Hybrid Solar & Wind Power Kits
- Hybrid Solar Wind:
- Planning, Design & Installation Tips:
- Resource Documents:
Hybrid stand-alone power system technology has advanced with the pace of the number of homeowners who want to live off the grid making remote home energy systems that are no longer dependent on a single technology. In areas of the country with an average sustained winds of 6 M/S or 9 - 14 MPH, good exposure to prevailing winds like the top of hills or clearings at a 98 ft. height are generally considered to have a suitable wind resource for small wind applications.
To start the process of selecting a hybrid system, you first need to make a list of the equipment you intend to power. The hybrid solar and wind system kit you choose depends on the amount of electricity you require (Watts & Duty Hours/Day), and the where the equipment will be located. (Average sun hours & average wind speed.)
Energy Harvest in All Areas are Not Equal.
"Hello, we have lots of wind in our area and I want to add a wind generator to my off-grid home. It is always windy here." Many a homeowner has learn an expensive lesson the hard way because they have not taken the time to understand the basics of wind generation which is wind generators placed in areas of insufficient average wind are like dams placed in streams with little water, they do not work.
Wind is far more location-specific than solar. Another way to put it, everyday the sun will rise and set but not so with wind. Wind follows daily geographic patterns as well as seasonal peaks and valleys. (USA Wind Resource Map)
In many selected areas of the country, wind and solar are complementary power sources. Wind generation peaks during late afternoon, evening and during winter storms when solar is at a minimum. Conversely, a solar system will shine while wind may be in the doldrums.
Initial Planning Steps:
- Consult Wind Resource Maps: Click on the planning, design and installation tips tab above where you will find a resource map link for wind and solar. Use these maps to determine how much wind and solar in your area is available.
- Airport Wind Speed Data: Though not definitive, your nearby airport can provide good information about the average local wind speed for your area. You need to be a little cautious because the information recorded at the local airport may be on land that is flatter and less obstructed than your lot and is usually measured at heights of 20 - 30 feet off the ground.
- Use a Wind Speed Measuring System: Though not as accurate as more expensive system, you can purchase for under $60 equipment to directly monitor your sites wind speed allowing you to record to your satisfaction your available wind resource. (Tech Solar Transmitter Wireless Weather Station WA-1070T.) The measurement equipment must be set high enough to avoid buffering created by buildings and trees. The best location would be at the top of the proposed tower height you intent to place your turbine.
- Zoning, Permitting and Local Restrictions: Before you invest in a hybrid wind power system, you should check with your local code officials and association (If Applicable)
to find out if there are any restrictions. In addition to zoning issues, your neighbors might object to a wind turbine that
interferes with their view.
- Height Restrictions: Some towns or HOA have restrictions on the height of structures in their zoned areas. Althought you can sometimes get a variance, many zoning laws limit the height to 35 feet.
- Noise Issues: Small wind turbine noise is only slightly above wind noise. (Click On Video Tab Above) You may be able to pick out the sound of a hybrid wind turbine if you strain to listen but most people would not find it objectionable. However, if there is any doubt if your wind turbine will disturb your neighbor, be a good neighbor and have a conversation with your the family living next door in advance.
- Shadow Flicker: Shadow flicker occurs when the blades of the wind turbine rotor cast a shadow across nearby windows. This shadow can have a disturbing effect sometimes referred to as the strobe light effect. Small turbines are less of a problem but you should give it some thought.
- Birds: There is no way to dance around this discussion. Wind energy does kill some birds some of the time, but no more than tall structures and most sources of energy.
Attaching anything related to a wind turbine to your house is a bad idea.
Never attach the tower to your house. If the tower were attached anywhere to a structure, the structure itself would begin to vibrate ever so slightly. This reverberation would vibrate the building with the possiblity over time of structural damage.
Ok, You Are Satisfied You Have Enough Wind in Your Area, Now What?
