Many people are excited by the idea of producing electricity from the sun to power their home. However, they may be discouraged when they think of all the paperwork they will need to wade through to get permission from the utility company to install a system. You don't always need to ask your Utility Company for permission to install a solar power system on your home. One could take advantage of a grid-zero configuration.
Grid-tie solar systems are appearing in more and more neighborhoods as homeowners seek to reduce their rising electricity bills, charge electric vehicles, or just “green up” their energy footprint. However, many people are surprised to learn that the grid-tie solar panels on their roofs don’t supply power to the home when there is a utility blackout. This is due to the ani-islanding safety requirements of a grid tie solar power system.
When you purchase a complete Victron system from NAZ, we support you for the life of your system. One way we can help you ensure your system is configured correctly and working at maximum efficiency is by enabling remote monitoring and configuration over the internet.
There are an endless number of options when it comes to configuring your solar power system, which is excellent! But it can make decisions a bit more challenging. In this video, James, our sales manager and application engineer, talks about why he installed the Sol-Ark 12K Inverter on his home as part of his grid-tied battery backup installation as a grid-interactive system.
When looking at what is an ideal full system configuration for an RV, typically one would want to consider the expectations of a system and limitations of the RV, and then build the system around these expectations and limitations. In most cases you want to start from the roof and work your way down.
Solar for Roof
Roof space is usually the biggest limitation when considering solar power for an RV. Being that solar panels are one of the least expensive aspects of a complete system, maximizing production value for a given space is the most advantageous plan. In most cases putting as many panels on the roof as will fit is the best idea. Measure or use pieces of cardboard, targeting a sixty-cell panel format (~67”x40”). These are technically the best panels and the cheapest, due to the volume of sales these panels enjoy. Other panel sizes are available. Mixing sizes and shapes is complicated so plan wisely. We’ve never had a customer complain about having too much power (because this isn’t possible) but having too little power can result in too little energy production which may not meet your expectations. This can be frustrating and could lead to premature battery failure or other system wide issues.
Inverter Integration
Next you need to plan for an inverter if you need to run AC appliances and devices. The inverter converts power from the batteries to your basic household outlet AC power, 120VAC or 120/240VAC. You need to decide whether you want a fully integrated inverter system or a simple stand-alone inverter. In most cases, this decision will be dictated by what you want to power from the inverter. If you simply want to plug in a laptop or charge a phone from time to time, then a stand-alone inverter should work fine. Most of these smaller inverters will have an outlet on the front allowing low power devices to be connected. Anything more demanding than this requires a fully integrated inverter/charger. These inverter/chargers have a built-in transfer switch and the ability to charge the batteries at a much higher current than a typical converter. These are advanced inverter/chargers with powerful features and thus are usually the best solution for medium to large installations. The inverter/charger is typically placed between the shore power input and the main electric panel, the output from this inverter would go to the main electric panel. This essentially will power up all or most of the electrical circuits within the RV, depending on the configuration of the electrical panel. When AC input power is present from either shore power or generator, the inverter/charger will qualify the input (making sure it’s acceptable) and transfer that power through. It will pull from the AC input dynamically depending on certain limitations to charge the batteries. When shore power or the generator are not present the inverter uses energy from the batteries to power the AC loads. There are many more advanced features available from this type of inverter/charger, but in general if you power to all the outlets and appliances like the micro wave or the air conditioner then an inverter/charger is the way to go. Special care needs to be taken if you wish the inverter/charger to power air conditioners. Air conditioners consume large amounts of energy and need careful planning.
Battery Bank
The final step in a design is sizing the battery bank. An RV is a terribly abusive environment for batteries. It’s common to have significant deficit cycling (infrequent full charges), over discharge is very likely, and temperature can vary significantly. There are two types of batteries that work for an RV system; lead acid and lithium-ion. Lead-acid batteries include flooded batteries (AGM), or Gel. However, gel lead acid batteries are not designed for the demands present in a typical RV system.
Lithium
Advantages
No maintenance
Lightweight
Can be placed inside the living space
Smaller size
Battery bank can be added to over time
Low chance of damage if left uncharged
Higher level of efficiency
Charges faster
Disadvantages
Cost- Lithium batteries are more expensive, however, over the life of the system Lithium is cheaper.
AGM
Advantages
Low cost
Disadvantages
Larger and heavier than Lithium
It’s not recommended to add to a lead acid battery bank after it’s installed
Life is significantly reduced if they are left uncharged for any length of time
Flooded
Advantages
Cheapest battery option
Disadvantages
Must be placed in a vented enclosure designed to handle the gas fumes they create
Extremely heavy - it’s important to make sure that the location can handle the weight
Poorly suited to handle the abuse present in an RV system
Not recommended to add to their battery bank.
