Oasis Montana Inc.
Renewable Energy Supply and Design
406-777-4321or 4309
(877-627-4768 toll-free order line)
Tech. Support: 1 (406) 777-4321 or 4309
e-mail: info@oasismontana.com
Home Page: www.oasismontana.com

Visit us on the web for product and project information!
For grid-tied power systems, www.grid-tie.com
Solar water pumping:  www.PVsolarpumps.com
Non-electric gas appliances, www.LPappliances.com
Efficient and DC appliances, www.eco-fridge.com
And our main page at www.oasismontana.com

Oasis Montana Renewable Energy Newsletter July 2002 page 3

RV Power Products Solar Boost™ MPPT
 Charge Controllers

Who says you can’t get something for nothing? The line of Solar Boost™ charge controllers from RV Power Products can increase your solar array’s output by 30% or more* when compared to conventional charge controllers. Depending on the size of your solar array, that could be like getting the output of an additional solar module (or two) for free! The Solar Boost™ charge controllers do this by using maximum power point tracking (MPPT) to extract the highest amount of power from your solar array. MPPT forces the solar module(s) to operate at a higher voltage than normal which puts them as close to their maximum power point as possible. Other charge controllers simply connect the solar module(s) to the battery and let them operate at whatever the battery voltage is. If the battery voltage is low, this can be wasting 30% or more of the solar module’s output.

There are three different Solar Boost™ charge controllers available and they are all covered by a 3 year limited warranty. The SB2000E is a 12V, 25A unit intended mainly for RV applications and it comes with a built in LCD display. Then there are the SB50L and SB3048L units that are UL listed and intended for residential or commercial applications. The SB50L is a 50A, 12 or 24V unit while the SB3048L is a 30A, 24 or 48V unit. Both the SB50L and SB3048L will allow you to step up your solar array voltage to 24 or 48V respectively while charging a lower voltage battery bank. This feature comes in handy if you have a large solar array that is some distance away from your battery bank because it minimizes the voltage drop as well as the array wire size required. RV Power Products offers several options for their Solar Boost charge controllers including LCD displays (front panel & remote), a battery temperature sensor and a wall mount box (SB2000E). Call us for prices on all of these options as well as sizing assistance. While the line of Solar Boost charge controllers might be more expensive than other units on the market, keep in mind that in addition to getting a state of the art charge controller you are also getting additional solar power from your modules. Now that’s a great deal!


Problems cannot be solved at the same level of awareness that created them.         —Albert Einstein


SMA Sunny Boy Inverters

You don’t have to live out in the boonies to use solar power!
The exciting line of Sunny Boy grid-tie inverters from SMA makes it easy for the majority of us that are connected to the utility grid to use the clean energy from the sun. Founded in Germany in 1981 as an engineering/control systems company, SMA started producing the Sunny Boy line of inverters in 1996. They currently manufacture 1800 and 2500W units for use here in the United States as well as 700 and 1100W units for the European market. These inverters allow you to install a photovoltaic system without having to worry about purchasing an expensive heavy battery bank. The DC power that is produced by the solar array is inverted to AC by the Sunny Boy inverter after which it is either used by your AC appliances or sold back to the utility grid to lower your monthly utility bill. The Sunny Boy units are called "string" inverters because they are designed to be wired to a single series string of 12-24 solar modules. This makes the solar array wiring very easy since you don’t have to worry about paralleling multiple strings of solar modules together in a combiner box. However, the high DC voltage that this series string of solar modules produces needs to be handled very carefully because it can be lethal! To minimize the potential shock hazard of this system’s high DC voltage, the solar array wiring should be done with all of the solar modules lying flat on the ground or roof after which the entire array can be lifted or tilted into place. If that is not possible, be sure to completely and securely cover each and every solar module with a heavy opaque material (blanket, cardboard, tarp, etc.) before wiring the array. A professional installer is recommended for those not familiar with these systems.

The 1800 and 2500W Sunny Boy inverters are both UL listed, come with a 5 year warranty and have a built-in ground fault protection device that is required by the NEC for roof mounted solar arrays. The optional Sunny Boy Display (SBD) can be ordered separately or integrated into the front of the inverter at the time of purchase. The SBD is the simplest meter option and it continuously scrolls through the following 6 parameters: AC power (W), PV voltage (VDC), total energy yield (kWh), daily energy yield (kWh), operating hours and inverter status. The other option for monitoring and controlling the output of a single Sunny Boy inverter is to install an optional RS-232 module inside the inverter. This in conjunction with the Sunny Data software running on your PC will allow you to monitor the performance of your Sunny Boy inverter. If you plan to install a large solar array that would require multiple Sunny Boy inverters, then your best bet is to install a power line carrier module in each inverter and connect them all to a single Sunny Boy Control unit where the data can be monitored and/or stored for later use.

We could go on and on about all of the features and options of the SMA Sunny Boy inverters, but we don’t have enough space here to do so. We have listed some of the key components below along with a short description and price. If you would like some more specific information on any of these items or would like to place an order for one of these exciting new grid-tie inverters, please don’t hesitate to call us.

SWR 2500U, 2500W, 240VAC, 60 Hz, UL listed string inverter, ground fault protection device included
SWR 2500U SBD, 2500W, 240VAC, 60 Hz, UL listed string inverter with GFP device and LCD display $
SWR 2500U-208, 2500W, 208VAC 3-phase, 60 Hz, UL listed string inverter, GFP device included $
SWR 2500U-208 LCD, 208VAC 3-phase, 60 hz, UL listed inverter with GFP device and LCD display $
SWR 1800U, 1800W, 240VAC, 60 Hz, UL listed string inverter with GFP device included $
SWR 1800U SBD, 1800W, 240VAC, 60 Hz, UL listed string inverter with GFP device and LCD display $
SBD Sunny Boy Display, 2-line LCD  continuously scrolling through six operating parameters $

Other options available, including data communications with a PC, remote communications, and modular control systems.  email us for more details.


Efficient Appliances — one of the first steps in energy independence is to reduce your electrical power requirements. Here are some viable options.
ConServ AC refrigerator/freezer white or with stainless steel doors and matching gray sides.
Energy Star rated clothes washers
For more info see http://www.eco-fridge.com

Current Summer 2002 Newsletter

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