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Frequently Asked Questions (FAQs)
about
Renewable Energy Systems and Net Metering |
RELATED LiNKS |
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What
type of system should I invest in?
This is dependent upon many factors: how much sun or wind you have in your
area, the orientation of your building, the amount of energy you will
need, and the amount of space you have available for equipment.
There are also zoning laws for your area to consider.
Beginning with your needs, you should first determine whether you want to generate electricity, or to heat water for your building.
Why chose solar water heating?
Solar hot water heating systems are relatively easy to have
installed, and despite the winter cold and summer fog, work very well year-round at preheating water before it enters your building’s water
heating tank. This saves burning the
fuel your system would normally use to bring the water up to temperature.
Some Bay area systems have been in place since the 1970’s and are
still functioning with very little maintenance. The most basic, and most energy-efficient system is a thermosiphon system that does not require electric pumps to operate. This system is passive, letting the sun heat the fluid until it rises to the top of the panels, where it flows into a tank or heat exchanger. From the heat exchanger, only the hottest water is skimmed off from the top of the tank as you draw down the hot water. This water can reach 150 F., far hotter than what you need for a shower. The other most common type of system is a drain-back system with a heat exchanger. This type has a glycol-based fluid that circulates when the sun is out (a sensor triggers the pumps to come on) and runs from the panels to the heat exchanger inside a storage tank. the heat is absorbed by the water in the tank, which is drawn upon when you turn on the tap. Generally, water from the storage tank is also routed through your existing water heater, so the temperature can be boosted if it is needed, especially early in the morning in the middle of winter. There is also usually a temperature regulator installed just before the water leaves the final storage tank, so that any super heater water can be cooled down to avoid scalding (also called an anti-scald valve).
Solar water heating for Space Heating It is also possible to use solar hot water to heat your home. Radiant heating, either under-floor or traditional radiators, uses hot water pumped from the storage tank through pipes to each room to heat it. Since water has 3,000 times the heat carrying capacity of air, it is much better at delivering and holding the heat in the pipes and maintaining a stable temperature. There are also new systems that will use a water-to-air heat exchanger, capturing the heat from the water using blowers that will then deliver the heated air using your existing ductwork. Contact your plumbing supplier or a solar hot water installer for more information.
What other benefits are there to solar hot water? Unlike electricity prices, natural gas prices are unregulated, which means that the price for a therm (100,000 Btu) of natural gas can fluctuate from $1.00 to as much as $3.00. During the 2000 Energy Crisis in California, retail prices went over $3.00 per therm. Solar hot water can significantly protect consumers from this highly unstable market, with a very small investment. Another advantage of solar hot water is that you do NOT need to sign an agreement with your local utility before installing one; there is no paperwork needed, and no additional fees associated with this type of system. See how to link a solar water heater to your existing water heater.
How do Solar Electric or Wind systems compare?
Electrical
generation systems, such as photovoltaic and windmills involve more
complicated equipment, maintenance, and initial costs -- as much as
$50,000+ for a typical system.
There may also be zoning issues to consider at your site.
Contact the Permit Service Center at 2120 Milvia Street for
more information on Zoning regulations. What
types of photovoltaic systems are there? There are 2 main types: 1) a utility “inter-tie” system which connects you to the grid, but will disconnect from it when the grid goes down in a black out our seismic event; and 2) the stand-alone system that is completely independent from the electrical grid and includes all the components from 1) plus a bank of batteries that allows you to store energy either when the power goes down, or when the sun goes down. These are generally found in rural areas where power is either not reliable, or where utility power is unavailable. The inter-tie system consists of the photovoltaic panels (~$350 per 110-watt panel); an inverter to change DC (direct current) power from the panel to AC (alternating current) power that is on the grid and in your home; an inter-tie switching system and shut-down capability; and optional batteries to back up and store excess power on sunny days for use at night and in emergencies. Note that windmill systems have similar requirements. However, there are new developments in residential-sized wind turbines that incorporate the inverter, allowing a simple 'plug and play" installation. See the American Wind Energy Association website for more information. What size solar electric system would I need? This is entirely dependent upon the amount of energy you use. The first step you should take is to implement every single energy-conservation measure that you can, to reduce your energy load. These measures include purchasing energy-efficient appliances, using power strips to turn off equipment that run on "stand-by" power, such as TVs, VCRs and stereos, and using compact fluorescent lamps in all light fixtures. Some people discover that once they have taken these conservation measures that their electricity consumption is so low that they really don't need to install a solar energy system. ENERGY TIP #1: A home using about 70 kWh per month (2.34 kWh per day) will have an electric bill of about $11.00+/- per month. Efficiency measures are considered essential before installing any renewable energy system. If you do not perform these efficiency measures, you will be paying for a much larger, and therefore much more expensive photovoltaic system than you really need, and you will be adding many years to the pay-back period. Once the measures have been implemented, if your energy consumption still exceeds 7 or 8 kWh per day, you may want to look into getting a photovoltaic system. ENERGY TIP #2: Bear in mind that your utility will still charge you ~ $7 per month to read your meter, even if your energy use is less than the amount you generate. Reducing your energy use to about 100 kWh per month will be far less expensive and less complicated than purchasing a $30,000 solar electric system for your home. There is no way to eliminate this monthly meter reading charge. Where
can I find out more about renewable energy equipment, including purchasing
and installation?
Start with your local phone
book; be aware that many installers are very busy these days and you may
not find one right away who can take the time to answer your questions.
There are many non-profit organizations which provide information
on renewable energy systems, including the American
Wind Energy Association, and the Northern
California Solar Energy Association which can assist you.