It’s important to have an accurate battery monitor installed in the system, one that uses a shunt. This will allow for accurate tracking of the battery state of charge. Regardless of the type of battery bank, this accessory can really help prevent excessive discharge and confirm regular recharging.
You can do all the research you want but some of the best recommendations you’ll get are going to come from experts in the industry. NAZ Solar Electric has several engineers on site happy to consult and design a system to suit your application, no matter how unique or complicated. Feel free to give us a call to discuss your project today.
A lot of people assume they need a transfer switch for an off-grid system when they are using a generator to charge the batteries or power loads. If you are using an inverter/charger there is an internal transfer switch to select between the inverter’s output and an incoming AC source. Most inverter/chargers will remain in “Invert” mode unless they see an acceptable AC source coming through (Shore / Grid Power or Generator Power). Once the inverter/charger accepts the AC voltage, it transfers over to supply power to loads and dump excess power into the batteries. Once this AC source is disconnected, the inverter will transfer back to “invert” mode and use battery power to run the loads. Some inverter/chargers will accept two AC sources and transfer between either of those and the inverter’s output. So if this is how your system would be set up, then there is no need for an external transfer switch.
You may need an external transfer switch if you have an inverter/charger with only one AC input and you want to switch between two AC sources like a generator and shore/grid power. This is the case in most mobile/RV applications. Another scenario is when you have a generator that can deliver more power than the inverter/charger can pass through and you want to power some heavy loads. The inverter charger is limited by the rating of the internal transfer switch. For example: Let’s say we have a Schneider 3.8kW inverter/charger with an internal 30A transfer switch with a split phase 120/240VAC output. The max load we can run by passing the generator power through is 7.2kW (30A x 240VAC = 7200 W). If we had a load that exceeded this 7.2 kW, and we had a generator that was able to satisfy this load, we would want the inverter/charger to be bypassed, allowing the generator to power the load directly. In this event we could use an external transfer switch to select between the inverter’s output and the generator’s output. If the inverter/charger is properly sized, this scenario does not occur often.
For more info on this call NAZ Solar Electric 1-800-383-0195 or email sales@solar-electric.com.
Lithium batteries cost more up front, but in the long run they are superior to lead acid batteries for several reasons. They are maintenance free, extremely efficient, safe, can be recharged very quickly.
This guide is primarily about DC powered pumps, as used in typical solar electric systems. Information is also provided on using AC powered pumps on systems that have an inverter available.
LG’s NeON™2 solar panel is one of the most efficient commonly available 60-cell modules on the market. LG considers the fact that the amount of energy generated by solar panels differs from day to day due to factors such as weather, temperature, and shading. This is why they create their solar panels with quality and efficiency in mind.
The Magnum E-Panels made by Midnite Solar come with an inverter breaker, 2/0 inverter cables, pre-wired AC input and bypass, 500amp 50mV shunt, AC terminal blocks, 100 amp DC positive and DC negative bus bars, PV input bus bar, din rails, 3 panel mount breaker knockouts, Ground bus bar, DC wiring cover, top shield, remote display mounting bracket, wall mounting brackets, charge controller bracket and lots of hardware and grommets.
Magnum Energy is a leading manufacturer of premium inverter/chargers for Mobile, RV, Marine, Off-grid and Solar applications. New technology battery charger design using power factor correction techniques, innovative first in modified sine wave platforms.
As the global specialist in energy management, Schneider Electric provides complete photovoltaic solutions for any size installation, from grid‐tie residential rooftops and utility‐scale farms to off‐grid solar and battery backup application.
Exeltech inverters have an MTBF (mean time between failure) in excess of 20 years and offer the most competitively priced ultra-reliable true sine inverters available anywhere. Exeltech provides back up power for the communications room in every U.S. Embassy, worldwide.
The Samlex America name is synonymous with power supply value. Since 1991, Samlex has manufactured and distributed power supply products to more than 90 countries worldwide. Innovative product designs, strict quality control, and responsible after-sales service provide customers with high-quality power conversion products at extremely competitive prices.
The latest and greatest Fronius grid-tie inverters are the IG Galvo and Primo lines, which are fully NEC 2014 and UL compliant. They come with built-in ground fault protection, DC reverse polarity protection, islanding protection, over temperature protection, and arc-fault circuit protection.
The Sunny Boy solar inverters characterize the technology and quality-leadership of the company. They are optimally suitable for use in small and mid-range systems. They impress with first class efficiency, user-friendliness, and reliability.
