Small Wind Electric Systems: An Arizona Consumer's Guide

Small Wind Electric Systems 19Hybrid Power SystemsCombine multiple sources to deliver non-intermittent electric powerPV modulesA hybrid systemthat combines awind system with asolar and/or dieselgenerator canprovide reliable offgridpower aroundthe clock.GeneratorWindturbineRegulation andconversionAC orDCLoad02979301mBattery bankCan I Go "Off-Grid"?Hybrid SystemsHybrid wind energy systems canprovide reliable off-grid power forhomes, farms or even entire communities(a co-housing project, forexample) that are far from the nearestutility lines. According to manyrenewable energy experts, a "hybrid"system that combines wind andphotovoltaic (PV) technologies offersseveral advantages over either singlesystem. In much of the United States,wind speeds are low in the summerwhen the sun shines brightest andlongest. The wind is strong in thewinter when there is less sunlightavailable. Because the peak operatingtimes for wind and PV occur at differenttimes of the day and year, hybridsystems are more likely to producepower when you need it. (For moreinformation on solar electric orPV systems, contact the EnergyEfficiency and Renewable EnergyClearinghouse—see For MoreInformation.)For the times when neither the windnor the PV modules are producing,most hybrid systems provide powerthrough batteries and/or an enginegeneratorpowered by conventionalfuels such as diesel. If the batteriesrun low, the engine-generator canprovide power and recharge the batteries.Adding an engine-generatormakes the system more complex, butmodern electronic controllers canoperate these systems automatically.An engine-generator can also reducethe size of the other componentsneeded for the system. Keep in mindthat the storage capacity must belarge enough to supply electricalneeds during non-charging periods.Battery banks are typically sized tosupply the electric load for one tothree days.An off-grid hybrid system may bepractical for you if:• You live in an area with averageannual wind speed of at least9 mph (4.0 m/s).• A grid connection is not availableor can only be made through an