Updated 1/28/96
Remote Use of my Lap Top Computer
Is it Possable to have Solar Electricity for a
Camper?
Is it Possable to have Solar Electricity for a
Cabin?
Computor is Campatable with Solar Electricity
Solar for R V
© Copyright 1998 "Ask Mr. Solar" Column Backhome Magazine
I am reading with great interest your column about alternative energy in BackHome. It is very informative and it gave me a lot of new ideas. But it also confused me a little. I have an Airstream motor home which I wanted to be equipped with two 53 watt solar panels. After reading your comments on RV's {in newsletter} I'm not sure if I want to do it anymore.
I know that your time is precious and that you probably answer the same questions over and over every day, but I can't find anybody here in Germany to give me the straight estimates and answers. Everybody wants to sell me something and most of the salesmen don't really know what they're talking about. So if you could spend a little time with my question, it will be greatly appreciated. The RV is equipped as follows:
- 1 battery 120 amp-hour for engine
- 2 batteries deep-cycle 120 amp-hour for coach
- 1 Onan generator 4 kilowatt
- 1 alternator for the RV engine
The coach is used mostly in Scandinavia around the Polar Circle--summertime only of course. That means about twenty hours light per day--not necessarily strong sun, but light. I always camp away from shore power (stationary plug) and only sometimes when I visit with friends can I plug in to 220-volts AC and charge the batteries. Usually I have to move every 4th day to charge the system. I use the coach power very sparingly and TV very seldom, and only one light bulb at a time, etc. The only item used over longer periods is the heater (24 watt) in cold weather or the fantastic fan ventilator (wattage unknown) in hot weather. There is no DC to AC inverter. Of course it is easy to run the generator when the batteries get low on power, but I hate to do it. It bothers me to make noise, and stinky fumes in this beautiful quiet of the northern wilderness. So my question is, if some kind of compact renewable energy system could be installed to prolong my stays to a week or ten days before having to plug-in at shore power, what would I need and how big should it be? Sorry about the bad english!
Alex, in Germany
Hello Alex -
Please do NOT apologize for your poor English - it is MUCH better than my German. In regards to your set up solar is used a lot here in the states for R.V.'s with great success, however at times some people are over sold with the belief that they can operate their solar system for many hours only using a few watts of generating power. I am sad to hear of your dealings with your local suppliers. Apparently the salesman that you have talked with in your country are from the same school as here in the US as they just want to sell and really don't understand what or why of alternative power.
In the southern part of the US you will only generate about 200 watts per day with a 50 watt solar panel that is pointed to the sun. By this I mean that you should always install your panels so that they art tilted upwards so that between noon and 2:00 PM you will have the sun striking them at approximately 90 degrees. This arrangement will enable you to get the maximum amount of power from them, naturally sense you have a Airstream you will have to lower them when traveling.
This 200 watts is per panel in our location on a daily average. This means in your location is that you will get only about 100 watts per panel. Therefore if you plan to use say 600 watts per day with your TV, lights, water pump, heater fan and etc. you will need 6 panels.
Since you have a Onan generator as well as an alternator for your RV engine I would recommend that you install a good small inverter / charger such as the Heart 750 watt. This inverter charger will charge your batteries at a rate of 25 amps or 300 watts per hour. This will enable you to run your generator for 2 hours a day to charge your batteries with 600 watts of power or the same amount of power that 6 solar panels will do with much less cost to you. This inverter / charger cost a little less than two 50 watt solar panels. You will also have the advantage of having an inverter for your AC usage.
You did not say if you have any from of battery metering. This is very important as I am sure that you are aware if you over discharge you batteries then this is the quickest way to ruin them. Actually for the longest life of deep cycle batteries you should NOT use more than 50% of their rated capacity. However if you really want to care for them then you should only use the top 30% for them. To properly know what you have and use I would strongly recommend that you install some from of digital volt meter so that you will beware of the condition of your system. Here you have a choice of getting a simple digital volt meter and connecting it to your batteries for under $50.00. Or you can get a very good Emeter that will let you know your charging rate as well as the condition of your batteries costing about $275.00.