Now, it is time to consider site specific issues associated with installing the hybrid solar wind system. The most important factor in maximizing the performance of your wind generator is the correct siting on your property. The better the siting, the greater the performance. Small increases in average site specific wind speeds result in dramatic increases in energy output of your wind generator. For example, an increase in wind speed of 10% (10 mph - 11 mph; 4.5 m/s - 5 m/s) results in approximately a 30% increase in the power available from the wind. Therefore, the better the location the better the performance. As a rule, the small wind generator should be mounted as high and as far away from obstructions as possible.
- Two basic necessities for a good hybrid site pick are average wind speed and low ground turbulence. The lower the turbulence or buffering, the less stress you will put on your wind
generator and the more energy it will produce.
- A good rule of thumb if your tower is downwind from a building it should be 20' above the height of the building as well as any barrier such as a stand of trees that are closer than a 500' radius.
- Surface Roughness: Rough ground is land covered with small bushes, trees or other obstructions. Smooth land is an area covered only by grass or dirt. The smoother the ground, the less the friction. The rougher the ground the greater the friction, thereby requiring the tower to be higher.
- Place your tower on the highest land point around your home as practical. There are circumstances where the highest point available may not be the best place for your tower. Highest land nearby may be awkward to get to, may be too far away from where you need the power, or may expose your wind turbine to potentially damaging turbulent conditions.
- How high is your tower? Hands down, the biggest mistake a homeowner can make with a small wind turbine is putting the turbine on too short of a tower. Like solar in the full sun with no shade, any renewable energy source must have good access to the fuel that drives the electricity. There is nearly 100% more power available in 10 MPH winds than 8 MPH winds.
TIP: The power output of a wind generator decreases roughly 3% for every 1,000' of elevation above sea level due to lower air pressure.
Hybrid MidNite Solar / Primus Wind OFF-GRID BATTERY BASED POWER SYSTEMS
These Primus Wind Power and MidNite Solar/Magnum Energy E-panels, combines one of the worlds best top brand smallwind turbines, inverters and charge controllers. The power centers are shipped pre-wired with the high quality Canadian Solar panels at affordable prices. Mechanically and electrically engineered, every component of this kit has been specially selected to assure the highest performance in a safe simple-to-install system. Primus Wind Power is located in Colorado, USA and is a leading provider of high-precision, high-complexity assemblies and components for the energy, aerospace, defense and medical industries. Primus, MidNite Solar and Magnum Energy, American companies producing products made in America, creating American jobs. We like it... a lot!
MidNite / Magnum
|Item #||Voltage DC (Battery) / AC||Daily Watts @ 5 Sun Hours /Day STC*||Wind Daily Watts @ 13 MPH**||# Solar Panels||Price before 30% Federal Tax Credit|
500 Watts Solar &
Primus Air 40 Turbine
|Prim1524AE-500|| 24 / 120VAC
|2,500 Watts||1,440 Watts||2 - 250W|
|1000 Watts Solar &
Primus Air 40 Turbine
|Prim1524AE-1000|| 24 / 120VAC
|5,000 Watts||1,440 Watts||4 - 250W|
|1000 Watts Solar &
Primus Air 40 Turbine
|Prim4024-1000||24 / 120VAC||5,000 Watts||1,440 Watts||4 - 250W|
|1500 Watts Solar &
Primus Air 40 Turbine
|Prim4024-1000||24 / 120VAC||7,500 Watts||1,440 Watts||6 - 250W|
Conservation of Energy is Better Than Investing.
Most American households can easily halve their electrical usage. You should be asking yourself how much you're willing to pay to generate your own power? Conserve as much energy as possible before investing in a hybrid system. It is always cheaper to save energy than to create it.
*STC - To learn more about solar panels and how they are measured you need to know what STC stands for. STC in an acronym for "Standard Test Conditions". All solar panels are rated in Watts. The watt rating is how much power (amps times volts) the panel will produce in full sunlight at 25 degrees C (77F). This is the industry standard (STC) for all PV panel ratings (PV means Photovoltaics which is a fancy word for solar). Solar panel manufactures have long used this test standard which is 1,000 watts per square meter solar irradiance, 1.5 Air Mass and a 25 degrees C. cell temperature.
