What about battery maintenance and replacement?

When a system is properly designed and the battery bank receives regular maintenance, larger batteries can last 7-10 years.  Otherwise, expect 3-5 years for the L-16 type batteries.  Lead-acid batteries are 100% recyclable and should never be thrown in a landfill.
SWNL offers maintenance agreements on a quarterly, bi annual, and yearly basis.We'll visit the site inspect and verify your system is functioning at it's best.You'll never have to worry about your systems performance. 

What happens during a blackout?

A grid tied solar electric system with no batteries will automatically shut down in the event of a utility outage.You will not have backup power.Once utility power is restored the solar system will automatically reconnect to the grid and start to produce power when the sun shines. This is a fully automatic operation.

Battery Based Grid tie
This is a grid-tied system with a battery backup. This system will give you limited backup power in the event of a utility outage. The system charges the batteries from the sun,wind,utility,etc. When the batteries are fully charged the excess power will feed into the grid and spin your meter backwards.   With a battery based system the duration of the backup capacity is dependent upon the size of the battery bank, the state-of-charge at the time of the blackout.  

How reliable are these systems?

How reliable are these systems?

Solar electric systems are extremely reliable. Solar panels have no moving parts & typically last for 40 years or more. The inverters are made with the latest electrical technical advancements & components. All systems have manufacturers warranties as well as a ten year warranty for systems installed in conjunction with the California Solar Initiative. We service what we sell.


Solar hot water systems are extremely reliable as well. The collectors have no moving parts & could last for 20-40 years. Depending on maintenance & location.

How does a solar electric system work?

Photovoltaic (PV) cells are typically made of silicon, the same material used to make computer chips.  A PV panel (sometimes called a solar panel, solar module or solar collector) is made up of many PV cells strung together.  PV panels convert light directly into electricity.  This electricity is in the form of DC, or direct current, like that of a car battery.  The electricity flows from the PV panels to an inverter, where the electricity is turned into AC (alternating current), which is what you need to run your appliances.  
Grid-tied systems are set up to deliver energy to the grid during the daytime and consume energy from the grid at night.  When a system is delivering more power than the customer is using, the meter spins backwards and the utility credits the customer for the amount of energy delivered.  With PG&E’s time-of-use (TOU) rate system, electricity prices are higher during the daytime and lower at night.  This is perfect for a  grid-tied solar system because it delivers energy to the grid during the day and receives more credit per Kwh than if that energy were delivered at night.  The customer then draws power from the grid at night when the system is not producing and electricity prices are low.  With grid-tied solar, you can eliminate your electricity bill without needing to install a system that produces 100% of your energy needs.
As the name implies, off-grid systems have no connection to the grid and operate independently.  Off-grid systems are most popular and practical for sites that don’t have power lines nearby.  The cost to build new power lines varies wildly, depending on location, from $15,000 to $80,000 per mile.  Off-grid systems offer a clear economic advantage in these cases.  An off-grid system includes a battery bank that stores energy produced by the system to be used when it is not producing.  When the system is generating power, energy is sent to a charge controller—a device that regulates the flow of energy from a wind turbine or solar panel to the battery bank.  The inverter taps off the DC power of the battery bank and converts it to AC power to be used in the building.   The battery bank typically consists of  deep cycle lead-acid batteries strung together to form one large battery.  When a system generates more power than the electrical loads are consuming, the battery bank charges up.  If the battery bank is fully charged and the system is still overproducing, the excess energy (energy produced above and beyond fully charged batteries and satisfied electrical demand) can be blocked by the charge controller or shed by a dump load—a large resistor that “dumps” the excess electricity by converting it into heat.  These systems can be either fully automated or user-assisted, depending on the customer’s budget and abilities.  It is possible to connect a generator that automatically starts up to keep the batteries charged when there are long periods of no sun, wind, or hydro.  Every off grid system should have a back up generator.

Is clean energy cheaper than dirty energy?

Yes. Renewable energy has grown by leaps and bounds in recent years, bringing costs down while utility prices skyrocket.  For every dollar spent on efficiency, you can save $6 on a renewable energy system.
No matter what method you choose to purchase a renewable energy system, you will easily save more than what you paid for it over the course of its lifetime.  The cheapest and easiest method is to pay with cash, which eliminates loan interest payments and provides the highest life-cycle savings.  If this is an option for you, we highly recommend it.  Clearly, not everyone can pay for 30 years’ worth of energy bills in one lump sum, so most of our clients opt for methods that convert the upfront cost into a monthly payment by financing their installation.  Even though this entails paying interest on a loan, falling prices for renewable energy systems and rising utility costs leave many of our clients with an improved monthly cash flow after installing renewable energy.  Talk to your local bank to learn more about financing a renewable energy system.

Is my site suitable for a renewable energy system installation?

 All of our projects begin with an in-depth site survey and analysis, with a proposal handed to you - free of charge.  However, before we visit your site we will contact you with some basic questions to eliminate unnecessary site visits so we can continue to offer low prices.  Here is an idea of what we’re looking for.

Solar Photovoltaic
It is best to have unshaded south-facing roof space for optimum energy production.  Southwest, west-facing and flat surfaces are suitable as well.  The roof should be in fairly good condition.  If it needs to be replaced soon, that should be done before a solar installation.  If your site doesn’t meet any of these requirements, you can opt to install a pole-mounted array if you have an unshaded area on site, though this option is more expensive.  Typically photovoltaic systems requires about 120sq. ft. of panels to produce 1 Kw of AC electricity.  Commercial systems are typically larger and vary widely in their space requirements.  Look around on the south side of your site.  Are there young trees that may shade the rooftop or pole-mount array in a few years?  Will there be tall buildings built there?  A free site survey is the best way to assess the suitability of your site.

Solar Hot Water
The site requirements for solar hot water systems are very similar to that of photovoltaics.  It is best to have unobstructed south-facing roof space for optimum thermal collection.  Southwest, west-facing and flat surfaces are suitable as well.  The roof should be in fairly good condition.  If it needs to be replaced soon, that should be done before a solar installation.  Solar thermal collectors require about 3/4sq. ft.of collector area to create one gallon of hot water.  Commercial systems are typically larger and vary widely in their space requirements.       

Sites that have streams may be suitable for a microhydro generator.  There are many factors that determine whether a microhydro system is practical and economical for a given site.  Flow rate, head level (elevation change from intake point to the turbine), and distance from the turbine to the electric load are all determining factors in the viability of microhydro.  See www.homepower.com/basics/hydro/ for a more complete explanation.  

Wind turbines operate most efficiently and last longer when situated in laminar-flow airstreams.  Laminar-flow refers to the directional uniformity and lack of turbulence in the wind.  Turbulence reduces efficiency and adds more wear and tear to the turbine.
To take advantage of laminar-flow winds, a wind turbine must be mounted on top of a tower or pole that is at least 30 ft higher than anything within a 500 ft radius.  For some sites, like those with 200 ft redwoods nearby, it is impractical and expensive to mount a turbine that high and other sources of energy should be examined.  Since the tower can often be more expensive than the turbine, it can be very misleading to only consider the price and output of the turbine itself.
Wind speed is another important consideration.  The energy content of wind is proportional to the cube of the wind speed.  If the wind blows twice as fast, there is eight times more energy available.  Wind speed in any given location is affected by a number of factors, including roughness of the terrain, nearby obstacles and weather.  The most accurate way to measure wind speed is to mount an anemometer with a data logger on a pole at the same height of the proposed turbine and gather data over a period of one year.  There are wind-speed maps available for the entire US but these cannot reliably be used for siting a wind turbine, given local variations due to topography, obstructions and microclimates.