Remote Use of my Lap Top Computer
© Copyright 1995 By Charlie Collins From "Ask Mr. Solar" Column Daily Spectrum
Question from Dennis C. Josifovich, Boston,Mass
Question:
Hello there Mr. Collins I have the latest state of the art computer, but there is
one problem - it is portable. I travel a lot and have to carry a lot of batteries
to keep operating - I also have to keep account of my batteries and charge them
whenever I get to "friendly" electricity. this is getting to me as it seams that
I spend more time thinking about my power than doing actual work, just working
when I will stop 'cause of no power. Do you have any suggestions?
Mr. Solar: ,Yes, Dennis now you are not alone as Jerry Spencerą 's wife Janet, is a writer who does her research from a remote forest fire lookout in the mountains of southwest Montana. She thought that she had the perfect setup for writing: lots of solitude, a great view for inspiration, and nice neighbors who would not bother her while she worked. There was only one problem - most lookout towers don't have AC power! She wanted to compose on her nice new PowerBook, but there was no place to plug it in! Thus, she demanded (and here is the source of the marital strife) that Jerry help her come up with some way to keep a PowerBook going on a lookout. So, the search was on for solar energy for portable computers..."It took us about three years of studying the solar industry to come up with the panels we thought would work for everybody", says Spencer. "We looked at probably two dozen 'classic' solar panels. But they were all so fragile that I knew they wouldn't last long in the windy, rocky environment that they would be subjected to. And we wanted something that all PowerBook owners could use. Then his partner, Bill Crane, found the flexible amorphous silicon panels that they are now using. These panels are capable of being bent nearly in half, they are practically impact-proof, and they are lightweight. They have even been known to continue to work after being punctured. Janet is now able to do all of her work with just the power provided by her Solar System - and the sun. And there is peace in the Spencer household...
You can also have the piece of mind that Janet has found by getting and using
one of their kiss (keep it simple systems) systems. I understand that they sell
for much less than $500.00 and will operate as long as you have sunlight. They
are good for back packing, desert , Antarctica, jungle as well as New York City.
If you would like more information about them please contact me and I will be
happy to send it to you.
Is it Possable to have Solar Electricity for a Camper?
© Copyright 1992 By Charlie Collins From "Ask Mr. Solar" Column Published 7/5/92 Daily Spectrum
Question: I do a lot of camping and I was wondering if you know if I could use a solar panel to charge my batteries.
John Johanson , St George, Utah
Mr. Solar: John, that is an excellent idea to use solar electric panels to keep your batteries charged. We realize that now you are having to hook up to an electrical charging source to charge your batteries every few days. We are currently working with several excellent local companies which will be more than happy to help you decide on what you actually need for you to have a trouble free set up.
There are self regulating solar electric panels available for such a purpose. They will automatically self control the charge to your batteries. However we feel that your batteries would be happier and last longer with a separate controller in your system. In other words when the charge in your batteries reach a pre set level then the solar electric panels would stop charging. As we are sure you are aware the temperature has a direct effect on the charge of your panels and the amount of power sent to your batteries. Therefore we feel that you should have a separate controller connected between your batteries and electric solar panels which would extend the life of your batteries as well as reduce the amount of battery maintaince required.
With this type of set up it means that you will be able to charge your batteries every day when the sun shines and not worry about over charging them. You also may wish to consider a tilt rack when you have your solar electric panels installed. This would enable you to receive the maxim benefit from the seasonal changes of the angle of the sun upon the earth.
Of course you should also have fuses, switches and meters installed with your system so that you will be able to monitor your solar electric in put as well as know what is happing in your system.
Is it Possable to have Solar Electricity for a Cabin?
© Copyright 1993 By Charlie Collins From "Ask Mr. Solar" Column Published 3/7/93 Daily Spectrum
Question:Is it possible to have lights and maybe a radio on a solar system and how expensive is it?