PTC is an acronym for "PV-USA". The PV-USA test conditions was developed at the PV USA test site at the University of Davis, California for standards established by the California Energy Commission that are considered closer to real world conditions (Real World Vs STC factory test conditions). The PTC rating test is 1,000 watts per square meter solar irradiance, 1.5 Air Mass, and 20 degrees C. ambient temperature at 10 meters above ground level and wind speed of 1 meter per second. In California, solar panels manufactures must be tested and rated independently at the PV USA test facility at the University of Davis (CA) to be considered for rebates.
The ambient temperature rating (PTC) is generally considered a better real world standard than factory conditions because silicon solar cells average about 20 degrees C. above ambient temperature in the real world, cell voltage drops as temperature increases. A module's power output in real life conditions is lower than the power measured at the panel manufacturing factory where cell temperature is maintained at a controlled 77 degrees F. (25 C).
STC Vs PTC Cell voltage drops about 0.08 volts per degree C. in environments which exceed 25 degrees C. That means an STC rating of 17 volts can actually become a PTC (PV-USA) rating of 15 or 16 volts. Using Ohm's Law, volts times amps is equal to watts which equals power, so a reduced voltage, means reduced watts.
Neither PTC nor STC account for all "real-world" losses. Actual solar systems will produce lower outputs due to soiling, shading, module mismatch, wire losses, inverter and transformer losses, shortfalls in actual nameplate ratings, panel degradation over time, and high-temperature losses for arrays mounted close to or integrated within a roofline.
**Freight Shipping (Freight Delivery is Dock to Commercial Dock)
Item that are too large or heavy to ship UPS and have to be palletized are shipped by ground freight. In circumstances where we offer shipping, free or otherwise, that means dock to commercial dock (not residential) to any of the lower 48 states. If the customer does not specify a local commercial dock that is available, we will ship to the nearest terminal where the shipment will be held for will call pick up by the customer. If you choose to have your order shipped to your residence, most orders require special handling for unloading and the pallet has to be transferred to a truck with a lift gate. In most cases, truck freight companies do NOT require their drivers to unload shipments. An additional "Residential" as well as a "Lift Gate" special handling fee will apply if the driver unloads the merchandise to the curb at your residence. The special handling fee is $89.00 and is available at checkout. If you have selected this add on service, the shipping carrier will call and schedule delivery of your solar kit, (provided the weight and dimensions of the product fits the criteria for lift gate service). You can avoid the residential and lift gate fees by arranging a "Will Call" pickup at the closest freight company terminal. In that case, you will need a pickup truck, a copy of the bill of laden, and a photo ID. When you arrive at the freight company terminal, the freight company will load your order into the bed of the truck with their forklift. The most common pallet size = 65" X 44" (Height depends on Product). Be sure and check for hidden damage.
Estimate Your Loads
Appliance & Equipment Load List: List and add up your daily electrical equipment load demand in watt hours (wh):
Watt hours (wh) and amp-hours (aH); Watts = Amps X Volts. Watt hours are the most common measure of electricity usage and are the easiest to understand. Amp Hours = Watt hours / System Voltage. Many professional system designers will use amp hours to size a system because amp hours takes into account real world behavior of solar panels and battery banks. Either method will arrive at the same conclusion if done properly. For our purposes here, we will primarily use watt hours (wh) when sizing the number of solar panels (and inverter) and amp hours (aH) for our battery selection.
TIP; Higher battery voltage means less resistance which allows equipment to run cooler. Cooler electrical equipment = longer life.
Your system voltage means the nominal voltage you select for your battery bank, charge controller and inverter (if you are planning to use one). Here are some things to consider when choosing your systems voltage:
- The DC system voltage is established by the battery bank in off-grid systems. A major factor in making this decision is how much power will be required from the batteries. As power demands increase it is advisable to raise the battery voltage. This voltage is important because establishes the type of charge controller and inverter that will be selected. The selection of the battery bank voltage affects the currents. A 1200 watt off-grid system operating at 12 volts draws 100 amps. (1200w / 12v = 100A). The same system draws only 25A at 48 volts. Lower amps reduces the size of conductors, over current protection devices, disconnects and charge controllers. Additionally, since voltage drop and power losses are smaller at lower amps, higher voltage off-grid systems are more efficient. As a rule of thumb, off-grid systems up to 1000 watts use a minimum 12 volt battery bank which limits DC currents to less than 84 amps. For 2000 watt systems, 24 volt battery banks are used. For 5000 watt system a 48 volt battery bank should be selected.