Additionally, there are several local manufacturers of solar panels
as well as retailers for you to chose from. Is
there any financial assistance available for installing renewable energy
systems?
Yes—there are several
programs available. Connect to the City of Berkeley’s page of Rebates
and Financial Incentives for a list. Is
there a way to sell my excess power back to my utility company? Yes; this
is called “net metering”. Beware
that it is not as profitable as you might think.
Here’s why: only utilities formed before January 1, 1998 are
obligated to purchase your excess power.
If your utility is one of the newer ones formed recently, they are
not obligated to purchase it. Older
utilities must purchase it, but they will only pay you their wholesale
cost, not the retail cost you pay them when you use electricity.
Additionally, you must sign a Net Metering Agreement form before
you begin to generate power.
What about my excess energy? Will my utility pay me for energy I produce but don't use? Not under current laws. Your utility will "store" your excess energy for your use at night time or on cloudy days when you use more energy than your system can produces. The Net Metering agreement will balance your energy production over your energy use for one calendar year, and any excess energy you produce will be voided. You will not be paid for this excess energy, so your system should be sized very carefully. What
is Net Metering, exactly?
Net metering measures the
difference between the electricity you buy from your utility and the
electricity you produce using your own generating equipment. Your electric
meter keeps track of this "net" difference as you generate
electricity and take electricity from the electric grid. Am
I eligible for Net Metering?
In California, any residential
or small commercial electricity customer who generates at least some of
their electricity is potentially eligible for net metering. Your
generating system must be powered by solar or wind energy, or some
combination of the two, and must not exceed 10 kilowatts of peak power
output. Your current utility or electric service provider (ESP) should be
able to tell you if your electric account is the right type. What
is the best way to take advantage of Net Metering?
First implement as many energy
conservations measures as you can, then size your system as closely as
possible to meet your needs. This
will reduce the size of the system that you need, saving you thousands of
dollars in equipment, and will allow you to
“store” excess retail-priced electricity on the grid to retrieve
later, free of charge, for your use. Your excess electricity now offsets
electricity you would otherwise have to buy at full retail prices. Getting
this high retail value for your excess electricity makes owning your own
generating system more cost-effective. Does
Net Metering take special equipment?
In most cases, the meter you
currently have will work. A bi-directional meter is what is needed if you
do not already have one. Will
my electrical service provider charge (ESP) a service fee for Net
Metering?
Your Electrical Service Provider (ESP) cannot charge you
anything extra for being a net metered customer and no charges can be
imposed on the electricity you generate. How
will I be billed for Net Metering? Just as they do presently, your ESP will continue to read your meter monthly. However, with net metering, they will not send you a monthly bill. Instead, they will send you a monthly statement showing the net amount of electricity you consumed that month or the net amount generated and put into the electric grid. If you ran the meter backwards more than forwards, you would be a net generator for that month. If you took more electricity from the electric grid than you fed back, you would be a net consumer. Twelve of these monthly statements are then totaled up by your ESP. Once a year, on your anniversary of starting net metering, your ESP will bill you for only the amount of net electricity consumed over the last twelve months. If instead you were a net generator over the past year, the ESP is not required to buy any net generation, if they were formed after January 1, 1998. However, some ESPs might buy your net generation. If your current ESP will not buy your excess generation, under California's utility deregulation, you may be free to select an ESP that will.
While under net metering you
need only be billed once a year for your net consumption, you may request
the option of monthly billing as well. What
size should my generating system be?
Under California's net metering law, eligible systems cannot be
larger than 10 kilowatts of peak power output. However, economically your
system should be sized so that it is capable of supplying some or all of
expected annual electricity needs, but not more than your needs. Estimate
your annual needs and size system to produce this amount of electricity,
or less, over a twelve month period. Excess generation your system one
month can be used to offset consumption of electricity from your ESP in
another month. However, because your ESP may not be required to purchase
excess electricity from you at the end of the year, keep the size of your
system at or below your expected annual needs. It does not pay to oversize
a system. There is no minimum system size to be eligible for net metering. Most residential systems are in the 2 to 4 kilowatt range, but they can be larger or smaller depending on your needs and how much of your own electricity you want to generate. Also, it is possible to start with a smaller system and expand it later and still be eligible for net metering as long as your total system output is not greater than 10 kilowatts (or 100 of the 100-watt panels). How
do I sign up for Net Metering?
Contact
your current electric service provider (ESP) to see if they offer net
metering or select another provider who does. A list of ESPs who provide
renewable electricity can be found on the California
Energy Commission's website. For a list of all ESPs registered to
serve California's residential and small commercial customers, visit the Public
Utilities Commission's website.
In
addition to requesting net metering from your ESP, you may also need to
sign an Interconnection Agreement with your local distribution company (LDC). How
do I connect my system to the grid?
While your electric service provider (ESP) will handle
the billing and accounting for net metering, your local distribution
company (LDC) will handle how your generating system will be connected to
the electrical grid. Your LDC and ESP may be the same or different
companies Your LDC is typically the company that supplied you with
electricity prior to 1998, when utility deregulation began. Your LDC may
have a standard Interconnection Agreement for net metered customers to
sign and follow. It will spell out the LDCs requirements for you to safely
connect your generating system to the LDCs electric grid. LDCs are not
required to have an Interconnection Agreement, but most do. Regardless of whether or not your LDC has a written agreement, there are several things your LDC cannot require of you to be interconnected with the grid:
For more information, contact: Updated January 25, 2008 |
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