RVers Online conducted and electronic interview with Sovran Solar Systems Ltd., a Canadian manufacturer of solar systems. We were pleased to find Sovran has an interesting and instructive Home Page which many RVers will find helpful in considering the potential of solar power as an additional power source for their RVs. While RVers Online does not endorse specific products or services, or accept paid advertising, we do favor bringing to our Online RVers information about products and services which can be explored here on the Internet. We wish to thank Suzanne Price, and her colleagues at Sovran, for their contribution to the subject of RV solar options.
Q: Without using technical terms, what is "solar" energy?
A: Solar energy is simply energy that has been generated by the sun. Currently, we are able to transform sunshine (or solar energy) into heat (thermal) or electricity (PV - photovoltaics). Examples of solar energy are: (1) in the winter, that nice warm spot on the rug where the sun is shining and, (2) in the summer, the incredibly hot interior of your car on a bright sunny day. Think of solar energy as your own personal utility company. Thermal systems (which harness the sun's energy through water or air energy transfer) are not practical for RV's and will therefore not be included in answers in this questionaire. Solar PV (photovoltaic) panels convert solar energy into electricity. Once the solar energy is transformed into electricity it must be stored, ready for use. That is where batteries come in. Batteries store the energy until it is needed. In summary, the solar panel charges your batteries which in turn supply the electricty as you need it. The only other main component of a solar system is an inverter. Solar panels create Direct Current (DC) electricity. Batteries can only store and supply DC. DC is what most portable electrical devices use, such as cordless power tools, childrens toys, portable tape players/radios, etc. Most households in North America use Alternating Current (AC). AC is what you get from your normal wall sockets (in North America, plugs have two vertical prongs with sometimes a round prong underneath). An inverter converts DC into AC. If you have an inverter, you can use either AC or DC electrical devices.
Q: Is solar power intended to be used to just supplement traditional energy sources, or can it actually "replace" my need for batteries and/or shore power?
A: Batteries or shore power will always be required if you want to use electric devices at night or during poor light conditions. The amount of additional electricity you need will depend on the area of solar collectors that you have and how much electricity you consume. You can have any size system you desire from one solar panel powering a couple of electrical devices with small power requirements to many solar panels for many electrical devices with large power requirements. The amount you use your RV and where you use your RV determines the amount of electricity you collect from your solar panels. If you are a full time user of an RV in the desert , a solar electric system could look after all your needs. If your favorite holiday spot is in Western Canada during the winter, that same RV would require significantly more solar panels. This is because the amount of solar energy you receive from the sun in the winter time in Northern North America is significantly less than the amount of energy available in the summer time. Batteries are also key to your solar system. If you don't have enough battery storage to store all of the energy created by the solar panel, then the excess electricity will be lost. You always want to make sure your batteries are sized appropriately to your solar system. To determine the system required to meet your needs, refer to the "Our Products" section on our homepage located at http://www.sentex.net/~nova
Q: Does solar power offer any advantages to me here in rainy Washington in the winter months? Or is it really suited only to the few months a year we're able to spend in the Southwestern deserts?
A: Technically, you could put solar panels over your entire RV and it may be enough power for your RV in Northern North America in the winter. Realistically however, your system will work great anywhere in the summer and all year in the Southern USA. In northern North America in the winter, the solar panels will "trickle charge" your batteries which is also advantageous. Batteries will slowly drain when not in use. Batteries that are "deep cycled" (drained completely and then recharged fully) too many times or sit idle for several months can be permanently damaged. Solar panels provide a daily maintenance charge or "trickle charge" to your batteries and eliminate this problem. By recharging every day, the depth of discharge is reduced, and battery life and performance are greatly improved.
Q: Do solar panels need to "point" at the sun in order to be effective? Or can they be mounted in a fixed position on top of my RV?
A: If you want to receive every "Watt" of energy available to you from the sun, you will actually want to move the solar panel every half hour or so, just to make sure it "points" directly at the sun. Most RV users, however, lay them flat on the roof for three reasons: most RV's are used in the summer when the sun is directly overhead; adjustable mounts are expensive and must be raised and lowered for travel, and; the more often you climb up onto the roof of your RV the more likely you are to fall off.
Q: Is solar energy used just to charge my batteries, or can it actually "run" electrical appliances?
A: Technically you do not need batteries but the quality of electricity you will get from a solar panel will directly depend on the weather. If a cloud goes in front of the sun, the electrical energy produced from the solar panel will drop significantly. Think of it as someone randomly turning up and down the volume on your stereo. In practicality, you will want batteries in virtually all applications. Batteries can store energy even though the electrical supply to them is not "clean" ie. wide variations in supply current. When power is drawn from batteries, however, they will supply your electrical appliances with continuous, good quality electricity.