- TIP; How long each day does a refrigerator run? 120VAC Refrigerators can be a large load for off-grid systems or they can be no draw. How often a refrigerator will run during a 24 hour day depends on many factors and will vary from home to home for the same refrigerator. Some of the variables include; the room temperature throughout the day, how full your refrigerator is (Full refrigerators run less often once the contents are cooled), and how often you open the door throughout the day. You can lower the run time of your refrigerator by turning off the automatic defrost function and keeping your refrigerator full. One off the grid living tricks is to keep full jugs of water in a 1/2 full refrigerator. Once the contents of the refrigerator are cooled, an energy efficient model in your home that is full might be expected to run 24% - 35% of the time with a room temperature of 70 degrees or about 6 hours out of 24.
Daily Off-grid System Charge Requirement in Amp Hours:
- Since the energy output to the loads must be balanced by the energy input from your solar panels and wind turbine, we need to calculate your daily charge requirement in amp hours as that number will come in handy later. Take your total daily watt hours x 20% (rule of thumb) to account for losses in inverter, circuits and wire transfer. Now divide by the system voltage you chose based on the previous section and write this number down. This is the charge in amp hours your solar panels will have to provide each day to meet your load requirements you have set. Example 5,000 watts daily load total X 20% = 6,000 watts / 48 volt system = 125 amp hours that will need to be generated. Example #2, 5,000 watts daily load total X 20% = 6,000 watts / 24 volt system = 250 amp hours that will need to be generated.
Wind Turbine Site Selection & PV Sizing; Input Must Equal Output.
(A) The size and or number of solar panels is calculated from the total energy requirements + allowing for wire and inverter transmission loss (20% rule of thumb) less the lowest solar irradiance available in the area of the system which is usually the shortest daylight month of the year (December). In a hybrid system, you are not only considering the solar array but also the average available wind for your area. The combined input of both systems must equal your daily output during the shortest day of the year or you will certainly strain your battery bank capacity.
Find the nearest city to your home and write down the lowest daily sun hours. Divide your daily load calculation (+ 20%) use by lowest sun hours per day. For example, if the daily average electricity load demand is 5,000 watts, and the site is in Salt Lake City UT, you would take 5,000 watts X 20% = 6,000 watts less 1,270 watts produced by the wind turbine / 4 sun hours = 1,183 watt solar array. That means if you choose 250 watt panels you would need 5 - 6 solar panel kit. Especially for off-grid systems its a good idea to always round up, but this is where your budget comes into play and a personal choice to aggressively manage your daily energy usage.
TIP; Match the number of solar panels and wind turbine average daily output to the battery capacity: After you finish sizing the number of solar panels combined with the average daily output of your wind turbine to off-set your load requirements, you will need to consider whether the panels power and your battery bank's capacity are sized to work together, or are matched, within reason. You will want the hybrid system to have the capacity to ideally fully charge your battery bank on the shortest day of the year or be prepared to lower your power needs during the wintertime. If the hybrid system is too large, you waste money and power because your charge controllers will not send all the current the hybrid system produce because your battery bank will not be capable accepting too much power too quickly. If the hybrid system is too small, it will not be able to fully charge your battery bank.
Evaluating your off-grid site. Key Considerations:
- Check out areas available to install your solar kit. A few things to consider; array dimensions, orientation, tilt and obstructions. For off-grid installations, ground mount systems are the most popular. (Top-of-Pole or Rack Mounted)
- Shading of array location. This is important in any solar installation but a must in off-grid systems.
- Roof type and age.
- TIP; If you plan on re-roofing within 5 years but are not ready yet, some homeowners will replace only the shingles located under the solar array when the panels are installed and leave the rest for later.
- Battery Bank and Inverter Location.
- TIP; Solar cells are activated by visible light not ultra-violet or infra-red. Solar panels produce electricity when exposed to sun light, but plan to keep your inverter and battery bank in the shade and or indoors. Inverter and charge controllers should be located as close to the battery bank as possible.
