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Q:I currently have 2 solar arrays, each consisting of 4 180 watt panels. They each have their own inverter. Each inverter is rated for only 550 watts, and each array has never peaked over 500 watts. The question is each inverter is plugged into a outlet, but both outlets are on the same circuit. Is this a problem???

A:

Wow - scary question!

It sounds like you are back-feeding electricity straight into an outlet. This can be done, but you should not trying this without an electrician around. You can cause a lot of damage to yourself and your property if you don't have a master electrician working on this system.

Critical to this are two things: one, are the solar inverters you are using grid tie inverters? This is required - if they are not grid-tie your solar energy system won't work. Two, if they are plugged into two separate outlets on the same circuit the circuit breaker will trip if the amperage exceeds the circuit breaker (typically 15A or 20A).

Most solar inverters on smaller solar energy systems are designed to provide power for a specified load. In this instance you are trying to back-feed to the grid with an uknown inverter. It is also not known how much other load you are carrying on the circuit. You need to identify everything on the circuit so you know how much load is being accommodated by the circuit.

05-12-2011 by garrett Category: Solar Panels

Q:How to choose a suitable inverter to connect let say a 10kWp PV to the main grid? Please advise

A:

In general, when choosing an inverter you want to first check the maximum input values for the inverter that you wish to use. For example, the SMA manufactures a Sunny Boy 10000TL-US that has a maximum recommended PV power at 12,500 watt. Carefully evaluate the STC value of the home or commercial solar panels you will be using and ensure that it does not exceed the maximum threshold. Solar inverter manufacturers will have the technical benchmarks in which the solar energy system you're targeting should not exceed. Satcon is also manufacturer of larger central inverters used for home solar installation or commercial solar installation or you can choose a microinverter. 

For more information on inverters and microinverters please visit the SolarTown Learning center for an article on choosing between a central inverter and a microinverter.

Secondly but more importantly, be careful when handling large solar energy production from your solar energy system. High voltage system should be handled with care and every safety precaution should be used when working with the high current.

04-11-2011 by rflamun Category: Solar Panels

Q:If I get a Sunling 6.5 watt foldable solar panel, what accessories do I need to charge a battery that can later be used to recharge a smartphone? Can such a battey also be charged with a cigarette lighter or wall plug? Will this solar unit charge a Motorola Droix X?Please advise.

A:

The Sunlinq 6.5 watt foldable solar panel comes with a cigarette receptor that you can connect your device directly to as long as you use the cigarette charger that comes normally with your smart phone. For mobile devices, you will receive a power adaptor with a cigarette plug that is used to charge in mobile applications. That same connector will plug into the Sunlinq 6.5 watt foldable module. For solar charging and backup use, you can take a look at a Brunton Freedom or the Brunton Restore Power Devices that offer secondary charging from the internal battery bank or from the solar panels itself. For other suggestions, take a look at our portable solar modules. Whether you want to charge the device from the solar panel or an internal battery, the Brunton mobile energy solution should fit your application.

04-05-2011 by John S Category: Solar Electronics

Q:I have a working 5 KWDC 4 KWAC system with a conventional central inverter. When the inverter fails, can I purchase and install micro-inverters on my system? The panels have a 25-year warranty. How can an owner of a centrally wired system with a single inverter know when a single panel has dropped below the manufacturer's warranty output?

A:

A solar energy system could replace a central inverter with Enphase micro inverters (or other micro inverters when they hit the market), assuming the following:

1. The panels that comprise the array are on the Enphase compatibility list, located at this link.

2. The owner of a central inverter system may not discover if one module out of his or her entire home solar panel system has failed. Modules do not fail very often, but last year, SolarTown had a customer with a large system on his home--and one of the solar panels failed. He had installed micro inverters for his system, so it was clearly shown on his monitor that he was not getting any juice out of one module. Therein is the market opportunity for micro inverters.

3. Remember that the panels in a string on a central inverter are ON (electrified) when they are in the sun! Your electrician should know to cover the panels before attempting to disconnect them prior to connecting micro inverters! A good tool for your electrician is an Ammeter, which can tell you how much current is flowing through a line BEFORE disconnecting it.

04-01-2011 by Rich C Category: Solar Panels

Q:I want to connect a 100kWp PV system to the main grid. What steps do i need? Help me..

A:

A 100 kW system is a very large solar energy system and you are correct to assume that you will need more than an extension cord. A grid-tie system is the system of choice for the vast majority of homeowners because you can essentially use the grid as your battery storage system. Never ever consider doing any of the electrical work yourself, unless you want to exit this world with one quick jolt of electricity. You will need a master electrician (or whatever the equivalent licensed electrician in your jurisdiction) who has experience with solar energy systems. To properly configure the system, he or she will need to know a more about the solar installation, the site and how far along you are in the installation. 

03-27-2011 by Ronald Fr Category: Solar Electronics

Q:How do solar panels transfer the energy from the sun into electricity? (How do solar panels work)

A:

Solar panels that you find on homes are usually made of silicon. When solar rays hit silicon, a chemical reaction happens, moving electrons and making an electric current. Photons in the sunlight displace electrons in the silicon, which creates an electric charge. You can use this electricity to power your home, your RV, your boat, or whatever. There are different kinds of modules and each kind of solar module has different efficiencies. We have lots of resources that you can explore both in our SolarTown Learning Center and on our sister site for kids at solartownkids.com where right on the home page, we answer your question with a diagram showing how electricity is generated from the sun.