The Enphase Energy Solar Micro-inverter system is a set of small units that connect directly to each solar module to convert DC power into grid-compliant AC power and transmits valuable performance data on each module to the system owner.
A Conext XW solar system provides up to 36 kW by using modular components. All components communicate with each other with out‐of‐the‐box network capability. They include the Conext XW Inverter/Chargers, the Solar Charge Controllers, the Conext XW Automatic Generator Start (AGS), and the Conext XW System Control Panel (SCP).
Whether you lack the experience or knowledge to build your own system or if you simply want to save time on installation, the MidNite Solar Prewired E-panels are an excellent option.
Grid-Interactive? What does THAT mean?? Grid-interactive is kind of a hybrid system, battery-based but they also feed any excess power back to the grid and draw from the power grid when the solar panels are not producing enough.
This table lists the American Wire Gauge (AWG) sizes for copper conductors. In addition to wire size, the table provides values for load (current) carrying capacity, resistance, and maximum frequency. The resistance and skin depth noted are for copper conductors only.
Includes 12, 24, and 120-volt charts and a metric to AWG size conversion table. This is a five percent table which means at these amperage ratings at the listed distances, 5% of the power would be lost to resistance.
MC connectors are specially designed for low contact resistance and good stable connections under a wide range of conditions. MC means "multi-contact." The term "multi-contact" comes from the fact that the connectors have a bunch of little spring loaded gold plated fingers that ensure good contact.
What is an MC4 connector? If you're asking this question, you've probably noticed that most modern high power solar modules are manufactured with wire leads that have MC4 connectors on the ends.
Numerous charts and lists have been published with long lists of appliances and how much power they draw. You are then supposed to add up all the watts, then find out how many hours of sun you get, etc etc.
An "RV system" (small boat and cabin systems are practically identical) can mean different things to different people. It might be just a small 5-watt panel that keeps the battery charged up between a few trips a year or over the winter.
We carry many types, sizes, brands, and models of inverters. Various options are also available. Choosing which one is best from such a long list can be a chore. There is no "best" inverter for all purposes - what might be great for an ambulance would not be suited for an RV.
NAZ Solar Electric can custom build almost any kind of off-grid or grid-tie inverter power panel. We can also mix and match different brands of equipment if you prefer something different than what we specify. These systems are very easy to customize to your specifications.
An MPPT, or maximum power point tracker is an electronic DC to DC converter that optimizes the match between the solar array (PV panels), and the battery bank or utility grid. To put it simply, they convert a higher voltage DC output from solar panels (and a few wind generators) down to the lower voltage needed to charge batteries.
A charge controller or charge regulator is basically a voltage and/or current regulator to keep batteries from overcharging. It regulates the voltage and current coming from the solar panels going to the battery. Most "12 volt" panels put out about 16 to 20 volts, so if there is no regulation the batteries will be damaged from overcharging.
Lithium batteries stand apart from other battery chemistries due to their high energy density and low cost per cycle. However, "lithium battery" is an ambiguous term. There are about six common chemistries of lithium batteries, all with their own unique advantages and disadvantages.
Absorbed Glass Mat batteries are constructed differently than the traditional flooded battery. This write-up covers mainly the Concorde Sun-Xtender AGM's, but also applies to most other brands of deep cycle AGM batteries.
There is more to comparing batteries than just cost or amp-hour ratings. For example, based only on cost, the Concorde AGM's do not look so good. On the other hand, you probably would not want to store a flooded battery in your computer room. There is no one best battery for all applications.
The subject of batteries could take up many pages. All we have room for here is a basic overview of batteries commonly used in photovoltaic power systems. These are nearly all various variations of Lead-Acid batteries. For a very brief discussion on the advantages and disadvantages of these and other types of batteries...
When designing an off-grid (not connected to utility power) solar or wind power system, it's very important to have an accurate estimate for how much energy you need.
Lightning is the number one cause of catastrophic failures in solar electric systems and components. The first major reason is that many PV systems are poorly grounded and poorly protected. That is also the 2nd and 3rd major reason.
This information is mainly aimed at reducing or eliminating radio, TV, cell phone, and other electronic noise and interference in photovoltaic and other DC powered systems and from equipment used in PV systems.
You often see inverters rated in volt-amps (VA or va) instead of watts. For a perfect resistance, such as a heating element, watts and VA are essentially the same. However, many appliances, especially motors, are not a "perfect" load. Thus, the watts actually used may be less than the VA - but the inverter sees the VA. The motor or appliance may be using only 100 watts, but the inverter sees an "apparent" power of 150 VA.
