Basic system design:  A basic Solar electric power system is simply comprised of 7 building blocks.  (click on building block for explanation)

Sun:  The sun is the power source for your solar electric power system.  It is powerful, free, clean, and endless.  Nothing else needs to be said.  No rate increases, no taxes, no green house gasses and no fuel adjustment costs.  Normal levels of solar density is about 1 KWH/m^2.  Average sunlight varies from location to location.  Check out the Technical Stuff web page for helpful insolation data.  

Solar Panels:  Solar panels are made of many individual Solar Cells.  The solar panels are the solid state device that convert sunlight directly into electricity.  Modern solar panels are guaranteed for 25-10 years.  There are no moving parts to wear out or break down.  There are three main designs in use today: Single crystal, polycrystalline, and amorphous.  There are hundred of parameters and characteristics to consider when choosing a design.  Each type have their own benefits.  The most important thing for the person putting in a  Solar Electric System to remember is the Cost per Kilowatt or Watt ($/W).  Everything else blurs in importance.  SESP has researched all the available designs and manufacturers and recommends Siemens Single Crystal solar panels.    They have the highest efficiency, highest fill factor, longest warranty, lowest leakage and most importantly, the lowest cost per Kilowatt-hour ($/KWH).  Please check out our Kits and Products web page.

Battery Charge Controller (BCC):  A modern solid state device which makes your life much easier.  It takes care of the batteries health condition.  It determines when to charge the batteries, how fast to charge them, when the batteries are full and provides a sustaining charge for long periods of non-use.  It also disconnects form the solar panels at night to prevent discharge.  The manufacturer guarantees their BCC's from 2-5 years.  SESP recommends Xantrex C-Series Battery Charge Controllers.  Please check out our Kits and Products web page.

Deep cycle Lead-acid storage batteries:  The battery bank is your fuel tank.  It stores all the energy from your solar array.  It holds all the energy that you will be using during the day when the sun is up and shining and more importantly at night when the sun is down.  It provides the instantaneous power you need when starting a large load.  The most important thing for the person putting in a Solar Electric system to remember is the Cost per Amp-hour or cost per Kilowatt-hour ($/A-hr).  Deep cycle Lead-acid batteries are the best choice and most cost effective available today.   (Automotive batteries are shallow cycle and will be destroyed if used in a Solar Electric system.) Fuel cells will be a great replacement when they become available and cost effective.   Batteries used in modern systems are almost always 6 Volts/3 cells and  will typically come in one of two sizes:  "Automotive size" (220 A-hr, 63 lbs) (This size battery is used by most of the Solar Electric Systems in use today because they are the best value in terms of $/A-hr) and "Forklift" or L-16 (350 A-hr, 130 lbs).    Please check out our Kits and Products web page.

Batteries are the item that require the most maintenance.  The electrolyte is converted to Hydrogen and Oxygen gas during the charging cycle and needs to be replaced periodically.  With proper charge/discharge cycles, a battery bank should last approximately 3000 cycles or 7 years.  When calculating the LCC cost of a Solar Electric System, battery bank replacement must be considered.  

Battery banks can rapidly release energy and stores all the energy and therefore are the source of the most danger to personnel or equipment.  Danger can come from metal objects shorting the terminals, burns from the electrolyte and explosions from the Hydrogen gas that is generated.  

Inverter:  The inverter is the device that converts the 12 or 24 Volt DC battery/system voltage to 120 AC, 60 Hz power that typical household appliances use.  This allows the Solar Electric System owner to enjoy all the same conveniences that they enjoy with normal household, grid-connected utility power.  The inverter monitors the battery bank voltage and shuts down (LVD) to protect the batteries from damage when they are depleted and needs recharging.   It can also be back fed by a stand alone generator to charge the batteries during long periods of overcast days.  Modern inverters are over 90% efficient and are guaranteed for typically 2 years but usually last much much longer.  SESP has researched available inverter manufacturers and recommends Trace Engineering inverters (now Xantrex) for their advanced design, performance and efficiency.  