03-22-2011 by Maddie H Category: Solar Panels

Q:we are looking to run a summer camp (about 7 cabins and a larger dining hall) completely off natural energy, mostly solar power from solar panels. We are looking at rechargeable batteries, what rechargeable batteries would be best to colect this solar energy and power the camp?

A:

Camps and lodges are ideally suited for off-grid solar applications. If you can't get easy electricity to your camp, then an off-grid solar energy system is perfect for you. Using solar energy is a great way to power any off-grid application or remote facility, especially when conventional energy sources are inaccessible. Also for a camp filled with kids, the solar energy is a perfect focus for an educational program on renewable energy. Once you have the system setup you can have an activity where you can show them how solar works in powering different devices.

As for the right solar energy system for summer camps and cabins, you will probably look at a small energy system to provide essential lighting and emergency energy when needed. Before you go much further, you will have to figure out how much electricity you will need. But we will assume here, that you are looking just for the basics. In the instance for lighting and emergency use, you can go with a setup of two solar panels with a 100aH battery. This will provide enough power for sufficient lighting and backup power in the event of an emergency.

The only thing we would like to mention is that depending on what is connected, the runtime will vary. For example, if you were to run an AC (not recommended) you will not have enough power or can reduce the life of the battery. The amount of runtime will vary with what is connected to the system and always take safety precautions when working with DC or any energy source. Confirm with a master electrician or an electrical expert to ensure safety.For electronic devices like laptops, desktops, phone charges and the like, you will have enough power to run these devices in conjunction with lights (use LED lights). Try to avoid large appliances like refrigerators, ac units, ovens or water heating.

On a separate note, if you need refrigeration, take a look at our solar outdoors section of our solar energy store. You will find solar refrigerators and solar freezers that you can use with solar panels. And if you need hot water, then why not try a solar water heater and there are relatively inexpensive applications that you can find for use just in the summer.

For a specific breakdown of what components you will need for your solar energy system, please contact us at SolarTown.

03-16-2011 by Maddie H Category: Solar Panels

Q:In general,is a solar panel designed to get more energy if the solar panel is facing different directions? If so,which direction will produce the most energy if you live in the northern hemisphere?(EX for directions;north, south,east,west)

A:

There are a number of considerations in choosing the best location for your home solar panels. The best orientation for your panels, to the extent possible, is to have them facing the south, assuming you live in the Northern Hemisphere. But there are other considerations as well, for example, are there any obstructions that may limit the direct sunshine. If there is a tree casting a long shadow on your solar panels, then that would considerably reduce the output. If you place a solar panel behind a chimney, that will reduce your output.  You may also want to consider the angle of your solar array, although do not forget about aesthetics if your home is facing south. The short answer is that you generally want as much direct, unobstructed sunlight on your solar panels as possible.

02-23-2011 by agness c Category: Solar Panels

Q:If I wanted to power my entire community, or maybe my block, in efforts to go green, how would I do this? Can it be done? Going by your average home size, and voltage usage, what would be needed to power 15 homes?

A:

We like your vision for providing solar energy not only for your home, but for your entire neighborhood.  The short answer is that it is easy for a neighborhood to go solar, but there are definitely nuances that you will need to consider.  Since you didn't give us any details about where you live and what are the electricity needs of you and your neighbors, we will make some gross generalizations.  We will assume that an average size solar array of 5kW will produce about 500kWh of energy per month. If there are 15 homes in your group, you are talking about a 75kW combined capacity for your solar energy systems.

To install these home solar panels on your roofs, you will need about 500 square feet of roof space on each home.  And if we assume that there is this much space available on each roof and that space does not have any obstructions and is facing south, you are set and you can get started tomorrow.  Well, almost. But since you are buying in bulk, you have some bargaining power to get preferred rates for your solar energy systems from SolarTown and preferred rates from your installer. In some parts of the country, solar cooperatives have cropped up that prescreen solar installers and help their members tackle the many other issues that may arise dealing with, among other things, permits and rebates.

Now what happens if some of the homeowners still want to participate in your cooperative but don't have the roof space to site the solar energy system. The answer is that it still may be possible but it depends on the law in your specific jurisdiction.

02-07-2011 by Ricky D Category: Solar Panels

Q:What is the difference between a off grid inverter and a rv inverter?

A:

You are not the first one to be confused by the terminology for solar inverters. There are basically 3 kinds of solar inverters:

1. Grid-tie inverters: these solar inverters synchronize with the utility electricity and send power onto the grid.

2. On-grid inverters: these solar inverters pull power from the utility as a battery-charging source when a solar array's battery bank needs power and there isn't enough sunlight for the solar modules to provide this power. These inverters are also known as grid-tie with battery backup. They don't push power onto the grid, they only use it to assure a battery bank is charged.

3. Off-grid inverters: this is probably what you have in mind when you are referring to a "RV inverter." These solar inverters provide battery charging (DC current) for a battery bank from a PV array. They can provide either AC or DC electricity for the electric load used by the vehicle or off-grid home. They have no capability to connect to the utility grid, and are also known as "stand alone" inverters.

01-07-2011 by merle Category: RV and Marine