Choosing Your Battery Bank:
Battery bank sizing is the part of the hybrid solar wind system that has a higher probability of causing you problems that other parts of your system. Use the battery sizing worksheet to help you through this critical stage. Factors such as your budget may tempt you to look to cheaper battery alternatives, but a quality battery will pay off over the years. We recommend you choose a 2V or 6V battery and connect them in series so that the total equals the system voltage you initially selected.
To properly design a battery bank, you need to account for the storage capacity required, the maximum discharge rate (the sum of all the loads which might be run simultaneously), the maximum charge rate (the current output from the solar array or wind turbine though the charge controller), and the minimum ambient temperature at which the batteries will be used. Whichever of these factors requires the largest capacity will dictate the size of the battery bank. The storage capacity of a battery the amount of electrical energy it can hold is usually expressed in amp-hours (Ah). Using one amp for 100 hours means 100 Ah have been used. A battery bank in a off-grid solar power system should have sufficient capacity to supply needed power during the longest expected period of cloudy weather. A lead-acid (vented or sealed AGM) battery should be sized 20% to 50% larger than this amount.
TIP; Only similar batteries should be connected together in one bank. Do not connect old and new batteries or wet and gel cell batteries together.
Battery Sizing Worksheet
Use this worksheet to determine what size battery bank is required for your system. Battery size, or capacity, is measured in amp-hours. Battery voltage is determined by the number of "cells" in series. All lead-acid battery cells have a nominal output of 2 VDC. Actual cell voltage varies from about 1.7 VDC at full discharge to 2.4 VDC at full charge. 12 VDC lead-acid batteries are made of 6 separate cells in one case. 6 VDC batteries are made of 3 cells in one case. Putting battery cells in parallel increases amp-hour capacity, but does not change voltage.
Tip: An off-grid battery bank should be large enough to deliver about 3 days of power with a discharge of no more than 50% of the battery banks total capacity. Less than 3 days and your charge and discharge number of cycles will shorten the life of the battery bank.
Battery bank sizing is the capacity to store electrons and is expressed in amp hours (AH) and at the rate the battery will charge or discharge not the physical size of the battery. Be careful when you are considering the Ah capacity of a battery and compare batteries that are advertising a 20 Ah discharge and not more (An apples to apple thing). Choose the 20-hour rate when sizing and selecting batteries.
Hybrid solar wind battery banks can be made up of many small batteries which are connected in series and or parallel to give you the wattage (Volts X Amps) capacity needed. As a rule of thumb, battery banks with lower voltage (large cells) are going to last longer, take less work to maintain but are going to cost more initially. Keep your battery bank the same age, size and brand. Mismatched batteries will cause the smaller ones to have to work harder and the larger ones to coast and sulfate. (That's a bad thing)
This Ah battery calculation shows that a battery bank of 24 325 Ah batteries will provide ample energy storage in this example to meet the daily requirements, inverter loss, cold temperature inefficiency and days of autonomy while keeping the DOD above 50%.
Tip: The number of batteries or series strings of batteries connected in parallel should be limited to no more than 3 per charge controller. This minimizes the chance of unequal charging from one battery or string to the next and will increase the life of the batteries all other things being equal.
Power Center (Inverter) Selection:
Before we discuss power centers (Inverters), lets hit on what a charge controller does. A charge controller is an electronic voltage regulator used in off-grid hybrid solar wind systems with battery banks to properly control the charge from the solar panels or wind turbine keep the voltage to the battery bank within acceptable limits. The charge controller automatically tapers, stops, or diverts power when batteries become fully charged. Without a charge controller your solar panels or wind generator would continue to send electricity to the battery bank and eventually destroy your batteries.
Your charge controller will:
- Provide an optimum charge to the batteries.
- Prevent your battery bank for being overcharged from your solar panels or wind turbine.
- Prevent unwanted discharging.
- Provide information on the state of charge of the battery bank.