John D. St George, Utah
Mr. Solar: John, it is possible to have a small solar system for lights, a radio and even a T. V. with a video player for under $1,000.00 complete or for the cost of a medium size gasoline generator.
This system would include a new large electric solar panel which would produce approximately 3 amps per hour of 12 volts D.C. current when the sun shines. You then connect the power to your batteries through a diode so that the stored current will not drain at night.
This system must include a set of storage batteries. Here you have several choices, either to use industrial type deep cycle lead acid, reconditioned Nickel Cadium or new Nickel Iron batteries. The lead acid ones are much cheaper, however they will freeze at low temperatures and have a very short life in comparisons to the Nickel ones. Therefore in the long run it is much more economical to include these in your system. There are some Nickel Iron Batteries that been in service for over 40 years and are still operating very well.
John , there are several other items that you need to make your system safe and function properly. You will need fuses, switches and a controller to keep your battery from over charging.
You may wish to add a small inverter to your system which will allow you to use your normal A.C. appliances and computer. This addition will increase your cost only a few of hundred dollars, however it will greatly expand your usage.
Now, after you have your electric solar system installed all you need to do is to hook up your D.C. lights, radio and T.V. then enjoy your pollution free electricity that is environmentally clean, without the smell and maintenance of a noisy generator.
Computor is Campatable with Solar Electricity
© Copyright 1992 By Charlie Collins From "Ask Mr. Solar" Column Published 7/5/92 Daily Spectrum
Question: Can I run my computer on solar electric power?
Marie Webster, Charlotte, N.C.
Mr. Solar: Marie, yes you can run your computer using solar power. You will need a simple hook up, consisting of a solar panel, batteries, and an invertor along with a few fuses and switches. We live completely on solar electric power here at the DO IT HOMESTEAD and use a computer,power tools, micro wave oven, washing machine, TV, radio, and all the modern toys that our friends on the power grid have without any monthly bills.
Basically you will need a solar panel which will be used to generate D.C. electricity directly from the sun and then transfer this current through a series of controls to your batteries used to store the power. Then power will be available on demand from your storage batteries when you wish to use it for your computer or whatever electrical item you wish to use. In order to run your A.C. computer you will need an inverter which is a device that changes D.C. current in to A.C. current, the type you buy from your local power company.
For you to have the set up that will enable you to use all the toys that we use and more than you can start with a small system, as we did and then build on to it as you have the need. One of the main advantages of solar electric power is that when you choose your building blocks (components) wisely then you will be able to increase your power in and therefore your usable power without a financial loss. There are several major building blocks you will easily be in a position to add, providing that you have chosen your components wisely. The reason it is so very important to be careful in choosing is that some blocks will fit together nicely where some won't. As far as the electric solar cells are concerned you actually should install the same size output however it is not absolutely necessary as you will be able to mix and match these. In regards to storage the batteries must be of the ni-cad type only as with the lead acid type you will find that because they have memory and they deteriorate and therefore they cannot be added to for increased capacity. In regards to the invertor you have several choices.You can buy a very large one which will handle future needs, or one that can be added on to with another one of the same type which are refereed to as stackable ones or buy one that can be returned to the factory to have it's power increased at a small cost. Also you should make sure that the invertor which you choose is compatible with your computer. The other major item that you will need is a charge controller or voltage regulator which we feel you should buy a large one, larger than your current power input, so that you will be able to add more electric solar panels to your system without having to buy another controller.
So Marie you see you can have a small simple system to run your computer and you will not experience brown outs, or spikes which cause problems with your equipment, which I am sure you are aware. There is also another advantage in using solar power, in that you can be away from the grid,using all the modern toys and not pollute our beautiful environment, as we do here on our homestead as well as not having those monthly power bills.
You will be able to start small for under $1,000 as we did and add to your system as you need and not be penalized as long as you have a long range plan and wisely buy your components, or building blocks.