Q: Is there a risk that if I use solar panels I might overcharge my batteries?
A: Solar panels are normally wired through a charge controller to prevent overcharging. The regulator shuts off the solar electrical energy when the battery is fully charged. However, if you use a small solar panel (less than 20W) and your RV has significantly greater battery storage than what this panel can supply, it wouldn't hurt your batteries if they were overcharged by this small panel. Self regulating panels do not require a charge controller either.
Q: How much is enough? How many panels of what approximate dimension would I have to mount on my RV rooftop to let me "boondock" -- i.e., enjoy a modest use of electricity indefinitely without draining my batteries?
A: The amount of energy required by your RV depends on how much electricity you used the night before. A 24 foot RV used in the summer can usually get by with 5 amps of input with 200 amps of battery storage. In english, you will need a solar panel about 47" x 21" (120 cm x 53 cm) in size. To be exact you will need to know how much power the electrical devices in your RV consume. NOVA Solar Systems has a significant amount of experience in system design and can quickly tell you what type of system you will need after talking to you and looking at your application. However, to get a feel for what type of system your RV will require, refer to NOVA's "Electricity for Recreational Vehicles" brochure. You can request your own copy of this brochure or visit NOVA's homepage and you will find the information under "Our Products".
Q: Are there differences in brands of solar panels? What are the characteristics I should look for when I want to buy one or more of them?
A: Most of the different brands of solar panels are good quality. All panels should come with at least a 10 year warranty. Instead, what you should be looking for are the larger sized panels because they tend to be cheaper per watt of energy. The most popular panels are 50 watt however NOVA uses an 85 watt module as well. When deciding how big a system to purchase, don't go too small. Consider your needs in the coming years. If you think you may need more modules later, stay away from the self regulating type. [BECAUSE ONE CAN'T EASILY "ADD ON"?]
Q: Our new RV came equipped with a single solar panel. Is there a limit to the number of panels I could add without risking harm to the batteries?
A: Assuming that you have a charge controller in your system, you can ususally add panels to your system. There are two basic questions to consider when adding more panels to your RV: does the regulator have the capacity to handle additional current, and; how much battery storage do you have. A rule of thumb is 1 Amp of solar input for 50 Amps of storage. Keep in mind that once your batteries are fully charged, any further electricity that is generated cannot be stored. In other words you may need to replace your regulator and add battery storage to your system if you want to add additional panels. Whether the purchase of this additional equipment is necessary or not will depend on what you currently have and the size of solar system you want.
Q: If I also have a power inverter, does the installation of solar panels work independently of the inverter or somehow in conjunction with it?
A: Solar Panels are battery chargers and so is a generator if you have one. Both devices supply electricity to your batteries. All inverter power comes from your battery bank. Inverters take DC energy and convert it to AC power. Please review the first question for further details. Note that you only require an inverter if you want to operate AC electrical equipment - ie., most household appliances.
Q: What approximate range of cost would I be looking at to equip my RV with sufficient solar power?
A: Depending on the size of your RV, our systems start at $330 ranging up to more than $850 CDN. The addition of an inverter adds to the cost. Our RV brochure explains the size breakdown.
Q: Is there anything else I should know before purchasing an RV system?
A: You need to know three more things: buy from a reputable dealer that you are comfortable with. Make sure that your dealer will be there to back up the solar system if something goes wrong; when doing price comparisons, don't just ask the price of the panel. The solar panel is just a fraction of the total system cost. Ask for the total cost of the system, including installation. NOVA has developed a new, low cost (approximately $150) self contained inverter fuse disconnect for RV's that greatly reduces the space required to mount the electrical boxes in an RV. A charge controller can also be included in the box. This is a real bonus for NOVA's RV customers!
Q: If our RVers Online want to follow up with you either with additional questions they may have, or to purchase your products, how can they most easily contact you? .
A: We have a variety of communication methods available as follows: Sovran Solar Systems Ltd. 144D Old Vernon Road Kelowna, British Columbia V1X 4R2 CANADA
Tel: (604) 765-9020 1-800-661-8484 (in BC)
Fax: (604) 765-9021
Homepage: http://www.inforamp.net/~sovran/
We are located just off Highway 97 in Kelowna. Please contact us. We would love to hear from you.
Melodee Halko (our RV specialist), Harold Lunner, Chuck Price, Suzanne Price
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