can account for six months to one year of that time. Quicker energy paybacks, down to one to two years, are expected in the future, as more “solar grade” silicon feedstock becomes available, and simpler standardized mounting frames are developed.
What is the maintenance on an installed solar power system?
It’s almost laughable how easy the maintenance is for PV modules.
Because they have no moving parts, they are virtually maintenance free.
Basically, you keep them clean. If it rains irregularly or if the birds
leave their calling cards, hose the modules down. Do not hose them off
when they’re hot, since uneven thermal shock could theoretically break
the glass. Wash them in the morning or evening. For PV maintenance,
that’s it.
What is an inverter?
An inverter is an electronic device that converts (transforms) the
low-voltage DC power we can store in batteries to conventional AC
power as needed by lights and appliances. This makes it possible to
utilize the lower-cost (and often higher quality) mass-produced appliances
made for the conventional grid-supplied market. Inverters are available in
a wide range of wattage capabilities. We commonly deal with inverters that
have a capacity of anywhere between 150 and 500 Kilo-watts.
What is a PV module?
This is what you might call a “solar panel” that makes electricity
when exposed to direct sunlight. PV is shorthand for photovoltaic. We call
these panels PV modules to differentiate them from solar hot-water panels
or collectors, which are a completely different technology and are often
what folks think of when we say “solar panel.” PV modules do not make
hot water.
I'm not sure if my house gets "full sun". What does that mean exactly?
Most people seldom see 100% full-Sun conditions. If you are not getting
full, bright, shadow-free sunlight, then your PV output will be reduced.
If you are not getting bright enough sunlight to cast fairly sharp edged
shadows, then you do not have enough sunlight to harvest much useful
electricity. Most of us actually receive 80%-85% of a “full Sun”
(defined as 1,000 watts per square meter) on a clear sunny day. High
altitudes and desert locations will do better on sunlight availability. On
the high desert plateaus, 105%-110% of full Sun is normal. They don’t
call it the “sunbelt” for nothing!
What is a 'utility intertie' system? It seems really complicated?
These are actually very easy. Whatever your renewable energy system
doesn’t cover, your existing utility company will. So we don’t need to
account for every watt-hour beforehand. Tell us either how much you want
to spend, or how many kilowatt-hours of utility power you’d like to
displace on an average day. For direct-intertie systems without batteries,
you’ll invest about $2,500 for every kilowatt-hour per day your solar
system delivers. For battery-based systems that can provide limited
emergency back-up power, you invest about $3,500-$4,500 for every
kilowatt-hour per day. These are very general ballpark figures for initial
system costs.
