Ask an Expert

Q:Hi, I haven't even scratched the surface of your web site and have concluded that when I'm ready to install a solar system for electricity, I'll come to you folks. I've been reading in the Aks an Expert section and have come up with some very different or, shall I say, more technical questions. They are: 1. I noticed in one answer, you stated not to clean the panels with cold water, especially if and or when they are hot as they may crack. So, my question is: In the Summer here in TX, they would be HOT! and would they tend to crack if we had a thunderstorm? The rain that comes from those storms are usually very cold! 2. For the same storm scenario, It could develop and deliver large hail as they very often do here. Would hail damage the panels? Golf ball sized hail is common here. 3. You answered another question of mine and that was about the home owners insurance covering such damage. I'll be checking my insurance company to find that answer. When I do install a system, I'm looking for something in the 4k to 5k range. Many kudos for being such a helpful site! 

A:

Q1. Will solar modules crack in the event of a cold thunderstorm on an otherwise hot day in Texas?

A: Not likely. Solar panels are quite durable once they are installed. The biggest hazard is commonly when home solar panels are being installed - they won't fare well if dropped from a roof top. Solar panels are made to withstand high wind forces (5400 Pa is common) which is a measure of force per unit area. Panels are also made to endure severe weather conditions - wind, rain, sleet and snow. Weather variability is the main challenge for any solar panel as there are no moving parts (assuming a fixed mount installation). If panels cracked due to weather variations the solar industry would not be growing as quickly as it is.

Q2. Can hail damage solar panels?

A: Again, not likely - Solar modules have a layer of toughened glass something like your automobile windshield. And yes, windshields can crack - but do they crack in a hail storm? It may be possible, but  have never heard of this happening. More important, some manufacturers even detail their hail-impact ratings. Take a look at Sanyo's HIT Power 210 spec sheet - look at the operating conditions and safety ratings section at the end of the spec sheet. If a solar panel did crack in a hail storm, the manufacturer's warranty should cover the panel. Again, although it may be possible, I have never heard of a panel cracking due to a hail storm. Panels can get damaged though - but this is often such a calamity that your home owner insurance should cover it as more than just the panels might be damaged - perhaps a fire or a fallen tree that has damaged not only the solar array but the underlying structure. This of course depends on the insurance policy you have.

07-14-2010 by mntnman Category: Solar Panels

Q:I'm building a 35,000 square foot home. How many solar panels would i need for an average day of electricity?

A:

That is a very big house. You must be someone very famous and we offer discounts on all of our solar energy products to all of our famous customers. Only one minor problem. We assume that you probably have many other homes throughout the world, and so you probably don't live in this house. To conserve energy, you keep the electricity turned off most of the time, which we applaud. You may have a big house but if you never turn on the AC, your electricity usage is probably not very much. You may not be a good candidate for putting home solar panels on your roof. As a very rough rule of thumb, most systems are around 5 or 6kW for an average house. Your house is way over 10 times the average, so figure you should be thinking about a 60kW system or roughly 250-300 panels. We have some discount solar panels that we are sure would be ideal for your home.

06-26-2010 by Ashley Category: Solar Panels

Q:How many watts to run a 3 bedroom home?

A:

Every home is different and how much electricity you use depends on your individual habits and the condition of your home. In the US the average home consumes about 900 kwH per month. If you lived in the mid-Atlantic region, where you get about 4.5 peak sun hours per day, you would need a system of about 7 or 8 kW-you are looking at about 30 solar modules for your home. Most solar energy systems are sized not to absorb 100% of the electrical usage. If for example, you wanted to take care of 2/3 of your use, you would install about 20 home solar panels for your residence, and you would need roughly 500 square feet of roof space for these solar modules. We have a lot of information in the  SolarTown Learning Center  that you should read for more information.

06-21-2010 by Russell Category: Solar Panels

Q:which pump pumps the best (highest) psi rating.and how much solar watttage does it take. we have a number of livestock wells and they range in static 5gpm depth of 45feet down to 265 feet.?

A: 

There are many solar power water pumps available on the market today, and each has its own advantages and disadvantages. Based on your short description of the solar water pump system that you are looking for, the solar water pump that may suit your needs the best is the Lorrentz ECDRIVE 600. These submersible solar pumps
can handle volumes up to 20 gallons per minute and have a maximum lift of 250 feet. The amount of power determines the amount of output and lift. To meet your requirements, you would need to have approximately 300W of solar power to drive the pumps.

05-21-2010 by WWSVC Category: Solar Water Pumps

Q:What is the energy consumption of this solar water pump in watts.

