The simplest arrangement is a bank of wire wound ceramic resistors of appropriate ohms resistance to absorb the maximum wattage plus a safety factor the generator is capable of producing. The advantages are simplicity, reliability and durability. The disadvantage of the resistor bank is that it can get hot. In the case of a wind generator capable of producing 400 watts such as the D-400, if all the batteries are charged and there are no other loads to absorb the produced power it is like having four 100 watt light bulbs side by side. As a practical matter that is only rarely going to occur because there are almost always loads, a pump, the refrigerator lights, propane valves, etc. The most likely occurrence is if the boat is left with the wind generator operating and no loads, but even in that case the worst that can happen if the resistor bank is properly installed and ventilated is that the temperature will go up. Since with most wind generators, wind speeds of 15 knots are only going to produce about 100 watts the temperature effect will be a lot less. Bench tests at 385 watts would produce resistor temperatures as high as 360C (680F.) although the bus bars and heat sinks were considerably cooler. The composite base of the bus bars was 60C. (140F.),or the temperature of hot water in a tank. Actually they were only barely warm to the touch. It is of course a rare situation when all batteries are completely charged or there are no loads, so there is always some reduction in current available to the diversion load. If a load comes on such as a refrigerator at 5 amps we will reduce the current to the resistors by about 70 watts. On the average boat with a consistent 15 amp load, or about 200 watts, temperatures would fall accordingly. With only 100 watts of power production and usage in excess of that, the diversion load will actually seldom come on.

price: $185.00