Power load:  Power load is how much power you take out of your battery bank.  With a Solar Electric System, you own your own power generation.  With that comes responsibilities.  SESP will assist you in engineering a system that will match your power load.  If the system is too large for your needs, the cost will be unnecessarily high and if the system is too small for you needs you will be dissatisfied with your system.  A Power load calculation, modern efficient appliances and proper maintenance are necessary for a system that will provide many years of satisfaction and autonomy. 

Generator, Stand-alone:   SESP recommends a stand-alone generator on all home or cabin systems.  All locations can have long stretches of overcast days which will deplete your battery bank.  A stand-alone generator will effectively extend your system availability to 100% or in otherwise increase your "Days of Autonomy" to infinity.  However, with a generator, disadvantages come along with it, i.e., fuel, noise, maintenance, exhaust fumes and cost.  You have to decide if the disadvantages are worth not having overcast day blackouts.  

2.  Steps for designing a system.

a) Determine your motivation to acquire a Solar Electric System.

You must your decide why you want a system.  Reasons can include doing your part in saving the environment, reducing your electric bill, avoid paying that huge public utility line installation bill, increase you confidence over rolling blackouts or have a better home environment to live in.  Some of these reasons are worth much more than the cost of a system.  

b)  Decide the scope of you Solar Electric System.

Do you have a complete stand alone home system, light a barn, power a remote pumping system, reduce galvanic corrosion on a pipe, power a remote cabin or supplement the batteries in a boat or RV where there is no plug to plug in.  The sky's the limit on this step.  SESP will be glad to explain the possible system configurations that are available.  

c)  Calculate or measure your present power consumption.  

You must determine how much power you are presently using and where your money is going.  You will be definitely surprised how much energy (money) you are spending that you could be saving. SESP has a power budget form to assist you.  

d)  Recalculate your power budget needs.

The second time calculating your power budget, you need to determine what appliances should be powered by your Solar Electric System, what should be powered by other fuel sources and where you can save. Thermal heating devices are terrible waste of electric power.  These include: electric ranges, electric ovens, electric water heaters, electric clothes dryers, toasters, etc.  It is much cheaper to power these thermal heating devices by Propane or Natural Gas.  Next, Find ways to save on your present usages.  There are several modern devices to save here. 

Compact fluorescent lights use 8-14 Watts where incandescent lights use 60-100 Watts.  For example: If your home has 100-60 Watt lights in it and they are on 3 hours a day and switch all to Compact fluorescent lights using only 8 Watts you will reduce your power consumption from 6570 KW-hr to 876 KW-hr.  At 17.7 cents a KW-hr, that will save you over $1000 per year.  

Modern refrigerators, such as the ConServ^tm or Sunfrost^tm brands will save over $200 per year. 

Switching from your  electric water heater and electric clothes dryer to gas will save over five hundred dollars a year.  Should we go on? 

The point to all this is there are several ways to save energy and reduce the size of a Solar Electric System you will need.  All of these are wise ideas that will maintain the comforts you presently enjoy.  SESP will personally and thoroughly guide you through the process.  

e)  Calculate the number of Days of Autonomy you will need. 

This will depend on your situation and how often you will be using the facility.  This number will change if you decide to include a stand-alone generator with your system.  The battery life is also impacted by the "days of autonomy".  

f)  Have SESP engineer a properly balanced system for you.  

SESP has electrical engineers and electrical contractors on staff, all of the knowledge and learning from Sandia National Labs, manufacturer's personal research, DOE, NCPV, ASES, NREL, etc. to assure that your system is properly balanced and designed.   

g)  Procure financing.

The cost for your system is all up front.  There are several methods for obtaining financing.  It can be included in your mortgage on a new home.  It can be financed by Solar Bank or other methods.   But, the important thing to remember is the cost per Kilowatt hour ($/KWH) over the life of the system will be lower than what you will be paying the Public Utility company.  There are also Federal and local tax credits to help reduce the total system cost.  SESP will provide information on all available incentives.  Check out SESP's Financial Incentive page. 

k)  Procure the components you will need.

SESP has established relationships with the best manufacturers and can provide very competitive pricing.  Check out SESP's Kits and Products page.  

l)  Install the system.

SESP has electrical contractors on staff to provide installation services.  

m)  Enjoy a clean, quiet, trouble free and inexpensive lifestyle. 

At SESP, that is what we call true SOLAR FREEDOM ^tm.