- The Primus AIR turbine’s internal regulator or charge controller will monitor the battery and maintain the charge as necessary independent of the solar arrays charge controller.
|Modified Sine Wave Inverters(Sometimes Called Square Wave)|
|You can save a few dollars by purchasing a modified sine wave over a pure sine wave inverter but consider this first before you buy. Modified sine wave inverters may not run:|
|• Laser printers, photocopiers, and anything with an electrical component called a thyristor|
|• Anything with a silicon-controlled rectifier (SCR), like those used in some washing machine controls|
|• Some laptop computers (Apple Products can be particularly fussy about their energy source)|
|• Some fluorescent lights|
|• Some new furnaces and pellet heaters with microprocessor controls|
|• Digital clocks with radios|
|• Appliances having speed controls|
|• Medical equipment should not be power with modified sine wave inverters.|
|Because the total harmonic distortion is higher in modified sine wave inverters, motors will run hotter and not last as long. You may hear a buzzing from your stereo system and you might see lines on your TV screen.|
Choosing your Off-grid Power Center:
Living off the grid means you will be generating, storing and processing every watt your off-grid home or cabin sucks up. AC power center is going to be of particular interest to you because you will be depending on it day in and day out.
To determing what size inverter (power center) you are going to require, you first need to add up the demand from all your appliances that are likely to operate at the same time. Your inverter (power center) should be sized to handle both the surge requirements plus their continous power demands.
Off-grid inverters are sold either sine wave or modified sine wave. Sine wave output, which has low total harmonic distortion, will power virtually any type of load, even sensitive audio electronics. Modified sine wave inverters may not run some types of equipment satisfactorily, and some loads won’t run at all.
An off-grid inverter must supply enough power to meet the needs of all the appliances running simultaneously. Before selecting an inverter, you must know the watts your appliances will require and their amp and surge needs. Sizing an inverter for an off-grid system, which is based on instantaneous load, is very different from sizing a grid tied inverter, which is determined by the solar panel array size. In the case of an off-grid inverter, the inverter has to provide enough energy to all the AC loads, sometimes at the same time. Say you need to simultaneously power 3,000 Watts from various appliances. For an off-grid system, you’d need an inverter that could supply at least that amount. Note that the solar array size does not enter into this inverter sizing since the inverter pulls its power from the battery bank.
Blue Pacific Solar only sells power centers and inverters that meet Underwriters Laboratories (UL) 1741 standards. So if you are on the fence between two choices of inverters, you might ask and find out if it is UL listed and is it an inverter specifically made for off-grid solar or wind applications.
Inverter Surge Capacity
The ability of an off-grid inverter to surge to a higher level than its rated continuous output for a short duration to turn over the locked rotor of large loads like well pumps is critical. The inverter specifications that should be looked at are the Maximum Output Amps and the AC overload capability. If there are large loads a good number to look for is a five second surge capability of at least 1 ½ times the rated output of the inverter. If you have a deep well pump, the minimum requirement may be 3X the continuous run amps.
Wire Size Electrical Distribution Parts
Combiner / circuit breaker box is a key piece of equipment that begins to bring the pieces of equipment together that allows you to generate electricity. We use almost exclusively Midnite Solar and OutBack combiners and breakers because they are safe, durable and easy to wire. NEC (National Electrical Code) says that each series of strings of panels are to be wired to it's own circuit breaker. Midnite Solar and OutBack combiner boxes make this task easy providing a breaker to turn off and on each string for any purpose. The combiner box is usually located directly under a ground mount array.
Wire size and breakers are the final items in your hybrid solar wind design to consider, but no less important. To have a safe off-grid system, you will need to install breakers and choose the right size wire. If you select one of our pre-wired power systems with your kit, we do all the heavy lifting for you because right size breakers are pre-engineered and pre-wired into each of our power centers. You simply have to hang and connect it following our wire diagram which is supplied with all our kits. It is no accident you will only find Midnite Solar and OutBack combiner boxes built into our off-grid systems. They are reliable, UL listed and simple to install.