A:

Please let us know which solar water pump you are referring to. Most of the solar power water pumps have a minimum wattage requirement before they will engage. However, based on your pumping requirements, in terms of distance and head, the wattage will vary. We would be happy to help you select the best solar water pump system to meet your requirements if you provide us with specifics.

05-16-2010 by Valentine A Category: Solar Water Pumps

Q:-What is the energy need of your solar freezer model 225dc expressed in watts? - How many solar panels & Batteries does one need to effectively power the freezer? - what is the total expected cost of the panels and DC batteries?

A:

The power requirements for a solar freezer or solar refrigerator are determined by the ambient temperature where the solar freezer or fridge is located and the number of hours of sunlight per day. A system in North America, for example, would require approximately 75-100 watts of power,  a 90amp hr 12v battery, and a solar charge controller to optimize freezer operation and battery life. A solar energy system of this design would cost around $2000. That figure could vary, however, depending on your personal needs and component selection. We would be happy to help figure out your exact requirements, and to provide support on how to set up and install the system. Please let us know if you have any additional questions.

05-16-2010 by Valentine A Category: Solar Outdoors

Q:Hello there! I'm wondering if you can help me? We've got an older model solar panel system and are looking to replace the battery and/or the charge control system. Our solar system is 3kW I believe and we currently have a lead acid battery. So, I have a few questions: 1. If we were to keep our lead acid battery, what charge controllers would you recommend to replace our old ones (something efficient)? 2. If we were to replace the battery and charge controller, what models of each would you recommend for our system?

A:

It is time to replace your batteries for your solar energy system when they can only hold 80% of the original capacity.

You should test each solar battery individually, and the batteries typically need to be replaced every 10 years. Depending on the type of batteries you have, the solar battery charge controller may not be able to optimize new AGM batteries, so you may need to replace that as well.

We have many recommendations about which solar batteries and solar battery charge controllers to use for various applications. Please contact us and we would be glad to help you determine what equipment is right for your needs.

05-07-2010 by Teresa D Category: Solar Panels

Q:can one solar panel of 240 watts power a large window air conditioning unit through the day? i want to power my major energy appliances through the day hoping to reduce cost. what do you recommend? thankyou

A:

Window air conditioning units consume a lot of energy. A 5,000BTU unit will use about 600 watts per hour. In order to meet this demand, you would need three solar modules such as the Canadian Solar 230 watt panels as well as a sine wave solar inverter with an outlet to convert from DC to AC to make the power immediately useable. How were you planning on powering the A/C at night? If you wanted to use solar power energy you would need to incorporate a battery bank into the solar energy system as well. We would be happy to help guide you through this process so please feel free to contact us.

05-02-2010 by eli g Category: Heating and Cooling

Q:Trying to circulate water through a 4' x 20' solar panel with a pump powered by the sun. Highest lift is 5' above waterlevel. The Mocal 12 volt Water Circulation Pump fits the bill (cintinuous use brushless 12 volt DC motor with up to 7 GPM) but don't know how to mate with which solar panel? Want it to operate on sun only like many solar fountains on the market. (No charger, battery, etc.) Max 2.2 amps = 26 watts max? Can you recommend a panel that won't damage the motor? Thanks!

A:

The Mocal pump that you are looking at is an AC pump, and solar modules produce DC current. In order for you to use a simple pump + panel setup you would need a DC pump. The Shurflo 3.6GPM is an excellent solar water pump that is direct current. The BP 50W solar panel would provide ample output for this solar water pump, allowing it to meet your requirements. You may also want to check out our solar water pump systems, which include both the solar water pump and solar module. If you have any additional questions, we would be happy to help you design your solar water pump system to meet your needs.

04-27-2010 by Carl Category: Solar Water Pumps

Q:I am wondering about how much solar power would actually be needed to run a 550 HP motor on a 100' boat at mid-range RPM's (This may sound like a ridiculous notion - but I don't know how to measure the amount of energy for the task - or to determine if the grade/type of Solar Panels - capable of putting out that much power - exist?)

A: 

Your question is a little bit confusing as I assume you are referring to a diesel engine, because electrical motors are rated in watts. One horsepower is equivalent to 746 watts of power per hour. Most solar panels on the market today generate on the order of 200 watts/hour. In order to power your 550hp engine at full tilt for 1 hour would require 410,300 watts or approximately  2100 conventional solar modules. However, since you are not running the engine at maximum capacity, you are not using all 550hp. Your actual energy requirement would be much lower.

While it may not be possible to replace the main engine on your vessel with solar, you may retrofit the boat's non-critical power systems to have a solar component to it. Take a look at our marine solar kits to see what some of your choices are. If you have any additional questions or are interested in how to solarize your boat, please let us know. We are happy to help.

04-20-2010 by Jason Category: RV and Marine