The distance between the combiner box, which is usually located near the solar panels, and the charge controller will be a factor in choosing the best string voltage for the charge controller and battery system. The higher the input voltage the smaller the wire can be for any given amount of power. For example, a system with a 12 volt battery and solar panels consisting of four 6.75 amp 12 volt DC nominal modules located at a distance of 40’ from the batteries could have the modules wired in series, parallel or series and parallel. Input design possibilities in this example are 12, 24, and 48 volts DC. If the panels was configured with the panels wired in parallel the input voltage would be 12 volts DC with an input current of 26 amps. The same panels wired in series would have an input voltage of 48 volts DC and an input current of 6.5 amps. In this example #1, the 26 amp 12 volts DC panels #1/0 wire, which is prohibitively expensive, would be required to limit voltage drop to 2% which is recommended for 12 volt DC systems. The same panels wired for 48 volts dc would only require a #8 wire. With the #8 AWG wire the 12 volt dc panels would have to be within 7’ of the batteries. The distance that #8 wire can be used is over 5 times greater at 48 volts DC than 12 volts DC.
The amount of current (amps) traveling through any electrical circuit depends on the size of the wire (AWG), the voltage of the array or battery bank, and the one way distance of the wire run. Lower AWG gauge wire has less resistance than larger gauge wire. The longer the distance of your wire run while using lower voltage the larger gauge wire you are going to need. If your solar array consists of 4 or more 90 watt panels and is more than 50' from your battery bank, you should consider using 24V as a minimum with 48V being a better choice.
This chart is useful for finding the correct wire size for any voltage, length, or amperage flow in any AC or DC circuit. For most DC circuits, particularly between the solar panels, the wind turbine and the batteries, we try to keep the voltage drop to 3% or less. You will need to consider the solar array and the wind turbine as separate calculations because of the unlikely proximity of one to the other and the common battery bank.
TIP; NEC 690.8 CALCULATION of MAXIMUM CIRCUIT CURRENT. (A)1 Solar Source Circuit Currents. The maximum current (Amps) shall be the sum of parallel solar panel rated short circuit currents multiplied by 125 percent.
- Amps = Maximum Number of Amps Through the Circuit
- Feet = One Way Distance of Wire
- % Voltage Drop = Percent of Voltage Drop Desired (2 = 2%)
- Voltage = Voltage Carried by the Wire
|Voltage Drop Index Chart (VDI)|
|AWG Wire Size||Copper Wire||Aluminum Wire|
Hybrid Solar Wind Power Kits, Cabin, Home Off-Grid Systems
Tax Credits for Hybrid Solar Wind Systems
As environmental and economic concerns about traditional energy sources grow, renewable energy is becoming more and more popular in homes and businesses. While costs are decreasing, devices to capture renewable energy, such as wind turbines, can still be expensive. Federal government tax credits provide an excellent incentive to make the investment in a residential wind turbine.
Most of the world gets electricity from coal-fired power plants; the energy from burning coal heats water, creating steam that turns a turbine, and the kinetic energy is used to generate electricity. Wind turbines eliminate the fossil fuel, turning an exposed turbine with clean, renewable wind power. Wind power has been used for centuries by windmills; blades turned by the wind turned a millstone to grind grain. Instead of using kinetic energy directly, wind turbines capture the wind and convert kinetic energy to electricity with a small generator.
There are a variety of residential wind turbine designs available. Manufacturers don’t recommend that homeowners make wind power their only power source, since winds are not consistent, but wind turbines can provide a significant supplement to other power sources.
The current tax credit for hybrid solar wind is set to expire at the end of 2016. The tax credit is 30% of the total cost of the wind turbine, including the cost of installation. The credit may be applied to wind turbines added to existing homes or built for new homes, and unlike many credits, it also applies to wind turbines placed at second homes. Wind turbines are required to have a nameplate capacity no higher than 100 kilowatts; most turbines suitable for residential use are below this capacity.
Wind turbines which qualify for the tax credit will have a Manufacturer’s Certification Statement attesting to the fact (it should be available on the manufacturer’s website). The statement doesn’t have to be submitted with tax forms to receive the credit, but should be kept for the owner’s records.
Over time, investing in a hybrid solar wind system can provide a significant benefit for the environment and significant savings on electricity. The tax credit program for residential hybrid solar wind systems is just one more reason to begin a transition to renewable energy sources. If off-grid, it may be your only choice.